logjam

Logjam client for Go

This package provides integration with the Logjam monitoring tool for Go web-applications.

It buffers all log output for a request and sends the result to a configured logjam device when the request was finished.

Requirements

This package depends on github.com/pebbe/zmq4 which requires ZeroMQ version 4.0.1 or above. Make sure you have it installed on your machine.

E.g. for MacOS:

brew install zmq

How to use it

Install via go get github.com/xing/logjam-agent-go.

Initialize the client

// create a logger
logger := logjam.Logger{
    Logger: log.New(os.Stderr, "", log.StdFlags),
    LogLevel: logjam.ERROR,
}

// create the agent
agent := logjam.NewAgent(&logjam.Options{
	AppName: "MyApp",
	EnvName: "production",
    Logger: logger,
    LogLevel: logjam.INFO,
})

Use the logjam middleware

r := mux.NewRouter()
...
r.Use(agent.NewMiddleware)
...

This example uses the Gorilla Mux package but it should also work with other router packages.

You also need to set environment variables to point to the actual logjam broker instance:

export LOGJAM_BROKER=my-logjam-broker.host.name

Shutting down

Make sure to shut down the agent upon program termination in order to properly close the ZeroMQ socket used to send messages to logjam.

agent.Shutdown()

Adapting logjam action names

By default, the logjam middleware fabricates logjam action names from the escaped request path and request method. For example, a GET request to the endpoint "/users/123/friends" will be translated to "Users::Id::Friends#get". If you're not happy with that, you can override the action name in your request handler, as the associated logjam request is available from the request context:

func ShowFriends(w http.ResponseWriter, r *http.Request) {
	request := logjam.GetRequest(r)
	request.ChangeAction(w, "Users#friends")
	fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
})

If you're using the gorilla mux package, you can configure the desired logjam action name when declaring the route. The following examples uses a Rails inspired naming:

import ("github.com/xing/logjam-agent-go/gorilla")

gorilla.ActionName(router.Path("/users").Methods("GET").HandlerFunc(...), "Users#index")
gorilla.ActionName(router.Path("/users").Methods("POST").HandlerFunc(...), "Users#create")
gorilla.ActionName(router.Path("/users/{user_id}").Methods("GET").HandlerFunc(...), "Users#show")
gorilla.ActionName(router.Path("/users/{user_id}").Methods("PUT", "PATCH").HandlerFunc(...), "Users#update")
gorilla.ActionName(router.Path("/users/{user_id}").Methods("DELETE").HandlerFunc(...), "Users#destroy")
gorilla.ActionName(router.Path("/users/{user_id}/friends").Methods("GET").HandlerFunc(...), "Users#friends")

Make sure to have the route fully configured before calling gorilla.ActionName.

How to contribute?

Please fork the repository and create a pull-request for us.