trigger pipeline by git tag about erda

[JdaieLin]

Since refName is possible to be a git tag or a branch name, some modification might be needed in /modules/dop/endpoints/release.go

        isTag := req.Content.IsTag
	refName := ""
	branchName := ""
	if isTag {
		refName = strings.TrimPrefix(req.Content.Ref, "refs/tags/")
		// TODO: get branchName by tag name from gittar
                // git branch -r --contains <tag> 
	} else {
		refName = strings.TrimPrefix(req.Content.Ref, "refs/heads/")
		branchName = refName
	}

	// 从 gittar 获取 pipeline.yml
	strPipelineYml, err := e.pipeline.FetchPipelineYml(req.Content.Repository.URL, refName, apistructs.DefaultPipelineYmlName)
	if err != nil {
		logrus.Errorf("failed to fetch pipeline.yml from gittar, req: %+v, (%+v)", req, err)
		return apierrors.ErrReleaseCallback.InternalError(err).ToResp(), nil
	}

	pipelineYml, err := pipelineyml.New([]byte(strPipelineYml))
	if err != nil {
		logrus.Errorf("failed to parse pipeline.yml yaml:%v \n err:%v", pipelineYml, err)
		return apierrors.ErrReleaseCallback.InternalError(err).ToResp(), nil
	}

	// 应用级设置
	if pipelineYml.Spec().On != nil && pipelineYml.Spec().On.Push != nil {
		// 满足 branches规则 或者 tags规则 都可以通过
		if (!isTag && !diceworkspace.IsRefPatternMatch(refName, pipelineYml.Spec().On.Push.Branches)) {
			return httpserver.OkResp("")
		}
		if (isTag && !diceworkspace.IsRefPatternMatch(refName, pipelineYml.Spec().On.Push.Tags)) {
			return httpserver.OkResp("")
		}
	} else {
		// 项目级设置
		validBranch := diceworkspace.GetValidBranchByGitReference(refName, rules)
		if !validBranch.IsTriggerPipeline {
			return httpserver.OkResp("")
		}
	}

	// 创建pipeline流程
        // TODO: use branchName instead of refName
	reqPipeline := &apistructs.PipelineCreateRequest{
		AppID:              uint64(req.Content.Repository.ApplicationID),
		Branch:             branchName, 
		Source:             apistructs.PipelineSourceDice,
		PipelineYmlSource:  apistructs.PipelineYmlSourceGittar,
		PipelineYmlContent: strPipelineYml,
		AutoRun:            true,
		UserID:             req.Content.Pusher.ID,
	}

[Muzry]

PR #959 has already Merged，close this issue