Initial webhook implementation

cmd/poll.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"github.com/nlewo/comin/config"
 	"github.com/nlewo/comin/deploy"
+	"github.com/nlewo/comin/webhook"
 	"github.com/nlewo/comin/worker"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -30,6 +31,7 @@ var pollCmd = &cobra.Command{
 
 		wk := worker.NewWorker(deployer.Deploy)
 		go worker.Scheduler(wk, config.Poller.Period)
+		go webhook.Run(wk, config.Webhook)
 		wk.Run()
 	},
 }

config/config.go

@@ -29,6 +29,20 @@ func Read(path string) (config types.Configuration, err error) {
 			config.Remotes[i].Auth.AccessToken = string(content)
 		}
 	}
+
+	if config.Webhook.Address == "" {
+		config.Webhook.Address = "127.0.0.1"
+	}
+	if config.Webhook.Port == 0 {
+		config.Webhook.Port = 4242
+	}
+	if config.Webhook.SecretPath != "" {
+		content, err := ioutil.ReadFile(config.Webhook.SecretPath)
+		if err != nil {
+			return config, err
+		}
+		config.Webhook.Secret = string(content)
+	}
 	logrus.Debugf("Config is '%#v'", config)
 	return
 }

types/types.go

@@ -62,10 +62,18 @@ type Poller struct {
 	Period int `yaml:"period"`
 }
 
+type Webhook struct {
+	Address    string `yaml:"address"`
+	Port       int    `yaml:"port"`
+	Secret     string
+	SecretPath string `yaml:"secret_path"`
+}
+
 type Configuration struct {
 	Hostname string   `yaml:"hostname"`
 	StateDir string   `yaml:"state_dir"`
 	Remotes  []Remote `yaml:"remotes"`
 	Branches Branches `yaml:"branches"`
 	Poller   Poller   `yaml:"poller"`
+	Webhook  Webhook  `yaml:"webhook"`
 }

webhook/webhook.go

@@ -0,0 +1,47 @@
+package webhook
+
+import (
+	"fmt"
+	"github.com/nlewo/comin/types"
+	"github.com/nlewo/comin/worker"
+	"github.com/sirupsen/logrus"
+	"io"
+	"net/http"
+	"os"
+)
+
+func Run(worker worker.Worker, cfg types.Webhook) {
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		var secret string
+		logrus.Infof("Getting webhook request %s from %s", r.URL, r.RemoteAddr)
+		if cfg.Secret != "" {
+			secret = r.Header.Get("X-Gitlab-Token")
+			if secret == "" {
+				logrus.Infof("Webhook called from %s without the X-Gitlab-Token header", r.RemoteAddr)
+				w.WriteHeader(http.StatusUnauthorized)
+				io.WriteString(w, "The header X-Gitlab-Token is required\n")
+				return
+			}
+			if secret != cfg.Secret {
+				logrus.Infof("Webhook called from %s with the invalid secret %s", r.RemoteAddr, secret)
+				w.WriteHeader(http.StatusUnauthorized)
+				io.WriteString(w, "Invalid X-Gitlab-Token header value\n")
+				return
+			}
+		}
+		if worker.Beat() {
+			w.WriteHeader(http.StatusOK)
+			io.WriteString(w, "A deployment has been triggered\n")
+		} else {
+			w.WriteHeader(http.StatusConflict)
+			io.WriteString(w, "A deployment is already running\n")
+		}
+	}
+	http.HandleFunc("/deploy", handler)
+	url := fmt.Sprintf("%s:%d", cfg.Address, cfg.Port)
+	logrus.Infof("Starting the webhook server on %s", url)
+	if err := http.ListenAndServe(url, nil); err != nil {
+		logrus.Errorf("Error while running the webhook server: %s", err)
+		os.Exit(1)
+	}
+}