feat: add secrets from file and prepare a release

changelog/1.0.0_2023-10-26/file-secrets.md

@@ -0,0 +1,7 @@
+Change: Read secrets form files
+
+We have added proper support to load secrets like tokens from files or from
+base64-encoded strings. Just provide the flags or environment variables with a
+DSN formatted string like `file://path/to/file` or `base64://Zm9vYmFy`.
+
+https://github.com/promhippie/prometheus-hcloud-sd/pulls/

changelog/1.0.0_2023-10-26/update-deps.md

@@ -0,0 +1,7 @@
+Enhancement: Update all releated dependencies
+
+We've updated all dependencies to the latest available versions, including more
+current versions of build tools and used Go version to build the binaries. It's
+time to mark a stable release.
+
+https://github.com/promhippie/prometheus-hcloud-sd/pulls/

pkg/action/server.go

@@ -2,6 +2,7 @@ package action
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"os"
@@ -39,9 +40,21 @@ func Server(cfg *config.Config, logger log.Logger) error {
 		clients := make(map[string]*hcloud.Client, len(cfg.Target.Credentials))
 
 		for _, credential := range cfg.Target.Credentials {
+			token, err := config.Value(credential.Token)
+
+			if err != nil {
+				level.Error(logger).Log(
+					"msg", "Failed to read token secret",
+					"project", credential.Project,
+					"err", err,
+				)
+
+				return fmt.Errorf("failed to read token secret for %s", credential.Project)
+			}
+
 			clients[credential.Project] = hcloud.NewClient(
 				hcloud.WithToken(
-					credential.Token,
+					token,
 				),
 			)
 		}

pkg/config/config.go

@@ -1,5 +1,12 @@
 package config
 
+import (
+	"encoding/base64"
+	"fmt"
+	"os"
+	"strings"
+)
+
 // Credential defines a single project credential.
 type Credential struct {
 	Project string `json:"project" yaml:"project"`
@@ -42,3 +49,32 @@ func Load() *Config {
 		},
 	}
 }
+
+// Value returns the config value based on a DSN.
+func Value(val string) (string, error) {
+	if strings.HasPrefix(val, "file://") {
+		content, err := os.ReadFile(
+			strings.TrimPrefix(val, "file://"),
+		)
+
+		if err != nil {
+			return "", fmt.Errorf("failed to parse secret file: %w", err)
+		}
+
+		return string(content), nil
+	}
+
+	if strings.HasPrefix(val, "base64://") {
+		content, err := base64.StdEncoding.DecodeString(
+			strings.TrimPrefix(val, "base64://"),
+		)
+
+		if err != nil {
+			return "", fmt.Errorf("failed to parse base64 value: %w", err)
+		}
+
+		return string(content), nil
+	}
+
+	return val, nil
+}