# cockroach gen

The `cockroach gen` command can generate command-line interface (CLI) utilities (`man` pages and a `bash` autocompletion script), example SQL data suitable to populate test databases, and an HAProxy configuration file for load balancing a running cluster.

## Subcommands

Subcommand | Usage
--- | ---
`man` | Generate man pages for CockroachDB.
`autocomplete` | Generate `bash` or `zsh` autocompletion script for CockroachDB. Default: `bash`
`example-data` | Generate example SQL datasets. You can also use the `cockroach workload` command to generate these sample datasets in a persistent cluster and the `cockroach demo <dataset>` command to generate these datasets in a temporary, in-memory cluster.
`haproxy` | Generate an HAProxy config file for a running CockroachDB cluster. The node addresses included in the config are those advertised by the nodes. Make sure hostnames are resolvable and IP addresses are routable from HAProxy. New in v20.1: Decommissioned nodes are excluded from the config file.

## Synopsis

Generate man pages:

    $ cockroach gen man

Generate bash autocompletion script:

    $ cockroach gen autocomplete

Generate example SQL data:

    $ cockroach gen example-data intro | cockroach sql

    $ cockroach gen example-data startrek | cockroach sql

Generate an HAProxy config file for a running cluster:

    $ cockroach gen haproxy

View help:

    $ cockroach gen --help

    $ cockroach gen man --help

    $ cockroach gen autocomplete --help

    $ cockroach gen example-data --help

    $ cockroach gen haproxy --help

## Flags

The `gen` subcommands supports the following general-use and logging flags.

### General

#### `man`

Flag | Description
--- | ---
`--path` | The path where man pages will be generated. Default: `man/man1` under the current directory

#### `autocomplete`

Flag | Description
--- | ---
`--out` | The path where the autocomplete file will be generated. Default: `cockroach.bash` in the current directory

#### `example-data`

No flags are supported. See the Generate Example Data example for guidance.

#### `haproxy`

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`
`--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
`--out` | The path where the `haproxy.cfg` file will be generated. If an `haproxy.cfg` file already exists in the directory, it will be overwritten. Default: `haproxy.cfg` in the current directory
`--locality` | If nodes were started with locality details, you can use the `--locality` flag here to filter the nodes included in the HAProxy config file, specifying the explicit locality tier(s) or a regular expression to match against. This is useful in cases where you want specific instances of HAProxy to route to specific nodes. See the Generate an HAProxy configuration file example for more details.

### Logging

By default, the `gen` command logs errors to `stderr`.

If you need to troubleshoot this command's behavior, you can change its logging behavior.

## Examples

### Generate `man` pages

Generate man pages:

    $ cockroach gen man

Move the man pages to the man directory:

    $ sudo mv man/man1/* /usr/share/man/man1

Access man pages:

    $ man cockroach

### Generate a `bash` autocompletion script

Generate bash autocompletion script:

    $ cockroach gen autocomplete

Add the script to your `.bashrc` and `.bash_profle`:

    $ printf "\n\n#cockroach bash autocomplete\nsource '<path to>cockroach.bash'" >> ~/.bashrc

    $ printf "\n\n#cockroach bash autocomplete\nsource '<path to>cockroach.bash'" >> ~/.bash_profile

You can now use `tab` to autocomplete `cockroach` commands.

### Generate example data

Tip:

You can also use the `cockroach workload` command to generate these sample datasets in a persistent cluster and the `cockroach demo <dataset>` command to generate these datasets in a temporary, in-memory cluster.

To test out CockroachDB, you can generate an example `startrek` database, which contains 2 tables, `episodes` and `quotes`.

    $ cockroach gen example-data startrek | cockroach sql --insecure

    CREATE DATABASE
    SET
    DROP TABLE
    DROP TABLE
    CREATE TABLE
    INSERT 79
    CREATE TABLE
    INSERT 200

Launch the built-in SQL client to view it:

    $ cockroach sql --insecure

    > SHOW TABLES FROM startrek;

    +------------+
    | table_name |
    +------------+
    | episodes   |
    | quotes     |
    +------------+
    (2 rows)

You can also generate an example `intro` database, which contains 1 table, `mytable`, with a hidden message:

    $ cockroach gen example-data intro | cockroach sql --insecure

    CREATE DATABASE
    SET
    DROP TABLE
    CREATE TABLE
    INSERT 1
    INSERT 1
    INSERT 1
    INSERT 1
    ...

    # Launch the built-in SQL client to view it:
    $ cockroach sql --insecure

    > SHOW TABLES FROM intro;

    +-------------+
    | table_name  |
    +-------------+
    | mytable     |
    +-------------+
    (1 row)

    > SELECT * FROM intro.mytable WHERE (l % 2) = 0;

    +----+------------------------------------------------------+
    | l  |                          v                           |
    +----+------------------------------------------------------+
    |  0 | !__aaawwmqmqmwwwaas,_        .__aaawwwmqmqmwwaaa,  |
    |  2 | !"VT?!"""^~~^"""??T$Wmqaa,_auqmWBT?!"""^~~^^""??YV^  |
    |  4 | !                    "?##mW##?"-                     |
    |  6 | !  C O N G R A T S  _am#Z??A#ma,           Y         |
    |  8 | !                 _ummY"    "9#ma,       A           |
    | 10 | !                vm#Z(        )Xmms    Y             |
    | 12 | !              .j####mmm#####mm#m##6.                |
    | 14 | !   W O W !    jmm###mm######m#mmm##6                |
    | 16 | !             ]#me*Xm#m#mm##m#m##SX##c               |
    | 18 | !             dm#||+*$##m#mm#m#Svvn##m               |
    | 20 | !            :mmE=|+||S##m##m#1nvnnX##;     A        |
    | 22 | !            :m#h+|+++=Xmm#m#1nvnnvdmm;     M        |
    | 24 | ! Y           $#m>+|+|||##m#1nvnnnnmm#      A        |
    | 26 | !  O          ]##z+|+|+|3#mEnnnnvnd##f      Z        |
    | 28 | !   U  D       4##c|+|+|]m#kvnvnno##P       E        |
    | 30 | !       I       4#ma+|++]mmhvnnvq##P`       !        |
    | 32 | !        D I     ?$#q%+|dmmmvnnm##!                  |
    | 34 | !           T     -4##wu#mm#pw##7'                   |
    | 36 | !                   -?$##m####Y'                     |
    | 38 | !             !!       "Y##Y"-                       |
    | 40 | !                                                    |
    +----+------------------------------------------------------+
    (21 rows)

### Generate an HAProxy config file

HAProxy is one of the most popular open-source TCP load balancers, and CockroachDB includes a built-in command for generating a configuration file that is preset to work with your running cluster.

To generate an HAProxy config file for an entire secure cluster, run the `cockroach gen haproxy` command, specifying the location of certificate directory and the address of any instance running a CockroachDB node:

    $ cockroach gen haproxy \
    --certs-dir=<path to certs directory> \
    --host=<address of any node in the cluster>

To limit the HAProxy config file to nodes matching specific "localities", use the `--localities` flag, specifying the explicit locality tier(s) or a regular expression to match against:

    $ cockroach gen haproxy \
    --certs-dir=<path to certs directory> \
    --host=<address of any node in the cluster>
    --locality=region=us.*

To generate an HAProxy config file for an entire insecure cluster, run the `cockroach gen haproxy` command, specifying the address of any instance running a CockroachDB node:

    $ cockroach gen haproxy \
    --insecure \
    --host=<address of any node in the cluster>

To limit the HAProxy config file to nodes matching specific "localities", use the `--localities` flag, specifying the explicit locality tier(s) or a regular expression to match against:

    $ cockroach gen haproxy \
    --insecure \
    --host=<address of any node in the cluster>
    --locality=region=us.*

By default, the generated configuration file is called `haproxy.cfg` and looks as follows, with the `server` addresses pre-populated correctly:

    global
      maxconn 4096

    defaults
        mode                tcp
        # Timeout values should be configured for your specific use.
        # See: https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#4-timeout%20connect
        timeout connect     10s
        timeout client      1m
        timeout server      1m
        # TCP keep-alive on client side. Server already enables them.
        option              clitcpka

    listen psql
        bind :26257
        mode tcp
        balance roundrobin
        option httpchk GET /health?ready=1
        server cockroach1 <node1 address>:26257 check port 8080
        server cockroach2 <node2 address>:26257 check port 8080
        server cockroach3 <node3 address>:26257 check port 8080

The file is preset with the minimal configurations needed to work with your running cluster:

Field | Description
--- | ---
`timeout connect` `timeout client` `timeout server` | Timeout values that should be suitable for most deployments.
`bind` | The port that HAProxy listens on. This is the port clients will connect to and thus needs to be allowed by your network configuration. This tutorial assumes HAProxy is running on a separate machine from CockroachDB nodes. If you run HAProxy on the same machine as a node (not recommended), you'll need to change this port, as `26257` is likely already being used by the CockroachDB node.
`balance` | The balancing algorithm. This is set to `roundrobin` to ensure that connections get rotated amongst nodes (connection 1 on node 1, connection 2 on node 2, etc.). Check the HAProxy Configuration Manual for details about this and other balancing algorithms.
`option httpchk` | The HTTP endpoint that HAProxy uses to check node health. `/health?ready=1` ensures that HAProxy doesn't direct traffic to nodes that are live but not ready to receive requests.
`server` | For each included node, this field specifies the address the node advertises to other nodes in the cluster, i.e., the addressed pass in the `--advertise-addr` flag on node startup. Make sure hostnames are resolvable and IP addresses are routable from HAProxy.

Note:

For full details on these and other configuration settings, see the HAProxy Configuration Manual.

## See also

- Other Cockroach Commands
- Deploy CockroachDB On-Premises (using HAProxy for load balancing)