Merge pull request #140 from launchdarkly/eb/ch82940/configtypes-lib

(v6 - #8) use configtypes library for config validation

cmd/ld-relay/ld-relay.go

@@ -36,7 +36,7 @@ func main() {
 	flag.BoolVar(&useEnvironment, "from-env", false, "read configuration from environment variables")
 	flag.Parse()
 
-	c := config.DefaultConfig
+	var c config.Config
 	loggers := logging.MakeDefaultLoggers()
 
 	if configFile == "" && !useEnvironment {
@@ -87,23 +87,25 @@ func main() {
 	errs := make(chan error)
 	defer close(errs)
 
-	startHTTPServer(&c, r, loggers, errs)
+	port := c.Main.Port.GetOrElse(config.DefaultPort)
+
+	startHTTPServer(&c, port, r, loggers, errs)
 
 	for err := range errs {
-		loggers.Errorf("Error starting http listener on port: %d  %s", c.Main.Port, err)
+		loggers.Errorf("Error starting http listener on port: %d  %s", port, err)
 		os.Exit(1)
 	}
 }
 
-func startHTTPServer(c *config.Config, r *relay.Relay, loggers ldlog.Loggers, errs chan<- error) {
+func startHTTPServer(c *config.Config, port int, r *relay.Relay, loggers ldlog.Loggers, errs chan<- error) {
 	srv := &http.Server{
-		Addr:    fmt.Sprintf(":%d", c.Main.Port),
+		Addr:    fmt.Sprintf(":%d", port),
 		Handler: r,
 	}
 
 	go func() {
 		var err error
-		loggers.Infof("Starting server listening on port %d\n", c.Main.Port)
+		loggers.Infof("Starting server listening on port %d\n", port)
 		if c.Main.TLSEnabled {
 			loggers.Infof("TLS Enabled for server")
 			err = srv.ListenAndServeTLS(c.Main.TLSCert, c.Main.TLSKey)

config/config.go

@@ -3,10 +3,14 @@ package config
 import (
 	"time"
 
+	ct "github.com/launchdarkly/go-configtypes"
 	"github.com/launchdarkly/ld-relay/v6/internal/logging"
 )
 
 const (
+	// DefaultPort is the port that Relay runs on if not otherwise specified.
+	DefaultPort = 8030
+
 	// DefaultBaseURI is the default value for the base URI of LaunchDarkly services (polling endpoints).
 	DefaultBaseURI = "https://app.launchdarkly.com"
 
@@ -16,6 +20,9 @@ const (
 	// DefaultEventsURI is the default value for the base URI of LaunchDarkly services (event endpoints).
 	DefaultEventsURI = "https://events.launchdarkly.com"
 
+	// DefaultEventCapacity is the default value for EventsConfig.Capacity if not specified.
+	DefaultEventCapacity = 1000
+
 	// DefaultHeartbeatInterval is the default value for MainConfig.HeartBeatInterval if not specified.
 	DefaultHeartbeatInterval = time.Minute * 3
 
@@ -24,19 +31,19 @@ const (
 
 	// DefaultDatabaseCacheTTL is the default value for the LocalTTL parameter for databases if not specified.
 	DefaultDatabaseCacheTTL = time.Second * 30
+
+	// DefaultPrometheusPort is the default value for PrometheusConfig.Port if not specified.
+	DefaultPrometheusPort = 8031
 )
 
 const (
-	defaultPort           = 8030
-	defaultEventCapacity  = 1000
-	defaultRedisHost      = "localhost"
-	defaultRedisPort      = 6379
-	defaultConsulHost     = "localhost"
-	defaultPrometheusPort = 8031
+	defaultRedisHost  = "localhost"
+	defaultRedisPort  = 6379
+	defaultConsulHost = "localhost"
 )
 
 var (
-	defaultRedisURL = newOptAbsoluteURLMustBeValid("redis://localhost:6379")
+	defaultRedisURL, _ = ct.NewOptURLAbsoluteFromString("redis://localhost:6379")
 )
 
 // DefaultLoggers is the default logging configuration used by Relay.
@@ -46,8 +53,17 @@ var DefaultLoggers = logging.MakeDefaultLoggers()
 
 // Config describes the configuration for a relay instance.
 //
-// If you are incorporating Relay into your own code and configuring it programmatically, it is best to
-// start by copying relay.DefaultConfig and then changing only the fields you need to change.
+// Some fields use special types that enforce validation rules, such as URL fields which must
+// be absolute URLs, port numbers which must be greater than zero, or durations. This validation
+// is done automatically when reading the configuration from a file or from environment variables.
+//
+// If you are incorporating Relay into your own code and configuring it programmatically, you
+// may need to use functions from go-configtypes such as NewOptDuration to set fields that have
+// validation rules.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type Config struct {
 	Main        MainConfig
 	Events      EventsConfig
@@ -56,98 +72,129 @@ type Config struct {
 	DynamoDB    DynamoDBConfig
 	Environment map[string]*EnvConfig
 	Proxy       ProxyConfig
+
+	// Optional configuration for metrics integrations. Note that unlike the other fields in Config,
+	// MetricsConfig is not the name of a configuration file section; the actual sections are the
+	// structs within this struct (Datadog, etc.).
 	MetricsConfig
 }
 
 // MainConfig contains global configuration options for Relay.
 //
 // This corresponds to the [Main] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type MainConfig struct {
-	ExitOnError             bool
-	ExitAlways              bool
-	IgnoreConnectionErrors  bool
-	StreamURI               OptAbsoluteURL
-	BaseURI                 OptAbsoluteURL
-	Port                    int
-	HeartbeatInterval       OptDuration
-	MaxClientConnectionTime OptDuration
-	TLSEnabled              bool
-	TLSCert                 string
-	TLSKey                  string
-	LogLevel                OptLogLevel
+	ExitOnError             bool                     `conf:"EXIT_ON_ERROR"`
+	ExitAlways              bool                     `conf:"EXIT_ALWAYS"`
+	IgnoreConnectionErrors  bool                     `conf:"IGNORE_CONNECTION_ERRORS"`
+	StreamURI               ct.OptURLAbsolute        `conf:"STREAM_URI"`
+	BaseURI                 ct.OptURLAbsolute        `conf:"BASE_URI"`
+	Port                    ct.OptIntGreaterThanZero `conf:"PORT"`
+	HeartbeatInterval       ct.OptDuration           `conf:"HEARTBEAT_INTERVAL"`
+	MaxClientConnectionTime ct.OptDuration           `conf:"MAX_CLIENT_CONNECTION_TIME"`
+	TLSEnabled              bool                     `conf:"TLS_ENABLED"`
+	TLSCert                 string                   `conf:"TLS_CERT"`
+	TLSKey                  string                   `conf:"TLS_KEY"`
+	LogLevel                OptLogLevel              `conf:"LOG_LEVEL"`
 }
 
 // EventsConfig contains configuration parameters for proxying events.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type EventsConfig struct {
-	EventsURI     OptAbsoluteURL
-	SendEvents    bool
-	FlushInterval OptDuration
-	Capacity      int
-	InlineUsers   bool
+	EventsURI     ct.OptURLAbsolute        `conf:"EVENTS_HOST"`
+	SendEvents    bool                     `conf:"USE_EVENTS"`
+	FlushInterval ct.OptDuration           `conf:"EVENTS_FLUSH_INTERVAL"`
+	Capacity      ct.OptIntGreaterThanZero `conf:"EVENTS_CAPACITY"`
+	InlineUsers   bool                     `conf:"EVENTS_INLINE_USERS"`
 }
 
 // RedisConfig configures the optional Redis integration.
 //
-// Redis is enabled if URL or Host is non-empty or if Port is non-zero. If only Host or Port is set,
+// Redis is enabled if URL or Host is non-empty or if Port is set. If only Host or Port is set,
 // the other value is set to defaultRedisPort or defaultRedisHost. It is an error to set Host or
 // Port if URL is also set.
 //
 // This corresponds to the [Redis] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type RedisConfig struct {
-	Host     string
-	Port     int
-	URL      OptAbsoluteURL
-	LocalTTL OptDuration
-	TLS      bool
-	Password string
+	Host     string `conf:"REDIS_HOST"`
+	Port     ct.OptIntGreaterThanZero
+	URL      ct.OptURLAbsolute `conf:"REDIS_URL"`
+	LocalTTL ct.OptDuration    `conf:"CACHE_TTL"`
+	TLS      bool              `conf:"REDIS_TLS"`
+	Password string            `conf:"REDIS_PASSWORD"`
 }
 
 // ConsulConfig configures the optional Consul integration.
 //
 // Consul is enabled if Host is non-empty.
 //
 // This corresponds to the [Consul] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type ConsulConfig struct {
-	Host     string
-	LocalTTL OptDuration
+	Host     string         `conf:"CONSUL_HOST"`
+	LocalTTL ct.OptDuration `conf:"CACHE_TTL"`
 }
 
 // DynamoDBConfig configures the optional DynamoDB integration, which is used only if Enabled is true.
 //
 // This corresponds to the [DynamoDB] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type DynamoDBConfig struct {
-	Enabled   bool
-	TableName string
-	URL       OptAbsoluteURL
-	LocalTTL  OptDuration
+	Enabled   bool              `conf:"USE_DYNAMODB"`
+	TableName string            `conf:"DYNAMODB_TABLE"`
+	URL       ct.OptURLAbsolute `conf:"DYNAMODB_URL"`
+	LocalTTL  ct.OptDuration    `conf:"CACHE_TTL"`
 }
 
 // EnvConfig describes an environment to be relayed. There may be any number of these.
 //
 // This corresponds to one of the [environment "env-name"] sections in the configuration file. In the
 // Config.Environment map, each key is an environment name and each value is an EnvConfig.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type EnvConfig struct {
-	SDKKey             SDKKey
-	APIKey             string // deprecated, equivalent to SdkKey
-	MobileKey          MobileKey
-	EnvID              EnvironmentID
-	Prefix             string // used only if Redis, Consul, or DynamoDB is enabled
-	TableName          string // used only if DynamoDB is enabled
-	AllowedOrigin      []string
-	SecureMode         bool
-	InsecureSkipVerify bool
-	LogLevel           OptLogLevel
-	TTL                OptDuration
+	SDKKey             SDKKey           // set from env var LD_ENV_envname
+	MobileKey          MobileKey        `conf:"LD_MOBILE_KEY_"`
+	EnvID              EnvironmentID    `conf:"LD_CLIENT_SIDE_ID_"`
+	Prefix             string           `conf:"LD_PREFIX_"`     // used only if Redis, Consul, or DynamoDB is enabled
+	TableName          string           `conf:"LD_TABLE_NAME_"` // used only if DynamoDB is enabled
+	AllowedOrigin      ct.OptStringList `conf:"LD_ALLOWED_ORIGIN_"`
+	SecureMode         bool             `conf:"LD_SECURE_MODE_"`
+	InsecureSkipVerify bool             // deliberately not settable by env vars
+	LogLevel           OptLogLevel      `conf:"LD_LOG_LEVEL_"`
+	TTL                ct.OptDuration   `conf:"LD_TTL_"`
 }
 
 // ProxyConfig represents all the supported proxy options.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type ProxyConfig struct {
-	URL         OptAbsoluteURL
-	NTLMAuth    bool
-	User        string
-	Password    string
-	Domain      string
-	CACertFiles string
+	URL         ct.OptURLAbsolute `conf:"PROXY_URL"`
+	NTLMAuth    bool              `conf:"PROXY_AUTH_NTLM"`
+	User        string            `conf:"PROXY_AUTH_USER"`
+	Password    string            `conf:"PROXY_AUTH_PASSWORD"`
+	Domain      string            `conf:"PROXY_AUTH_DOMAIN"`
+	CACertFiles ct.OptStringList  `conf:"PROXY_CA_CERTS"`
 }
 
 // MetricsConfig contains configurations for optional metrics integrations.
@@ -159,55 +206,43 @@ type MetricsConfig struct {
 	Prometheus  PrometheusConfig
 }
 
-// CommonMetricsConfig contains fields that are common to DatadogCOnfig, StackdriverConfig, and PrometheusConfig.
-type CommonMetricsConfig struct {
-	Enabled bool
-	Prefix  string
-}
-
 // DatadogConfig configures the optional Datadog integration, which is used only if Enabled is true.
 //
 // This corresponds to the [Datadog] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type DatadogConfig struct {
-	TraceAddr string
-	StatsAddr string
-	Tag       []string
-	CommonMetricsConfig
+	Enabled   bool     `conf:"USE_DATADOG"`
+	Prefix    string   `conf:"DATADOG_PREFIX"`
+	TraceAddr string   `conf:"DATADOG_TRACE_ADDR"`
+	StatsAddr string   `conf:"DATADOG_STATS_ADDR"`
+	Tag       []string // special handling in LoadConfigFromEnvironment
 }
 
 // StackdriverConfig configures the optional Stackdriver integration, which is used only if Enabled is true.
 //
 // This corresponds to the [StackdriverConfig] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type StackdriverConfig struct {
-	ProjectID string
-	CommonMetricsConfig
+	Enabled   bool   `conf:"USE_STACKDRIVER"`
+	Prefix    string `conf:"STACKDRIVER_PREFIX"`
+	ProjectID string `conf:"STACKDRIVER_PROJECT_ID"`
 }
 
 // PrometheusConfig configures the optional Prometheus integration, which is used only if Enabled is true.
 //
 // This corresponds to the [PrometheusConfig] section in the configuration file.
+//
+// Since configuration options can be set either programmatically, or from a file, or from environment
+// variables, individual fields are not documented here; instead, see the `README.md` section on
+// configuration.
 type PrometheusConfig struct {
-	Port int
-	CommonMetricsConfig
-}
-
-// DefaultConfig contains defaults for all relay configuration sections.
-//
-// If you are incorporating Relay into your own code and configuring it programmatically, it is best to
-// start by copying relay.DefaultConfig and then changing only the fields you need to change.
-var DefaultConfig = Config{
-	Main: MainConfig{
-		BaseURI:   newOptAbsoluteURLMustBeValid(DefaultBaseURI),
-		StreamURI: newOptAbsoluteURLMustBeValid(DefaultStreamURI),
-		Port:      defaultPort,
-	},
-	Events: EventsConfig{
-		Capacity:  defaultEventCapacity,
-		EventsURI: newOptAbsoluteURLMustBeValid(DefaultEventsURI),
-	},
-	MetricsConfig: MetricsConfig{
-		Prometheus: PrometheusConfig{
-			Port: defaultPrometheusPort,
-		},
-	},
+	Enabled bool                     `conf:"USE_PROMETHEUS"`
+	Prefix  string                   `conf:"PROMETHEUS_PREFIX"`
+	Port    ct.OptIntGreaterThanZero `conf:"PROMETHEUS_PORT"`
 }