Adding a Makefile and basic tests.

This approach uses bats to create a generic docker-compose test. It
checks that images are pullable, projects are buildable, up works, and
if ports are exposed that something is listening.

The tests can be tailored for each example. As long as they are the same
though, you can edit lib/test.bats.example and then `make update-tests`
and all the tests will be synced.

Signed-off-by: Chad Metcalf <chad@docker.com>

nginx-golang-postgres/test.bats

@@ -0,0 +1,60 @@
+#!/usr/bin/env bats
+
+load '../lib/test_helper.bash'
+
+cd ${BATS_TEST_DIRNAME}
+
+function setup_file() {
+    check_deps
+    compose_cleanup
+}
+
+function teardown_file() {
+    compose_cleanup
+}
+
+@test "$(basename ${BATS_TEST_DIRNAME}): pull check" {
+    run docker-compose pull
+    [ "${status}" -eq 0 ]
+}
+
+@test "$(basename ${BATS_TEST_DIRNAME}): build check" {
+    run docker-compose build
+     [ "${status}" -eq 0 ]
+}
+
+@test "$(basename ${BATS_TEST_DIRNAME}): up check" {
+    run docker-compose up -d
+    [ "${status}" -eq 0  ]
+
+}
+
+@test "$(basename ${BATS_TEST_DIRNAME}): ports check" {
+
+    for service in $(docker-compose ps -q); do
+
+        # simple test to check that any exposed port has something actually listening
+        # assumes format 22/tcp, 0.0.0.0:3000->3000/tcp
+        ports_string=$(docker ps --filter="ID=${service}" --format "{{.Ports}}")
+
+        OIFS=${IFS}; IFS=','; service_port=($ports_string); IFS=${OIFS}; unset OIFS;
+
+        for i in ${service_port[@]}; do
+
+            protocol=$(expr match ${i} '.*\(tcp\|udp\)')
+
+            # the || true here just makes sure bats doesn't fail the test because a
+            # port wasn't matched. We will check for empty ports later
+            port=$(expr match ${i} '.*:\([0-9]*\)->' || true)
+
+            if [[ ${protocol} == "tcp" ]] && [[ ! -z ${port} ]]; then
+                run nc -z -v localhost ${port}
+                [ "${status}" -eq 0  ]
+            elif [[ "${protocol}" = "udp" ]] && [[ ! -z ${port} ]]; then
+                run nc -z -v -u localhost ${port}
+                [ "${status}" -eq 0  ]
+            fi
+
+        done
+    done
+}