cockroach gen

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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.

Decommissioned nodes are excluded from the config file.

Synopsis

Generate man pages:

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$ cockroach gen man

Generate bash autocompletion script:

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$ cockroach gen autocomplete

Generate example SQL data:

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

Generate an HAProxy config file for a running cluster:

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$ cockroach gen haproxy

View help:

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$ cockroach gen --help
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$ cockroach gen man --help
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$ cockroach gen autocomplete --help
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$ cockroach gen example-data --help
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$ cockroach gen haproxy --help

Flags

The gen subcommands supports the following general-use, logging, and client connection 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, this command logs messages to stderr. This includes events with WARNING severity and higher.

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

Client Connection

haproxy

Flag Description
--cluster-name The cluster name to use to verify the cluster's identity. If the cluster has a cluster name, you must include this flag. For more information, see cockroach start.
--disable-cluster-name-verification Disables the cluster name check for this command. This flag must be paired with --cluster-name. For more information, see cockroach start.

Examples

Generate man pages

Generate man pages:

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$ cockroach gen man

Move the man pages to the man directory:

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

Access man pages:

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$ man cockroach

Generate a bash autocompletion script

Generate bash autocompletion script:

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$ cockroach gen autocomplete

Add the script to your .bashrc and .bash_profle:

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

  1. Start up a demo cluster:

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    cockroach demo
    
  2. Pipe the output from cockroach gen to the URL to the demo cluster:

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    cockroach gen example-data startrek | cockroach sql --url='postgres://demo:demo11762@127.0.0.1:26257?sslmode=require'
    
    CREATE DATABASE
    SET
    DROP TABLE
    DROP TABLE
    CREATE TABLE
    INSERT 1
    ...
    CREATE TABLE
    INSERT 1
    ...
    
  3. Open a SQL shell to view it:

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    cockroach sql --url='postgres://demo:demo11762@127.0.0.1:26257?sslmode=require'
    
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    SHOW TABLES FROM startrek;
    
      schema_name | table_name | type  | estimated_row_count
    --------------+------------+-------+----------------------
      public      | episodes   | table |                  79
      public      | quotes     | table |                 200
    (2 rows)
    
  4. Generate an example intro database, which contains 1 table, mytable, with a hidden message:

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    cockroach gen example-data intro | cockroach sql --url='postgres://demo:demo11762@127.0.0.1:26257?sslmode=require'
    
    CREATE DATABASE
    SET
    DROP TABLE
    CREATE TABLE
    INSERT 1
    INSERT 1
    INSERT 1
    INSERT 1
    ...
    
  5. Launch the SQL client to view it:

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    cockroach sql --url='postgres://demo:demo11762@127.0.0.1:26257?sslmode=require'
    
  6. Show the tables in the intro database:

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    > SHOW TABLES FROM intro;
    
      schema_name | table_name | type  | estimated_row_count
    --------------+------------+-------+----------------------
      public      | mytable    | table |                  42
    (1 row)
    
  7. Select the message from the table:

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    > 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:

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$ 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:

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$ 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:

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$ 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:

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$ 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


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