LogLayer for Go

Plugin Management ​

Plugins on a *loglayer.LogLayer can be added, removed, replaced, and inspected at runtime. All mutators are safe to call from any goroutine, including concurrently with emission.

For construction-time setup (Config.Plugins, ID semantics), see Plugin Configuration.

Add ​

go
log.AddPlugin(redact.New(...))
log.AddPlugin(redact.New(...), audit.New(...))   // multiple at once
log.AddPlugin(plugins...)                        // splat a slice

AddPlugin replaces by ID: re-adding the same ID updates the plugin in place. Plugins registered without an ID get an auto-generated one, so they can never be replaced by another no-ID plugin: each call adds a new entry.

Remove, inspect, count ​

go
log.RemovePlugin("redact")     // returns true if it was present
got, ok := log.GetPlugin("redact")
log.PluginCount()

Worked example: replace and remove by ID ​

go
log := loglayer.New(loglayer.Config{Transport: structured.New(structured.Config{})})

// Initial registration. The ID "audit" is the handle.
log.AddPlugin(loglayer.NewDataHook("audit", func(p loglayer.BeforeDataOutParams) loglayer.Data {
    return loglayer.Data{"audited": true}
}))

// Hot-swap the plugin: same ID, new behavior. The previous "audit"
// plugin is discarded.
log.AddPlugin(loglayer.NewDataHook("audit", func(p loglayer.BeforeDataOutParams) loglayer.Data {
    return loglayer.Data{"audited": true, "v": 2}
}))

// Tear it down at shutdown.
if log.RemovePlugin("audit") {
    fmt.Println("audit plugin removed")
}

Plugins added without an ID can't be retrieved or replaced this way: their auto-generated ID isn't surfaced anywhere. Use the ID-supplied form when management is part of the workflow.

Concurrency ​

AddPlugin and RemovePlugin publish a new immutable plugin set via atomic.Pointer, so the dispatch hot path only loads a pointer. Concurrent mutators on the same logger serialize via an internal mutex. Child() clones the plugin set by reference; once either side mutates, the snapshots fork (copy-on-write).