Add GitLab PR generator for applicationset (#9264)

Signed-off-by: Ivo Verberk <ivo.verberk@gmail.com>

applicationset/generators/pull_request.go

@@ -87,6 +87,14 @@ func (g *PullRequestGenerator) selectServiceProvider(ctx context.Context, genera
 		}
 		return pullrequest.NewGithubService(ctx, token, providerConfig.API, providerConfig.Owner, providerConfig.Repo, providerConfig.Labels)
 	}
+	if generatorConfig.GitLab != nil {
+		providerConfig := generatorConfig.GitLab
+		token, err := g.getSecretRef(ctx, providerConfig.TokenRef, applicationSetInfo.Namespace)
+		if err != nil {
+			return nil, fmt.Errorf("error fetching Secret token: %v", err)
+		}
+		return pullrequest.NewGitLabService(ctx, token, providerConfig.API, providerConfig.Project, providerConfig.Labels)
+	}
 	if generatorConfig.Gitea != nil {
 		providerConfig := generatorConfig.Gitea
 		token, err := g.getSecretRef(ctx, providerConfig.TokenRef, applicationSetInfo.Namespace)

applicationset/services/pull_request/fixtures/gitlab_mr_list_response.json

@@ -0,0 +1,89 @@
+[
+  {
+    "id": 35385049,
+    "iid": 15442,
+    "project_id": 278964,
+    "title": "Draft: Use structured logging for DB load balancer",
+    "description": "",
+    "state": "opened",
+    "created_at": "2019-08-20T10:58:54.413Z",
+    "updated_at": "2019-08-20T12:01:49.849Z",
+    "merged_by": null,
+    "merged_at": null,
+    "closed_by": null,
+    "closed_at": null,
+    "target_branch": "master",
+    "source_branch": "use-structured-logging-for-db-load-balancer",
+    "user_notes_count": 1,
+    "upvotes": 0,
+    "downvotes": 0,
+    "assignee": {
+      "id": 4088036,
+      "name": "Hordur Freyr Yngvason",
+      "username": "hfyngvason",
+      "state": "active",
+      "avatar_url": "https://assets.gitlab-static.net/uploads/-/system/user/avatar/4088036/avatar.png",
+      "web_url": "https://gitlab.com/hfyngvason"
+    },
+    "author": {
+      "id": 4088036,
+      "name": "Hordur Freyr Yngvason",
+      "username": "hfyngvason",
+      "state": "active",
+      "avatar_url": "https://assets.gitlab-static.net/uploads/-/system/user/avatar/4088036/avatar.png",
+      "web_url": "https://gitlab.com/hfyngvason"
+    },
+    "assignees": [
+      {
+        "id": 4088036,
+        "name": "Hordur Freyr Yngvason",
+        "username": "hfyngvason",
+        "state": "active",
+        "avatar_url": "https://assets.gitlab-static.net/uploads/-/system/user/avatar/4088036/avatar.png",
+        "web_url": "https://gitlab.com/hfyngvason"
+      }
+    ],
+    "reviewers": [
+      {
+        "id": 2535118,
+        "name": "Thong Kuah",
+        "username": "tkuah",
+        "state": "active",
+        "avatar_url": "https://secure.gravatar.com/avatar/f7b51bdd49a4914d29504d7ff4c3f7b9?s=80&d=identicon",
+        "web_url": "https://gitlab.com/tkuah"
+      }
+    ],
+    "source_project_id": 278964,
+    "target_project_id": 278964,
+    "labels": [
+      "backend",
+      "backstage",
+      "database",
+      "database::review pending",
+      "group::autodevops and kubernetes"
+    ],
+    "work_in_progress": true,
+    "milestone": null,
+    "merge_when_pipeline_succeeds": false,
+    "merge_status": "can_be_merged",
+    "sha": "2fc4e8b972ff3208ec63b6143e34ad67ff343ad7",
+    "merge_commit_sha": null,
+    "discussion_locked": null,
+    "should_remove_source_branch": null,
+    "force_remove_source_branch": true,
+    "reference": "!15442",
+    "web_url": "https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/15442",
+    "time_stats": {
+      "time_estimate": 0,
+      "total_time_spent": 0,
+      "human_time_estimate": null,
+      "human_total_time_spent": null
+    },
+    "squash": true,
+    "task_completion_status": {
+      "count": 12,
+      "completed_count": 0
+    },
+    "approvals_before_merge": 1
+  }
+]

applicationset/services/pull_request/gitlab.go

@@ -0,0 +1,77 @@
+package pull_request
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	gitlab "github.com/xanzy/go-gitlab"
+)
+
+type GitLabService struct {
+	client  *gitlab.Client
+	project string
+	labels  []string
+}
+
+var _ PullRequestService = (*GitLabService)(nil)
+
+func NewGitLabService(ctx context.Context, token, url, project string, labels []string) (PullRequestService, error) {
+	var clientOptionFns []gitlab.ClientOptionFunc
+
+	// Set a custom Gitlab base URL if one is provided
+	if url != "" {
+		clientOptionFns = append(clientOptionFns, gitlab.WithBaseURL(url))
+	}
+
+	if token == "" {
+		token = os.Getenv("GITLAB_TOKEN")
+	}
+
+	client, err := gitlab.NewClient(token, clientOptionFns...)
+	if err != nil {
+		return nil, fmt.Errorf("error creating Gitlab client: %v", err)
+	}
+
+	return &GitLabService{
+		client:  client,
+		project: project,
+		labels:  labels,
+	}, nil
+}
+
+func (g *GitLabService) List(ctx context.Context) ([]*PullRequest, error) {
+
+	// Filter the merge requests on labels, if they are specified.
+	var labels *gitlab.Labels
+	if len(g.labels) > 0 {
+		labels = (*gitlab.Labels)(&g.labels)
+	}
+
+	opts := &gitlab.ListProjectMergeRequestsOptions{
+		ListOptions: gitlab.ListOptions{
+			PerPage: 100,
+		},
+		Labels: labels,
+	}
+
+	pullRequests := []*PullRequest{}
+	for {
+		mrs, resp, err := g.client.MergeRequests.ListProjectMergeRequests(g.project, opts)
+		if err != nil {
+			return nil, fmt.Errorf("error listing merge requests for project '%s': %v", g.project, err)
+		}
+		for _, mr := range mrs {
+			pullRequests = append(pullRequests, &PullRequest{
+				Number:  mr.IID,
+				Branch:  mr.SourceBranch,
+				HeadSHA: mr.SHA,
+			})
+		}
+		if resp.NextPage == 0 {
+			break
+		}
+		opts.Page = resp.NextPage
+	}
+	return pullRequests, nil
+}

applicationset/services/pull_request/gitlab_test.go

@@ -0,0 +1,103 @@
+package pull_request
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func writeMRListResponse(t *testing.T, w io.Writer) {
+	f, err := os.Open("fixtures/gitlab_mr_list_response.json")
+	if err != nil {
+		t.Fatalf("error opening fixture file: %v", err)
+	}
+
+	if _, err = io.Copy(w, f); err != nil {
+		t.Fatalf("error writing response: %v", err)
+	}
+}
+
+func TestGitLabServiceCustomBaseURL(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	defer server.Close()
+
+	path := "/api/v4/projects/278964/merge_requests"
+
+	mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, path+"?per_page=100", r.URL.RequestURI())
+		writeMRListResponse(t, w)
+	})
+
+	svc, err := NewGitLabService(context.Background(), "", server.URL, "278964", nil)
+	assert.NoError(t, err)
+
+	_, err = svc.List(context.Background())
+	assert.NoError(t, err)
+}
+
+func TestGitLabServiceToken(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	defer server.Close()
+
+	path := "/api/v4/projects/278964/merge_requests"
+
+	mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "token-123", r.Header.Get("Private-Token"))
+		writeMRListResponse(t, w)
+	})
+
+	svc, err := NewGitLabService(context.Background(), "token-123", server.URL, "278964", nil)
+	assert.NoError(t, err)
+
+	_, err = svc.List(context.Background())
+	assert.NoError(t, err)
+}
+
+func TestList(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	defer server.Close()
+
+	path := "/api/v4/projects/278964/merge_requests"
+
+	mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, path+"?per_page=100", r.URL.RequestURI())
+		writeMRListResponse(t, w)
+	})
+
+	svc, err := NewGitLabService(context.Background(), "", server.URL, "278964", []string{})
+	assert.NoError(t, err)
+
+	prs, err := svc.List(context.Background())
+	assert.NoError(t, err)
+	assert.Len(t, prs, 1)
+	assert.Equal(t, prs[0].Number, 15442)
+	assert.Equal(t, prs[0].Branch, "use-structured-logging-for-db-load-balancer")
+	assert.Equal(t, prs[0].HeadSHA, "2fc4e8b972ff3208ec63b6143e34ad67ff343ad7")
+}
+
+func TestListWithLabels(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	defer server.Close()
+
+	path := "/api/v4/projects/278964/merge_requests"
+
+	mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, path+"?labels=feature%2Cready&per_page=100", r.URL.RequestURI())
+		writeMRListResponse(t, w)
+	})
+
+	svc, err := NewGitLabService(context.Background(), "", server.URL, "278964", []string{"feature", "ready"})
+	assert.NoError(t, err)
+
+	_, err = svc.List(context.Background())
+	assert.NoError(t, err)
+}

docs/operator-manual/applicationset/Generators-Pull-Request.md

@@ -53,6 +53,40 @@ spec:
 * `tokenRef`: A `Secret` name and key containing the GitHub access token to use for requests. If not specified, will make anonymous requests which have a lower rate limit and can only see public repositories. (Optional)
 * `labels`: Labels is used to filter the PRs that you want to target. (Optional)
 
+## GitLab
+
+Specify the project from which to fetch the GitLab merge requests.
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: ApplicationSet
+metadata:
+  name: myapps
+spec:
+  generators:
+  - pullRequest:
+      gitlab:
+        # The GitLab project.
+        project: myproject
+        # For self-hosted GitLab (optional)
+        api: https://git.example.com/
+        # Reference to a Secret containing an access token. (optional)
+        tokenRef:
+          secretName: gitlab-token
+          key: token
+        # Labels is used to filter the MRs that you want to target. (optional)
+        labels:
+        - preview
+  requeueAfterSeconds: 1800
+  template:
+  # ...
+```
+
+* `project`: Required name of the GitLab project.
+* `api`: If using self-hosted GitLab, the URL to access it. (Optional)
+* `tokenRef`: A `Secret` name and key containing the GitLab access token to use for requests. If not specified, will make anonymous requests which have a lower rate limit and can only see public repositories. (Optional)
+* `labels`: Labels is used to filter the MRs that you want to target. (Optional)
+
 ## Gitea
 
 Specify the repository from which to fetch the Gitea Pull requests.