feat: collect and prefetch actions specified by use as urls

internal/actions/act.go

@@ -0,0 +1,54 @@
+// Implementation for basic Action-related operations.
+package actions
+
+import (
+	logger "courgette/internal/logging"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+type CliClient interface {
+	Clone(url string, destination string) error
+	Exec(args ...string) error
+}
+
+type GitClient struct{}
+
+func (g GitClient) Exec(args ...string) error {
+	cmd := exec.Command("git", args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}
+
+func (g GitClient) Clone(url string, destination string) error {
+	return g.Exec("clone", url, destination, "--depth", "1")
+}
+
+// Returns a key that can be used as a directory / cache-key string
+// based on the provided Action repository url.
+func GetActionKey(url string) string {
+	url = strings.ToLower(url)
+
+	if strings.HasPrefix(url, "http://") {
+		url = strings.TrimPrefix(url, "http://")
+	} else if strings.HasPrefix(url, "https://") {
+		url = strings.TrimPrefix(url, "https://")
+	}
+
+	parts := strings.Split(url, "/")
+
+	return strings.Join(parts, "__")
+}
+
+// Prefetches and caches the action defined by <actionName> at <destination>.
+//
+// <actionName> is expected to be the full url of the repository where
+// the action lives.
+func PrefetchAction(client CliClient, actionName string, destination string) error {
+	logger.Info("Prefetching action: %s to %s", actionName, destination)
+
+	return client.Clone(actionName, destination)
+}

internal/cache/cache_manager.go

@@ -30,14 +30,14 @@ func (c CacheManager) Path(elems ...string) string {
 
 // Checks whether a specific top-level items exists in the cache.
 func (c CacheManager) Exists(key string) bool {
-    if _, err := os.Stat(c.Path(key)); errors.Is(err, os.ErrNotExist) {
+	if _, err := os.Stat(c.Path(key)); errors.Is(err, os.ErrNotExist) {
 		return false
 	}
 
-    return true
+	return true
 }
 
 // Deletes an element from the cache, if it exists.
 func (c CacheManager) Evict(key string) {
-    os.RemoveAll(c.Path(key))
+	os.RemoveAll(c.Path(key))
 }

internal/commands/execute_workflow.go

@@ -19,7 +19,7 @@ func ExecuteWorkflow(configuration Configuration, workflowFile string) error {
 	runnerInstance := runner.NewRunner(
 		driver,
 		configuration.Runner.Labels,
-		configuration.Cache.Dir,
+		configuration.GetCacheDir(),
 	)
 
 	workflow, err := workflow.FromYamlFile(workflowFile)

internal/runner/runner.go

@@ -2,10 +2,11 @@ package runner
 
 import (
 	"context"
+	actions "courgette/internal/actions"
 	cache "courgette/internal/cache"
 	driver "courgette/internal/driver"
 	logger "courgette/internal/logging"
-	workflow "courgette/internal/workflow"
+	workflows "courgette/internal/workflow"
 	"errors"
 	"fmt"
 	"sync"
@@ -36,7 +37,7 @@ func NewRunner(driver driver.ContainerDriver, labels map[string]string, cacheRoo
 // This is the high-level call that will set up the container
 // that the jobs will be executed in, run the jobs's steps and
 // tear down the container once no longer useful.
-func (r *Runner) RunWorkflow(workflow workflow.Workflow) TaskTracker {
+func (r *Runner) RunWorkflow(workflow workflows.Workflow) TaskTracker {
 	logger.Info("Executing workflow: %s", workflow.SourcePath)
 	rootTracker := NewTaskTracker(nil)
 
@@ -44,6 +45,15 @@ func (r *Runner) RunWorkflow(workflow workflow.Workflow) TaskTracker {
 
 	defer r.deferred.RunAllDeferredTasks()
 
+	workflow.Walk(func(n interface{}) {
+		switch n.(type) {
+		case workflows.Step:
+			if useAction := n.(workflows.Step).Use; useAction != "" {
+				actions.PrefetchAction(actions.GitClient{}, useAction, r.Cache.Path(actions.GetActionKey(useAction)))
+			}
+		}
+	})
+
 	for _, group := range workflow.GetJobsAsGroups() {
 		var groupWait sync.WaitGroup
 
@@ -72,7 +82,7 @@ func (r *Runner) RunWorkflow(workflow workflow.Workflow) TaskTracker {
 // a WaitGroup to coordinate concurrent tasks) and updates the tracker with results.
 
 func (r Runner) runJob(jobContext context.Context, jobTracker *TaskTracker, jobWaitGroup *sync.WaitGroup) {
-	job := jobContext.Value("currentJob").(workflow.Job)
+	job := jobContext.Value("currentJob").(workflows.Job)
 	containerName := fmt.Sprintf("runner-%s", jobTracker.TaskId)
 
 	defer jobWaitGroup.Done()
@@ -134,11 +144,11 @@ func (r *Runner) RunJobInContainer(imageUri string, containerId string, jobConte
 		r.Driver.Stop(containerId)
 	})
 
-	job := jobContext.Value("currentJob").(workflow.Job)
+	job := jobContext.Value("currentJob").(workflows.Job)
 
 	logger.Info("Started %s", containerId)
 	for stepIndex, step := range job.Steps {
-		workflow := jobContext.Value("workflow").(workflow.Workflow)
+		workflow := jobContext.Value("workflow").(workflows.Workflow)
 		stepCwd := workflow.GetWorkingDirectory(job.Name, stepIndex)
 		stepEnv := workflow.GetEnv(job.Name, stepIndex)
 		stepShell := workflow.GetShell(job.Name, stepIndex)

internal/workflow/models.go

@@ -22,6 +22,13 @@ type Job struct {
 	} `yaml:"defaults"`
 }
 
+func (j Job) Walk(handler func(node interface{})) {
+	handler(j)
+
+	for _, step := range j.Steps {
+		step.Walk(handler)
+	}
+}
 func (j Job) Validate() []error {
 	validationErrors := []error{}
 
@@ -46,13 +53,18 @@ type Step struct {
 	ContinueOnError  bool              `yaml:"continue-on-error"`
 	Env              map[string]string `yaml:"env"`
 	Shell            string            `yaml:"shell"`
+	Use              string            `yaml:"use"`
+}
+
+func (s Step) Walk(handler func(node interface{})) {
+	handler(s)
 }
 
 func (s Step) Validate() []error {
 	validationErrors := []error{}
 
-	if s.Run == "" {
-		validationErrors = append(validationErrors, errors.New("Missing \"run\" field on step."))
+	if s.Run == "" && s.Use == "" {
+		validationErrors = append(validationErrors, errors.New("Must have a \"run\" or \"step\" clause."))
 	}
 
 	return validationErrors
@@ -64,6 +76,14 @@ type Workflow struct {
 	Env        map[string]string `yaml:"env"`
 }
 
+func (w Workflow) Walk(handler func(node interface{})) {
+	handler(w)
+
+	for _, job := range w.Jobs {
+		job.Walk(handler)
+	}
+}
+
 // Returns the given workflow's job+step working directory inside the container
 // that runs the job.
 //