gh

Commands and packages for GitHub services.

Installation

~ $ go get -u github.com/rjeczalik/gh

webhook

Package webhook implements middleware for GitHub Webhooks. User provides webhook service object that handles events delivered by GitHub. Webhook handler verifies payload signature delivered along with the event, unmarshals it to corresponding event struct and dispatches control to user service.

Documentation

https://godoc.org/github.com/rjeczalik/gh/webhook

Examples

Notify Slack's channel about recent push:

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	"net/url"

	"github.com/rjeczalik/gh/webhook"
)

var (
	secret  = flag.String("secret", "", "GitHub webhook secret")
	token   = flag.String("token", "", "Slack API token")
	channel = flag.String("channel", "", "Slack channel name")
)

type slack struct{}

func (s slack) Push(e *webhook.PushEvent) {
	const format = "https://slack.com/api/chat.postMessage?token=%s&channel=%s&text=%s"
	text := url.QueryEscape(fmt.Sprintf("%s pushed to %s", e.Pusher.Email, e.Repository.Name))
	if _, err := http.Get(fmt.Sprintf(format, *token, *channel, text)); err != nil {
		log.Println(err)
	}
}

func main() {
	flag.Parse()
	log.Fatal(http.ListenAndServe(":8080", webhook.New(*secret, slack{})))
}

Notify HipChat's room about recent push:

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	"strings"

	"github.com/rjeczalik/gh/webhook"
)

var (
	secret = flag.String("secret", "", "GitHub webhook secret")
	token  = flag.String("token", "", "HipChat personal API token")
	room   = flag.String("room", "", "HipChat room ID")
)

type hipchat struct{}

func (h hipchat) Push(e *webhook.PushEvent) {
	url := fmt.Sprintf("https://api.hipchat.com/v2/room/%s/notification", *room)
	body := fmt.Sprintf(`{"message":"%s pushed to %s"}`, e.Pusher.Email, e.Repository.Name)
	req, err := http.NewRequest("POST", url, strings.NewReader(body))
	if err != nil {
		log.Println(err)
		return
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+*token)
	if _, err := http.DefaultClient.Do(req); err != nil {
		log.Println(err)
	}
}

func main() {
	flag.Parse()
	log.Fatal(http.ListenAndServe(":8080", webhook.New(*secret, hipchat{})))
}

cmd/webhook

Command webhook starts a web server which listens on GitHub's POST requests. The payload of each request is verified against its signature, unmarshalled into corresponding event struct and the applied to the template script provided by a user.

Examples

Notify Slack's channel about recent push:

~ $ cat >slack.tsc <<EOF
> {{with $e := .}}
>   {{if eq $e.Name "push"}}
>     {{with $text := (urlquery (printf "%s pushed to %s" $e.Payload.Pusher.Email $e.Payload.Repository.Name))}}
>     {{with $url := (printf "https://slack.com/api/chat.postMessage?token=%s&channel=%s&text=%s" (env "SLACK_TOKEN") (env "SLACK_CHANNEL") $text)}}
>       {{exec "curl" "-X" "GET" $url}}
>     {{end}}
>     {{end}}
>   {{end}}
> {{end}}
> EOF

~ $ SLACK_TOKEN=token SLACK_CHANNEL=channel123 webhook -secret secret123 slack.tsc

Notify HipChat's room about recent push:

~ $ cat >hipchat.tsc <<EOF
> {{with $e := .}}
>   {{if eq $e.Name "push"}}
>     {{with $auth := (printf "authorization: bearer %s" (env "HIPCHAT_TOKEN"))}}
>     {{with $msg := (printf "{\"message_format\": \"text\", \"message\": \"%s pushed to %s\"}" $e.Payload.Pusher.Email $e.Payload.Repository.Name)}}
>     {{with $url := (printf "https://api.hipchat.com/v2/room/%s/notification" (env "HIPCHAT_ROOM"))}}
>       {{exec "curl" "-h" "content-type: application/json" "-h" $auth "-x" "post" "-d" $msg $url | log}}
>     {{end}}
>     {{end}}
>     {{end}}
>   {{end}}
> {{end}}
> EOF

~ $ HIPCHAT_TOKEN=token HIPCHAT_ROOM=123 webhook -secret secret123 hipchat.tsc

Troubleshooting

cmd/webhook provides -debug flag, which when enabled, makes tool dump to disk every received payload and log all commands executed via exec function within a template.

All event payload structs are auto-generated - initially they've been generated by scrapping GitHub on-line documentation. If the actual payloads contain more or different fields than current representation, updating it is as easy as putting dumped JSON files to testdata/ directory and running:

~ $ go generate -v github.com/rjeczalik/gh/...