So currently there is a review out for pre-hooks ( https://reviews.apache.org/r/36185/) before a docker container launches.
We can also add a post hook, but like to see if the specified hook satifies what you guys are looking for. Tim On Tue, Aug 11, 2015 at 4:28 PM, Tom Fordon <[email protected]> wrote: > We ended up implementing a solution where we did the pre/post steps as > separate mesos tasks and adding logic to our scheduler to ensure they were > run on the same machine. If anybody knows of a standard / openly available > DockerExecutor like what is described below, my team would be greatly > interested. > > > On Fri, Aug 7, 2015 at 4:01 AM, Kapil Malik <[email protected]> wrote: > >> Hi, >> >> >> >> We have a similar usecase while running multi-user workloads on mesos. >> Users provide docker images encapsulating application logic, which we (we = >> say some “Central API”) schedule on Chronos / Marathon. However, we need to >> run some standard pre / post steps for every docker submitted by users. We >> have following options – >> >> >> >> 1. Ask every user to embed their logic inside a pre-defined docker >> template which will perform pre/post steps. >> >> è This is error prone, makes us dependent on whether the users followed >> template, and not very popular with users either. >> >> >> >> 2. Extend every user docker (FROM <>) and find a way to add >> pre-post steps in our docker. Refer this docker when scheduling on chronos >> / marathon. >> >> è Building new dockers does not scale as users and applications grow >> >> >> >> 3. Write a custom executor which will perform the pre-post steps >> and manage the user docker lifetime. >> >> è Deals with user docker lifetime and is obviously complex. >> >> >> >> Is there a standard / openly available DockerExecutor which manages the >> docker lifetime and which I can extend to build my custom executor? This >> way I will be concerned only with my custom logic (pre/post steps) and >> still get benefits of a standard way to manage docker containers. >> >> >> >> Btw, thanks for the meaningful discussion below, it is very helpful. >> >> >> >> Thanks and regards, >> >> >> >> Kapil Malik | [email protected] | 33430 / 8800836581 >> >> >> >> *From:* James DeFelice [mailto:[email protected]] >> *Sent:* 09 April 2015 18:12 >> *To:* [email protected] >> *Subject:* Re: Custom python executor with Docker >> >> >> >> If you can run the pre/post steps in a container then I'd recommend >> building a Docker image that includes your pre/post step scripting + your >> algorithm and launching it using the built-in mesos Docker containerizer. >> It's much simpler than managing the lifetime of the Docker container >> yourself. >> >> >> >> On Thu, Apr 9, 2015 at 8:29 AM, Tom Fordon <[email protected]> wrote: >> >> Thanks for all the responses, I really appreciate the help. Let me try >> to state my problem more clearly >> >> >> >> Our project is performing file-based data processing. I would like to >> keep the actual algorithm as contained as possible since we are in an R&D >> setting and will be getting untested code. We have some pre/post steps >> that need to be run on the same box as the actual algorithm: >> downloading/uploading files and database calls. >> >> >> >> We can run the pre/post steps and algorithm within the same container. >> The algorithm will be a little less contained, but it will work. >> >> >> >> Docker letting you specify a cgroup parent is really exciting. If I >> invoke a docker container with the executor as the cgroup-parent are there >> any other steps I need to perform? Would I need to do anything special to >> make mesos aware of the resource usage, or is that handled since the docker >> process would be in the executors cgroup? >> >> >> >> Thanks again, >> >> Tom >> >> >> >> On Tue, Apr 7, 2015 at 8:10 PM, Timothy Chen <[email protected]> wrote: >> >> Hi Tom(s), >> >> Tom Arnfeld is right, if you want to launch your own docker container >> in your custom executor you will have to handle all the issues >> yourself and not able to use the Docker containerizer at all. >> >> Alternatively, you can actually launch your custom executor in a >> Docker container by Mesos, by specifying the ContainerInfo in the >> ExecutorInfo. >> What this means is that your custom executor is already running in a >> docker container, and you can do your custom logic afterwards. This >> does means you can simply just launch multiple containers in the >> executor anymore. >> >> If there is something you want to do and doesnt' fit these let us know >> what you're trying to achieve and we can see what we can do. >> >> Tim >> >> On Tue, Apr 7, 2015 at 4:15 PM, Tom Arnfeld <[email protected]> wrote: >> >> > It's not possible to invoke the docker containerizer from outside of >> Mesos, >> > as far as I know. >> > >> > If you persue this route, you can run into issues with orphaned >> containers >> > as your executor may die for some unknown reason, and the container is >> still >> > running. Recovering from this can be tricky business, so it's better if >> you >> > can adapt your framework design to fit within the Mesos Task/Executor >> > pattern. >> > >> > -- >> > >> > Tom Arnfeld >> > Developer // DueDil >> > >> > (+44) 7525940046 >> > 25 Christopher Street, London, EC2A 2BS >> > >> > >> > On Mon, Apr 6, 2015 at 7:00 PM, Vinod Kone <[email protected]> >> wrote: >> >> >> >> Tim, do you want answer this? >> >> >> >> On Wed, Apr 1, 2015 at 7:27 AM, Tom Fordon <[email protected]> >> wrote: >> >>> >> >>> Hi. I'm trying to understand using docker within a custom executor. >> For >> >>> each of my tasks, I would like to perform some steps on the node >> before >> >>> launching a docker container. I was planning on writing a custom >> python >> >>> executor for this, but I wasn't sure how to launch docker from within >> this >> >>> executor. >> >>> >> >>> Can I just call docker in a subprocess using the ContainerInfo from >> the >> >>> Task? If I do this, how does the Containerizer fit in? >> >>> >> >>> Thank you, >> >>> Tom Fordon >> >> >> >> >> > >> >> >> >> >> >> >> >> -- >> >> James DeFelice >> 585.241.9488 (voice) >> 650.649.6071 (fax) >> > >
