Note:
Cockroach Labs supports the current stable release and two releases prior. Therefore, this version will no longer be supported after the Spring 2020 release.

Client applications, including cockroach client commands, work by establishing a network connection to a CockroachDB cluster. The client connection parameters determine which CockroachDB cluster they connect to, and how to establish this network connection.

Supported connection parameters

Most client apps, including cockroach client commands, determine which CockroachDB server to connect to using a PostgreSQL connection URL. When using a URL, a client can also specify additional SQL-level parameters. This mode provides the most configuration flexibility.

In addition, all cockroach client commands also accept discrete connection parameters that can specify the connection parameters separately from a URL.

When to use a URL and when to use discrete parameters

Specifying client parameters using a URL may be more convenient during experimentation, as it facilitates copy-pasting the connection parameters (the URL) between different tools: the output of cockroach start, other cockroach commands, GUI database visualizer, programming tools, etc.

Discrete parameters may be more convenient in automation, where the components of the configuration are filled in separately from different variables in a script or a service manager.

Connect using a URL

A connection URL has the following format:

postgres://<username>:<password>@<host>:<port>/<database>?<parameters>
Component Description Required
<username> The SQL user that will own the client session.
<password> The user's password. It is not recommended to pass the password in the URL directly.

Find more detail about how CockroachDB handles passwords.
<host> The host name or address of a CockroachDB node or load balancer. Required by most client drivers.
<port> The port number of the SQL interface of the CockroachDB node or load balancer. The default port number for CockroachDB is 26257. Use this value when in doubt. Required by most client drivers.
<database> A database name to use as current database. Defaults to defaultdb.
<parameters> Additional connection parameters, including SSL/TLS certificate settings.
Note:

For cockroach commands that accept a URL, you can specify the URL with the command-line flag --url. If --url is not specified but the environment variable COCKROACH_URL is defined, the environment variable is used. Otherwise, the cockroach command will use discrete connection parameters as described below.

Note:

The <database> part is not used for cockroach commands other than cockroach sql. A warning is currently printed if it is mistakenly specified, and future versions of CockroachDB may return an error in that case.

Additional connection parameters

The following additional parameters can be passed after the ? character in the URL:

Parameter Description Default value
application_name An initial value for the application_name session variable.

Note: For Java JBDC, use ApplicationName.
Empty string.
sslmode Which type of secure connection to use: disable, allow, prefer, require, verify-ca or verify-full. See Secure Connections With URLs for details. disable
sslrootcert Path to the CA certificate, when sslmode is not disable. Empty string.
sslcert Path to the client certificate, when sslmode is not disable. Empty string.
sslkey Path to the client private key, when sslmode is not disable. Empty string.

Secure connections with URLs

The following values are supported for sslmode, although only the first and the last are recommended for use.

Parameter Description Recommended for use
sslmode=disable Do not use an encrypted, secure connection at all. Use during development.
sslmode=allow Enable a secure connection only if the server requires it.

Not supported in all clients.
sslmode=prefer Try to establish a secure connection, but accept an insecure connection if the server does not support secure connections.

Not supported in all clients.
sslmode=require Force a secure connection. An error occurs if the secure connection cannot be established.
sslmode=verify-ca Force a secure connection and verify that the server certificate is signed by a known CA.
sslmode=verify-full Force a secure connection, verify that the server certificate is signed by a known CA, and verify that the server address matches that specified in the certificate. Use for secure deployments.
Warning:

Some client drivers and the cockroach commands do not support sslmode=allow and sslmode=prefer. Check the documentation of your SQL driver to determine whether these options are supported.

Example URL for an insecure connection

The following URL is suitable to connect to a CockroachDB node using an insecure connection:

postgres://root@servername:26257/mydb?sslmode=disable

This specifies a connection for the root user to server servername on port 26257 (the default CockroachDB SQL port), with mydb set as current database. sslmode=disable makes the connection insecure.

Example URL for a secure connection

The following URL is suitable to connect to a CockroachDB node using a secure connection:

postgres://root@servername:26257/mydb?sslmode=verify-full&sslrootcert=path/to/ca.crt&sslcert=path/to/client.username.crt&sslkey=path/to/client.username.key

This uses the following components:

  • User root
  • Host name servername, port number 26257 (the default CockroachDB SQL port)
  • Current database mydb
  • SSL/TLS mode verify-full:
    • Root CA certificate path/to/ca.crt
    • Client certificate path/to/client.username.crt
    • Client key path/to/client.username.key

For details about how to create and manage SSL/TLS certificates, see Create Security Certificates and Rotate Certificates.

Connect using discrete parameters

Most cockroach commands accept connection parameters as separate, discrete command-line flags, in addition (or in replacement) to --url which specifies all parameters as a URL.

For each command-line flag that directs a connection parameter, CockroachDB also recognizes an environment variable. The environment variable is used when the command-line flag is not specified.

Flag Description
--host The server host and port number to connect to. This can be the address of any node in the cluster.

Env Variable: COCKROACH_HOST
Default: localhost:26257
--port
-p
The server port to connect to. Note: The port number can also be specified via --host.

Env Variable: COCKROACH_PORT
Default: 26257
--user
-u
The SQL user that will own the client session.

Env Variable: COCKROACH_USER
Default: root
--insecure Use an insecure connection.

Env Variable: COCKROACH_INSECURE
Default: false
--certs-dir The path to the certificate directory containing the CA and client certificates and client key.

Env Variable: COCKROACH_CERTS_DIR
Default: ${HOME}/.cockroach-certs/
--url A connection URL to use instead of the other arguments.

Env Variable: COCKROACH_URL
Default: no URL

Example command-line flags for an insecure connection

The following command-line flags establish an insecure connection:

--user=root \
--host=<servername>
--insecure

This specifies a connection for the root user to server servername on port 26257 (the default CockroachDB SQL port). --insecure makes the connection insecure.

Example command-line flags for a secure connection

The following command-line flags establish a secure connection:

--user=root \
--host=<servername>
--certs-dir=path/to/certs

This uses the following components:

  • User root
  • Host name servername, port number 26257 (the default CockroachDB SQL port)
  • SSL/TLS enabled, with settings:
    • Root CA certificate path/to/certs/ca.crt
    • Client certificate path/to/client.<user>.crt (path/to/certs/client.root.crt with --user root)
    • Client key path/to/client.<user>.key (path/to/certs/client.root.key with --user root)
Note:

When using discrete connection parameters, the file names of the CA and client certificates and client key are derived automatically from the value of --certs-dir.

Using both URL and client parameters

Most cockroach commands accept both a URL and client parameters. The information contained therein is combined in the order it appears in the command line.

This combination is useful so that discrete command-line flags can override settings not otherwise set in the URL.

Example override of the current database

The cockroach start command prints out the following connection URL, which connects to the defaultdb database:

postgres://root@servername:26257/?sslmode=disable

To specify mydb as the current database using cockroach sql, run the following command:

cockroach sql \
--url "postgres://root@servername:26257/?sslmode=disable" \
--database mydb

This is equivalent to:

cockroach sql --url "postgres://root@servername:26257/mydb?sslmode=disable"

See also



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