successfully able to run simple workflows

Signed-off-by: Casey Lee <cplee@nektos.com>

act/runner/run_context.go

@@ -0,0 +1,269 @@
+package runner
+
+import (
+	"archive/tar"
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/nektos/act/pkg/container"
+
+	"github.com/nektos/act/pkg/common"
+	"github.com/nektos/act/pkg/model"
+	log "github.com/sirupsen/logrus"
+)
+
+// RunContext contains info about current job
+type RunContext struct {
+	Config    *Config
+	Run       *model.Run
+	EventJSON string
+	Env       map[string]string
+	Outputs   map[string]string
+	Tempdir   string
+}
+
+// GetEnv returns the env for the context
+func (rc *RunContext) GetEnv() map[string]string {
+	if rc.Env == nil {
+		rc.Env = mergeMaps(rc.Run.Workflow.Env, rc.Run.Job().Env)
+	}
+	return rc.Env
+}
+
+// StepEnv returns the env for a step
+func (rc *RunContext) StepEnv(step *model.Step) map[string]string {
+	env := make(map[string]string)
+	env["HOME"] = "/github/home"
+	env["GITHUB_WORKFLOW"] = rc.Run.Workflow.Name
+	env["GITHUB_RUN_ID"] = "1"
+	env["GITHUB_RUN_NUMBER"] = "1"
+	env["GITHUB_ACTION"] = step.ID
+	env["GITHUB_ACTOR"] = "nektos/act"
+
+	repoPath := rc.Config.Workdir
+	repo, err := common.FindGithubRepo(repoPath)
+	if err != nil {
+		log.Warningf("unable to get git repo: %v", err)
+	} else {
+		env["GITHUB_REPOSITORY"] = repo
+	}
+	env["GITHUB_EVENT_NAME"] = rc.Config.EventName
+	env["GITHUB_EVENT_PATH"] = "/github/workflow/event.json"
+	env["GITHUB_WORKSPACE"] = "/github/workspace"
+
+	_, rev, err := common.FindGitRevision(repoPath)
+	if err != nil {
+		log.Warningf("unable to get git revision: %v", err)
+	} else {
+		env["GITHUB_SHA"] = rev
+	}
+
+	ref, err := common.FindGitRef(repoPath)
+	if err != nil {
+		log.Warningf("unable to get git ref: %v", err)
+	} else {
+		log.Infof("using github ref: %s", ref)
+		env["GITHUB_REF"] = ref
+	}
+	job := rc.Run.Job()
+	if job.Container != nil {
+		return mergeMaps(rc.GetEnv(), job.Container.Env, step.GetEnv(), env)
+	}
+	return mergeMaps(rc.GetEnv(), step.GetEnv(), env)
+}
+
+// Close cleans up temp dir
+func (rc *RunContext) Close(ctx context.Context) error {
+	return os.RemoveAll(rc.Tempdir)
+}
+
+// Executor returns a pipeline executor for all the steps in the job
+func (rc *RunContext) Executor() common.Executor {
+	steps := make([]common.Executor, 0)
+	steps = append(steps, rc.setupTempDir())
+
+	for _, step := range rc.Run.Job().Steps {
+		containerSpec := new(model.ContainerSpec)
+
+		var stepExecutor common.Executor
+		if step.Run != "" {
+			stepExecutor = common.NewPipelineExecutor(
+				rc.setupContainerSpec(step, containerSpec),
+				rc.pullImage(containerSpec),
+				rc.runContainer(containerSpec),
+			)
+		} else if step.Uses != "" {
+			stepExecutor = common.NewErrorExecutor(fmt.Errorf("Not yet implemented - job:%s step:%+v", rc.Run, step))
+			// clone action repo
+			// read action.yaml
+			// if runs.using == node12, start node12 container and run `main`
+			// if runs.using == docker, pull `image` and run
+			// set inputs as env
+			// caputre output
+		} else {
+			stepExecutor = common.NewErrorExecutor(fmt.Errorf("Unable to determine how to run job:%s step:%+v", rc.Run, step))
+		}
+		steps = append(steps, stepExecutor)
+	}
+	return common.NewPipelineExecutor(steps...).Finally(rc.Close)
+}
+
+func (rc *RunContext) setupContainerSpec(step *model.Step, containerSpec *model.ContainerSpec) common.Executor {
+	return func(ctx context.Context) error {
+		job := rc.Run.Job()
+
+		containerSpec.Env = rc.StepEnv(step)
+
+		if step.Uses != "" {
+			containerSpec.Image = step.Uses
+		} else if job.Container != nil {
+			containerSpec.Image = job.Container.Image
+			containerSpec.Args = step.Run
+			containerSpec.Ports = job.Container.Ports
+			containerSpec.Volumes = job.Container.Volumes
+			containerSpec.Options = job.Container.Options
+		} else if step.Run != "" {
+			containerSpec.Image = platformImage(job.RunsOn)
+			containerSpec.Args = step.Run
+		} else {
+			return fmt.Errorf("Unable to setup container for %s", step)
+		}
+		return nil
+	}
+}
+
+func platformImage(platform string) string {
+	switch platform {
+	case "ubuntu-latest", "ubuntu-18.04":
+		return "ubuntu:18.04"
+	case "ubuntu-16.04":
+		return "ubuntu:16.04"
+	case "windows-latest", "windows-2019", "macos-latest", "macos-10.15":
+		return ""
+	default:
+		return ""
+	}
+}
+
+func mergeMaps(maps ...map[string]string) map[string]string {
+	rtnMap := make(map[string]string)
+	for _, m := range maps {
+		for k, v := range m {
+			rtnMap[k] = v
+		}
+	}
+	return rtnMap
+}
+
+func (rc *RunContext) setupTempDir() common.Executor {
+	return func(ctx context.Context) error {
+		var err error
+		rc.Tempdir, err = ioutil.TempDir("", "act-")
+		return err
+	}
+}
+
+func (rc *RunContext) pullImage(containerSpec *model.ContainerSpec) common.Executor {
+	return func(ctx context.Context) error {
+		return container.NewDockerPullExecutor(container.NewDockerPullExecutorInput{
+			Image:     containerSpec.Image,
+			ForcePull: rc.Config.ForcePull,
+		})(ctx)
+	}
+}
+
+func (rc *RunContext) runContainer(containerSpec *model.ContainerSpec) common.Executor {
+	return func(ctx context.Context) error {
+		ghReader, err := rc.createGithubTarball()
+		if err != nil {
+			return err
+		}
+
+		envList := make([]string, 0)
+		for k, v := range containerSpec.Env {
+			envList = append(envList, fmt.Sprintf("%s=%s", k, v))
+		}
+		var cmd, entrypoint []string
+		if containerSpec.Args != "" {
+			cmd = []string{
+				"/bin/sh",
+				"-c",
+				containerSpec.Args,
+			}
+		}
+		if containerSpec.Entrypoint != "" {
+			entrypoint = strings.Fields(containerSpec.Entrypoint)
+		}
+
+		return container.NewDockerRunExecutor(container.NewDockerRunExecutorInput{
+			Cmd:        cmd,
+			Entrypoint: entrypoint,
+			Image:      containerSpec.Image,
+			WorkingDir: "/github/workspace",
+			Env:        envList,
+			Name:       rc.createContainerName(),
+			Binds: []string{
+				fmt.Sprintf("%s:%s", rc.Config.Workdir, "/github/workspace"),
+				fmt.Sprintf("%s:%s", rc.Tempdir, "/github/home"),
+				fmt.Sprintf("%s:%s", "/var/run/docker.sock", "/var/run/docker.sock"),
+			},
+			Content:         map[string]io.Reader{"/github": ghReader},
+			ReuseContainers: rc.Config.ReuseContainers,
+		})(ctx)
+	}
+}
+
+func (rc *RunContext) createGithubTarball() (io.Reader, error) {
+	var buf bytes.Buffer
+	tw := tar.NewWriter(&buf)
+	var files = []struct {
+		Name string
+		Mode int64
+		Body string
+	}{
+		{"workflow/event.json", 0644, rc.EventJSON},
+	}
+	for _, file := range files {
+		log.Debugf("Writing entry to tarball %s len:%d", file.Name, len(rc.EventJSON))
+		hdr := &tar.Header{
+			Name: file.Name,
+			Mode: file.Mode,
+			Size: int64(len(rc.EventJSON)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			return nil, err
+		}
+		if _, err := tw.Write([]byte(rc.EventJSON)); err != nil {
+			return nil, err
+		}
+	}
+	if err := tw.Close(); err != nil {
+		return nil, err
+	}
+
+	return &buf, nil
+
+}
+
+func (rc *RunContext) createContainerName() string {
+	containerName := regexp.MustCompile("[^a-zA-Z0-9]").ReplaceAllString(rc.Run.String(), "-")
+
+	prefix := fmt.Sprintf("%s-", trimToLen(filepath.Base(rc.Config.Workdir), 10))
+	suffix := ""
+	containerName = trimToLen(containerName, 30-(len(prefix)+len(suffix)))
+	return fmt.Sprintf("%s%s%s", prefix, containerName, suffix)
+}
+
+func trimToLen(s string, l int) string {
+	if len(s) > l {
+		return s[:l]
+	}
+	return s
+}