refactor: move act/model and act/exprparser to actionslib

Gitea needs the workflow model and the expression evaluator to parse
workflows and to build the task payload this runner consumes, so it had
to depend on gitea.com/gitea/runner for it. Both packages now live in
gitea.dev/actionslib, the module both sides already share, and this
repository consumes them from there.

The GithubContext helpers that need a git checkout on disk (SetRef,
SetSha and SetRepositoryAndOwner) are not moved: they are runner only and
would drag a git client and the act context logger into the shared
module. They become functions of the new act/ghcontext package, together
with their tests.

act/common.CartesianProduct moved to the shared model package as well,
act/model was its only user. act/model/testdata/container-volumes is now
act/runner/testdata/container-volumes, its only user is runner_test.go.

The x-runner-uuid and x-runner-token header names come from
actionslib too, so the runner and Gitea cannot drift apart.

The generated runner API code moved along with the repository, from
gitea.dev/actions-proto-go to gitea.dev/actionslib, so the imports of
ping/v1 and runner/v1 follow the new module path. Both cannot be used at
once: the generated types would no longer be the same types.

Signed-off-by: Lunny Xiao <xiaolunwen@gmail.com>

act/ghcontext/github_context.go

@@ -0,0 +1,138 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Copyright 2021 The nektos/act Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// Package ghcontext fills a model.GithubContext from the local git checkout.
+// The pure data parts of the context live in the shared
+// gitea.dev/actionslib/pkg/model package, only the helpers that need a
+// git repository on disk are kept here.
+package ghcontext
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitea.com/gitea/runner/act/common"
+	"gitea.com/gitea/runner/act/common/git"
+
+	"gitea.dev/actionslib/pkg/model"
+)
+
+var (
+	findGitRef      = git.FindGitRef
+	findGitRevision = git.FindGitRevision
+	findGithubRepo  = git.FindGithubRepo
+)
+
+func withDefaultBranch(ctx context.Context, b string, event map[string]any) map[string]any {
+	repoI, ok := event["repository"]
+	if !ok {
+		repoI = make(map[string]any)
+	}
+
+	repo, ok := repoI.(map[string]any)
+	if !ok {
+		common.Logger(ctx).Warnf("unable to set default branch to %v", b)
+		return event
+	}
+
+	// if the branch is already there return with no changes
+	if _, ok = repo["default_branch"]; ok {
+		return event
+	}
+
+	repo["default_branch"] = b
+	event["repository"] = repo
+
+	return event
+}
+
+// SetRef resolves the ref of the context from its event payload, falling back
+// to the ref checked out in repoPath.
+func SetRef(ctx context.Context, ghc *model.GithubContext, defaultBranch, repoPath string) {
+	logger := common.Logger(ctx)
+
+	// https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows
+	// https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads
+	switch ghc.EventName {
+	case "pull_request_target":
+		ghc.Ref = "refs/heads/" + ghc.BaseRef
+	case "pull_request", "pull_request_review", "pull_request_review_comment":
+		ghc.Ref = fmt.Sprintf("refs/pull/%.0f/merge", ghc.Event["number"])
+	case "deployment", "deployment_status":
+		ghc.Ref = model.AsString(model.NestedMapLookup(ghc.Event, "deployment", "ref"))
+	case "release":
+		ghc.Ref = "refs/tags/" + model.AsString(model.NestedMapLookup(ghc.Event, "release", "tag_name"))
+	case "push", "create", "workflow_dispatch":
+		ghc.Ref = model.AsString(ghc.Event["ref"])
+	default:
+		defaultBranch := model.AsString(model.NestedMapLookup(ghc.Event, "repository", "default_branch"))
+		if defaultBranch != "" {
+			ghc.Ref = "refs/heads/" + defaultBranch
+		}
+	}
+
+	if ghc.Ref == "" {
+		ref, err := findGitRef(ctx, repoPath)
+		if err != nil {
+			logger.Warningf("unable to get git ref: %v", err)
+		} else {
+			logger.Debugf("using github ref: %s", ref)
+			ghc.Ref = ref
+		}
+
+		// set the branch in the event data
+		if defaultBranch != "" {
+			ghc.Event = withDefaultBranch(ctx, defaultBranch, ghc.Event)
+		} else {
+			ghc.Event = withDefaultBranch(ctx, "master", ghc.Event)
+		}
+
+		if ghc.Ref == "" {
+			ghc.Ref = "refs/heads/" + model.AsString(model.NestedMapLookup(ghc.Event, "repository", "default_branch"))
+		}
+	}
+}
+
+// SetSha resolves the commit of the context from its event payload, falling
+// back to the revision checked out in repoPath.
+func SetSha(ctx context.Context, ghc *model.GithubContext, repoPath string) {
+	logger := common.Logger(ctx)
+
+	// https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows
+	// https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads
+	switch ghc.EventName {
+	case "pull_request_target":
+		ghc.Sha = model.AsString(model.NestedMapLookup(ghc.Event, "pull_request", "base", "sha"))
+	case "deployment", "deployment_status":
+		ghc.Sha = model.AsString(model.NestedMapLookup(ghc.Event, "deployment", "sha"))
+	case "push", "create", "workflow_dispatch":
+		if deleted, ok := ghc.Event["deleted"].(bool); ok && !deleted {
+			ghc.Sha = model.AsString(ghc.Event["after"])
+		}
+	}
+
+	if ghc.Sha == "" {
+		_, sha, err := findGitRevision(ctx, repoPath)
+		if err != nil {
+			logger.Warningf("unable to get git revision: %v", err)
+		} else {
+			ghc.Sha = sha
+		}
+	}
+}
+
+// SetRepositoryAndOwner resolves the repository of the context from the git
+// remote in repoPath when it is not set yet, and derives its owner.
+func SetRepositoryAndOwner(ctx context.Context, ghc *model.GithubContext, githubInstance, remoteName, repoPath string) {
+	if ghc.Repository == "" {
+		repo, err := findGithubRepo(ctx, repoPath, githubInstance, remoteName)
+		if err != nil {
+			common.Logger(ctx).Warningf("unable to get git repo (githubInstance: %v; remoteName: %v, repoPath: %v): %v", githubInstance, remoteName, repoPath, err)
+			return
+		}
+		ghc.Repository = repo
+	}
+	ghc.RepositoryOwner = strings.Split(ghc.Repository, "/")[0]
+}