relay smoke test

[mpeck]

Note: This will most likely be one of several issues for smoke testing communications between the various components of Cog.

Cog admins need an easy way to smoke test a Cog installation. Previously we were using Docker's healthcheck hook to provide some insight into Cog's status, but that proved to be a bit too broad to be useful. So instead we will provide a simple smoke test script to be installed alongside relay. This should give admins a bit more flexibility and provide a sanity check during installation and/or troubleshooting.

The smoke test script should be easily accessible via docker exec so we should copy it to somewhere in the path when building the image.

Checks

• the host running Cog is accessible
• the services endpoint in accessible

Done Criteria

• write a simple smoke test script
• update Dockerfile to install the script in the path (admins should be able to run the script with something like docker exec cog_smoke_test
• Add usage documentation to Cog book

[christophermaier]

This issue was moved to operable/go-relay#75