add gogs support

gogs/gogs.go

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2018, 奶爸<1@5.nu>
+ * All rights reserved.
+ */
+
+package gogs
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/naiba/webhooks"
+	client "github.com/gogits/go-gogs-client"
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/hex"
+)
+
+// Webhook instance contains all methods needed to process events
+type Webhook struct {
+	provider   webhooks.Provider
+	secret     string
+	eventFuncs map[Event]webhooks.ProcessPayloadFunc
+}
+
+// Config defines the configuration to create a new Gogs Webhook instance
+type Config struct {
+	Secret string
+}
+
+// Event defines a Gogs hook event type
+type Event string
+
+// Gogs hook types
+const (
+	CreateEvent       Event = "create"
+	DeleteEvent       Event = "delete"
+	ForkEvent         Event = "fork"
+	PushEvent         Event = "push"
+	IssuesEvent       Event = "issues"
+	IssueCommentEvent Event = "issue_comment"
+	PullRequestEvent  Event = "pull_request"
+	ReleaseEvent      Event = "release"
+)
+
+// New creates and returns a WebHook instance denoted by the Provider type
+func New(config *Config) *Webhook {
+	return &Webhook{
+		provider:   webhooks.Gogs,
+		secret:     config.Secret,
+		eventFuncs: map[Event]webhooks.ProcessPayloadFunc{},
+	}
+}
+
+// Provider returns the current hooks provider ID
+func (hook Webhook) Provider() webhooks.Provider {
+	return hook.provider
+}
+
+// RegisterEvents registers the function to call when the specified event(s) are encountered
+func (hook Webhook) RegisterEvents(fn webhooks.ProcessPayloadFunc, events ...Event) {
+
+	for _, event := range events {
+		hook.eventFuncs[event] = fn
+	}
+}
+
+// ParsePayload parses and verifies the payload and fires off the mapped function, if it exists.
+func (hook Webhook) ParsePayload(w http.ResponseWriter, r *http.Request) {
+	webhooks.DefaultLog.Info("Parsing Payload...")
+
+	event := r.Header.Get("X-Gogs-Event")
+	if len(event) == 0 {
+		webhooks.DefaultLog.Error("Missing X-Gogs-Event Header")
+		http.Error(w, "400 Bad Request - Missing X-Gogs-Event Header", http.StatusBadRequest)
+		return
+	}
+	webhooks.DefaultLog.Debug(fmt.Sprintf("X-Gogs-Event:%s", event))
+
+	gogsEvent := Event(event)
+
+	fn, ok := hook.eventFuncs[gogsEvent]
+	// if no event registered
+	if !ok {
+		webhooks.DefaultLog.Info(fmt.Sprintf("Webhook Event %s not registered, it is recommended to setup only events in gogs that will be registered in the webhook to avoid unnecessary traffic and reduce potential attack vectors.", event))
+		return
+	}
+
+	payload, err := ioutil.ReadAll(r.Body)
+	if err != nil || len(payload) == 0 {
+		webhooks.DefaultLog.Error("Issue reading Payload")
+		http.Error(w, "Issue reading Payload", http.StatusInternalServerError)
+		return
+	}
+	webhooks.DefaultLog.Debug(fmt.Sprintf("Payload:%s", string(payload)))
+
+	// If we have a Secret set, we should check the MAC
+	if len(hook.secret) > 0 {
+		webhooks.DefaultLog.Info("Checking secret")
+		signature := r.Header.Get("X-Gogs-Signature")
+		if len(signature) == 0 {
+			webhooks.DefaultLog.Error("Missing X-Gogs-Signature required for HMAC verification")
+			http.Error(w, "403 Forbidden - Missing X-Gogs-Signature required for HMAC verification", http.StatusForbidden)
+			return
+		}
+		webhooks.DefaultLog.Debug(fmt.Sprintf("X-Gogs-Signature:%s", signature))
+
+		mac := hmac.New(sha1.New, []byte(hook.secret))
+		mac.Write(payload)
+
+		expectedMAC := hex.EncodeToString(mac.Sum(nil))
+
+		if !hmac.Equal([]byte(signature[5:]), []byte(expectedMAC)) {
+			webhooks.DefaultLog.Error("HMAC verification failed")
+			http.Error(w, "403 Forbidden - HMAC verification failed", http.StatusForbidden)
+			return
+		}
+	}
+
+	// Make headers available to ProcessPayloadFunc as a webhooks type
+	hd := webhooks.Header(r.Header)
+
+	switch gogsEvent {
+	case CreateEvent:
+		var pe client.CreatePayload
+		json.Unmarshal([]byte(payload), &pe)
+		hook.runProcessPayloadFunc(fn, pe, hd)
+
+	case ReleaseEvent:
+		var re client.ReleasePayload
+		json.Unmarshal([]byte(payload), &re)
+		hook.runProcessPayloadFunc(fn, re, hd)
+
+	case PushEvent:
+		var pe client.PushPayload
+		json.Unmarshal([]byte(payload), &pe)
+		hook.runProcessPayloadFunc(fn, pe, hd)
+
+	case DeleteEvent:
+		var de client.DeletePayload
+		json.Unmarshal([]byte(payload), &de)
+		hook.runProcessPayloadFunc(fn, de, hd)
+
+	case ForkEvent:
+		var fe client.ForkPayload
+		json.Unmarshal([]byte(payload), &fe)
+		hook.runProcessPayloadFunc(fn, fe, hd)
+
+	case IssuesEvent:
+		var ie client.IssuesPayload
+		json.Unmarshal([]byte(payload), &ie)
+		hook.runProcessPayloadFunc(fn, ie, hd)
+
+	case IssueCommentEvent:
+		var ice client.IssueCommentPayload
+		json.Unmarshal([]byte(payload), &ice)
+		hook.runProcessPayloadFunc(fn, ice, hd)
+
+	case PullRequestEvent:
+		var pre client.PullRequestPayload
+		json.Unmarshal([]byte(payload), &pre)
+		hook.runProcessPayloadFunc(fn, pre, hd)
+	}
+}
+
+func (hook Webhook) runProcessPayloadFunc(fn webhooks.ProcessPayloadFunc, results interface{}, header webhooks.Header) {
+	go func(fn webhooks.ProcessPayloadFunc, results interface{}, header webhooks.Header) {
+		fn(results, header)
+	}(fn, results, header)
+}

webhooks.go

@@ -19,6 +19,8 @@ func (p Provider) String() string {
 		return "Bitbucket"
 	case GitLab:
 		return "GitLab"
+	case Gogs:
+		return "Gogs"
 	default:
 		return "Unknown"
 	}
@@ -26,9 +28,10 @@ func (p Provider) String() string {
 
 // webhooks available providers
 const (
-	GitHub Provider = iota
+	GitHub    Provider = iota
 	Bitbucket
 	GitLab
+	Gogs
 )
 
 // Webhook interface defines a webhook to receive events