🌱 Support token secret key for HCLOUD_TOKEN hot-reload

README.md

@@ -62,8 +62,9 @@ See [CAPH docs](https://syself.com/docs/caph/topics/baremetal/creating-workload-
 
 ## Usage
 
-We recommend to mount the secret `hetzner` as volume and make it avaiable for the container as `/etc/hetzner-secret`.
+We recommend to mount the secret `hetzner` as volume and make it available for the container as `/etc/hetzner-secret`.
 Then the credentials are automatically reloaded, when the secret changes.
+When you use hot-reloading, the secret keys must be named `hcloud` (or `token`, for upstream hcloud-ccm compatibility), `robot-user`, and `robot-password`.
 You see an example in the [ccm helm chart](https://github.com/syself/charts/tree/main/charts/ccm-hetzner)
 
 ## Env Variables

internal/credentials/hotreload.go

@@ -1,6 +1,7 @@
 package credentials
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -91,7 +92,7 @@ func handleEvent(credentialsDir, baseName string, hcloudClient *hcloud.Client, r
 		// This case is executed, when the process is running on a local machine.
 		return loadRobotCredentials(credentialsDir, robotClient)
 
-	case "hcloud":
+	case "hcloud", "token":
 		// This case is executed, when the process is running on a local machine.
 		err := loadHcloudCredentials(credentialsDir, hcloudClient)
 		if err != nil {
@@ -237,12 +238,19 @@ func GetInitialHcloudCredentialsFromDirectory(credentialsDir string) (string, er
 }
 
 func readHcloudCredentials(credentialsDir string) (string, error) {
-	hcloudTokenFile := filepath.Join(credentialsDir, "hcloud")
-	data, err := os.ReadFile(hcloudTokenFile)
-	if err != nil {
-		return "", fmt.Errorf("reading hcloud token from %q failed: %w", hcloudTokenFile, err)
+	var allErrors []error
+	for _, key := range []string{"hcloud", "token"} {
+		// The upstream hcloud-ccm uses "token" as key name in the mounted secret.
+		// To ease migration between both CCMs, we support both key names.
+		hcloudTokenFile := filepath.Join(credentialsDir, key)
+		data, err := os.ReadFile(hcloudTokenFile)
+		if err != nil {
+			allErrors = append(allErrors, fmt.Errorf("reading hcloud token from %q failed: %w", hcloudTokenFile, err))
+			continue
+		}
+		return strings.TrimSpace(string(data)), nil
 	}
-	return strings.TrimSpace(string(data)), nil
+	return "", errors.Join(allErrors...)
 }
 
 // GetDirectory returns the directory where the credentials are stored.

internal/credentials/hotreload_test.go

@@ -0,0 +1,79 @@
+package credentials
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestReadHcloudCredentials(t *testing.T) {
+	t.Run("reads hcloud key", func(t *testing.T) {
+		dir := t.TempDir()
+		err := os.WriteFile(filepath.Join(dir, "hcloud"), []byte(" token-from-hcloud \n"), 0o600)
+		if err != nil {
+			t.Fatalf("write hcloud token: %v", err)
+		}
+
+		token, err := readHcloudCredentials(dir)
+		if err != nil {
+			t.Fatalf("readHcloudCredentials() error = %v", err)
+		}
+		if token != "token-from-hcloud" {
+			t.Fatalf("readHcloudCredentials() token = %q, want %q", token, "token-from-hcloud")
+		}
+	})
+
+	t.Run("falls back to token key", func(t *testing.T) {
+		dir := t.TempDir()
+		err := os.WriteFile(filepath.Join(dir, "token"), []byte("token-from-token-key"), 0o600)
+		if err != nil {
+			t.Fatalf("write token key: %v", err)
+		}
+
+		token, err := readHcloudCredentials(dir)
+		if err != nil {
+			t.Fatalf("readHcloudCredentials() error = %v", err)
+		}
+		if token != "token-from-token-key" {
+			t.Fatalf("readHcloudCredentials() token = %q, want %q", token, "token-from-token-key")
+		}
+	})
+
+	t.Run("prefers hcloud key over token key", func(t *testing.T) {
+		dir := t.TempDir()
+		err := os.WriteFile(filepath.Join(dir, "hcloud"), []byte("first-token"), 0o600)
+		if err != nil {
+			t.Fatalf("write hcloud token: %v", err)
+		}
+		err = os.WriteFile(filepath.Join(dir, "token"), []byte("second-token"), 0o600)
+		if err != nil {
+			t.Fatalf("write token key: %v", err)
+		}
+
+		token, err := readHcloudCredentials(dir)
+		if err != nil {
+			t.Fatalf("readHcloudCredentials() error = %v", err)
+		}
+		if token != "first-token" {
+			t.Fatalf("readHcloudCredentials() token = %q, want %q", token, "first-token")
+		}
+	})
+
+	t.Run("returns error if no key exists", func(t *testing.T) {
+		dir := t.TempDir()
+
+		_, err := readHcloudCredentials(dir)
+		if err == nil {
+			t.Fatal("readHcloudCredentials() error = nil, want non-nil")
+		}
+
+		errText := err.Error()
+		if !strings.Contains(errText, filepath.Join(dir, "hcloud")) {
+			t.Fatalf("error does not mention hcloud key path: %q", errText)
+		}
+		if !strings.Contains(errText, filepath.Join(dir, "token")) {
+			t.Fatalf("error does not mention token key path: %q", errText)
+		}
+	})
+}