Configuration

This topic describes how to configure Тarantool Cluster Manager. For the complete list of TCM configuration parameters, see the TCM configuration reference.

Тarantool Cluster Manager configuration is a set of parameters that define various aspects of TCM functioning. Parameters are grouped by the particular aspect that they affect. There are the following groups:

• HTTP
• logging
• configuration storage
• security
• add-ons
• limits
• TCM running mode

Parameter groups can be nested. For example, in the http group there are tls and websession-cookie groups, which define TLS encryption and cookie settings.

Parameter names are the full paths from the top-level group to the specific parameter. For example:

• http.host is the host parameter that is defined directly in the http group.
• http.tls.enabled is the enabled parameter that is defined in the tls nested group within http.

There are three ways to pass TCM configuration parameters:

• a YAML file
• environment variables
• command-line options of the TCM executable

TCM configuration can be stored in a YAML file. Its structure must reflect the configuration parameters hierarchy.

The example below shows a fragment of a TCM configuration file:

 
# a fragment of a YAML configuration filecluster: # top-level group    connection-rate-limit: 512    tarantool-timeout: 10s    tarantool-ping-timeout: 5shttp: # top-level group    network: tcp    host: 127.0.0.1    port: 8080    request-size: 1572864    websocket: # nested group        read-buffer-size: 16384        write-buffer-size: 16384        keepalive-ping-interval: 20s        handshake-timeout: 10s        init-timeout: 15s

To start TCM with a YAML configuration, pass the location of the configuration file in the -c command-line option:

 
$ tcm -c=config.yml

TCM can take values of its configuration parameters from environment variables. The variable names start with TCM_. Then goes the full path to the parameter, converted to upper case. All delimiters are replaced with underscores (_). Examples:

• TCM_HTTP_HOST is a variable for the http.host parameter.
• TCM_HTTP_WEBSESSION_COOKIE_NAME is a variable for the http.websession-cookie.name parameter.

The example below shows how to start TCM with configuration parameters passed in environment variables:

 
$ export TCM_HTTP_HOST=0.0.0.0$ export TCM_HTTP_PORT=8888$ tcm

The TCM executable has -- command-line options for each configuration parameter. Their names reflect the full path to the parameter, with configuration levels separated by periods (.). Examples:

• --http.host is an option for http.host.
• --http.websession-cookie.name is an option for http.websession-cookie.name.

The example below shows how to start TCM with configuration parameters passed in command-line options:

 
$ tcm --storage.etcd.embed.enabled --addon.enabled --http.host=0.0.0.0 --http.port=8888

TCM configuration options are applied from multiple sources with the following precedence, from highest to lowest:

1. tcm executable arguments.
2. TCM_* environment variables.
3. Configuration from a YAML file.

If the same option is defined in two or more locations, the option with the highest precedence is applied. For options that aren't defined in any location, the default values are used.

You can combine different ways of TCM configuration for efficient management of multiple TCM installations:

• A single YAML file for all installations can contain the common configuration parts. For example, a single configuration storage that is used for all installations, or TLS settings.
• Environment variables that set specific parameters for each server, such as local directories and paths.
• Command-line options for parameters that must be unique for different TCM instances running on a single server. For example, http.port.

TCM configuration parameters have the Go language types. Note that this is different from the Tarantool configuration parameters, which have Lua types.

Most options have the Go's basic types: int and other numeric types, bool, string.

 
http:    network: tcp # string    host: 127.0.0.1 # string    port: 8080 # int    request-size: 1572864 # int64

Parameters that can take multiple values are arrays. In YAML, they are passed as YAML arrays: each item on a new line, starting with a dash.

 
storage:provider: etcdetcd:    endpoints: # array        - https://192.168.0.1:2379 # item 1        - https://192.168.0.2:2379 # item 2

Parameters that set timeouts, TTLs, and other duration values, have the Go's time.Duration type. Their values can be passed in time-formatted strings such as 4h30m25s.

 
cluster:    tarantool-timeout: 10s # duration    tarantool-ping-timeout: 5s # duration

Finally, there are parameters whose values are constants defined in Go packages. For example, http.websession-cookie.same-site values are constants from the Go's http.SameSite type. To find out the exact values available for such parameters, refer to the Go packages documentation.

 
http:    websession-cookie:        same-site: SameSiteStrictMode

You can create a YAML configuration template for TCM with all parameters and their default values using the generate-config option of the tcm executable.

To write a default TCM configuration to the tcm.example.yml file, run:

 
$ tcm generate-config > tcm.example.yml.

You can use YAML configuration files to create entities in TCM automatically upon the first start. These entities are defined in the tcm_configuration_reference_initial section of the configuration file.

To add clusters to TCM upon the first start, specify their settings in the initial-settings.clusters configuration section.

The initial-settings.clusters section is an array whose items describe separate clusters, for example:

 
initial-settings:  clusters:    - name: Cluster 1      description: First cluster      # cluster settings    - name: Cluster 2      description: Second cluster      # cluster settings

In this configuration, you can specify all cluster settings that you define when connecting clusters through the TCM web interface. This includes:

• the cluster name
• description
• additional URLs
• configuration storage connection
• Tarantool instances connection
• and other settings.

For the full list of cluster configuration parameters, see the initial-settings.clusters reference. For example, this is how you add a cluster that uses an etcd configuration storage:

 
initial-settings:  clusters:    - name: My cluster      description: Cluster description      urls:      - label: Test        url: http://example.com      storage-connection:        provider: etcd        etcd-connection:          endpoints:            - http://127.0.0.1:2379          username: ""          password: ""          prefix: /cluster1        tarantool-connection:          username: guest          password: ""

By default, TCM contains a cluster named Default cluster with ID 00000000-0000-0000-0000-000000000000. You can use this ID to modify the default cluster settings upon the first TCM start. For example, rename it and add its connection settings:

 
initial-settings:  clusters:    - id: 00000000-0000-0000-0000-000000000000      name: My cluster      storage-connection:        provider: etcd        etcd-connection:          endpoints:            - http://127.0.0.1:2379          username: etcd-user          password: secret          prefix: /cluster1        tarantool-connection:          username: guest          password: ""