Configuration

The key artifact that defines the tt environment and various aspects of its execution is its configuration file. You can generate it with a tt init call. In the default launch mode, the file is generated in the current directory, making it the environment root.

By default, the configuration file is called tt.yaml and located in the tt environment root directory. It depends on the launch mode.

It is also possible to pass the configuration file name and location explicitly using the following ways:

1. -c/--cfg global option
2. TT_CLI_CFG environment variable.

The TT_CLI_CFG variable has a lower priority than the --cfg option.

The tt configuration file is a YAML file with the following structure:

 
env:  instances_enabled: path/to/available/applications  bin_dir: path/to/bin_dir  inc_dir: path/to/inc_dir  restart_on_failure: bool  tarantoolctl_layout: boolmodules:  directory: path/to/modules/dirapp:  run_dir: path/to/run_dir  log_dir: path/to/log_dir  wal_dir: path/to/wal_dir  vinyl_dir: path/to/vinyl_dir  memtx_dir: path/to/memtx_dirrepo:  rocks: path/to/rocks  distfiles: path/to/installee:  credential_path: path/to/filetemplates:  - path: path/to/app/templates1  - path: path/to/app/templates2

• instances_enabled – the directory where instances are stored. Default: instances.enabled.

• bin_dir – the directory where binary files are stored. Default: bin.

• inc_dir – the base directory for storing header files. They will be placed in the include subdirectory inside the specified directory. Default: include.

• restart_on_failure – restart the instance on failure: true or false. Default: false.

• tarantoolctl_layout – use a layout compatible with the deprecated tarantoolctl utility for artifact files: control sockets, .pid files, log files. Default: false.

• directory – the directory where external modules are stored.

• run_dir– the directory for instance runtime artifacts, such as console sockets or PID files. Default: var/run.
• log_dir – the directory where log files are stored. Default: var/log.
• wal_dir – the directory where write-ahead log (.xlog) files are stored. Default: var/lib.
• memtx_dir – the directory where memtx stores snapshot (.snap) files. Default: var/lib.
• vinyl_dir – the directory where vinyl files or subdirectories are stored. Default: var/lib.

• rocks – the directory where rocks files are stored.

• distfiles – the directory where installation files are stored.

• credential_path – a path to the file with credentials used for downloading Tarantool Enterprise Edition (Tarantool customer zone credentials). The file should contain a username and a password, each on a separate line. Find an example in the tt install command reference.

• path – a path to application templates used for creating applications with tt create. May be specified more than once.

tt launch mode defines its working directory and the way it searches for the configuration file. There are three launch modes:

• default
• system
• local

Global option: none

Configuration file: searched from the current directory to the root. Taken from /etc/tarantool if the file is not found.

Working directory: The directory where the configuration file is found.

Global option: --system or -S

Configuration file: Taken from /etc/tarantool.

Working directory: Current directory.

Global option: --local=DIRECTORY or -L=DIRECTORY

Configuration file: Searched from the specified directory to the root. Taken from /etc/tarantool if the file is not found.

Working directory: The specified directory. If tarantool or tt executable files are found in the working directory, they will be used.

The tt configuration and application layout were changed in version 2.0. If you are using tt 1.*, complete the following steps to migrate to tt 2.0 or later:

1. Update the tt configuration file. In tt 2.0, the following changes were made to the configuration file:

   • The root section tt was removed. Its child sections – app, repo, modules, and other – have been moved to the top level.
   • Environment configuration parameters were moved from the app section to the new section env. These parameters are instances.enabled, bin_dir, inc_dir, and restart_on_failure.
   • The paths in the app section are now relative to the app directory in instances.enabled instead of the environment root.

   You can use tt init to generate a configuration file with the new structure and default parameter values.

2. Move application artifacts. With tt 1.*, application artifacts (logs, snapshots, pid, and other files) were created in the var directory inside the environment root. Starting from tt 2.0, these artifacts are created in the var directory inside the application directory, which is instances.enabled/<app-name>. This is how an application directory looks:

    
   instances.enabled/app/├── init.lua├── instances.yml└── var    ├── lib    │   ├── instance1    │   └── instance2    ├── log    │   ├── instance1    │   └── instance2    └── run        ├── instance1        └── instance2

   To continue using existing application artifacts after migration from tt 1.*:

   1. Create the var directory inside the application directory.
   2. Create the lib, log, and run directories inside var.
   3. Move directories with instance artifacts from the old var directory to the new var directories in applications' directories.

3. Move the files accessed from the application code. The working directory of instance processes was changed from the tt working directory to the application directory inside instances.enabled. If the application accesses files using relative paths, move the files accordingly or adjust the application code.