add test suite. See #197

This test suite is implemented using [bats](https://github.com/sstephenson/bats).

Not all features are tested. For instance ssl features and custom nginx config are missing. Probably others.

This test suite won't work with TravisCI. Too many evenings were wasted trying to overcome [issues](http://stackoverflow.com/questions/32846800/travis-fails-to-stop-docker-containers) that arises only on the TravisCI platform. However it runs on [CircleCI](https://circleci.com) which is also free for opensource projects.

test/multiple-ports.bats

@@ -0,0 +1,54 @@
+#!/usr/bin/env bats
+load test_helpers
+SUT_CONTAINER=bats-nginx-proxy-${TEST_FILE}
+
+function setup {
+	# make sure to stop any web container before each test so we don't
+	# have any unexpected contaiener running with VIRTUAL_HOST or VIRUTAL_PORT set
+	docker ps -q --filter "label=bats-type=web" | xargs -r docker stop >&2
+}
+
+
+@test "[$TEST_FILE] start a nginx-proxy container" {
+	# GIVEN nginx-proxy
+	run nginxproxy $SUT_CONTAINER -v /var/run/docker.sock:/tmp/docker.sock:ro
+	assert_success
+	docker_wait_for_log $SUT_CONTAINER 3 "Watching docker events"
+}
+
+
+@test "[$TEST_FILE] nginx-proxy defaults to the service running on port 80" {
+	# WHEN
+	prepare_web_container bats-web-${TEST_FILE}-1 "80 90" -e VIRTUAL_HOST=web.bats
+
+	# THEN 
+	assert_response_is_from_port 80
+}
+
+
+@test "[$TEST_FILE] VIRTUAL_PORT=90 while port 80 is also exposed" {
+	# GIVEN
+	prepare_web_container bats-web-${TEST_FILE}-2 "80 90" -e VIRTUAL_HOST=web.bats -e VIRTUAL_PORT=90
+
+	# THEN 
+	assert_response_is_from_port 90
+}
+
+
+@test "[$TEST_FILE] single exposed port != 80" {
+	# GIVEN
+	prepare_web_container bats-web-${TEST_FILE}-3 1234 -e VIRTUAL_HOST=web.bats
+
+	# THEN 
+	assert_response_is_from_port 1234
+}
+
+
+# assert querying nginx-proxy provides a response from the expected port of the web container
+# $1 port we are expecting an response from
+function assert_response_is_from_port {
+	local -r port=$1
+	run curl_container $SUT_CONTAINER /data --header "Host: web.bats"
+	assert_output "answer from port $port"
+}
+