feat(pkg/tasks): load and run tasks

pkg/tasks/tasks.go

@@ -0,0 +1,130 @@
+package tasks
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/BurntSushi/toml"
+)
+
+var (
+	ErrNoTaskFile = errors.New(".draft-tasks.toml not found")
+)
+
+const (
+	PreUp      = "PreUp"
+	PostDeploy = "PostDeploy"
+	PostDelete = "PostDelete"
+)
+
+type Tasks struct {
+	PreUp      map[string]string `toml:"pre-up"`
+	PostDeploy map[string]string `toml:"post-deploy"`
+	PostDelete map[string]string `toml:"cleanup"`
+}
+
+type Result struct {
+	Kind    string
+	Command []string
+	Pass    bool
+	Message string
+}
+
+// Load takes a path to file where tasks are defined and loads them in tasks
+func Load(path string) (*Tasks, error) {
+	if _, err := os.Stat(path); err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrNoTaskFile
+		}
+		return nil, err
+	}
+
+	t := Tasks{}
+	if _, err := toml.DecodeFile(path, &t); err != nil {
+		return nil, err
+	}
+
+	return &t, nil
+}
+
+func (t *Tasks) Run(kind, podName string) ([]Result, error) {
+	results := []Result{}
+
+	switch kind {
+	case PreUp:
+		for _, task := range t.PreUp {
+			result := executeTask(task, kind)
+			results = append(results, result)
+		}
+	case PostDeploy:
+		for _, task := range t.PostDeploy {
+			cmd := preparePostDeployTask(evaluateArgs(task), podName)
+			result := runTask(cmd, kind)
+			results = append(results, result)
+		}
+	case PostDelete:
+		for _, task := range t.PostDelete {
+			result := executeTask(task, kind)
+			results = append(results, result)
+		}
+	default:
+		return results, fmt.Errorf("Task kind: %s not supported", kind)
+	}
+
+	return results, nil
+}
+
+func executeTask(task, kind string) Result {
+	args := evaluateArgs(task)
+	cmd := prepareTask(args)
+	return runTask(cmd, kind)
+}
+
+func runTask(cmd *exec.Cmd, kind string) Result {
+	result := Result{Kind: kind, Pass: false}
+	result.Command = append([]string{cmd.Path}, cmd.Args[0:]...)
+
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	err := cmd.Run()
+	if err != nil {
+		result.Pass = false
+		result.Message = err.Error()
+		return result
+	}
+	result.Pass = true
+
+	return result
+}
+
+func prepareTask(args []string) *exec.Cmd {
+	var cmd *exec.Cmd
+	if len(args) < 2 {
+		cmd = exec.Command(args[0])
+	} else {
+		cmd = exec.Command(args[0], args[1:]...)
+	}
+	return cmd
+}
+
+func preparePostDeployTask(args []string, podName string) *exec.Cmd {
+	args = append([]string{"exec", podName, "--"}, args[0:]...)
+	return exec.Command("kubectl", args[0:]...)
+}
+
+func evaluateArgs(task string) []string {
+	args := strings.Split(task, " ")
+	argsCopy := args
+	count := 0
+	for _, part := range argsCopy {
+		if strings.HasPrefix(part, "$") {
+			evaluatedPart := os.Getenv(strings.TrimPrefix(part, "$"))
+			args[count] = evaluatedPart
+		}
+		count = count + 1
+	}
+	return args
+}

pkg/tasks/tasks_test.go

@@ -0,0 +1,57 @@
+package tasks
+
+import (
+	"testing"
+)
+
+func TestLoad(t *testing.T) {
+	tasksFile, err := Load("testdata/tasks.toml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(tasksFile.PreUp) != 1 {
+		t.Errorf("Expected 1 pre-up task, got %v", len(tasksFile.PreUp))
+	}
+	if len(tasksFile.PostDeploy) != 1 {
+		t.Errorf("Expected 1 post-deploy task, got %v", len(tasksFile.PostDeploy))
+	}
+	if len(tasksFile.PostDelete) != 1 {
+		t.Errorf("Expected 1 post-delete task, got %v", len(tasksFile.PostDeploy))
+	}
+}
+
+func TestLoadError(t *testing.T) {
+	_, err := Load("testdata/nonexistent.yaml")
+	if err == nil {
+		t.Error(err)
+	}
+
+	_, err = Load("testdata/malformedTasks.yaml")
+	if err == nil {
+	}
+}
+
+func TestRun(t *testing.T) {
+	taskFile, err := Load("testdata/tasks.toml")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	results, err := taskFile.Run(PreUp, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(results) != 1 {
+		t.Errorf("Expected one pre-up command to be run, got %v", len(results))
+	}
+
+	results, _ = taskFile.Run(PostDeploy, "testpod")
+	if len(results) != 1 {
+		t.Errorf("Expected one post deploy command to be run, got %v", len(results))
+	}
+
+	results, _ = taskFile.Run(PostDelete, "")
+	if len(results) != 1 {
+		t.Errorf("Expected one post-delete command to be run, got %v", len(results))
+	}
+}

pkg/tasks/testdata/malformedTasks.toml

@@ -0,0 +1,2 @@
+lorem ipsum abra kadabra
+-- a lot of nothing

pkg/tasks/testdata/tasks.toml

@@ -0,0 +1,8 @@
+[pre-up]
+prep = "echo hello"
+
+[post-deploy]
+"setting up your app" = "echo setup"
+
+[cleanup]
+"cleaning up stuff" = "echo cleaning up"