Merge pull request 'cluster: add top level ReadLines(), WriteStringFile() and RemoveFile() helpers' (#36)

Reviewed-on: #36

pkg/cluster/cluster_file.go

@@ -1,9 +1,12 @@
 package cluster
 
 import (
+	"bufio"
+	"bytes"
 	"fmt"
 	"io"
 	"os"
+	"strings"
 
 	fs "github.com/hack-pad/hackpadfs"
 )
@@ -40,6 +43,21 @@ func (m *Cluster) openWriter(name string, flags int, args ...any) (io.WriteClose
 	panic("unreachable")
 }
 
+// RemoveFile deletes a file from the cluster's config directory
+func (m *Cluster) RemoveFile(name string, args ...any) error {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	err := fs.Remove(m.dir, name)
+	switch {
+	case os.IsNotExist(err):
+		return nil
+	default:
+		return err
+	}
+}
+
 // ReadFile reads a file from the cluster's config directory
 func (m *Cluster) ReadFile(name string, args ...any) ([]byte, error) {
 	if len(args) > 0 {
@@ -48,3 +66,41 @@ func (m *Cluster) ReadFile(name string, args ...any) ([]byte, error) {
 
 	return fs.ReadFile(m.dir, name)
 }
+
+// ReadLines reads a file from the cluster's config directory,
+// split by lines, trimmed, and accepting `#` to comment lines out.
+func (m *Cluster) ReadLines(name string, args ...any) ([]string, error) {
+	var out []string
+
+	data, err := m.ReadFile(name, args...)
+	if err != nil {
+		return nil, err
+	}
+
+	sc := bufio.NewScanner(bytes.NewReader(data))
+	for sc.Scan() {
+		s := strings.TrimSpace(sc.Text())
+		switch {
+		case s == "", strings.HasPrefix(s, "#"):
+			// ignore
+		default:
+			// accepted
+			out = append(out, s)
+		}
+	}
+
+	return out, nil
+}
+
+// WriteStringFile writes the given content to a file on the machine's config directory
+func (m *Cluster) WriteStringFile(value string, name string, args ...any) error {
+	f, err := m.CreateTruncFile(name, args...)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := bytes.NewBufferString(value)
+	_, err = buf.WriteTo(f)
+	return err
+}

pkg/cluster/machine_file.go

@@ -1,7 +1,6 @@
 package cluster
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"os"
@@ -43,16 +42,9 @@ func (m *Machine) openWriter(name string, flags int, args ...any) (io.WriteClose
 
 // RemoveFile deletes a file from the machine's config directory
 func (m *Machine) RemoveFile(name string, args ...any) error {
-	base := m.zone.zones.dir
 	fullName := m.getFilename(name, args...)
-	err := fs.Remove(base, fullName)
 
-	switch {
-	case os.IsNotExist(err):
-		return nil
-	default:
-		return err
-	}
+	return m.zone.zones.RemoveFile(fullName)
 }
 
 // ReadFile reads a file from the machine's config directory
@@ -65,15 +57,9 @@ func (m *Machine) ReadFile(name string, args ...any) ([]byte, error) {
 
 // WriteStringFile writes the given content to a file on the machine's config directory
 func (m *Machine) WriteStringFile(value string, name string, args ...any) error {
-	f, err := m.CreateTruncFile(name, args...)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
+	fullName := m.getFilename(name, args...)
 
-	buf := bytes.NewBufferString(value)
-	_, err = buf.WriteTo(f)
-	return err
+	return m.zone.zones.WriteStringFile(value, fullName)
 }
 
 func (m *Machine) getFilename(name string, args ...any) string {