Copy from test Pantheon install

https://git.ethitter.com/pantheon-origins/ethitter-com/-/blob/b948350a1845a0f71e80a5f56134564fd8aac430/.gitlab-ci.yml

README.md

 # GitLab CI for WordPress
 
-Shared `.gitlab-ci.yml` components for WordPress plugins and themes.
+Shared `.gitlab-ci.yml` components for WordPress.
+
+## Features
+
+* `plugins`: PHPUnit, PHPCS, and deploys to WordPress.org.
+* `pantheon`: deploy a site to Pantheon via their git integration.

pantheon/default.yml

+stages:
+  - test
+  - build
+
+variables:
+  GIT_SUBMODULE_STRATEGY: recursive
+
+test-deps:
+  stage: test
+  image: containers.ethitter.com:443/docker/images/php:7.3
+  before_script:
+    - curl -sL https://deb.nodesource.com/setup_10.x | bash -
+    - apt-get install -y nodejs
+  script:
+    - cd ${CI_PROJECT_DIR}/wp-content/mu-plugins/solr-power
+    - composer install --no-dev --no-ansi -n
+    - sed -i '/vendor\//d' .gitignore
+    - sed -i '/assets\/*/d' .gitignore
+    - npm install
+    - ./node_modules/grunt/bin/grunt
+    - rm -rf ./node_modules
+
+git-push:
+  stage: build
+  image: containers.ethitter.com:443/docker/images/php:7.3
+  only:
+    - main
+  allow_failure: false
+  before_script:
+    - 'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'
+    - eval $(ssh-agent -s)
+    - ssh-add <(echo "$GIT_SSH_PRIV_KEY")
+
+    - git config --global user.email "$GIT_USER_EMAIL"
+    - git config --global user.name "$GIT_USER_NAME"
+
+    - mkdir -p ~/.ssh
+    - echo "$SSH_KNOWN_HOSTS" >> ~/.ssh/known_hosts
+    - ssh-keygen -R "$PANTHEON_GIT_HOST"
+    - ssh-keyscan -t rsa -p "$PANTHEON_GIT_HOST_PORT" "$PANTHEON_GIT_HOST" >> ~/.ssh/known_hosts
+
+    - composer install --no-dev --no-ansi -n -d wp-content/mu-plugins/solr-power
+    - sed -i '/vendor\//d' wp-content/mu-plugins/solr-power/.gitignore
+    - sed -i '/assets\/*/d' wp-content/mu-plugins/solr-power/.gitignore
+
+    - curl -sL https://deb.nodesource.com/setup_10.x | bash -
+    - apt-get install -y nodejs
+
+    - cd ${CI_PROJECT_DIR}/wp-content/mu-plugins/solr-power
+    - npm install
+    - ./node_modules/grunt/bin/grunt
+    - rm -rf ./node_modules
+    # TODO: add Terminus to handle pushes and cache clearing.
+  script:
+    - cd ${CI_PROJECT_DIR}
+    - ls -la
+    - rm -rf ${CI_PROJECT_DIR}/.git/
+    - rm -rf ${CI_PROJECT_DIR}/.gitignore
+    - rm -rf ${CI_PROJECT_DIR}/.gitmodules
+    - rm -rf ${CI_PROJECT_DIR}/.gitlab-ci.yml
+    - rm -rf ${CI_PROJECT_DIR}/README.md
+    - rm -rf ${CI_PROJECT_DIR}/readme.txt
+    - ls -la
+
+    - git init
+    - git remote add pantheon "$PANTHEON_GIT_REMOTE"
+    - git status -s
+    - git add -A
+    - git status -s
+    - git commit -m "Build from $CI_COMMIT_SHORT_SHA"
+    - git diff --exit-code
+    - git status -s
+    - git log -n 1
+    - git push --force pantheon master