Support external database modules

aws/iam_auth.go

@@ -19,9 +19,15 @@ type AuthToken struct {
 }
 
 func NewAuthToken(username, hostname string, cfg aws.Config) AuthToken {
-	// RDS auth tokens require the :3306 suffix
+	return NewAuthTokenWithDefaultPort(username, hostname, "3306", cfg)
+}
+
+// NewAuthTokenWithDefaultPort constructs an RDS authentication token signer,
+// adding defaultPort when hostname does not already include a port.
+func NewAuthTokenWithDefaultPort(username, hostname, defaultPort string, cfg aws.Config) AuthToken {
+	// RDS auth tokens require the database port in the signed endpoint.
 	if !portRe.MatchString(hostname) {
-		hostname += ":3306"
+		hostname += ":" + defaultPort
 	}
 
 	return AuthToken{

blip.go

@@ -34,11 +34,11 @@ const (
 	EVENT
 )
 
-// Metrics are metrics collected for one plan level, from one MySQL instance.
+// Metrics are metrics collected for one plan level, from one monitor.
 type Metrics struct {
 	Begin     time.Time                // when collection started
 	End       time.Time                // when collection completed
-	MonitorId string                   // ID of monitor (MySQL)
+	MonitorId string                   // ID of monitor
 	Plan      string                   // plan name
 	Level     string                   // level name
 	Interval  uint                     // interval number
@@ -99,7 +99,7 @@ type SinkFactoryArgs struct {
 	Tags      map[string]string // config.monitor.tags
 }
 
-// DbCredentials are MySQL credentials parsed or loaded for a connection.
+// DbCredentials are database credentials parsed or loaded for a connection.
 type DbCredentials struct {
 	Username string
 	Password string
@@ -173,7 +173,7 @@ type Plugins struct {
 	// ModifyDB modifies the *sql.DB connection pool. Use with caution.
 	ModifyDB func(*sql.DB, string)
 
-	// ParsePasswordSecret maps an AWS Secrets Manager payload to MySQL credentials.
+	// ParsePasswordSecret maps an AWS Secrets Manager payload to database credentials.
 	// If nil, Blip uses DefaultPasswordSecretParser.
 	ParsePasswordSecret PasswordSecretParser
 
@@ -218,6 +218,23 @@ type DbFactory interface {
 	Make(ConfigMonitor) (*sql.DB, string, error)
 }
 
+// DbProvider owns the database connections associated with one monitor.
+// Primary returns the connection used by existing Blip subsystems and
+// collectors. Close releases the primary connection and any additional
+// database-specific resources owned by the provider.
+type DbProvider interface {
+	Primary() *sql.DB
+	Close() error
+}
+
+// DbProviderFactory is an optional DbFactory capability for database engines
+// that need to own more than one connection pool per monitor. Blip preserves
+// the existing DbFactory.Make path for factories that do not implement it.
+type DbProviderFactory interface {
+	DbFactory
+	MakeProvider(ConfigMonitor) (DbProvider, string, error)
+}
+
 type HTTPClientFactory interface {
 	MakeForSink(sinkName, monitorId string, opts, tags map[string]string) (*http.Client, error)
 }

collector.go

@@ -22,8 +22,8 @@ type Collector interface {
 	// Prepare prepares a plan for future calls to Collect. The return function
 	// is called once when the collector is destroyed; it allows the collector
 	// to clean up. If Prepare returns an error, Blip will retry preparing the
-	// plan. Therefore, Prepare should not retry on error (for example, if MySQL
-	// is not online yet).
+	// plan. Therefore, Prepare should not retry on error (for example, if the
+	// database is not online yet).
 	Prepare(ctx context.Context, plan Plan) (func(), error)
 
 	// Collect collects metrics for the previously prepared plan. Collect is only
@@ -111,13 +111,14 @@ func (h CollectorHelp) Validate(opts map[string]string) error {
 // a Collector. The factory must use the args to create the collector.
 type CollectorFactoryArgs struct {
 	// Config is the full and final monitor config. Most collectors do not need
-	// this, but some that collect metrics outside MySQL, like cloud metrics,
+	// this, but some that collect metrics outside the database, like cloud metrics,
 	// might need additional monitor config values.
 	Config ConfigMonitor
 
-	// DB is the connection to MySQL. It is safe for concurrent use, and it is
-	// used concurrently by other parts of a monitor. The Collector must not
-	// modify the connection, reconnect, and so forth--only use the connection.
+	// DB is the monitor's database connection. It is safe for concurrent use,
+	// and it is used concurrently by other parts of a monitor. The Collector
+	// must not modify the connection, reconnect, and so forth--only use the
+	// connection.
 	DB *sql.DB
 
 	// MonitorId is the monitor identifier. The Collector must include
@@ -135,5 +136,27 @@ type CollectorFactory interface {
 	Make(domain string, args CollectorFactoryArgs) (Collector, error)
 }
 
+// CollectorFactoryWithDBProvider is an optional CollectorFactory capability
+// for database-specific collectors that need access to the monitor-owned
+// database provider. Factories that do not implement it retain the historical
+// Make behavior.
+type CollectorFactoryWithDBProvider interface {
+	CollectorFactory
+	MakeWithDBProvider(domain string, args CollectorFactoryArgs, provider DbProvider) (Collector, error)
+}
+
+// CollectorFactoryDatabaseTypes is an optional CollectorFactory capability
+// that identifies the database types supported by a domain. Factories that do
+// not implement this interface retain Blip's historical MySQL behavior.
+//
+// The domain argument allows one factory to serve domains with different
+// compatibility, such as MySQL collectors and database-neutral cloud metrics.
+// Implementations must return at least one database type. Return
+// DatabaseTypeAny by itself for a database-neutral domain.
+type CollectorFactoryDatabaseTypes interface {
+	CollectorFactory
+	DatabaseTypes(domain string) []DatabaseType
+}
+
 // ErrMore signals that a collector will return more values. See https://block.github.io/blip/develop/collectors/#long-running.
 var ErrMore = errors.New("more metrics")