Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewExpandConverter ¶ added in v0.43.0
func NewExpandConverter() config.MapConverterFunc
NewExpandConverter returns a service.ConfigMapConverterFunc, that expands all environment variables for a given config.Map.
Notice: This API is experimental.
func NewOverwritePropertiesConverter ¶ added in v0.43.0
func NewOverwritePropertiesConverter(properties []string) config.MapConverterFunc
NewOverwritePropertiesConverter returns a service.ConfigMapConverterFunc, that overrides all the given properties into the input map.
Properties must follow the Java properties format, key-value list separated by equal sign with a "." as key delimiter.
["processors.batch.timeout=2s", "processors.batch/foo.timeout=3s"]
Types ¶
type ChangeEvent ¶
type ChangeEvent struct {
// Error is nil if the config is changed and needs to be re-fetched.
// Any non-nil error indicates that there was a problem with watching the config changes.
Error error
}
ChangeEvent describes the particular change event that happened with the config. TODO: see if this can be eliminated.
type CloseFunc ¶ added in v0.42.0
CloseFunc specifies the function invoked when the Retrieved.Close is being called.
type GetFunc ¶ added in v0.42.0
GetFunc specifies the function invoked when the Retrieved.Get is being called.
type Provider ¶
type Provider interface {
// Retrieve goes to the configuration source and retrieves the selected data which
// contains the value to be injected in the configuration and the corresponding watcher that
// will be used to monitor for updates of the retrieved value.
//
// `location` must follow the "<scheme>:<opaque_data>" format. This format is compatible
// with the URI definition (see https://datatracker.ietf.org/doc/html/rfc3986). The "<scheme>"
// must be always included in the `location`. The scheme supported by any provider MUST be at
// least 2 characters long to avoid conflicting with a driver-letter identifier as specified
// in https://tools.ietf.org/id/draft-kerwin-file-scheme-07.html#syntax.
//
// `watcher` callback is called when the config changes. watcher may be called from
// a different go routine. After watcher is called Retrieved.Get should be called
// to get the new config. See description of Retrieved for more details.
// watcher may be nil, which indicates that the caller is not interested in
// knowing about the changes.
//
// If ctx is cancelled should return immediately with an error.
// Should never be called concurrently with itself or with Shutdown.
Retrieve(ctx context.Context, location string, watcher WatcherFunc) (Retrieved, error)
// Shutdown signals that the configuration for which this Provider was used to
// retrieve values is no longer in use and the Provider should close and release
// any resources that it may have created.
//
// This method must be called when the Collector service ends, either in case of
// success or error. Retrieve cannot be called after Shutdown.
//
// Should never be called concurrently with itself or with Retrieve.
// If ctx is cancelled should return immediately with an error.
Shutdown(ctx context.Context) error
}
Provider is an interface that helps to retrieve a config map and watch for any changes to the config map. Implementations may load the config from a file, a database or any other source.
The typical usage is the following:
r := mapProvider.Retrieve("file:/path/to/config")
r.Get()
// wait for onChange() to be called.
r.Close()
r = mapProvider.Retrieve("file:/path/to/config")
r.Get()
// wait for onChange() to be called.
r.Close()
// repeat Retrieve/Get/wait/Close cycle until it is time to shut down the Collector process.
// ...
mapProvider.Shutdown()
func NewEnv ¶ added in v0.42.0
func NewEnv() Provider
NewEnv returns a new Provider that reads the configuration from the given environment variable.
This Provider supports "env" scheme, and can be called with a selector: `env:NAME_OF_ENVIRONMENT_VARIABLE`
func NewFile ¶
func NewFile() Provider
NewFile returns a new Provider that reads the configuration from a file.
This Provider supports "file" scheme, and can be called with a "location" that follows:
file-location = "file:" local-path local-path = [ drive-letter ] file-path drive-letter = ALPHA ":"
The "file-path" can be relative or absolute, and it can be any OS supported format.
Examples: `file:path/to/file` - relative path (unix, windows) `file:/path/to/file` - absolute path (unix, windows) `file:c:/path/to/file` - absolute path including drive-letter (windows) `file:c:\path\to\file` - absolute path including drive-letter (windows)
type Retrieved ¶
type Retrieved interface {
// Get returns the config Map. Should never be called after Close.
// Should never be called concurrently with itself or Close.
Get(ctx context.Context) (*config.Map, error)
// Close signals that the configuration for which it was used to retrieve values is
// no longer in use and should close and release any watchers that it may have created.
//
// Should block until all resources are closed, and guarantee that `onChange` is not
// going to be called after it returns except when `ctx` is cancelled.
//
// Should never be called concurrently with itself or Get.
Close(ctx context.Context) error
// contains filtered or unexported methods
}
Retrieved holds the result of a call to the Retrieve method of a Provider object. This interface cannot be directly implemented. Implementations must use the NewRetrieved helper.
func NewRetrieved ¶ added in v0.42.0
func NewRetrieved(getFunc GetFunc, options ...RetrievedOption) (Retrieved, error)
NewRetrieved returns a Retrieved configured with the provided options.
type RetrievedOption ¶ added in v0.42.0
type RetrievedOption func(*retrieved)
RetrievedOption represents the possible options for NewRetrieved.
func WithClose ¶ added in v0.42.0
func WithClose(closeFunc CloseFunc) RetrievedOption
WithClose overrides the default `Close` function for a Retrieved. The default always returns nil.
type WatcherFunc ¶ added in v0.43.0
type WatcherFunc func(*ChangeEvent)
Source Files