Hi there,
DockerContainerizer doesn't support isolators simply because we
delegate all container creation to Docker via docker client, and
therefore we don't have a way to run our isolators that's in
mesos-slave from docker.
We're working on unified containerizer that brings Docker images to
Mesos Containerizer, so you can launch containers with docker images
with it. There is a working initial code that's already in master that
you can try out, and once you have the isolator you can then launch
containers with docker images with your new isolator with
MesosContainerizer.
Tim
On Wed, Nov 25, 2015 at 2:48 AM, Frank Scholten <fr...@frankscholten.nl> wrote:
> Hi all,
>
> We (Frank Scholten and Phil Winder) are currently developing the Mesos
> Flocker framework. As part of this framework we want to develop a
> custom isolator module which interacts with the Flocker Control
> Service.
>
> After creating a simple stub isolator and installing it on one of the
> agents we noticed it gets picked up we run a regular task but it does
> not get picked up when we run a Docker container.
>
> To us it seems that this is because isolators can only be used by the
> MesosContainerizer. The MesosContainerizer configures isolation in its
> create factory method while the DockerContainerizes does not:
>
> MesosContainerizer
>
> Try<MesosContainerizer*> MesosContainerizer::create(
> const Flags& flags,
> bool local,
> Fetcher* fetcher)
> {
> string isolation;
>
> if (flags.isolation == "process") {
> LOG(WARNING) << "The 'process' isolation flag is deprecated, "
> << "please update your flags to"
> << " '--isolation=posix/cpu,posix/mem'.";
>
> isolation = "posix/cpu,posix/mem";
> } else if (flags.isolation == "cgroups") {
> LOG(WARNING) << "The 'cgroups' isolation flag is deprecated, "
> << "please update your flags to"
> << " '--isolation=cgroups/cpu,cgroups/mem'.";
>
> isolation = "cgroups/cpu,cgroups/mem";
> } else {
> isolation = flags.isolation;
> }
>
> DockerContainerizer
>
> Try<DockerContainerizer*> DockerContainerizer::create(
> const Flags& flags,
> Fetcher* fetcher)
> {
> Try<Docker*> create = Docker::create(flags.docker, flags.docker_socket,
> true);
> if (create.isError()) {
> return Error("Failed to create docker: " + create.error());
> }
>
> Shared<Docker> docker(create.get());
>
> if (flags.docker_mesos_image.isSome()) {
> Try<Nothing> validateResult = docker->validateVersion(Version(1, 5, 0));
> if (validateResult.isError()) {
> string message = "Docker with mesos images requires docker 1.5+";
> message += validateResult.error();
> return Error(message);
> }
> }
>
> return new DockerContainerizer(flags, fetcher, docker);
> }
>
> The question now is how can we create an isolator to work together
> with the DockerContainerizer. Should we subclass the
> DockerContainerizer and create a FlockerContainerizer instead? Any
> other suggestions?
>
> Thanks in advance.
>
> Cheers,
>
> Frank and Phil
