doozerconfig

What Is It?

doozerconfig is a Go package for managing json-encoded configuration in doozer. Configuration in doozer is directly mapped to a Go struct. Configuration changes made in doozer are automatically reflected in the struct. For details, see the example below.

API documentation

Installation

$ go get github.com/ActiveState/doozerconfig

Example

var Config struct {
    MaxItems  int                `doozer:"config/max_items"`
    DbUri     string             `doozer:"config/db_uri"`
    EnvVars   map[string]string  `doozer:"config/envvars"`
    Verbose   bool   // not in doozer
}

func init() {
    doozer, _ := doozer.Dial("localhost:8046")
    rev, _ := doozer.Rev()
    
    // Map Config fields to "/myapp/" + the struct tag above.
    // eg: MaxItems will be mapped to /myapp/config/max_items
    //     EnvVars will be mapped to /myapp/config/envvars/*
    cfg := doozerconfig.New(doozer, rev, &Config, "/myapp/")

    // Load config values from doozer and assign to Config fields
    _ = cfg.Load()  

    // Watch for live changes to doozer config, and automatically
    // update the struct fields. The callback function can be used to
    // handle errors, and to get notified of changes.
    go cfg.Monitor("/myapp/config/*", func(change *Change, err error) {
        fmt.Printf("config changed in doozer; %+v\n", change)            
    })
}

Notes

• If a file is deleted from doozer, the config struct is not updated (unless it a map entry). Perhaps we should update the value to a default value (as specified in a default struct tag).

• Writing configuration back to doozer is not supported yet.

Changes

• Oct 22, 2012:

  • Support for loading map types

  • API: Load now takes doozer revision as a mandatory argument.

  • API: Monitor doesn't take a revision argument anymore. Instead it uses the one passed to Load.

  • API: Monitor's callback function accepts a new Change struct.

• Sep 25, 2012:

  • Initial public release.