config: Support "include" directive

With this directive other configuration files can be imported into the
main config. Can be useful for keeping secrets out of the latter.

Closes: https://todo.xenrox.net/~xenrox/ntfy-alertmanager/23

config.scfg

@@ -1,3 +1,8 @@
+# Absolute path to another scfg configuration file which will be included.
+# This directive can be specified multiple times in the main configuration, 
+# but only the last occurrence of a setting will be used. Settings from
+# the main configuration will take precedence.
+include /etc/ntfy-alertmanager/ntfy.scfg
 # Public facing base URL of the service (e.g. https://ntfy-alertmanager.xenrox.net)
 # This setting is required for the "Silence" feature.
 base-url https://ntfy-alertmanager.xenrox.net

config/config.go

@@ -21,6 +21,7 @@ const (
 
 // Config is the configuration of the bridge.
 type Config struct {
+	Include     string
 	BaseURL     string
 	HTTPAddress string
 	LogLevel    string
@@ -82,6 +83,308 @@ type resolvedConfig struct {
 	Priority string
 }
 
+func parseBlock(block scfg.Block, config *Config) error {
+	d := block.Get("log-level")
+	if d != nil {
+		if err := d.ParseParams(&config.LogLevel); err != nil {
+			return err
+		}
+	}
+
+	d = block.Get("log-format")
+	if d != nil {
+		if err := d.ParseParams(&config.LogFormat); err != nil {
+			return err
+		}
+	}
+
+	d = block.Get("http-address")
+	if d != nil {
+		if err := d.ParseParams(&config.HTTPAddress); err != nil {
+			return err
+		}
+	}
+
+	d = block.Get("base-url")
+	if d != nil {
+		if err := d.ParseParams(&config.BaseURL); err != nil {
+			return err
+		}
+	}
+
+	d = block.Get("alert-mode")
+	if d != nil {
+		var mode string
+		if err := d.ParseParams(&mode); err != nil {
+			return err
+		}
+
+		switch strings.ToLower(mode) {
+		case "single":
+			config.AlertMode = Single
+
+		case "multi":
+			config.AlertMode = Multi
+
+		default:
+			return fmt.Errorf("%q directive: illegal mode %q", d.Name, mode)
+		}
+	}
+
+	d = block.Get("user")
+	if d != nil {
+		if err := d.ParseParams(&config.User); err != nil {
+			return err
+		}
+	}
+
+	d = block.Get("password")
+	if d != nil {
+		if err := d.ParseParams(&config.Password); err != nil {
+			return err
+		}
+	}
+
+	labelsDir := block.Get("labels")
+	if labelsDir != nil {
+		d = labelsDir.Children.Get("order")
+		if d != nil {
+			var order string
+			if err := d.ParseParams(&order); err != nil {
+				return err
+			}
+
+			config.Labels.Order = strings.Split(order, ",")
+		}
+
+		labels := make(map[string]labelConfig)
+		for _, labelName := range config.Labels.Order {
+			for _, labelDir := range labelsDir.Children.GetAll(labelName) {
+				labelConfig := new(labelConfig)
+				var name string
+
+				if err := labelDir.ParseParams(&name); err != nil {
+					return err
+				}
+
+				d = labelDir.Children.Get("priority")
+				if d != nil {
+					if err := d.ParseParams(&labelConfig.Priority); err != nil {
+						return err
+					}
+				}
+
+				d = labelDir.Children.Get("tags")
+				if d != nil {
+					var tags string
+					if err := d.ParseParams(&tags); err != nil {
+						return err
+					}
+
+					labelConfig.Tags = strings.Split(tags, ",")
+				}
+
+				d = labelDir.Children.Get("icon")
+				if d != nil {
+					if err := d.ParseParams(&labelConfig.Icon); err != nil {
+						return err
+					}
+				}
+
+				d = labelDir.Children.Get("email-address")
+				if d != nil {
+					if err := d.ParseParams(&labelConfig.EmailAddress); err != nil {
+						return err
+					}
+				}
+
+				d = labelDir.Children.Get("call")
+				if d != nil {
+					if err := d.ParseParams(&labelConfig.Call); err != nil {
+						return err
+					}
+				}
+
+				labels[fmt.Sprintf("%s:%s", labelName, name)] = *labelConfig
+			}
+		}
+
+		config.Labels.Label = labels
+	}
+
+	ntfyDir := block.Get("ntfy")
+	if ntfyDir != nil {
+		d = ntfyDir.Children.Get("topic")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.Topic); err != nil {
+				return err
+			}
+		}
+
+		d = ntfyDir.Children.Get("user")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.User); err != nil {
+				return err
+			}
+		}
+
+		d = ntfyDir.Children.Get("password")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.Password); err != nil {
+				return err
+			}
+		}
+
+		d = ntfyDir.Children.Get("access-token")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.AccessToken); err != nil {
+				return err
+			}
+		}
+
+		d = ntfyDir.Children.Get("certificate-fingerprint")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.CertFingerprint); err != nil {
+				return err
+			}
+
+			// hex.EncodeToString outputs a lower case string
+			config.Ntfy.CertFingerprint = strings.ToLower(strings.ReplaceAll(config.Ntfy.CertFingerprint, ":", ""))
+		}
+
+		d = ntfyDir.Children.Get("email-address")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.EmailAddress); err != nil {
+				return err
+			}
+		}
+
+		d = ntfyDir.Children.Get("call")
+		if d != nil {
+			if err := d.ParseParams(&config.Ntfy.Call); err != nil {
+				return err
+			}
+		}
+	}
+
+	cacheDir := block.Get("cache")
+	if cacheDir != nil {
+		d = cacheDir.Children.Get("type")
+		if d != nil {
+			if err := d.ParseParams(&config.Cache.Type); err != nil {
+				return err
+			}
+		}
+
+		var durationString string
+		d = cacheDir.Children.Get("duration")
+		if d != nil {
+			if err := d.ParseParams(&durationString); err != nil {
+				return err
+			}
+
+			duration, err := time.ParseDuration(durationString)
+			if err != nil {
+				return err
+			}
+
+			config.Cache.Duration = duration
+		}
+
+		// memory
+		var cleanupIntervalString string
+		d = cacheDir.Children.Get("cleanup-interval")
+		if d != nil {
+			if err := d.ParseParams(&cleanupIntervalString); err != nil {
+				return err
+			}
+
+			interval, err := time.ParseDuration(cleanupIntervalString)
+			if err != nil {
+				return err
+			}
+
+			config.Cache.CleanupInterval = interval
+		}
+
+		// redis
+		d = cacheDir.Children.Get("redis-url")
+		if d != nil {
+			if err := d.ParseParams(&config.Cache.RedisURL); err != nil {
+				return err
+			}
+		}
+	}
+
+	amDir := block.Get("alertmanager")
+	if amDir != nil {
+		var durationString string
+		d = amDir.Children.Get("silence-duration")
+		if d != nil {
+			if err := d.ParseParams(&durationString); err != nil {
+				return err
+			}
+
+			duration, err := time.ParseDuration(durationString)
+			if err != nil {
+				return err
+			}
+
+			config.Am.SilenceDuration = duration
+		}
+
+		d = amDir.Children.Get("user")
+		if d != nil {
+			if err := d.ParseParams(&config.Am.User); err != nil {
+				return err
+			}
+		}
+
+		d = amDir.Children.Get("password")
+		if d != nil {
+			if err := d.ParseParams(&config.Am.Password); err != nil {
+				return err
+			}
+		}
+
+		d = amDir.Children.Get("url")
+		if d != nil {
+			if err := d.ParseParams(&config.Am.URL); err != nil {
+				return err
+			}
+		}
+	}
+
+	resolvedDir := block.Get("resolved")
+	if resolvedDir != nil {
+		d = resolvedDir.Children.Get("tags")
+		if d != nil {
+			var tags string
+			if err := d.ParseParams(&tags); err != nil {
+				return err
+			}
+
+			config.Resolved.Tags = strings.Split(tags, ",")
+		}
+
+		d = resolvedDir.Children.Get("icon")
+		if d != nil {
+			if err := d.ParseParams(&config.Resolved.Icon); err != nil {
+				return err
+			}
+		}
+
+		d = resolvedDir.Children.Get("priority")
+		if d != nil {
+			if err := d.ParseParams(&config.Resolved.Priority); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 // ReadConfig reads an scfg formatted file and returns the configuration struct.
 func ReadConfig(path string) (*Config, error) {
 	cfg, err := scfg.Load(path)
@@ -103,327 +406,51 @@ func ReadConfig(path string) (*Config, error) {
 	// redis
 	config.Cache.RedisURL = "redis://localhost:6379"
 
-	d := cfg.Get("log-level")
+	includeDirs := cfg.GetAll("include")
-	if d != nil {
+	for _, d := range includeDirs {
-		if err := d.ParseParams(&config.LogLevel); err != nil {
+		var includePath string
-			return nil, err
+		if err := d.ParseParams(&includePath); err != nil {
-		}
-	}
-
-	d = cfg.Get("log-format")
-	if d != nil {
-		if err := d.ParseParams(&config.LogFormat); err != nil {
-			return nil, err
-		}
-	}
-
-	d = cfg.Get("http-address")
-	if d != nil {
-		if err := d.ParseParams(&config.HTTPAddress); err != nil {
-			return nil, err
-		}
-	}
-
-	d = cfg.Get("base-url")
-	if d != nil {
-		if err := d.ParseParams(&config.BaseURL); err != nil {
-			return nil, err
-		}
-	}
-
-	d = cfg.Get("alert-mode")
-	if d != nil {
-		var mode string
-		if err := d.ParseParams(&mode); err != nil {
 			return nil, err
 		}
 
-		switch strings.ToLower(mode) {
+		block, err := scfg.Load(includePath)
-		case "single":
+		if err != nil {
-			config.AlertMode = Single
+			return nil, fmt.Errorf("cannot load included config file %q: %v", includePath, err)
+		}
 
-		case "multi":
+		if err := parseBlock(block, config); err != nil {
-			config.AlertMode = Multi
+			return nil, fmt.Errorf("cannot parse included config file %q: %v", includePath, err)
-
-		default:
-			return nil, fmt.Errorf("%q directive: illegal mode %q", d.Name, mode)
 		}
 	}
 
-	d = cfg.Get("user")
+	err = parseBlock(cfg, config)
-	if d != nil {
+	if err != nil {
-		if err := d.ParseParams(&config.User); err != nil {
 		return nil, err
 	}
-	}
-
-	d = cfg.Get("password")
-	if d != nil {
-		if err := d.ParseParams(&config.Password); err != nil {
-			return nil, err
-		}
-	}
 
+	// Check settings
 	if (config.Password != "" && config.User == "") ||
 		(config.Password == "" && config.User != "") {
 		return nil, errors.New("user and password have to be set together")
 	}
 
-	labelsDir := cfg.Get("labels")
+	if config.Ntfy.Topic == "" {
-	if labelsDir != nil {
-		d = labelsDir.Children.Get("order")
-		if d != nil {
-			var order string
-			if err := d.ParseParams(&order); err != nil {
-				return nil, err
-			}
-
-			config.Labels.Order = strings.Split(order, ",")
-		}
-
-		labels := make(map[string]labelConfig)
-		for _, labelName := range config.Labels.Order {
-			for _, labelDir := range labelsDir.Children.GetAll(labelName) {
-				labelConfig := new(labelConfig)
-				var name string
-
-				if err := labelDir.ParseParams(&name); err != nil {
-					return nil, err
-				}
-
-				d = labelDir.Children.Get("priority")
-				if d != nil {
-					if err := d.ParseParams(&labelConfig.Priority); err != nil {
-						return nil, err
-					}
-				}
-
-				d = labelDir.Children.Get("tags")
-				if d != nil {
-					var tags string
-					if err := d.ParseParams(&tags); err != nil {
-						return nil, err
-					}
-
-					labelConfig.Tags = strings.Split(tags, ",")
-				}
-
-				d = labelDir.Children.Get("icon")
-				if d != nil {
-					if err := d.ParseParams(&labelConfig.Icon); err != nil {
-						return nil, err
-					}
-				}
-
-				d = labelDir.Children.Get("email-address")
-				if d != nil {
-					if err := d.ParseParams(&labelConfig.EmailAddress); err != nil {
-						return nil, err
-					}
-				}
-
-				d = labelDir.Children.Get("call")
-				if d != nil {
-					if err := d.ParseParams(&labelConfig.Call); err != nil {
-						return nil, err
-					}
-				}
-
-				labels[fmt.Sprintf("%s:%s", labelName, name)] = *labelConfig
-			}
-		}
-
-		config.Labels.Label = labels
-	}
-
-	ntfyDir := cfg.Get("ntfy")
-	if ntfyDir == nil {
-		return nil, fmt.Errorf("%q directive missing", "ntfy")
-	}
-
-	d = ntfyDir.Children.Get("topic")
-	if d == nil {
 		return nil, fmt.Errorf("%q missing from %q directive", "topic", "ntfy")
 	}
-	if err := d.ParseParams(&config.Ntfy.Topic); err != nil {
-		return nil, err
-	}
-
-	d = ntfyDir.Children.Get("user")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.User); err != nil {
-			return nil, err
-		}
-	}
-
-	d = ntfyDir.Children.Get("password")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.Password); err != nil {
-			return nil, err
-		}
-	}
 
 	if (config.Ntfy.Password != "" && config.Ntfy.User == "") ||
 		(config.Ntfy.Password == "" && config.Ntfy.User != "") {
 		return nil, errors.New("ntfy: user and password have to be set together")
 	}
 
-	d = ntfyDir.Children.Get("access-token")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.AccessToken); err != nil {
-			return nil, err
-		}
-	}
-
 	if config.Ntfy.User != "" && config.Ntfy.AccessToken != "" {
 		return nil, errors.New("ntfy: cannot use both an access-token and a user/password at the same time")
 	}
 
-	d = ntfyDir.Children.Get("certificate-fingerprint")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.CertFingerprint); err != nil {
-			return nil, err
-		}
-
-		// hex.EncodeToString outputs a lower case string
-		config.Ntfy.CertFingerprint = strings.ToLower(strings.ReplaceAll(config.Ntfy.CertFingerprint, ":", ""))
-	}
-
-	d = ntfyDir.Children.Get("email-address")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.EmailAddress); err != nil {
-			return nil, err
-		}
-	}
-
-	d = ntfyDir.Children.Get("call")
-	if d != nil {
-		if err := d.ParseParams(&config.Ntfy.Call); err != nil {
-			return nil, err
-		}
-	}
-
-	cacheDir := cfg.Get("cache")
-
-	if cacheDir != nil {
-		d = cacheDir.Children.Get("type")
-		if d != nil {
-			if err := d.ParseParams(&config.Cache.Type); err != nil {
-				return nil, err
-			}
-		}
-
-		var durationString string
-		d = cacheDir.Children.Get("duration")
-		if d != nil {
-			if err := d.ParseParams(&durationString); err != nil {
-				return nil, err
-			}
-
-			duration, err := time.ParseDuration(durationString)
-			if err != nil {
-				return nil, err
-			}
-
-			config.Cache.Duration = duration
-		}
-
-		// memory
-		var cleanupIntervalString string
-		d = cacheDir.Children.Get("cleanup-interval")
-		if d != nil {
-			if err := d.ParseParams(&cleanupIntervalString); err != nil {
-				return nil, err
-			}
-
-			interval, err := time.ParseDuration(cleanupIntervalString)
-			if err != nil {
-				return nil, err
-			}
-
-			config.Cache.CleanupInterval = interval
-		}
-
-		// redis
-		d = cacheDir.Children.Get("redis-url")
-		if d != nil {
-			if err := d.ParseParams(&config.Cache.RedisURL); err != nil {
-				return nil, err
-			}
-		}
-	}
-
-	amDir := cfg.Get("alertmanager")
-
-	if amDir != nil {
-		var durationString string
-		d = amDir.Children.Get("silence-duration")
-		if d != nil {
-			if err := d.ParseParams(&durationString); err != nil {
-				return nil, err
-			}
-
-			duration, err := time.ParseDuration(durationString)
-			if err != nil {
-				return nil, err
-			}
-
-			config.Am.SilenceDuration = duration
-		}
-
-		d = amDir.Children.Get("user")
-		if d != nil {
-			if err := d.ParseParams(&config.Am.User); err != nil {
-				return nil, err
-			}
-		}
-
-		d = amDir.Children.Get("password")
-		if d != nil {
-			if err := d.ParseParams(&config.Am.Password); err != nil {
-				return nil, err
-			}
-		}
-
 	if (config.Am.Password != "" && config.Am.User == "") ||
 		(config.Am.Password == "" && config.Am.User != "") {
 		return nil, errors.New("alertmanager: user and password have to be set together")
 	}
 
-		d = amDir.Children.Get("url")
-		if d != nil {
-			if err := d.ParseParams(&config.Am.URL); err != nil {
-				return nil, err
-			}
-		}
-	}
-
-	resolvedDir := cfg.Get("resolved")
-	if resolvedDir != nil {
-		d = resolvedDir.Children.Get("tags")
-		if d != nil {
-			var tags string
-			if err := d.ParseParams(&tags); err != nil {
-				return nil, err
-			}
-
-			config.Resolved.Tags = strings.Split(tags, ",")
-		}
-
-		d = resolvedDir.Children.Get("icon")
-		if d != nil {
-			if err := d.ParseParams(&config.Resolved.Icon); err != nil {
-				return nil, err
-			}
-		}
-
-		d = resolvedDir.Children.Get("priority")
-		if d != nil {
-			if err := d.ParseParams(&config.Resolved.Priority); err != nil {
-				return nil, err
-			}
-		}
-	}
-
 	return config, nil
 }