Flags

The NATS server has many flags to customize its behavior without having to write a configuration file.

The configuration flags revolve around:

  • Server Options

  • Logging

  • Authorization

  • TLS Security

  • Clustering

  • Information

Server Options

Flag

Description

-a, --addr

Host address to bind to (default: 0.0.0.0 - all interfaces).

-p, --port

NATS client port (default: 4222).

-P, --pid

File to store the process ID (PID).

-m, --http_port

HTTP port for monitoring dashboard (exclusive of --https_port).

-ms, --https_port

HTTPS port monitoring for monitoring dashboard (exclusive of --http_port).

-c, --config

Path to NATS server configuration file.

-sl, --signal

Send a signal to nats-server process. See process signaling.

--client_advertise

Client HostPort to advertise to other servers.

-t

Test configuration and exit

Authentication Options

The following options control straightforward authentication:

Flag

Description

--user

Required username for connections (exclusive of --token).

--pass

Required password for connections (exclusive of --token).

--auth

Required authorization token for connections (exclusive of --user and --password).

See token authentication, and username/password for more information.

Logging Options

The following flags are available on the server to configure logging:

Flag

Description

-l, --log

File to redirect log output

-T, --logtime

Specify -T=false to disable timestamping log entries

-s, --syslog

Log to syslog or windows event log

-r, --remote_syslog

The syslog server address, like udp://localhost:514

-D, --debug

Enable debugging output

-V, --trace

Enable protocol trace log messages

-DV

Enable both debug and protocol trace messages

--max_traced_msg_len

Maximum printable length for traced messages. 0 for unlimited

You can read more about logging configuration here.

TLS Options

Flag

Description

--tls

Enable TLS, do not verify clients

--tlscert

Server certificate file

--tlskey

Private key for server certificate

--tlsverify

Enable client TLS certificate verification

--tlscacert

Client certificate CA for verification

Cluster Options

The following flags are available on the server to configure clustering:

Flag

Description

--routes

Comma-separated list of cluster URLs to solicit and connect

--cluster

Cluster URL for clustering requests

--no_advertise

Do not advertise known cluster information to clients

--cluster_advertise

Cluster URL to advertise to other servers

--connect_retries

For implicit routes, number of connect retries

You can read more about clustering configuration here.

Common Options

Flag

Description

-h, --help

Show this message

-v, --version

Show version

--help_tls

TLS help