dapr/dapr · error

failed to get free port for internal grpc server: %w

Error message

failed to get free port for internal grpc server: %w

What it means

ports.GetStablePort failed while allocating the internal gRPC port (pkg/runtime/config.go:437). When --dapr-internal-grpc-port is unset or "0", Dapr derives a deterministic port in the 47300-49347 range from the app ID so restarts reuse it; this error means that derivation/acquisition failed. The wrapped error carries the exact cause.

Source

Thrown at pkg/runtime/config.go:437

	intc.profilePort, err = strconv.Atoi(c.ProfilePort)
	if err != nil {
		return nil, fmt.Errorf("error parsing profile-port flag: %w", err)
	}

	if c.DaprInternalGRPCPort != "" && c.DaprInternalGRPCPort != "0" {
		intc.internalGRPCPort, err = strconv.Atoi(c.DaprInternalGRPCPort)
		if err != nil {
			return nil, fmt.Errorf("error parsing dapr-internal-grpc-port: %w", err)
		}
	} else {
		// Get a "stable random" port in the range 47300-49,347 if it can be
		// acquired using a deterministic algorithm that returns the same value if
		// the same app is restarted
		// Otherwise, the port will be random.
		intc.internalGRPCPort, err = ports.GetStablePort(47300, intc.id)
		if err != nil {
			return nil, fmt.Errorf("failed to get free port for internal grpc server: %w", err)
		}
	}

	if c.DaprPublicPort != "" {
		var port int

		port, err = strconv.Atoi(c.DaprPublicPort)
		if err != nil {
			return nil, fmt.Errorf("error parsing dapr-public-port: %w", err)
		}

		intc.publicPort = &port
	}

	if c.ApplicationPort != "" {
		intc.appConnectionConfig.Port, err = strconv.Atoi(c.ApplicationPort)
		if err != nil {
			return nil, fmt.Errorf("error parsing app-port: %w", err)

View on GitHub (pinned to 74ad417027)

Solutions

1. Set --dapr-internal-grpc-port explicitly to a known-free port (e.g. 50002) to bypass stable-port derivation entirely
2. Inspect the wrapped error to see the exact failure inside GetStablePort
3. Verify the app ID (--app-id / id field) is a non-empty sane value

Example fix

# before
daprd --app-id myapp   # relies on GetStablePort, fails

# after
daprd --app-id myapp --dapr-internal-grpc-port 50002

When it happens

Trigger: Calling daprd without --dapr-internal-grpc-port where GetStablePort(47300, appID) errors — e.g. an appID that the deterministic algorithm rejects, or an environment failure inside the port helper.

Common situations: Sidecars launched with unusual/empty app IDs in custom hosts; embedders constructing runtime configs programmatically without a valid id; rare platform errors surfaced by the helper.

Related errors

• error parsing dapr-http-port flag: %w
• error parsing dapr-grpc-port flag: %w
• error parsing profile-port flag: %w
• error parsing dapr-internal-grpc-port: %w
• error parsing dapr-public-port: %w

AI-assisted analysis of dapr/dapr@74ad417027 (2026-08-16). Data as JSON: /api/errors/d3e7a522076351df. Report an issue: GitHub.