add knecht

knecht/stack/stack.go

@@ -0,0 +1,144 @@
+package stack
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Local struct {
+	Name        string
+	ComposePath string
+	EnvExample  string // path to .env.example, may not exist
+}
+
+// Discover finds all stacks in the services directory.
+func Discover(servicesPath string) ([]Local, error) {
+	entries, err := os.ReadDir(servicesPath)
+	if err != nil {
+		return nil, fmt.Errorf("reading services dir %s: %w", servicesPath, err)
+	}
+
+	var stacks []Local
+	for _, e := range entries {
+		if !e.IsDir() {
+			continue
+		}
+		composePath := filepath.Join(servicesPath, e.Name(), "docker-compose.yml")
+		if _, err := os.Stat(composePath); err != nil {
+			continue // no compose file, skip
+		}
+		s := Local{
+			Name:        e.Name(),
+			ComposePath: composePath,
+			EnvExample:  filepath.Join(servicesPath, e.Name(), ".env.example"),
+		}
+		stacks = append(stacks, s)
+	}
+	return stacks, nil
+}
+
+// Get returns a single local stack by name.
+func Get(servicesPath, name string) (*Local, error) {
+	composePath := filepath.Join(servicesPath, name, "docker-compose.yml")
+	if _, err := os.Stat(composePath); err != nil {
+		return nil, fmt.Errorf("no docker-compose.yml found for stack %q in %s", name, servicesPath)
+	}
+	return &Local{
+		Name:        name,
+		ComposePath: composePath,
+		EnvExample:  filepath.Join(servicesPath, name, ".env.example"),
+	}, nil
+}
+
+// ReadCompose returns the raw compose file content.
+func (s *Local) ReadCompose() (string, error) {
+	b, err := os.ReadFile(s.ComposePath)
+	if err != nil {
+		return "", err
+	}
+	return string(b), nil
+}
+
+// EnvExampleKeys returns the variable names defined in .env.example.
+// Returns empty slice if the file doesn't exist.
+func (s *Local) EnvExampleKeys() ([]string, error) {
+	f, err := os.Open(s.EnvExample)
+	if os.IsNotExist(err) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	var keys []string
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		key, _, _ := strings.Cut(line, "=")
+		keys = append(keys, strings.TrimSpace(key))
+	}
+	return keys, scanner.Err()
+}
+
+// WriteEnvExample creates a .env.example file from a list of keys (values left empty).
+// Existing file is overwritten.
+func (s *Local) WriteEnvExample(keys []string) error {
+	var sb strings.Builder
+	sb.WriteString("# Generated by knecht from Portainer env vars\n")
+	for _, k := range keys {
+		sb.WriteString(k + "=\n")
+	}
+	return os.WriteFile(s.EnvExample, []byte(sb.String()), 0644)
+}
+
+// AppendEnvExample appends missing keys to an existing .env.example file.
+func (s *Local) AppendEnvExample(keys []string) error {
+	f, err := os.OpenFile(s.EnvExample, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	f.WriteString("\n# Added by knecht\n")
+	for _, k := range keys {
+		f.WriteString(k + "=\n")
+	}
+	return nil
+}
+
+// ServicesPath resolves the services directory: uses cfg value if set,
+// otherwise walks up from cwd to find the git root and appends /services.
+func ServicesPath(cfgPath string) (string, error) {
+	if cfgPath != "" {
+		return cfgPath, nil
+	}
+	return findServicesDir()
+}
+
+func findServicesDir() (string, error) {
+	dir, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+	for {
+		if _, err := os.Stat(filepath.Join(dir, ".git")); err == nil {
+			p := filepath.Join(dir, "services")
+			if _, err := os.Stat(p); err == nil {
+				return p, nil
+			}
+			return "", fmt.Errorf("found git root at %s but no services/ directory", dir)
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			break
+		}
+		dir = parent
+	}
+	return "", fmt.Errorf("could not find git root with a services/ directory")
+}