Add GitLab support

gitlab/gitlab.go

@@ -0,0 +1,144 @@
+package gitlab
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+
+	"gopkg.in/go-playground/webhooks.v2"
+)
+
+// 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 GitHub Webhook instance
+type Config struct {
+	Secret string
+}
+
+// Event defines a GitHub hook event type
+type Event string
+
+// GitLab hook types
+const (
+	PushEvents          Event = "Push Hook"
+	TagEvents           Event = "Tag Push Hook"
+	IssuesEvents        Event = "Issue Hook"
+	CommentEvents       Event = "Note Hook"
+	MergerRequestEvents Event = "Merge Request Hook"
+	WikiPageEvents      Event = "Wiki Page Hook"
+	PipelineEvents      Event = "Pipeline Hook"
+	BuildEvents         Event = "Build Hook"
+)
+
+// New creates and returns a WebHook instance denoted by the Provider type
+func New(config *Config) *Webhook {
+	return &Webhook{
+		provider:   webhooks.GitLab,
+		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) {
+
+	event := r.Header.Get("X-Gitlab-Event")
+	if len(event) == 0 {
+		http.Error(w, "400 Bad Request - Missing X-Gitlab-Event Header", http.StatusBadRequest)
+		return
+	}
+
+	gitLabEvent := Event(event)
+
+	fn, ok := hook.eventFuncs[gitLabEvent]
+	// if no event registered
+	if !ok {
+		return
+	}
+
+	payload, err := ioutil.ReadAll(r.Body)
+	if err != nil || len(payload) == 0 {
+		http.Error(w, "Error reading Body", http.StatusInternalServerError)
+		return
+	}
+
+	// If we have a Secret set, we should check the MAC
+	if len(hook.secret) > 0 {
+
+		signature := r.Header.Get("X-Gitlab-Token")
+
+		if signature != hook.secret {
+			http.Error(w, "403 Forbidden - Token missmatch", http.StatusForbidden)
+			return
+		}
+	}
+
+	// Make headers available to ProcessPayloadFunc as a webhooks type
+	hd := webhooks.Header(r.Header)
+
+	switch gitLabEvent {
+	case PushEvents:
+		var pe PushEventPayload
+		json.Unmarshal([]byte(payload), &pe)
+		hook.runProcessPayloadFunc(fn, pe, hd)
+
+	case TagEvents:
+		var te TagEventPayload
+		json.Unmarshal([]byte(payload), &te)
+		hook.runProcessPayloadFunc(fn, te, hd)
+
+	case IssuesEvents:
+		var ie IssueEventPayload
+		json.Unmarshal([]byte(payload), &ie)
+		hook.runProcessPayloadFunc(fn, ie, hd)
+
+	case CommentEvents:
+		var ce CommentEventPayload
+		json.Unmarshal([]byte(payload), &ce)
+		hook.runProcessPayloadFunc(fn, ce, hd)
+
+	case MergerRequestEvents:
+		var mre MergeRequestEventPayload
+		json.Unmarshal([]byte(payload), &mre)
+		hook.runProcessPayloadFunc(fn, mre, hd)
+
+	case WikiPageEvents:
+		var wpe WikiPageEventPayload
+		json.Unmarshal([]byte(payload), &wpe)
+		hook.runProcessPayloadFunc(fn, wpe, hd)
+
+	case PipelineEvents:
+		var pe PipelineEventPayload
+		json.Unmarshal([]byte(payload), &pe)
+		hook.runProcessPayloadFunc(fn, pe, hd)
+
+	case BuildEvents:
+		var be BuildEventPayload
+		json.Unmarshal([]byte(payload), &be)
+		hook.runProcessPayloadFunc(fn, be, 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)
+}