Require approval to run actions for fork pull request (#22803)

Currently, Gitea will run actions automatically which are triggered by
fork pull request. It's a security risk, people can create a PR and
modify the workflow yamls to execute a malicious script.

So we should require approval for first-time contributors, which is the
default strategy of a public repo on GitHub, see [Approving workflow
runs from public
forks](https://docs.github.com/en/actions/managing-workflow-runs/approving-workflow-runs-from-public-forks).

Current strategy:

- don't need approval if it's not a fork PR;
- always need approval if the user is restricted;
- don't need approval if the user can write;
- don't need approval if the user has been approved before;
- otherwise, need approval.

https://user-images.githubusercontent.com/9418365/217207121-badf50a8-826c-4425-bef1-d82d1979bc81.mov

GitHub has an option for that, you can see that at
`/<owner>/<repo>/settings/actions`, and we can support that later.

<img width="835" alt="image"
src="https://user-images.githubusercontent.com/9418365/217199990-2967e68b-e693-4e59-8186-ab33a1314a16.png">

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

2 files changed, 45 insertions, 5 deletions

diff --git a/routers/web/repo/actions/view.go b/routers/web/repo/actions/view.go
index 5370310e8..dd2750f90 100644
--- a/routers/web/repo/actions/view.go
+++ b/routers/web/repo/actions/view.go
@@ -49,11 +49,12 @@ type ViewRequest struct {
 type ViewResponse struct {
 	State struct {
 		Run struct {
-			Link      string     `json:"link"`
-			Title     string     `json:"title"`
-			CanCancel bool       `json:"canCancel"`
-			Done      bool       `json:"done"`
-			Jobs      []*ViewJob `json:"jobs"`
+			Link       string     `json:"link"`
+			Title      string     `json:"title"`
+			CanCancel  bool       `json:"canCancel"`
+			CanApprove bool       `json:"canApprove"` // the run needs an approval and the doer has permission to approve
+			Done       bool       `json:"done"`
+			Jobs       []*ViewJob `json:"jobs"`
 		} `json:"run"`
 		CurrentJob struct {
 			Title  string         `json:"title"`
@@ -107,6 +108,7 @@ func ViewPost(ctx *context_module.Context) {
 	resp.State.Run.Title = run.Title
 	resp.State.Run.Link = run.Link()
 	resp.State.Run.CanCancel = !run.Status.IsDone() && ctx.Repo.CanWrite(unit.TypeActions)
+	resp.State.Run.CanApprove = run.NeedApproval && ctx.Repo.CanWrite(unit.TypeActions)
 	resp.State.Run.Done = run.Status.IsDone()
 	resp.State.Run.Jobs = make([]*ViewJob, 0, len(jobs)) // marshal to '[]' instead fo 'null' in json
 	for _, v := range jobs {
@@ -135,6 +137,9 @@ func ViewPost(ctx *context_module.Context) {
 
 	resp.State.CurrentJob.Title = current.Name
 	resp.State.CurrentJob.Detail = current.Status.LocaleString(ctx.Locale)
+	if run.NeedApproval {
+		resp.State.CurrentJob.Detail = ctx.Locale.Tr("actions.need_approval_desc")
+	}
 	resp.State.CurrentJob.Steps = make([]*ViewJobStep, 0) // marshal to '[]' instead fo 'null' in json
 	resp.Logs.StepsLog = make([]*ViewStepLog, 0)          // marshal to '[]' instead fo 'null' in json
 	if task != nil {
@@ -261,6 +266,40 @@ func Cancel(ctx *context_module.Context) {
 	ctx.JSON(http.StatusOK, struct{}{})
 }
 
+func Approve(ctx *context_module.Context) {
+	runIndex := ctx.ParamsInt64("run")
+
+	current, jobs := getRunJobs(ctx, runIndex, -1)
+	if ctx.Written() {
+		return
+	}
+	run := current.Run
+	doer := ctx.Doer
+
+	if err := db.WithTx(ctx, func(ctx context.Context) error {
+		run.NeedApproval = false
+		run.ApprovedBy = doer.ID
+		if err := actions_model.UpdateRun(ctx, run, "need_approval", "approved_by"); err != nil {
+			return err
+		}
+		for _, job := range jobs {
+			if len(job.Needs) == 0 && job.Status.IsBlocked() {
+				job.Status = actions_model.StatusWaiting
+				_, err := actions_model.UpdateRunJob(ctx, job, nil, "status")
+				if err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	}); err != nil {
+		ctx.Error(http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	ctx.JSON(http.StatusOK, struct{}{})
+}
+
 // getRunJobs gets the jobs of runIndex, and returns jobs[jobIndex], jobs.
 // Any error will be written to the ctx.
 // It never returns a nil job of an empty jobs, if the jobIndex is out of range, it will be treated as 0.
diff --git a/routers/web/web.go b/routers/web/web.go
index 88e27ad67..ff312992d 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -1286,6 +1286,7 @@ func RegisterRoutes(m *web.Route) {
 					m.Post("/rerun", reqRepoActionsWriter, actions.Rerun)
 				})
 				m.Post("/cancel", reqRepoActionsWriter, actions.Cancel)
+				m.Post("/approve", reqRepoActionsWriter, actions.Approve)
 			})
 		}, reqRepoActionsReader, actions.MustEnableActions)