Migrate CircleCI config to v2

[danielbachhuber]

Based on https://github.com/pantheon-systems/pantheon-advanced-page-cache/pull/123 See https://github.com/pantheon-systems/pantheon-advanced-page-cache/issues/122

[danielbachhuber]

@ataylorme Looks like http://solr-power.pantheon.website/wp-content/uploads/apache-solr-3.6.2.tgz disappeared (domain doesn't resolve). What's the best way to fix?

[ataylorme]

@danielbachhuber you can use https://dev-solr-power.pantheonsite.io/wp-content/uploads/apache-solr-3.6.2.tgz

[danielbachhuber]

Please use the pantheon-public/build-tools-ci Docker image as it has Terminus pre-installed.

Does it have the other dependencies we need? Which PHP version is it?

[ataylorme]

It is PHP 7.1 with all of our Terminus plugins and Composer. Not sure what else you need. You can see the Dockerfile here

[danielbachhuber]

Ok. WP SAML Auth requires PHP 5.6. I'd prefer to keep the circle.yml files consistent between plugin repos and don't see the benefit in using pantheon-public/build-tools-ci Docker image.

[ataylorme]

The benefit is faster build since the Docker image has Terminus and it doesn't need to be installed on each CircleCI build.

[danielbachhuber]

The benefit is faster build since the Docker image has Terminus and it doesn't need to be installed on each CircleCI build.

Given the Composer checkout is cached, what percentage of total build time does installing Terminus take?

[ataylorme]

The last build took 4 minutes, which seems okay.

Moving the setup to its own file would still be nice but not necessary.

[danielbachhuber]

👍 Thanks @ataylorme