-ldflags '-X github.com/caddyserver/caddy/v2.CustomVersion=v2.6.2'

APIError is a structured error that every API handler should return for consistency in logging and client responses. If Message is unset, then Err.Error() will be serialized in its place.

Field name	Field type	Comment
HTTPStatus	int	No comment on field.
Err	error	No comment on field.
Message	string	No comment on field.

AdminAccess specifies what permissions an identity or group of identities are granted.

Field name	Field type	Comment
PublicKeys	[]string	Base64-encoded DER certificates containing public keys to accept. (The contents of PEM certificate blocks are base64-encoded DER.) Any of these public keys can appear in any part of a verified chain.
Permissions	[]AdminPermissions	Limits what the associated identities are allowed to do. If unspecified, all permissions are granted.
publicKeys	[]crypto.PublicKey	No comment on field.

AdminConfig configures Caddy's API endpoint, which is used to manage Caddy while it is running.

Field name	Field type	Comment
Disabled	bool	If true, the admin endpoint will be completely disabled. Note that this makes any runtime changes to the config impossible, since the interface to do so is through the admin endpoint.
Listen	string	The address to which the admin endpoint's listener should bind itself. Can be any single network address that can be parsed by Caddy. Accepts placeholders. Default: the value of the CADDY_ADMIN environment variable, or localhost:2019 otherwise. Remember: When changing this value through a config reload, be sure to use the --address CLI flag to specify the current admin address if the currently-running admin endpoint is not the default address.
EnforceOrigin	bool	If true, CORS headers will be emitted, and requests to the API will be rejected if their Host and Origin headers do not match the expected value(s). Use origins to customize which origins/hosts are allowed. If origins is not set, the listen address is the only value allowed by default. Enforced only on local (plaintext) endpoint.
Origins	[]string	The list of allowed origins/hosts for API requests. Only needed if accessing the admin endpoint from a host different from the socket's network interface or if enforce_origin is true. If not set, the listener address will be the default value. If set but empty, no origins will be allowed. Enforced only on local (plaintext) endpoint.
Config	*ConfigSettings	Options pertaining to configuration management.
Identity	*IdentityConfig	Options that establish this server's identity. Identity refers to credentials which can be used to uniquely identify and authenticate this server instance. This is required if remote administration is enabled (but does not require remote administration to be enabled). Default: no identity management.
Remote	*RemoteAdmin	Options pertaining to remote administration. By default, remote administration is disabled. If enabled, identity management must also be configured, as that is how the endpoint is secured. See the neighboring "identity" object. EXPERIMENTAL: This feature is subject to change.
routers	[]AdminRouter	Holds onto the routers so that we can later provision them if they require provisioning.

AdminHandler is like http.Handler except ServeHTTP may return an error.

If any handler encounters an error, it should be returned for proper handling.

Field name	Field type	Comment
type	any	No comment on field.

AdminHandlerFunc is a convenience type like http.HandlerFunc.

Field name	Field type	Comment
type	func(http.ResponseWriter, *http.Request) error	No comment on field.

AdminPermissions specifies what kinds of requests are allowed to be made to the admin endpoint.

Field name	Field type	Comment
Paths	[]string	The API paths allowed. Paths are simple prefix matches. Any subpath of the specified paths will be allowed.
Methods	[]string	The HTTP methods allowed for the given paths.

AdminRoute represents a route for the admin endpoint.

Field name	Field type	Comment
Pattern	string	No comment on field.
Handler	AdminHandler	No comment on field.

AdminRouter is a type which can return routes for the admin API.

Field name	Field type	Comment
type	any	No comment on field.

App is a thing that Caddy runs.

Field name	Field type	Comment
type	any	No comment on field.

BaseLog contains the common logging parameters for logging.

Field name	Field type	Comment
WriterRaw	json.RawMessage	The module that writes out log entries for the sink.
EncoderRaw	json.RawMessage	The encoder is how the log entries are formatted or encoded.
CoreRaw	json.RawMessage	Tees entries through a zap.Core module which can extract log entry metadata and fields for further processing.
Level	string	Level is the minimum level to emit, and is inclusive. Possible levels: DEBUG, INFO, WARN, ERROR, PANIC, and FATAL
Sampling	*LogSampling	Sampling configures log entry sampling. If enabled, only some log entries will be emitted. This is useful for improving performance on extremely high-pressure servers.
WithCaller	bool	If true, the log entry will include the caller's file name and line number. Default off.
WithCallerSkip	int	If non-zero, and with_caller is true, this many stack frames will be skipped when determining the caller. Default 0.
WithStacktrace	string	If not empty, the log entry will include a stack trace for all logs at the given level or higher. See level for possible values. Default off.
writerOpener	WriterOpener	No comment on field.
writer	io.WriteCloser	No comment on field.
encoder	zapcore.Encoder	No comment on field.
levelEnabler	zapcore.LevelEnabler	No comment on field.
core	zapcore.Core	No comment on field.

CleanerUpper is implemented by modules which may have side-effects such as opened files, spawned goroutines, or allocated some sort of non-stack state when they were provisioned. This method should deallocate/cleanup those resources to prevent memory leaks. Cleanup should be fast and efficient. Cleanup should work even if Provision returns an error, to allow cleaning up from partial provisionings.

Field name	Field type	Comment
type	any	No comment on field.

CloudEvent is a JSON-serializable structure that is compatible with the CloudEvents specification. See https://cloudevents.io. EXPERIMENTAL: Subject to change.

Field name	Field type	Comment
ID	string	No comment on field.
Source	string	No comment on field.
SpecVersion	string	No comment on field.
Type	string	No comment on field.
Time	time.Time	No comment on field.
DataContentType	string	No comment on field.
Data	json.RawMessage	No comment on field.

Config is the top (or beginning) of the Caddy configuration structure. Caddy config is expressed natively as a JSON document. If you prefer not to work with JSON directly, there are many config adapters available that can convert various inputs into Caddy JSON.

Many parts of this config are extensible through the use of Caddy modules. Fields which have a json.RawMessage type and which appear as dots (•••) in the online docs can be fulfilled by modules in a certain module namespace. The docs show which modules can be used in a given place.

Whenever a module is used, its name must be given either inline as part of the module, or as the key to the module's value. The docs will make it clear which to use.

Generally, all config settings are optional, as it is Caddy convention to have good, documented default values. If a parameter is required, the docs should say so.

Go programs which are directly building a Config struct value should take care to populate the JSON-encodable fields of the struct (i.e. the fields with json struct tags) if employing the module lifecycle (e.g. Provision method calls).

Field name	Field type	Comment
Admin	*AdminConfig	No comment on field.
Logging	*Logging	No comment on field.
StorageRaw	json.RawMessage	StorageRaw is a storage module that defines how/where Caddy stores assets (such as TLS certificates). The default storage module is caddy.storage.file_system (the local file system), and the default path depends on the OS and environment.
AppsRaw	ModuleMap	AppsRaw are the apps that Caddy will load and run. The app module name is the key, and the app's config is the associated value.
apps	map[string]App	No comment on field.
storage	certmagic.Storage	No comment on field.
eventEmitter	eventEmitter	No comment on field.
cancelFunc	context.CancelFunc	No comment on field.
fileSystems	FileSystems	fileSystems is a dict of fileSystems that will later be loaded from and added to.

ConfigLoader is a type that can load a Caddy config. If the return value is non-nil, it must be valid Caddy JSON; if nil or with non-nil error, it is considered to be a no-op load and may be retried later.

Field name	Field type	Comment
type	any	No comment on field.

ConfigSettings configures the management of configuration.

Field name	Field type	Comment
Persist	*bool	Whether to keep a copy of the active config on disk. Default is true. Note that "pulled" dynamic configs (using the neighboring "load" module) are not persisted; only configs that are pushed to Caddy get persisted.
LoadRaw	json.RawMessage	Loads a new configuration. This is helpful if your configs are managed elsewhere and you want Caddy to pull its config dynamically when it starts. The pulled config completely replaces the current one, just like any other config load. It is an error if a pulled config is configured to pull another config without a load_delay, as this creates a tight loop. EXPERIMENTAL: Subject to change.
LoadDelay	Duration	The duration after which to load config. If set, config will be pulled from the config loader after this duration. A delay is required if a dynamically-loaded config is configured to load yet another config. To load configs on a regular interval, ensure this value is set the same on all loaded configs; it can also be variable if needed, and to stop the loop, simply remove dynamic config loading from the next-loaded config. EXPERIMENTAL: Subject to change.

ConfiguresFormatterDefault is an optional interface that encoder modules can implement to configure the default format of their encoder. This is useful for encoders which nest an encoder, that needs to know the writer in order to determine the correct default.

Field name	Field type	Comment
type	any	No comment on field.

Constructor is a function that returns a new value that can destruct itself when it is no longer needed.

Field name	Field type	Comment
type	func() (Destructor, error)	No comment on field.

Context is a type which defines the lifetime of modules that are loaded and provides access to the parent configuration that spawned the modules which are loaded. It should be used with care and wrapped with derivation functions from the standard context package only if you don't need the Caddy specific features. These contexts are canceled when the lifetime of the modules loaded from it is over.

Use NewContext() to get a valid value (but most modules will not actually need to do this).

Field name	Field type	Comment
	context.Context	No comment on field.
moduleInstances	map[string][]Module	No comment on field.
cfg	*Config	No comment on field.
ancestry	[]Module	No comment on field.
cleanupFuncs	[]func()	No comment on field.
exitFuncs	[]func(context.Context)	No comment on field.
metricsRegistry	*prometheus.Registry	No comment on field.

CtxKey is a value type for use with context.WithValue.

Field name	Field type	Comment
type	string	No comment on field.

CustomLog represents a custom logger configuration.

By default, a log will emit all log entries. Some entries will be skipped if sampling is enabled. Further, the Include and Exclude parameters define which loggers (by name) are allowed or rejected from emitting in this log. If both Include and Exclude are populated, their values must be mutually exclusive, and longer namespaces have priority. If neither are populated, all logs are emitted.

Field name	Field type	Comment
	BaseLog	No comment on field.
Include	[]string	Include defines the names of loggers to emit in this log. For example, to include only logs emitted by the admin API, you would include "admin.api".
Exclude	[]string	Exclude defines the names of loggers that should be skipped by this log. For example, to exclude only HTTP access logs, you would exclude "http.log.access".

Destructor is a value that can clean itself up when it is deallocated.

Field name	Field type	Comment
type	any	No comment on field.

Duration can be an integer or a string. An integer is interpreted as nanoseconds. If a string, it is a Go time.Duration value such as 300ms, 1.5h, or 2h45m; valid units are ns, us/µs, ms, s, m, h, and d.

Field name	Field type	Comment
type	time.Duration	No comment on field.

Event represents something that has happened or is happening. An Event value is not synchronized, so it should be copied if being used in goroutines.

EXPERIMENTAL: Events are subject to change.

Field name	Field type	Comment
Aborted	error	If non-nil, the event has been aborted, meaning propagation has stopped to other handlers and the code should stop what it was doing. Emitters may choose to use this as a signal to adjust their code path appropriately.
Data	map[string]any	The data associated with the event. Usually the original emitter will be the only one to set or change these values, but the field is exported so handlers can have full access if needed. However, this map is not synchronized, so handlers must not use this map directly in new goroutines; instead, copy the map to use it in a goroutine. Data may be nil.
id	uuid.UUID	No comment on field.
ts	time.Time	No comment on field.
name	string	No comment on field.
origin	Module	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
type	any	No comment on field.

IdentityConfig configures management of this server's identity. An identity consists of credentials that uniquely verify this instance; for example, TLS certificates (public + private key pairs).

Field name	Field type	Comment
Identifiers	[]string	List of names or IP addresses which refer to this server. Certificates will be obtained for these identifiers so secure TLS connections can be made using them.
IssuersRaw	[]json.RawMessage	Issuers that can provide this admin endpoint its identity certificate(s). Default: ACME issuers configured for ZeroSSL and Let's Encrypt. Be sure to change this if you require credentials for private identifiers.
issuers	[]certmagic.Issuer	No comment on field.

ListenerFunc is a function that can return a listener given a network and address. The listeners must be capable of overlapping: with Caddy, new configs are loaded before old ones are unloaded, so listeners may overlap briefly if the configs both need the same listener. EXPERIMENTAL and subject to change.

Field name	Field type	Comment
type	func(ctx context.Context, network, host, portRange string, portOffset uint, cfg net.ListenConfig) (any, error)	No comment on field.

ListenerWrapper is a type that wraps a listener so it can modify the input listener's methods. Modules that implement this interface are found in the caddy.listeners namespace. Usually, to wrap a listener, you will define your own struct type that embeds the input listener, then implement your own methods that you want to wrap, calling the underlying listener's methods where appropriate.

Field name	Field type	Comment
type	any	No comment on field.

LogSampling configures log entry sampling.

Field name	Field type	Comment
Interval	time.Duration	The window over which to conduct sampling.
First	int	Log this many entries within a given level and message for each interval.
Thereafter	int	If more entries with the same level and message are seen during the same interval, keep one in this many entries until the end of the interval.

Logging facilitates logging within Caddy. The default log is called "default" and you can customize it. You can also define additional logs.

By default, all logs at INFO level and higher are written to standard error ("stderr" writer) in a human-readable format ("console" encoder if stdout is an interactive terminal, "json" encoder otherwise).

All defined logs accept all log entries by default, but you can filter by level and module/logger names. A logger's name is the same as the module's name, but a module may append to logger names for more specificity. For example, you can filter logs emitted only by HTTP handlers using the name "http.handlers", because all HTTP handler module names have that prefix.

Caddy logs (except the sink) are zero-allocation, so they are very high-performing in terms of memory and CPU time. Enabling sampling can further increase throughput on extremely high-load servers.

Field name	Field type	Comment
Sink	*SinkLog	Sink is the destination for all unstructured logs emitted from Go's standard library logger. These logs are common in dependencies that are not designed specifically for use in Caddy. Because it is global and unstructured, the sink lacks most advanced features and customizations.
Logs	map[string]*CustomLog	Logs are your logs, keyed by an arbitrary name of your choosing. The default log can be customized by defining a log called "default". You can further define other logs and filter what kinds of entries they accept.
writerKeys	[]string	a list of all keys for open writers; all writers that are opened to provision this logging config must have their keys added to this list so they can be closed when cleaning up

Module is a type that is used as a Caddy module. In addition to this interface, most modules will implement some interface expected by their host module in order to be useful. To learn which interface(s) to implement, see the documentation for the host module. At a bare minimum, this interface, when implemented, only provides the module's ID and constructor function.

Modules will often implement additional interfaces including Provisioner, Validator, and CleanerUpper. If a module implements these interfaces, their methods are called during the module's lifespan.

When a module is loaded by a host module, the following happens: 1) ModuleInfo.New() is called to get a new instance of the module. 2) The module's configuration is unmarshaled into that instance. 3) If the module is a Provisioner, the Provision() method is called. 4) If the module is a Validator, the Validate() method is called. 5) The module will probably be type-asserted from 'any' to some other, more useful interface expected by the host module. For example, HTTP handler modules are type-asserted as caddyhttp.MiddlewareHandler values. 6) When a module's containing Context is canceled, if it is a CleanerUpper, its Cleanup() method is called.

Field name	Field type	Comment
type	any	No comment on field.

ModuleID is a string that uniquely identifies a Caddy module. A module ID is lightly structured. It consists of dot-separated labels which form a simple hierarchy from left to right. The last label is the module name, and the labels before that constitute the namespace (or scope).

Thus, a module ID has the form: <namespace>.<name>

An ID with no dot has the empty namespace, which is appropriate for app modules (these are "top-level" modules that Caddy core loads and runs).

Module IDs should be lowercase and use underscores (_) instead of spaces.

Examples of valid IDs:

• http
• http.handlers.file_server
• caddy.logging.encoders.json

Field name	Field type	Comment
type	string	No comment on field.

ModuleInfo represents a registered Caddy module.

Field name	Field type	Comment
ID	ModuleID	ID is the "full name" of the module. It must be unique and properly namespaced.
New	func() Module	New returns a pointer to a new, empty instance of the module's type. This method must not have any side-effects, and no other initialization should occur within it. Any initialization of the returned value should be done in a Provision() method (see the Provisioner interface).

ModuleMap is a map that can contain multiple modules, where the map key is the module's name. (The namespace is usually read from an associated field's struct tag.) Because the module's name is given as the key in a module map, the name does not have to be given in the json.RawMessage.

Field name	Field type	Comment
type	map[string]json.RawMessage	No comment on field.

NetworkAddress represents one or more network addresses. It contains the individual components for a parsed network address of the form accepted by ParseNetworkAddress().

Field name	Field type	Comment
Network	string	Should be a network value accepted by Go's net package or by a plugin providing a listener for that network type.
Host	string	The "main" part of the network address is the host, which often takes the form of a hostname, DNS name, IP address, or socket path.
StartPort	uint	For addresses that contain a port, ranges are given by [StartPort, EndPort]; i.e. for a single port, StartPort and EndPort are the same. For no port, they are 0.
EndPort	uint	No comment on field.

Provisioner is implemented by modules which may need to perform some additional "setup" steps immediately after being loaded. Provisioning should be fast (imperceptible running time). If any side-effects result in the execution of this function (e.g. creating global state, any other allocations which require garbage collection, opening files, starting goroutines etc.), be sure to clean up properly by implementing the CleanerUpper interface to avoid leaking resources.

Field name	Field type	Comment
type	any	No comment on field.

ProxyFuncProducer is implemented by modules which produce a function that returns a URL to use as network proxy. Modules in the namespace caddy.network_proxy must implement this interface.

Field name	Field type	Comment
type	any	No comment on field.

RemoteAdmin enables and configures remote administration. If enabled, a secure listener enforcing mutual TLS authentication will be started on a different port from the standard plaintext admin server.

This endpoint is secured using identity management, which must be configured separately (because identity management does not depend on remote administration). See the admin/identity config struct.

EXPERIMENTAL: Subject to change.

Field name	Field type	Comment
Listen	string	The address on which to start the secure listener. Accepts placeholders. Default: :2021
AccessControl	[]*AdminAccess	List of access controls for this secure admin endpoint. This configures TLS mutual authentication (i.e. authorized client certificates), but also application-layer permissions like which paths and methods each identity is authorized for.

ReplacementFunc is a function that is called when a replacement is being performed. It receives the variable (i.e. placeholder name) and the value that will be the replacement, and returns the value that will actually be the replacement, or an error. Note that errors are sometimes ignored by replacers.

Field name	Field type	Comment
type	func(variable string, val any) (any, error)	No comment on field.

Replacer can replace values in strings. A default/empty Replacer is not valid; use NewReplacer to make one.

Field name	Field type	Comment
providers	[]replacementProvider	No comment on field.
static	map[string]any	No comment on field.
mapMutex	*sync.RWMutex	No comment on field.

ReplacerFunc is a function that returns a replacement for the given key along with true if the function is able to service that key (even if the value is blank). If the function does not recognize the key, false should be returned.

Field name	Field type	Comment
type	func(key string) (any, bool)	No comment on field.

SinkLog configures the default Go standard library global logger in the log package. This is necessary because module dependencies which are not built specifically for Caddy will use the standard logger. This is also known as the "sink" logger.

Field name	Field type	Comment
	BaseLog	No comment on field.

StorageConverter is a type that can convert itself to a valid, usable certmagic.Storage value. (The value might be short-lived.) This interface allows us to adapt any CertMagic storage implementation into a consistent API for Caddy configuration.

Field name	Field type	Comment
type	any	No comment on field.

UsagePool is a thread-safe map that pools values based on usage (reference counting). Values are only inserted if they do not already exist. There are two ways to add values to the pool:

1. LoadOrStore will increment usage and store the value immediately if it does not already exist.
2. LoadOrNew will atomically check for existence and construct the value immediately if it does not already exist, or increment the usage otherwise, then store that value in the pool. When the constructed value is finally deleted from the pool (when its usage reaches 0), it will be cleaned up by calling Destruct().

The use of LoadOrNew allows values to be created and reused and finally cleaned up only once, even though they may have many references throughout their lifespan. This is helpful, for example, when sharing thread-safe io.Writers that you only want to open and close once.

There is no way to overwrite existing keys in the pool without first deleting it as many times as it was stored. Deleting too many times will panic.

The implementation does not use a sync.Pool because UsagePool needs additional atomicity to run the constructor functions when creating a new value when LoadOrNew is used. (We could probably use sync.Pool but we'd still have to layer our own additional locks on top.)

An empty UsagePool is NOT safe to use; always call NewUsagePool() to make a new one.

Field name	Field type	Comment
	sync.RWMutex	No comment on field.
pool	map[any]*usagePoolVal	No comment on field.

Validator is implemented by modules which can verify that their configurations are valid. This method will be called after Provision() (if implemented). Validation should always be fast (imperceptible running time) and an error must be returned if the module's configuration is invalid.

Field name	Field type	Comment
type	any	No comment on field.

WriterOpener is a module that can open a log writer. It can return a human-readable string representation of itself so that operators can understand where the logs are going.

Field name	Field type	Comment
type	any	No comment on field.

This type doesn't have documentation.

This type doesn't have documentation.

Field name	Field type	Comment
mux	*http.ServeMux	No comment on field.
enforceOrigin	bool	security for local/plaintext endpoint
enforceHost	bool	No comment on field.
allowedOrigins	[]*url.URL	No comment on field.
remoteControl	*RemoteAdmin	security for remote/encrypted endpoint

contextAndCancelFunc groups context and its cancelFunc

Field name	Field type	Comment
	context.Context	No comment on field.
	context.CancelFunc	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	*CustomLog	No comment on field.
logger	*zap.Logger	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	http.ResponseWriter	No comment on field.
status	int	No comment on field.

deleteListener is a type that simply deletes itself from the listenerPool when it closes. It is used solely for the purpose of reference counting (i.e. counting how many configs are using a given socket).

Field name	Field type	Comment
	net.Listener	No comment on field.
lnKey	string	No comment on field.

deletePacketConn is like deleteListener, but for net.PacketConns.

Field name	Field type	Comment
	net.PacketConn	No comment on field.
lnKey	string	No comment on field.

eventEmitter is a small interface that inverts dependencies for the caddyevents package, so the core can emit events without an import cycle (i.e. the caddy package doesn't have to import the caddyevents package, which imports the caddy package).

Field name	Field type	Comment
type	any	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
closed	int32	No comment on field.
	*sharedQuicListener	No comment on field.
context	context.Context	No comment on field.
contextCancel	context.CancelFunc	No comment on field.

fileReplacementsProvider handles {file.*} replacements, reading a file from disk and replacing with its contents.

filteringCore filters log entries based on logger name, according to the rules of a CustomLog.

Field name	Field type	Comment
	zapcore.Core	No comment on field.
cl	*CustomLog	No comment on field.

globalDefaultReplacementsProvider handles replacements that can be used in any context, such as system variables, time, or environment variables.

This type doesn't have documentation.

Field name	Field type	Comment
type	[]*url.URL	No comment on field.

notClosable is an io.WriteCloser that can't be closed.

Field name	Field type	Comment
	io.Writer	No comment on field.

replacementProvider is a type that can provide replacements for placeholders. Allows for type assertion to determine which type of provider it is.

Field name	Field type	Comment
type	any	No comment on field.

sharedQUICState manages GetConfigForClient see issue: https://github.com/caddyserver/caddy/pull/4849

Field name	Field type	Comment
rmu	sync.RWMutex	No comment on field.
tlsConfs	map[*tls.Config]contextAndCancelFunc	No comment on field.
activeTlsConf	*tls.Config	No comment on field.

sharedQuicListener is like sharedListener, but for quic.EarlyListeners.

Field name	Field type	Comment
	*quic.EarlyListener	No comment on field.
packetConn	net.PacketConn	No comment on field.
sqs	*sharedQUICState	No comment on field.
key	string	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	*net.UnixConn	No comment on field.
mapKey	string	No comment on field.
count	*int32	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	*net.UnixListener	No comment on field.
mapKey	string	No comment on field.
count	*int32	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
refs	int32	No comment on field.
value	any	No comment on field.
err	error	No comment on field.
	sync.RWMutex	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	io.WriteCloser	No comment on field.

ActiveContext returns the currently-active context. This function is experimental and might be changed or removed in the future.

AppConfigDir returns the directory where to store user's config.

If XDG_CONFIG_HOME is set, it returns: $XDG_CONFIG_HOME/caddy. Otherwise, os.UserConfigDir() is used; if successful, it appends "Caddy" (Windows & Mac) or "caddy" (every other OS) to the path. If it returns an error, the fallback path "./caddy" is returned.

The config directory is not guaranteed to be different from AppDataDir().

Unlike os.UserConfigDir(), this function prefers the XDG_CONFIG_HOME env var on all platforms, not just Unix.

Ref: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html

Uses: filepath.Join, os.Getenv, os.UserConfigDir, runtime.GOOS, zap.Error.

AppDataDir returns a directory path that is suitable for storing application data on disk. It uses the environment for finding the best place to store data, and appends a "caddy" or "Caddy" (depending on OS and environment) subdirectory.

For a base directory path: If XDG_DATA_HOME is set, it returns: $XDG_DATA_HOME/caddy; otherwise, on Windows it returns: %AppData%/Caddy, on Mac: $HOME/Library/Application Support/Caddy, on Plan9: $home/lib/caddy, on Android: $HOME/caddy, and on everything else: $HOME/.local/share/caddy.

If a data directory cannot be determined, it returns "./caddy" (this is not ideal, and the environment should be fixed).

The data directory is not guaranteed to be different from AppConfigDir().

Ref: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html

Uses: filepath.Join, os.Getenv, runtime.GOOS.

Exiting returns true if the process is exiting. EXPERIMENTAL API: subject to change or removal.

Uses: atomic.LoadInt32.

FastAbs is an optimized version of filepath.Abs for Unix systems, since we don't expect the working directory to ever change once Caddy is running. Avoid the os.Getwd() syscall overhead. It's overall the same as stdlib's implementation, the difference being cached working directory.

Uses: filepath.Clean, filepath.IsAbs, filepath.Join.

GetModule returns module information from its ID (full name).

Uses: fmt.Errorf.

GetModuleID returns a module's ID from an instance of its value. If the value is not a module, an empty string will be returned.

GetModuleName returns a module's name (the last label of its ID) from an instance of its value. If the value is not a module, an empty string will be returned.

GetModules returns all modules in the given scope/namespace. For example, a scope of "foo" returns modules named "foo.bar", "foo.loo", but not "bar", "foo.bar.loo", etc. An empty scope returns top-level modules, for example "foo" or "bar". Partial scopes are not matched (i.e. scope "foo.ba" does not match name "foo.bar").

Because modules are registered to a map under the hood, the returned slice will be sorted to keep it deterministic.

Uses: sort.Slice, strings.Split.

HomeDir returns the best guess of the current user's home directory from environment variables. If unknown, "." (the current directory) is returned instead, except GOOS=android, which returns "/sdcard".

Uses: runtime.GOOS.

InstanceID returns the UUID for this instance, and generates one if it does not already exist. The UUID is stored in the local data directory, regardless of storage configuration, since each instance is intended to have its own unique ID.

Uses: errors.Is, filepath.Join, fs.ErrNotExist, os.MkdirAll, os.ReadFile, os.WriteFile, uuid.NewRandom, uuid.ParseBytes.

IsFdNetwork returns true if the netw is a fd network.

Uses: strings.HasPrefix.

IsUnixNetwork returns true if the netw is a unix network.

Uses: strings.HasPrefix.

IsWriterStandardStream returns true if the input is a writer-opener to a standard stream (stdout, stderr).

JoinNetworkAddress combines network, host, and port into a single address string of the form accepted by ParseNetworkAddress(). For unix sockets, the network should be "unix" (or "unixgram" or "unixpacket") and the path to the socket should be given as the host parameter.

Uses: net.JoinHostPort.

ListenerUsage returns the current usage count of the given listener address.

Load loads the given config JSON and runs it only if it is different from the current config or forceReload is true.

Uses: errors.Is, http.MethodPost, notify.Error, notify.Ready, notify.Reloading, zap.Error, zap.String.

Log returns the current default logger.

Modules returns the names of all registered modules in ascending lexicographical order.

Uses: sort.Strings.

NewContext provides a new context derived from the given context ctx. Normally, you will not need to call this function unless you are loading modules which have a different lifespan than the ones for the context the module was provisioned with. Be sure to call the cancel func when the context is to be cleaned up so that modules which are loaded will be properly unloaded. See standard library context package's documentation.

Uses: context.WithCancel, log.Printf, prometheus.NewPedanticRegistry.

NewEmptyReplacer returns a new Replacer, without the global default replacements.

Uses: sync.RWMutex.

NewEvent creates a new event, but does not emit the event. To emit an event, call Emit() on the current instance of the caddyevents app insteaad.

EXPERIMENTAL: Subject to change.

Uses: fmt.Errorf, strings.ToLower, time.Now, uuid.NewRandom.

NewReplacer returns a new Replacer.

Uses: sync.RWMutex.

NewUsagePool returns a new usage pool that is ready to use.

OnExit registers a callback to invoke during process exit. This registration is PROCESS-GLOBAL, meaning that each function should only be registered once forever, NOT once per config load (etc).

EXPERIMENTAL API: subject to change or removal.

PIDFile writes a pidfile to the file at filename. It will get deleted before the process gracefully exits.

Uses: os.Getpid, os.WriteFile, strconv.Itoa.

ParseDuration parses a duration string, adding support for the "d" unit meaning number of days, where a day is assumed to be 24h. The maximum input string length is 1024.

Uses: fmt.Errorf, strconv.FormatFloat, strconv.ParseFloat, time.ParseDuration.

ParseNetworkAddress parses addr into its individual components. The input string is expected to be of the form "network/host:port-range" where any part is optional. The default network, if unspecified, is tcp. Port ranges are inclusive.

Network addresses are distinct from URLs and do not use URL syntax.

ParseNetworkAddressWithDefaults is like ParseNetworkAddress but allows the default network and port to be specified.

Uses: fmt.Errorf, strconv.ParseUint, strings.Cut.

ParseStructTag parses a caddy struct tag into its keys and values. It is very simple. The expected syntax is: caddy:"key1=val1 key2=val2 ..."

Uses: fmt.Errorf, strings.Cut, strings.Split.

ProvisionContext creates a new context from the configuration and provisions storage and app modules. The function is intended for testing and advanced use cases only, typically Run should be use to ensure a fully functional caddy instance. EXPERIMENTAL: While this is public the interface and implementation details of this function may change.

RegisterModule registers a module by receiving a plain/empty value of the module. For registration to be properly recorded, this should be called in the init phase of runtime. Typically, the module package will do this as a side-effect of being imported. This function panics if the module's info is incomplete or invalid, or if the module is already registered.

Uses: fmt.Sprintf.

RegisterNetwork registers a network type with Caddy so that if a listener is created for that network type, getListener will be invoked to get the listener. This should be called during init() and will panic if the network type is standard or reserved, or if it is already registered. EXPERIMENTAL and subject to change.

Uses: strings.HasPrefix, strings.ToLower, strings.TrimSpace.

RemoveMetaFields removes meta fields like "@id" from a JSON message by using a simple regular expression. (An alternate way to do this would be to delete them from the raw, map[string]any representation as they are indexed, then iterate the index we made and add them back after encoding as JSON, but this is simpler.)

Uses: bytes.HasPrefix, bytes.HasSuffix.

Run runs the given config, replacing any existing config.

Uses: json.Marshal.

SplitNetworkAddress splits a into its network, host, and port components. Note that port may be a port range (:X-Y), or omitted for unix sockets.

Uses: errors.Join, net.JoinHostPort, net.SplitHostPort, strings.Cut, strings.ToLower, strings.Trim, strings.TrimSpace.

Stop stops running the current configuration. It is the antithesis of Run(). This function will log any errors that occur during the stopping of individual apps and continue to stop the others. Stop should only be called if not replacing with a new config.

StrictUnmarshalJSON is like json.Unmarshal but returns an error if any of the fields are unrecognized. Useful when decoding module configurations, where you want to be more sure they're correct.

Uses: bytes.NewReader, json.NewDecoder.

ToString returns val as a string, as efficiently as possible. EXPERIMENTAL: may be changed or removed later.

Uses: fmt.Sprintf, fmt.Stringer, strconv.FormatFloat, strconv.FormatUint, strconv.Itoa.

TrapSignals create signal/interrupt handlers as best it can for the current OS. This is a rather invasive function to call in a Go program that captures signals already, so in that case it would be better to implement these handlers yourself.

Validate loads, provisions, and validates cfg, but does not start running it.

Version returns the Caddy version in a simple/short form, and a full version string. The short form will not have spaces and is intended for User-Agent strings and similar, but may be omitting valuable information. Note that Caddy must be compiled in a special way to properly embed complete version information. First this function tries to get the version from the embedded build info provided by go.mod dependencies; then it tries to get info from embedded VCS information, which requires having built Caddy from a git repository. If no version is available, this function returns "(devel)" because Go uses that, but for the simple form we change it to "unknown". If still no version is available (e.g. no VCS repo), then it will use CustomVersion; CustomVersion is always prepended to the full version string.

See relevant Go issues: https://github.com/golang/go/issues/29228 and https://github.com/golang/go/issues/50603.

This function is experimental and subject to change or removal.

Uses: debug.Module, debug.ReadBuildInfo, fmt.Sprintf, hex.DecodeString, strconv.ParseBool, time.Parse, time.RFC3339, time.RFC822, time.Time.

FileSystems returns a ref to the FilesystemMap. EXPERIMENTAL: This API is subject to change.

Uses: filesystems.FileSystemMap.

Returns the active metrics registry for the context EXPERIMENTAL: This API is subject to change.

OnCancel executes f when ctx is canceled.

OnExit executes f when the process exits gracefully. The function is only executed if the process is gracefully shut down while this context is active.

EXPERIMENTAL API: subject to change or removal.

WithValue returns a new context with the given key-value pair.

Uses: context.WithValue.

UnmarshalJSON satisfies json.Unmarshaler.

Uses: io.EOF, json.Unmarshal, strings.Trim, time.Duration.

Logger returns a logger that is ready for the module to use.

Uses: zap.Error, zap.New, zap.Option, zap.String, zapcore.Core, zapcore.NewTee.

Delete removes a variable with a static value that was created using Set.

Get gets a value from the replacer. It returns the value and whether the variable was known.

GetString is the same as Get, but coerces the value to a string representation as efficiently as possible.

Map adds mapFunc to the list of value providers. mapFunc will be executed only at replace-time.

ReplaceAll efficiently replaces placeholders in input with their values. All placeholders are replaced in the output whether they are recognized or not. Values that are empty string will be substituted with empty.

ReplaceFunc is the same as ReplaceAll, but calls f for every replacement to be made, in case f wants to change or inspect the replacement.

ReplaceKnown is like ReplaceAll but only replaces placeholders that are known (recognized). Unrecognized placeholders will remain in the output.

ReplaceOrErr is like ReplaceAll, but any placeholders that are empty or not recognized will cause an error to be returned.

Set sets a custom variable to a static value.

WithoutFile returns a copy of the current Replacer without support for the {file.*} placeholder, which may be unsafe in some contexts.

EXPERIMENTAL: Subject to change or removal.

Delete decrements the usage count for key and removes the value from the underlying map if the usage is 0. It returns true if the usage count reached 0 and the value was deleted. It panics if the usage count drops below 0; always call Delete precisely as many times as LoadOrStore.

Uses: atomic.AddInt32, fmt.Sprintf.

LoadOrNew loads the value associated with key from the pool if it already exists. If the key doesn't exist, it will call construct to create a new value and then stores that in the pool. An error is only returned if the constructor returns an error. The loaded or constructed value is returned. The loaded return value is true if the value already existed and was loaded, or false if it was newly constructed.

Uses: atomic.AddInt32.

LoadOrStore loads the value associated with key from the pool if it already exists, or stores it if it does not exist. It returns the value that was either loaded or stored, and true if the value already existed and was loaded, false if the value didn't exist and was stored.

Uses: atomic.AddInt32.

Range iterates the pool similarly to how sync.Map.Range() does: it calls f for every key in the pool, and if f returns false, iteration is stopped. Ranging does not affect usage counts.

This method is somewhat naive and acquires a read lock on the entire pool during iteration, so do your best to make f() really fast, m'kay?

References returns the number of references (count of usages) to a key in the pool, and true if the key exists, or false otherwise.

Uses: atomic.LoadInt32.

Unwrap returns the underlying ResponseWriter, necessary for http.ResponseController to work correctly.

Currently Accept ignores the passed context, however a situation where someone would need a hotswappable QUIC-only (not http3, since it uses context.Background here) server on which Accept would be called with non-empty contexts (mind that the default net listeners' Accept doesn't take a context argument) sounds way too rare for us to sacrifice efficiency here.

Uses: atomic.LoadInt32, context.Canceled, errors.Is.

Uses: atomic.CompareAndSwapInt32.

Check only allows the log entry if its logger name is allowed from the include/exclude rules of fc.cl.

With properly wraps With.

Destruct closes the underlying QUIC listener and its associated net.PacketConn.

Uses: atomic.AddInt32, syscall.Unlink.

Uses: atomic.AddInt32, syscall.Unlink.

ServeHTTP implements the Handler interface.

App returns the configured app named name. If that app has not yet been loaded and provisioned, it will be immediately loaded and provisioned. If no app with that name is configured, a new empty one will be instantiated instead. (The app module must still be registered.) This must not be called during the Provision/Validate phase to reference a module's own host app (since the parent app module is still in the process of being provisioned, it is not yet ready).

We return any type instead of the App type because it is NOT intended for the caller of this method to be the one to start or stop App modules. The caller is expected to assert to the concrete type.

Uses: fmt.Errorf.

AppIfConfigured is like App, but it returns an error if the app has not been configured. This is useful when the app is required and its absence is a configuration error; or when the app is optional and you don't want to instantiate a new one that hasn't been explicitly configured. If the app is not in the configuration, the error wraps ErrNotConfigured.

Uses: fmt.Errorf.

IdentityCredentials returns this instance's configured, managed identity credentials that can be used in TLS client authentication.

Uses: fmt.Errorf.

LoadModule loads the Caddy module(s) from the specified field of the parent struct pointer and returns the loaded module(s). The struct pointer and its field name as a string are necessary so that reflection can be used to read the struct tag on the field to get the module namespace and inline module name key (if specified).

The field can be any one of the supported raw module types: json.RawMessage, []json.RawMessage, map[string]json.RawMessage, or []map[string]json.RawMessage. ModuleMap may be used in place of map[string]json.RawMessage. The return value's underlying type mirrors the input field's type:

json.RawMessage              => any
[]json.RawMessage            => []any
[][]json.RawMessage          => [][]any
map[string]json.RawMessage   => map[string]any
[]map[string]json.RawMessage => []map[string]any

The field must have a "caddy" struct tag in this format:

caddy:"key1=val1 key2=val2"

To load modules, a "namespace" key is required. For example, to load modules in the "http.handlers" namespace, you'd put: namespace=http.handlers in the Caddy struct tag.

The module name must also be available. If the field type is a map or slice of maps, then key is assumed to be the module name if an "inline_key" is NOT specified in the caddy struct tag. In this case, the module name does NOT need to be specified in-line with the module itself.

If not a map, or if inline_key is non-empty, then the module name must be embedded into the values, which must be objects; then there must be a key in those objects where its associated value is the module name. This is called the "inline key", meaning the key containing the module's name that is defined inline with the module itself. You must specify the inline key in a struct tag, along with the namespace:

caddy:"namespace=http.handlers inline_key=handler"

This will look for a key/value pair like "handler": "..." in the json.RawMessage in order to know the module name.

To make use of the loaded module(s) (the return value), you will probably want to type-assert each 'any' value(s) to the types that are useful to you and store them on the same struct. Storing them on the same struct makes for easy garbage collection when your host module is no longer needed.

Loaded modules have already been provisioned and validated. Upon returning successfully, this method clears the json.RawMessage(s) in the field since the raw JSON is no longer needed, and this allows the GC to free up memory.

Uses: fmt.Errorf, fmt.Sprintf, json.RawMessage, reflect.Map, reflect.Slice, reflect.TypeOf, reflect.ValueOf, reflect.Zero.

LoadModuleByID decodes rawMsg into a new instance of mod and returns the value. If mod.New is nil, an error is returned. If the module implements Validator or Provisioner interfaces, those methods are invoked to ensure the module is fully configured and valid before being used.

This is a lower-level method and will usually not be called directly by most modules. However, this method is useful when dynamically loading/unloading modules in their own context, like from embedded scripts, etc.

Uses: fmt.Errorf, log.Printf, reflect.New, reflect.Ptr, reflect.ValueOf.

Logger returns a logger that is intended for use by the most recent module associated with the context. Callers should not pass in any arguments unless they want to associate with a different module; it panics if more than 1 value is passed in.

Originally, this method's signature was Logger(mod Module), requiring that an instance of a Caddy module be passed in. However, that is no longer necessary, as the closest module most recently associated with the context will be automatically assumed. To prevent a sudden breaking change, this method's signature has been changed to be variadic, but we may remove the parameter altogether in the future. Callers should not pass in any argument. If there is valid need to specify a different module, please open an issue to discuss.

PARTIALLY DEPRECATED: The Logger(module) form is deprecated and may be removed in the future. Do not pass in any arguments.

Uses: zap.NewDevelopment.

Module returns the current module, or the most recent one provisioned by the context.

Modules returns the lineage of modules that this context provisioned, with the most recent/current module being last in the list.

Slogger returns a slog logger that is intended for use by the most recent module associated with the context.

Uses: slog.New, zap.NewDevelopment, zapslog.NewHandler, zapslog.WithName.

Storage returns the configured Caddy storage implementation.

CaddyModule returns the Caddy module information.

OpenWriter returns io.Discard that can't be closed.

Uses: io.Discard.

WriterKey returns a unique key representing discard.

CloudEvent exports event e as a structure that, when serialized as JSON, is compatible with the CloudEvents spec.

Uses: json.Marshal.

Name returns the Name (last element) of a module ID.

Uses: strings.Split.

Namespace returns the namespace (or scope) portion of a module ID, which is all but the last label of the ID. If the ID has only one label, then the namespace is empty.

Uses: strings.LastIndex.

At returns a NetworkAddress with a port range of just 1 at the given port offset; i.e. a NetworkAddress that represents precisely 1 address only.

Expand returns one NetworkAddress for each port in the port range.

IsFdNetwork returns true if na.Network is fd or fdgram.

IsUnixNetwork returns true if na.Network is unix, unixgram, or unixpacket.

JoinHostPort is like net.JoinHostPort, but where the port is StartPort + offset.

Uses: net.JoinHostPort, strconv.FormatUint.

Listen is similar to net.Listen, with a few differences:

Listen announces on the network address using the port calculated by adding portOffset to the start port. (For network types that do not use ports, the portOffset is ignored.)

First Listen checks if a plugin can provide a listener from this address. Otherwise, the provided ListenConfig is used to create the listener. Its Control function, if set, may be wrapped by an internally-used Control function. The provided context may be used to cancel long operations early. The context is not used to close the listener after it has been created.

Caddy's listeners can overlap each other: multiple listeners may be created on the same socket at the same time. This is useful because during config changes, the new config is started while the old config is still running. How this is accomplished varies by platform and network type. For example, on Unix, SO_REUSEPORT is set except on Unix sockets, for which the file descriptor is duplicated and reused; on Windows, the close logic is virtualized using timeouts. Like normal listeners, be sure to Close() them when you are done.

This method returns any type, as the implementations of listeners for various network types are not interchangeable. The type of listener returned is switched on the network type. Stream-based networks ("tcp", "unix", "unixpacket", etc.) return a net.Listener; datagram-based networks ("udp", "unixgram", etc.) return a net.PacketConn; and so forth. The actual concrete types are not guaranteed to be standard, exported types (wrapping is necessary to provide graceful reloads).

Unix sockets will be unlinked before being created, to ensure we can bind to it even if the previous program using it exited uncleanly; it will also be unlinked upon a graceful exit (or when a new config does not use that socket). Listen synchronizes binds to unix domain sockets to avoid race conditions while an existing socket is unlinked.

ListenAll calls Listen for all addresses represented by this struct, i.e. all ports in the range. (If the address doesn't use ports or has 1 port only, then only 1 listener will be created.) It returns an error if any listener failed to bind, and closes any listeners opened up to that point.

Uses: io.Closer.

ListenQUIC returns a http3.QUICEarlyListener suitable for use in a Caddy module.

The network will be transformed into a QUIC-compatible type if the same address can be used with different networks. Currently this just means that for tcp, udp will be used with the same address instead.

NOTE: This API is EXPERIMENTAL and may be changed or removed.

Uses: http3.ConfigureTLSConfig, net.Addr, net.PacketConn, qlog.DefaultConnectionTracer, rate.NewLimiter, tls.Config.

PortRangeSize returns how many ports are in pa's port range. Port ranges are inclusive, so the size is the difference of start and end ports plus one.

String reconstructs the address string for human display. The output can be parsed by ParseNetworkAddress(). If the address is a unix socket, any non-zero port will be dropped.

CaddyModule returns the Caddy module information.

OpenWriter returns os.Stderr that can't be closed.

Uses: os.Stderr.

WriterKey returns a unique key representing stderr.

CaddyModule returns the Caddy module information.

OpenWriter returns os.Stdout that can't be closed.

Uses: os.Stdout.

WriterKey returns a unique key representing stdout.

ServeHTTP is the external entry point for API requests. It will only be called once per request.

Uses: net.SplitHostPort, zap.Bool, zap.Int, zap.Reflect, zap.String.

"<path> <hash>"

This type doesn't have documentation.

Field name	Field type	Comment
IntField	int	No comment on field.
StrField	string	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
configSet	*certmagic.Config	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	*mockIssuer	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	mockRouter	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	*mockProvisionableRouter	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
	mockRouter	No comment on field.
provisionErr	error	No comment on field.
provisioned	bool	No comment on field.

This type doesn't have documentation.

Field name	Field type	Comment
routes	[]AdminRoute	No comment on field.