Add Docker documentation to the installation docs; update and create the ”Scripts To Rule Them All” scripts for easy use of the Docker Composer environment.

Fixes #2425.

script/test

@@ -0,0 +1,47 @@
+#!/bin/bash
+
+# script/test: Run test suite for application. Optionally pass in a path to an
+#              individual test file to run a single test.
+
+set -e
+
+docker_compose="docker-compose --file docker-compose.yml"
+
+function cleanup() {
+  $docker_compose down
+}
+
+function die() {
+    echo $@
+    exit 1
+}
+
+trap cleanup EXIT
+
+script/poll-for-db
+
+if [ "$RAILS_ENV" = "test" ] || [ "$RACK_ENV" = "test" ]; then
+  # if executed and the environment is already set to `test`, then we want a
+  # clean from scratch application. This almost always means a ci environment,
+  # since we set the environment to `test` directly in `script/cibuild`.
+  script/setup
+else
+  # if the environment isn't set to `test`, set it to `test` and update the
+  # application to ensure all dependencies are met as well as any other things
+  # that need to be up to date, like db migrations. The environment not having
+  # already been set to `test` almost always means this is being called on its
+  # own from a `development` environment.
+  export RAILS_ENV="test" RACK_ENV="test"
+
+  script/update
+fi
+
+echo "==> Running tests…"
+
+if [ -n "$1" ]; then
+  # pass arguments to test call. This is useful for calling a single test.
+  $docker_compose run web bin/rake test "$1"
+else
+  $docker_compose run web bin/rake test
+fi
+