Golang tip of the day: admin dashboard and health checks in Beego applications

One litle-publicized feature of the BeeGo Go framework is its admin dashboard.

Features

Although it may look quite raw visually (think MIME: text/plain), it contains a wealth of information about goroutines, threads, memory usage, and request statistics. It even allows devs to add to a "healthcheck" list, and admins allowed dashboard access to run "tasks" defined in code. The diagram belows shows the hierarchy of features in the version coming with Beego 1.3.0.

Enabling and customizing the admin dashboard

The admin dashboard is not enabled by default. Its availability is controlled by the EnableAdmin global. The simplest (best ?) way to configure it is arguably to add it to the confg/app.conf configuration file:

appname = wego
httpport = 8080
runmode = dev
enableadmin = true

For the curious reader, the config loading happens in beego/config.ParseConfig(), which is itself triggered by beego/config init(), meaning it runs before the application main().

Some degree of configuration is available, via the two additional variables: AdminHttpAddr which take an IP address/name string (default: 127.0.01), and AdminHttpPort, which takes an integer port number (default: 8088).

Adding application health checks runnable from the admin dashboard

The dashboard provides access to a "healthcheck" section, allowing app developers to add their custom sanity checks on the running application.

Health checks are defined by the minimal HealthChecker interface, and stored in the AdminCheckList map. Although the is public, it is better to add checks to it using function AddHealthCheck():

// See beego/toolbox/healthcheck.go
type HealthChecker interface {
    Check() error
}

// add health checker with name string
func AddHealthCheck(name string, hc HealthChecker) {
    AdminCheckList[name] = hc
}

The dashboard-triggered healthcheck works by iterating on the checks in AdminCheckList, and printing the results from each check which returned a non-nil error.