Create Terminus Plugins

Learn how to create your own Terminus plugins.

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This section provides information on how to create Terminus plugins.

Creating a plugin allows you to add custom commands to Terminus. The sections below provide instructions on how to create Pantheon's example plugin and add new commands.

Create the Example Plugin

Terminus has a plugin manager that includes a command for scaffolding a new, empty plugin.

  1. Run the command below to create a new plugin:

    terminus self:plugin:create hello-world --project-name=terminus-plugin-project/hello-world

    This commands creates a directory called hello-world and populates it with an example plugin template, renamed to match the provided project name. The project name is only required if you plan to publish and distribute your plugin (e.g. on Packagist).

    The self:plugin:create command also installs your new plugin so that you can start using it immediately.

  2. Review the two files in the example plugin's Commands directory, each of which contains an example command.

  3. Open the src/Commands/HelloCommand.php file, and modify the output as shown below:

    namespace Pantheon\TerminusHello\Commands;
    
    use Pantheon\Terminus\Commands\TerminusCommand;
    
    class HelloCommand extends TerminusCommand
    {
        /**
         * Print the classic message to the log.
         *
         * @command hello
         * @param string $name Who to say "hello" to.
         * @option $first This is the first time we've said hello.
         */
        public function sayHello($name = 'World', $options = ['first' => false])
        {
            $this->log()->notice("Hello, {user}! THIS IS MY MODIFICATION TO THE PLUGIN.", ['user' => $name]);
            if ($options['first']) {
                $this->log()->notice("Pleased to meet you.");
            }
        }
    }
    

    The command should now be recognized and loaded by Terminus:

    terminus hello

    The provided example command should display the following when run:

    [notice] Hello, World! THIS IS MY MODIFICATION TO THE PLUGIN.
  4. Modify the @command line to change the name of your command. You can rename the source file in which the command is stored, as long as it ends in Command.php.

Distribute Plugin

You must complete the steps below if you want to share your plugin with others.

 Warning

Some of the following instructions may break your plugin temporarily. We recommend you to uninstall your plugin (terminus self:plugin:uninstall <plugin-name>) and then re-install it (terminus self:plugin:install <plugin-dir>) after executing them.

  1. Add a vendor name to the plugin name within the composer.json file. This makes your plugin distinguishable from other plugins that might share the same name. Most people use their GitHub user or organization name for the vendor. The name field for a plugin distributed by Pantheon (GitHub organization: pantheon-systems) would be:

    {
      "name": "pantheon-systems\terminus-hello-world"
    }
  2. Add a PSR-4 compatible namespace to your plugin command class name to avoid conflict with internal or third-party commands. This should contain your vendor name and the plugin name. Add a namespace declaration to the top of your PHP file (e.g. \$HOME/.terminus/plugins/hello-world/src/HelloCommand.php):

    namespace Pantheon\TerminusHelloWorld\Commands;

    The Commands part of the namespace is not necessary but it can help keep things organized if you need to add supporting classes to your plugin.

  3. Make sure your src directory and composer file reflect the new namespace. Move the HelloCommand.php file from src/ to the src/Commands directory to mirror the last part of the namespace. If you have a lot of commands in your plugin, you can organize them into command groups by adding another layer to the namespace and directory structure.

  4. Update the composer.json file with an autoload section to indicate how to load your namespace. Change my-username and Pantheon in the example to your vendor name. Your composer file should now look like:

    {
      "name": "my-username/terminus-hello-world",
      "description": "An Hello, World Terminus command",
      "type": "terminus-plugin",
      "autoload": {
        "psr-4": { "Pantheon\\TerminusHello\\": "src" }
      },
      "extra": {
        "terminus": {
          "compatible-version": "^3"
        }
      }
    }
  5. Update the composer.json file with a require section that lists all of the external projects you need, along with their version constraints.

Coding Standards

Pantheon recommends adopting Terminus core standards if you plan to distribute your plugin and/or add it to an open source license and encourage contributions. Some basic principles to follow are:

Plugin Versioning

We recommend following semantic versioning when versioning your plugins, just as Terminus does.

You can specify this in the compatible-version section of your composer.json file if your plugin has a minimum required version of Terminus.

  1. Use the standard composer version constraints syntax.

  2. Make sure that your constraint expression does not accidentally include the next major version of Terminus if you change compatible-version. For example, >=3.0 <4.0.0 is fine, but >=3.0 is not.

Test Plugins

Automated plugin testing is an important step to complete before you distribute your plugins. Automated tests give prospective new users the assurance that the plugin works, and provides a basis for evaluating changes to the plugin.

The instructions in this section demonstrate how to set up simple functional tests for Terminus plugins using Bats, the Bash Automated Testing System. Bats allows tests to be written with simple Bash statements.

  1. Copy the require-dev and scripts sections from the composer.json file below into the composer.json of your Terminus plugin:

    {
        "name": "my-username/terminus-hello-world",
        "description": "A Hello, World Terminus command",
        "type": "terminus-plugin",
        "autoload": {
            "psr-4": { "Pantheon\\TerminusHello\\": "src" }
        },
        "require": {
            "organization/project-name": "^1"
        },
        "extra": {
            "terminus": {
                "compatible-version": "^1.1"
            }
        }
        "require-dev": {
            "squizlabs/php_codesniffer": "^2.7"
        },
        "scripts": {
            "install-bats": "if [ ! -f bin/bats ] ; then git clone https://github.com/sstephenson/bats.git; mkdir -p bin; bats/install.sh .; fi",
            "bats": "TERMINUS_PLUGINS_DIR=.. bin/bats tests",
            "cs": "phpcs --standard=PSR2 -n src",
            "cbf": "phpcbf --standard=PSR2 -n src",
            "test": [
                "@install-bats",
                "@bats",
                "@cs"
            ]
        }
    }
  2. Install the PHP Code Sniffer:

      composer install
  3. Check the coding standards of your plugin for PSR-2 compliance:

      composer cs
  4. Use cbf to fix (most) PRS-2 compliance errors in your plugin:

      composer cbf
  5. Add the following lines to the .gitignorefile. This is strongly recommended because of the additional files created by these tests.

      vendor
      bats
      bin
      libexec
      share
  6. Define your Bats tests. Create a folder named tests, and create a file named confirm-install.bats. Place the content below in your Bats test file:

    #!/usr/bin/env bats
    
    #
    # confirm-install.bats
    #
    # Ensure that Terminus and the Composer plugin have been installed correctly
    #
    
    @test "confirm terminus version" {
      terminus --version
    }
    
    @test "get help on plugin command" {
      run terminus help MY:PLUGIN-COMMAND
      [[ $output == *"SOME OUTPUT FROM MY PLUGIN HELP"* ]]
      [ "$status" -eq 0 ]
    }
    ```
    
  7. Replace MY:PLUGIN-COMMAND with the name of one of your plugin's commands, and replace SOME OUTPUT FROM MY PLUGIN HELP in the test.

  8. Run your test:

     composer test

You can create more files with .bats extensions to add more tests. You must populate these files with @test blocks as shown above. Tests consist of simple bash expressions. A command that returns a non-zero result code signifies failure. Refer the documentation on writing BATS tests for more information.

Automate Tests

You can configure your project tests to run automatically on Circle CI. You must keep a Sandbox site online to run the tests against.

  1. Copy the contents below into a file named circle.yml in your plugin project:

    #
    # Test the Terminus Composer Plugin
    #
    machine:
      timezone:
        America/Chicago
      php:
        version: 7.0.11
      environment:
        PATH: $PATH:~/.composer/vendor/bin:~/.config/composer/vendor/bin:$HOME/bin
    
    dependencies:
      cache_directories:
        - ~/.composer/cache
      override:
        - composer install --prefer-dist -n
        - composer install-bats
        - composer global require -n "consolidation/cgr"
        - cgr "pantheon-systems/terminus:^1.1"
      post:
        - terminus auth:login --machine-token=$TERMINUS_TOKEN
    test:
      override:
        - composer test

    You can use another testing service by adapting the contents above. Most popular services should be easy to set up.

  2. Open the Circle CI settings to set up the following environment variables:

    • TERMINUS_SITE: The name of a Sandbox Pantheon site to run tests against.
    • TERMINUS_TOKEN: A Pantheon machine token that has access to the test site.
  3. Create an ssh key pair, add the public key to your account on Pantheon, and add the private key to Circle CI. Leave the Hostname field empty.

    Your tests should run successfully on Circle CI.

  4. Add an embeddable status badge to the top of your plugin's README.md file to show your passing build status.

A more complete version of the plugin created above can be found at: https://github.com/pantheon-systems/terminus-plugin-example

Plugin Commands

There is currently no published Plugin API documentation. The best way to learn how to write commands is to look through the internal commands in the Terminus source code: https://github.com/pantheon-systems/terminus

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