GitlabRequestParser -> GitlabRequestParserValidator

server/gitlab_request_parser_validator.go

@@ -0,0 +1,90 @@
+// Copyright 2017 HootSuite Media Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the License);
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//    http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an AS IS BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// Modified hereafter by contributors to runatlantis/atlantis.
+//
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/lkysow/go-gitlab"
+)
+
+const secretHeader = "X-Gitlab-Token" // #nosec
+
+//go:generate pegomock generate -m --use-experimental-model-gen --package mocks -o mocks/mock_gitlab_request_parser_validator.go GitlabRequestParserValidator
+
+// GitlabRequestParserValidator parses and validates GitLab requests.
+type GitlabRequestParserValidator interface {
+	// ParseAndValidate validates that the request has a token header matching secret.
+	// If the secret does not match it returns an error.
+	// If secret is empty it does not check the token header.
+	// It then parses the request as a GitLab object depending on the header
+	// provided by GitLab identifying the webhook type. If the webhook type
+	// is not recognized it will return nil but will not return an error.
+	// Usage:
+	//	event, err := GitlabRequestParserValidator.ParseAndValidate(r, secret)
+	//	if err != nil {
+	//		return
+	//	}
+	//	switch event := event.(type) {
+	//	case gitlab.MergeCommentEvent:
+	//		// handle
+	//	case gitlab.MergeEvent:
+	//		// handle
+	//	default:
+	//		// unsupported event
+	//	}
+	ParseAndValidate(r *http.Request, secret []byte) (interface{}, error)
+}
+
+// DefaultGitlabRequestParserValidator parses and validates GitLab requests.
+type DefaultGitlabRequestParserValidator struct{}
+
+// ParseAndValidate returns the JSON payload of the request.
+// See GitlabRequestParserValidator.ParseAndValidate().
+func (d *DefaultGitlabRequestParserValidator) ParseAndValidate(r *http.Request, secret []byte) (interface{}, error) {
+	const mergeEventHeader = "Merge Request Hook"
+	const noteEventHeader = "Note Hook"
+
+	// Validate secret if specified.
+	headerSecret := r.Header.Get(secretHeader)
+	secretStr := string(secret)
+	if len(secret) != 0 && headerSecret != secretStr {
+		return nil, fmt.Errorf("header %s=%s did not match expected secret", secretHeader, headerSecret)
+	}
+
+	// Parse request into a gitlab object based on the object type specified
+	// in the gitlabHeader.
+	bytes, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return nil, err
+	}
+	switch r.Header.Get(gitlabHeader) {
+	case mergeEventHeader:
+		var m gitlab.MergeEvent
+		if err := json.Unmarshal(bytes, &m); err != nil {
+			return nil, err
+		}
+		return m, nil
+	case noteEventHeader:
+		var m gitlab.MergeCommentEvent
+		if err := json.Unmarshal(bytes, &m); err != nil {
+			return nil, err
+		}
+		return m, nil
+	}
+	return nil, nil
+}