github-hook-server.go

package main

import (
    "fmt"
    "log"

    "flag"

    "strings"

    "os/exec"

    "net/http"

    "encoding/json"
)

var (
    httpPort int
    watchRepo string
)

func init() {
    flag.IntVar(&httpPort, "port", 26000, "HTTP Server port")
    flag.StringVar(&watchRepo, "repo", "", "Repository name")
    flag.Parse()
}

type PostReceiveHook struct {
    Ref string

    Repository struct {
        Name string
    }

    HeadCommit struct {
        Added, Modified, Removed []string
    } `json:"head_commit"`
}

func rootHandler(w http.ResponseWriter, r *http.Request) {
    payload := r.FormValue("payload")

    postHook := &PostReceiveHook{}

    var cmdName string

    if err := json.Unmarshal([]byte(payload), postHook); err != nil {
        log.Printf("Cannot decode: %v", err)
        http.Error(w, fmt.Sprintf("Cannot decode: %v", err), 500)
        return
    }

    hasChanged := func() (branch string) {
        repoName, ref := postHook.Repository.Name, postHook.Ref

        if repoName != watchRepo {
            log.Println("Wrong repo!")
            return ""
        }

        if refParts := strings.Split(ref, "/"); len(refParts) == 0 {
            log.Println("Ref is empty, should not be!")
            return ""
        } else {
            branch = refParts[len(refParts) - 1]
        }

        return
    }

    branch := hasChanged()

    if branch == "" {
        log.Println("Unchanged")

        return
    } else {
        cmdName = fmt.Sprintf("statics-%v-post-commit.sh", branch)

        log.Printf("Branch %v has changed, executing hook: %v", branch, cmdName)
    }

    cmd := exec.Command(cmdName)

    if err := cmd.Run(); err != nil {
        log.Printf("Cannot execute hook: %v", err)
        http.Error(w, fmt.Sprintf("Cannot run post commit hook: %v", err), 500)
        return
    }

    fmt.Fprint(w, "OK")
}

func main() {
    httpAddr := fmt.Sprintf(":%v", httpPort)

    log.Printf("Listening on: %v", httpAddr)

    http.HandleFunc("/favicon.ico", http.NotFound)
    http.HandleFunc("/", rootHandler)

    log.Fatal(http.ListenAndServe(httpAddr, nil))
}