Run tests using Docker-in-Docker so we can test multiple versions

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

CONTRIBUTING.md

@@ -24,8 +24,21 @@ that should get you started.
 
 ## Running the test suite
 
+Use the test script to run linting checks and then the full test suite:
+
     $ script/test
 
+Tests are run against a Docker daemon inside a container, so that we can test against multiple Docker versions. By default they'll run against only the latest Docker version - set the `DOCKER_VERSIONS` environment variable to "all" to run against all supported versions:
+
+    $ DOCKER_VERSIONS=all script/test
+
+Arguments to `script/test` are passed through to the `nosetests` executable, so you can specify a test directory, file, module, class or method:
+
+    $ script/test tests/unit
+    $ script/test tests/unit/cli_test.py
+    $ script/test tests.integration.service_test
+    $ script/test tests.integration.service_test:ServiceTest.test_containers
+
 ## Building binaries
 
 Linux:

Dockerfile

@@ -1,5 +1,18 @@
 FROM debian:wheezy
-RUN apt-get update -qq && apt-get install -qy python python-pip python-dev git && apt-get clean
+
+RUN apt-get update -qq
+
+# Compose dependencies
+RUN apt-get install -qqy python python-pip python-dev git
+
+# Test dependencies
+RUN apt-get install -qqy apt-transport-https ca-certificates curl lxc iptables
+RUN curl https://get.docker.com/builds/Linux/x86_64/docker-1.3.3 > /usr/local/bin/docker-1.3.3 && chmod +x /usr/local/bin/docker-1.3.3
+RUN curl https://get.docker.com/builds/Linux/x86_64/docker-1.4.1 > /usr/local/bin/docker-1.4.1 && chmod +x /usr/local/bin/docker-1.4.1
+RUN curl https://get.docker.com/builds/Linux/x86_64/docker-1.5.0 > /usr/local/bin/docker-1.5.0 && chmod +x /usr/local/bin/docker-1.5.0
+
+RUN apt-get clean
+
 RUN useradd -d /home/user -m -s /bin/bash user
 WORKDIR /code/
 

Dockerfile.tests

@@ -0,0 +1,5 @@
+FROM docker-compose
+
+ADD script/wrapdocker /usr/local/bin/wrapdocker
+VOLUME /var/lib/docker
+ENTRYPOINT ["/usr/local/bin/wrapdocker"]

script/test

@@ -1,5 +1,19 @@
-#!/bin/sh
+#!/bin/bash
+# See CONTRIBUTING.md for usage.
+
 set -ex
+
 docker build -t docker-compose .
-docker run -v /var/run/docker.sock:/var/run/docker.sock --rm --entrypoint flake8 docker-compose compose
-docker run -v /var/run/docker.sock:/var/run/docker.sock --rm --entrypoint nosetests docker-compose $@
+docker run --privileged --rm --entrypoint flake8 docker-compose compose
+
+docker build -f Dockerfile.tests -t docker-compose-tests .
+
+if [ "$DOCKER_VERSIONS" == "" ]; then
+  DOCKER_VERSIONS="1.5.0"
+elif [ "$DOCKER_VERSIONS" == "all" ]; then
+  DOCKER_VERSIONS="1.3.3 1.4.1 1.5.0"
+fi
+
+for version in $DOCKER_VERSIONS; do
+  docker run --privileged --rm -e "DOCKER_VERSION=$version" docker-compose-tests nosetests "$@"
+done

script/wrapdocker

@@ -0,0 +1,98 @@
+#!/bin/bash
+# Adapted from https://github.com/jpetazzo/dind
+
+# First, make sure that cgroups are mounted correctly.
+CGROUP=/sys/fs/cgroup
+: {LOG:=stdio}
+
+[ -d $CGROUP ] || 
+	mkdir $CGROUP
+
+mountpoint -q $CGROUP || 
+	mount -n -t tmpfs -o uid=0,gid=0,mode=0755 cgroup $CGROUP || {
+		echo "Could not make a tmpfs mount. Did you use --privileged?"
+		exit 1
+	}
+
+if [ -d /sys/kernel/security ] && ! mountpoint -q /sys/kernel/security
+then
+    mount -t securityfs none /sys/kernel/security || {
+        echo "Could not mount /sys/kernel/security."
+        echo "AppArmor detection and --privileged mode might break."
+    }
+fi
+
+# Mount the cgroup hierarchies exactly as they are in the parent system.
+for SUBSYS in $(cut -d: -f2 /proc/1/cgroup)
+do
+        [ -d $CGROUP/$SUBSYS ] || mkdir $CGROUP/$SUBSYS
+        mountpoint -q $CGROUP/$SUBSYS || 
+                mount -n -t cgroup -o $SUBSYS cgroup $CGROUP/$SUBSYS
+
+        # The two following sections address a bug which manifests itself
+        # by a cryptic "lxc-start: no ns_cgroup option specified" when
+        # trying to start containers withina container.
+        # The bug seems to appear when the cgroup hierarchies are not
+        # mounted on the exact same directories in the host, and in the
+        # container.
+
+        # Named, control-less cgroups are mounted with "-o name=foo"
+        # (and appear as such under /proc/<pid>/cgroup) but are usually
+        # mounted on a directory named "foo" (without the "name=" prefix).
+        # Systemd and OpenRC (and possibly others) both create such a
+        # cgroup. To avoid the aforementioned bug, we symlink "foo" to
+        # "name=foo". This shouldn't have any adverse effect.
+        echo $SUBSYS | grep -q ^name= && {
+                NAME=$(echo $SUBSYS | sed s/^name=//)
+                ln -s $SUBSYS $CGROUP/$NAME
+        }
+
+        # Likewise, on at least one system, it has been reported that
+        # systemd would mount the CPU and CPU accounting controllers
+        # (respectively "cpu" and "cpuacct") with "-o cpuacct,cpu"
+        # but on a directory called "cpu,cpuacct" (note the inversion
+        # in the order of the groups). This tries to work around it.
+        [ $SUBSYS = cpuacct,cpu ] && ln -s $SUBSYS $CGROUP/cpu,cpuacct
+done
+
+# Note: as I write those lines, the LXC userland tools cannot setup
+# a "sub-container" properly if the "devices" cgroup is not in its
+# own hierarchy. Let's detect this and issue a warning.
+grep -q :devices: /proc/1/cgroup ||
+	echo "WARNING: the 'devices' cgroup should be in its own hierarchy."
+grep -qw devices /proc/1/cgroup ||
+	echo "WARNING: it looks like the 'devices' cgroup is not mounted."
+
+# Now, close extraneous file descriptors.
+pushd /proc/self/fd >/dev/null
+for FD in *
+do
+	case "$FD" in
+	# Keep stdin/stdout/stderr
+	[012])
+		;;
+	# Nuke everything else
+	*)
+		eval exec "$FD>&-"
+		;;
+	esac
+done
+popd >/dev/null
+
+if [ "$DOCKER_VERSION" == "" ]; then
+    DOCKER_VERSION="1.5.0"
+fi
+
+ln -s "/usr/local/bin/docker-$DOCKER_VERSION" "/usr/local/bin/docker"
+
+# If a pidfile is still around (for example after a container restart),
+# delete it so that docker can start.
+rm -rf /var/run/docker.pid
+docker -d $DOCKER_DAEMON_ARGS &>/var/log/docker.log &
+
+>&2 echo "Waiting for Docker to start..."
+while ! docker ps &>/dev/null; do
+    sleep 1
+done
+
+exec "$@"