Configuration

go-doudou provides out-of-the-box support for local configuration files in dotenv and yaml formats, as well as Alibaba's Nacos and Ctrip's Apollo configuration centers. It can load configurations from local files or remote configuration centers into environment variables.

The priority between local configuration files and remote configuration centers is that local configuration files take precedence, meaning configurations already loaded from local files will not be overridden by those loaded from remote configuration centers.

Local Configuration Files

The usage of dotenv format and yaml format local configuration files is exactly the same, with only slight differences in file naming rules. These are explained separately below.

Tip

The two configuration file formats can be used simultaneously or you can use just one. When used simultaneously, yaml format configuration files are loaded first, and after all yaml files are loaded, dotenv format configuration files are loaded.

dotenv Files

If you have multiple .env files, such as .env.test, .env.prod, etc., to configure different environments, you can set the GDD_ENV environment variable to test or prod through the command line terminal, Dockerfile, or k8s configuration files to load the corresponding configuration file.

The configuration loading rules are as follows:

1. For the same environment variable, whether configured in the command line terminal or through configuration files, the value loaded first has the highest priority and will not be modified by subsequently loaded values.
2. The loading order of configuration files (taking the prod environment as an example) is: 1. Load .env.prod.local file 2. When the value of the environment variable GDD_ENV is not equal to test, load .env.local file 3. Load .env.prod file 4. Load .env file

Note: The prefix must be .env

yaml Files

Supports both .yml and .yaml suffix configuration files. If you have multiple yaml files, such as app-test.yml, app-prod.yml, etc., to configure different environments, you can set the GDD_ENV environment variable to test or prod through the command line terminal, Dockerfile, or k8s configuration files to load the corresponding configuration file.

The configuration loading rules are as follows:

1. For the same environment variable, whether configured in the command line terminal or through configuration files, the value loaded first has the highest priority and will not be modified by subsequently loaded values.
2. The loading order of configuration files (taking the prod environment as an example) is: 1. Load app-prod-local.yml file 2. When the value of the environment variable GDD_ENV is not equal to test, load app-local.yml file 3. Load app-prod.yml file 4. Load app.yml file

Note: The prefix must be app

Tip

When converting environment variables to yaml configuration, the rule is to use underscores as property separators. For very long property names, hyphens can be used to split them into multiple words for better readability. For example, the environment variable GDD_DB_MYSQL_DISABLEDATETIMEPRECISION converted to yaml configuration:

gdd:
	db:
		mysql:
			disable-datetime-precision:

Remote Configuration Solutions

go-doudou has built-in support for two remote configuration center solutions: Alibaba's Nacos and Ctrip's Apollo. It supports loading at service startup and also supports custom listener functions to monitor configuration changes.

To enable a remote configuration center, you need to configure the following environment variables in the local configuration file:

• GDD_CONFIG_REMOTE_TYPE: Remote configuration center name, options: nacos, apollo

Tip

Some of the service configurations in the go-doudou framework layer (i.e., configurations with the GDD_ prefix) support runtime dynamic modification through remote configuration centers. The priority of runtime dynamic modifications is the highest and will override all configurations loaded from the command line terminal, Dockerfile, k8s configuration files, local configuration files, and remote configuration centers at service startup.

Nacos Configuration Center

go-doudou service will automatically load configurations from Nacos at startup. You only need to configure some parameters in the local configuration file, making it ready to use out of the box.

• GDD_NACOS_NAMESPACE_ID: Nacos namespaceId, optional
• GDD_NACOS_SERVER_ADDR: Nacos server connection address, required
• GDD_NACOS_CONFIG_FORMAT: Configuration format, options: dotenv, yaml, default is dotenv
• GDD_NACOS_CONFIG_GROUP: Nacos group, default is DEFAULT_GROUP
• GDD_NACOS_CONFIG_DATAID: Nacos dataId, required, multiple dataIds separated by commas, the order in the configuration is the actual loading order, following the rule that configurations loaded first have the highest priority

The configmgr package provides an exported singleton NacosClient for interacting with the Nacos configuration center. You can call the AddChangeListener method to add custom listener functions. Example usage:

func main() {

	...

	if configmgr.NacosClient != nil {
		configmgr.NacosClient.AddChangeListener(configmgr.NacosConfigListenerParam{
			DataId: "statsvc-dev",
			OnChange: func(event *configmgr.NacosChangeEvent) {
				fmt.Println("group:" + event.Group + ", dataId:" + event.DataId + fmt.Sprintf(", changes: %+v\n", event.Changes))
			},
		})
	}

	...

	srv.Run()
}

Apollo Configuration Center

go-doudou service will automatically load configurations from Apollo at startup. You only need to configure some parameters in the local configuration file, making it ready to use out of the box.

• GDD_SERVICE_NAME: Service name is the Apollo AppId
• GDD_APOLLO_CLUSTER: Apollo cluster, default is default
• GDD_APOLLO_ADDR: Apollo server connection address, required
• GDD_APOLLO_NAMESPACE: Apollo namespace, equivalent to Nacos's dataId, default is application.properties, multiple namespaces separated by commas, the order in the configuration is the actual loading order, following the rule that configurations loaded first have the highest priority
• GDD_APOLLO_SECRET: Apollo configuration secret, optional

The configmgr package provides an exported singleton ApolloClient for interacting with the Apollo configuration center. You can call the AddChangeListener method to add custom listener functions. Example usage:

type ConfigChangeListener struct {
	configmgr.BaseApolloListener
}

func (c *ConfigChangeListener) OnChange(event *storage.ChangeEvent) {
	c.Lock.Lock()
	defer c.Lock.Unlock()
	if !c.SkippedFirstEvent {
		c.SkippedFirstEvent = true
		return
	}
	logger.Info("from OnChange")
	fmt.Println(event.Changes)
	for key, value := range event.Changes {
		fmt.Println("change key : ", key, ", value :", value)
	}
	fmt.Println(event.Namespace)
	logger.Info("from OnChange end")
}

func main() {

    ...

	var listener ConfigChangeListener

	configmgr.ApolloClient.AddChangeListener(&listener)

    ...

	srv.Run()
}

It's worth noting that the first configuration loading event will also be detected by custom listener functions. If you need to skip the first time, you need to "inherit" the BaseApolloListener struct provided by the configmgr package, and then add the following code at the beginning of the OnChange function:

c.Lock.Lock()
defer c.Lock.Unlock()
if !c.SkippedFirstEvent {
  c.SkippedFirstEvent = true
  return
}

Service Configuration

Configurations marked with a red asterisk in the table are dynamically modified by go-doudou at runtime by monitoring configuration changes in the remote configuration center.

Environment Variable	Description	Default Value	Required
GDD_BANNER	Enable banner	true
GDD_BANNER_TEXT	Banner text	go-doudou
GDD_LOG_LEVEL	Log level, options: panic, fatal, error, warn, warning, info, debug, trace	info
GDD_LOG_FORMAT	Log format, options: text, json	text
GDD_LOG_REQ_ENABLE	Enable HTTP request and response body logging	false
GDD_LOG_CALLER	Print "filename:line"	true
GDD_LOG_DISCARD	Disable logging	false
GDD_LOG_PATH	Log file path, if set, logs will be written to the file
GDD_LOG_STYLE	Log format style, only valid when GDD_LOG_PATH is set, options: json or console	json
GDD_GRACE_TIMEOUT	Graceful shutdown timeout	15s
GDD_WRITE_TIMEOUT	HTTP connection write timeout	15s
GDD_READ_TIMEOUT	HTTP connection read timeout	15s
GDD_IDLE_TIMEOUT	HTTP connection idle timeout	60s
GDD_ROUTE_ROOT_PATH	HTTP request path prefix
GDD_SERVICE_NAME	Service name		Required
GDD_SERVICE_GROUP	Service group name, valid when using zookeeper for service registration and discovery
GDD_SERVICE_VERSION	Service version name, valid when using zookeeper for service registration and discovery
GDD_HOST	HTTP server listening address
GDD_PORT	HTTP server listening port	6060
GDD_GRPC_PORT	gRPC server listening port	50051
GDD_RETRY_COUNT	Client request retry count	0
GDD_MANAGE_ENABLE	Enable built-in HTTP interfaces: /go-doudou/doc, /go-doudou/openapi.json, /go-doudou/prometheus, /go-doudou/registry, /go-doudou/config	true
*GDD_MANAGE_USER	HTTP basic authentication username for built-in HTTP interfaces	admin
*GDD_MANAGE_PASS	HTTP basic authentication password for built-in HTTP interfaces	admin
GDD_TRACING_METRICS_ROOT	metrics root for jaeger call chain monitoring	tracing
GDD_WEIGHT	Service instance weight	1
GDD_SERVICE_DISCOVERY_MODE	Service discovery mode, options: etcd, nacos, zk
GDD_ENABLE_RESPONSE_GZIP	Enable HTTP response body gzip compression	true
GDD_SQL_LOG_ENABLE	Enable SQL log printing	false
GDD_REGISTER_HOST	Service instance registration address, default is the host's private IP
GDD_FALLBACK_CONTENTTYPE	Default Content-Type header for HTTP response body	application/json; charset=UTF-8
GDD_CONFIG_REMOTE_TYPE	Remote configuration center, options: nacos, apollo
GDD_ROUTER_SAVEMATCHEDROUTEPATH	Save matched route path	true
GDD_STATS_FREQ	Service status statistics frequency	1s

Nacos Configuration

Environment Variable	Description	Default Value	Required
GDD_NACOS_NAMESPACE_ID	Namespace	public
GDD_NACOS_TIMEOUT_MS	Request timeout in milliseconds	10000
GDD_NACOS_NOTLOADCACHEATSTART	Whether to load service list from disk cache at program startup	false
GDD_NACOS_LOG_DIR	Log directory path	/tmp/nacos/log
GDD_NACOS_CACHE_DIR	Service list disk cache path	/tmp/nacos/cache
GDD_NACOS_LOG_LEVEL	Log level, options: debug, info, warn, error	info
GDD_NACOS_LOG_DISCARD	Disable Nacos logging	false
GDD_NACOS_SERVER_ADDR	Nacos server connection address, multiple addresses separated by commas
GDD_NACOS_REGISTER_HOST	IP address used for Nacos service registration
GDD_NACOS_CLUSTER_NAME	Nacos cluster name	DEFAULT
GDD_NACOS_GROUP_NAME	Nacos group name	DEFAULT_GROUP
GDD_NACOS_CONFIG_FORMAT	Configuration data format, supports: dotenv, yaml	dotenv
GDD_NACOS_CONFIG_GROUP	Configuration group	DEFAULT_GROUP
GDD_NACOS_CONFIG_DATAID	Configuration dataId		Required

Apollo Configuration

Environment Variable	Description	Default Value	Required
GDD_APOLLO_CLUSTER	Apollo cluster	default
GDD_APOLLO_ADDR	Apollo configuration service connection address		Required
GDD_APOLLO_NAMESPACE	Apollo namespace	application.properties
GDD_APOLLO_BACKUP_ENABLE	Enable configuration caching on local disk	true
GDD_APOLLO_BACKUP_PATH	Configuration cache folder path
GDD_APOLLO_MUSTSTART	Return error immediately if configuration service connection fails	false
GDD_APOLLO_SECRET	Apollo configuration secret
GDD_APOLLO_LOG_ENABLE	Enable Apollo log printing	false

Etcd Configuration

Environment Variable	Description	Default Value	Required
GDD_ETCD_ENDPOINTS	Etcd cluster connection address
GDD_ETCD_LEASE	Etcd service registration lease TTL time in seconds	5

Zookeeper Configuration

Environment Variable	Description	Default Value	Required
GDD_ZK_SERVERS	Zookeeper cluster connection address, multiple addresses separated by commas
GDD_ZK_SEQUENCE	Whether to add a sequence number to Zookeeper nodes	false
GDD_ZK_DIRECTORY_PATTERN	String fmt pattern for service registration node path, %s represents service name	/registry/%s/providers

Memberlist Configuration

Memberlist is a built-in service registration and discovery component in the go-doudou framework based on the gossip protocol.

Environment Variable	Description	Default Value	Required
GDD_MEM_SEED	Cluster seed nodes for joining
GDD_MEM_NAME	Unique name of the node in the cluster, hostname will be used if not set
GDD_MEM_HOST	Advertise address of the node, if starting with a dot (like .seed-svc), will be prefixed with hostname, supports K8s stateful services
GDD_MEM_PORT	Node communication port, randomly assigned if not set	7946
GDD_MEM_DEAD_TIMEOUT	Node death timeout in seconds, node will be removed if no refute messages are received within this time	60s
GDD_MEM_SYNC_INTERVAL	Node state synchronization interval in seconds	60s
GDD_MEM_RECLAIM_TIMEOUT	Dead node reclamation time in seconds, dead node will be replaced by a new node after this time	3s
GDD_MEM_PROBE_INTERVAL	Probe interval in seconds	5s
GDD_MEM_PROBE_TIMEOUT	Probe timeout in seconds	3s
GDD_MEM_SUSPICION_MULT	Suspicion multiplier, determines the time a node is considered suspicious before being declared dead	6
GDD_MEM_RETRANSMIT_MULT	Retransmission multiplier	4
GDD_MEM_GOSSIP_NODES	Number of remote nodes to gossip messages to	4
GDD_MEM_GOSSIP_INTERVAL	Gossip interval in seconds	500ms
GDD_MEM_TCP_TIMEOUT	TCP timeout in seconds	30s
GDD_MEM_WEIGHT	Node weight	1
GDD_MEM_WEIGHT_INTERVAL	Node weight calculation interval	0
GDD_MEM_INDIRECT_CHECKS	Number of indirect checks	3
GDD_MEM_LOG_DISABLE	Disable memberlist logging	false
GDD_MEM_CIDRS_ALLOWED	CIDRs allowed to connect, allows any connection if not set, must specify IPv6/IPv4 separately

Cache Configuration

Environment Variable	Description	Default Value	Required
GDD_CACHE_TTL	Cache TTL time in seconds	0
GDD_CACHE_STORES	Cache storage types, options: redis, ristretto, gocache
GDD_CACHE_REDIS_ADDR	Redis server address
GDD_CACHE_REDIS_USER	Redis username
GDD_CACHE_REDIS_PASS	Redis password
GDD_CACHE_REDIS_ROUTEBYLATENCY	Route Redis requests by latency	true
GDD_CACHE_REDIS_ROUTERANDOMLY	Route Redis requests randomly	false
GDD_CACHE_RISTRETTO_NUMCOUNTERS	Ristretto cache counter number	1000
GDD_CACHE_RISTRETTO_MAXCOST	Ristretto cache maximum cost	100
GDD_CACHE_RISTRETTO_BUFFERITEMS	Ristretto cache buffer items	64
GDD_CACHE_GOCACHE_EXPIRATION	GoCache default cache expiration time	5m
GDD_CACHE_GOCACHE_CLEANUP_INTERVAL	GoCache cleanup interval	10m

Gorm Configuration

Environment Variable	Description	Default Value	Required
GDD_DB_DISABLEAUTOCONFIGURE	Disable auto-configuration	false
GDD_DB_DRIVER	Database driver name, consistent with gorm: mysql, postgres, sqlite, sqlserver, tidb, clickhouse
GDD_DB_DSN	Database connection address
GDD_DB_TABLE_PREFIX	Database table prefix
GDD_DB_PREPARESTMT	Enable prepared statements	false
GDD_DB_SKIPDEFAULTTRANSACTION	Skip default transaction	false
GDD_DB_POOL_MAXIDLECONNS	Maximum number of idle connections	2
GDD_DB_POOL_MAXOPENCONNS	Maximum number of connections, -1 means unlimited	-1
GDD_DB_POOL_CONNMAXLIFETIME	Maximum time period a connection can be reused, -1 means unlimited	-1
GDD_DB_POOL_CONNMAXIDLETIME	Maximum idle time for a connection, if it expires it will be closed before reuse, -1 means unlimited	-1
GDD_DB_LOG_SLOWTHRESHOLD	Slow query log threshold	200ms
GDD_DB_LOG_IGNORERECORDNOTFOUNDERROR	Ignore record not found error	false
GDD_DB_LOG_PARAMETERIZEDQUERIES	Hide SQL parameters	false
GDD_DB_LOG_LEVEL	Log level, consistent with gorm: silent, error, warn, info	warn
GDD_DB_MYSQL_SKIPINITIALIZEWITHVERSION	Gorm's SkipInitializeWithVersion parameter	false
GDD_DB_MYSQL_DEFAULTSTRINGSIZE	Gorm's DefaultStringSize parameter	0
GDD_DB_MYSQL_DISABLEWITHRETURNING	Gorm's DisableWithReturning parameter	false
GDD_DB_MYSQL_DISABLEDATETIMEPRECISION	Gorm's DisableDatetimePrecision parameter	false
GDD_DB_MYSQL_DONTSUPPORTRENAMEINDEX	Gorm's DontSupportRenameIndex parameter	false
GDD_DB_MYSQL_DONTSUPPORTRENAMECOLUMN	Gorm's DontSupportRenameColumn parameter	false
GDD_DB_MYSQL_DONTSUPPORTFORSHARECLAUSE	Gorm's DontSupportForShareClause parameter	false
GDD_DB_MYSQL_DONTSUPPORTNULLASDEFAULTVALUE	Gorm's DontSupportNullAsDefaultValue parameter	false
GDD_DB_MYSQL_DONTSUPPORTRENAMECOLUMNUNIQUE	Gorm's DontSupportRenameColumnUnique parameter	false
GDD_DB_POSTGRES_PREFERSIMPLEPROTOCOL	Gorm's PreferSimpleProtocol parameter	false
GDD_DB_POSTGRES_WITHOUTRETURNING	Gorm's WithoutReturning parameter	false
GDD_DB_PROMETHEUS_ENABLE	Enable Prometheus monitoring	false
GDD_DB_PROMETHEUS_REFRESHINTERVAL	Prometheus monitoring refresh interval in seconds	15
GDD_DB_PROMETHEUS_DBNAME	Database name used for Prometheus monitoring
GDD_DB_CACHE_ENABLE	Enable database query caching	false