Hi Sam, You're a wizard - this got me *way* farther than my previous attempts. Here's a PR https://github.com/sambvfx/beam-flink-k8s/pull/1 with a couple of changes I had to make.
I had to make some additional changes that do not make sense to share, but here they are for the record: - Because I'm running on k8s engine and not minikube, I had to put the docker-flink image on GCR, changing flink.yaml "image: docker-flink:1.10" -> "image: us.gcr.io/$PROJECT_ID/docker-flink:1.10". I of course also had to build and push the container. - Because I'm running with a custom container based on an unreleased version of Beam, I had to push my custom container to GCR too, and change your instructions to use that image name instead of the default one - To fetch the containers from GCR, I had to log into Docker inside the Flink nodes, specifically inside the taskmanager container, using something like "kubectl exec pod/flink-taskmanager-blahblah -c taskmanager -- docker login -u oauth2accesstoken --password $(gcloud auth print-access-token)" - Again because I'm using an unreleased Beam SDK (due to a bug whose fix will be released in 2.24), I had to also build a custom Flink job server jar and point to it via --flink_job_server_jar. In the end, I got my pipeline to start, create the uber jar (about 240MB in size), take a few minutes to transmit it to Flink (which is a long time, but it'll do for a prototype); the Flink UI was displaying the pipeline, and was able to *start* the worker container - however it quickly failed with the following error: 2020/08/28 15:49:09 Initializing python harness: /opt/apache/beam/boot --id=1-1 --provision_endpoint=localhost:45111 2020/08/28 15:49:09 Failed to retrieve staged files: failed to get manifest caused by: rpc error: code = Unimplemented desc = Method not found: org.apache.beam.model.job_management.v1.LegacyArtifactRetrievalService/GetManifest (followed by a bunch of other garbage) I'm assuming this might be because I got tangled in my custom images related to the unreleased Beam SDK, and should be fixed if running on clean Beam 2.24. Thank you again! On Fri, Aug 28, 2020 at 10:21 AM Eugene Kirpichov <ekirpic...@gmail.com> wrote: > Holy shit, thanks Sam, this is more help than I could have asked for!! > I'll give this a shot later today and report back. > > On Thu, Aug 27, 2020 at 10:27 PM Sam Bourne <samb...@gmail.com> wrote: > >> Hi Eugene! >> >> I’m struggling to find complete documentation on how to do this. There >> seems to be lots of conflicting or incomplete information: several ways to >> deploy Flink, several ways to get Beam working with it, bizarre >> StackOverflow questions, and no documentation explaining a complete working >> example. >> >> This *is* possible and I went through all the same frustrations of >> sparse and confusing documentation. I’m glossing over a lot of details, but >> the key thing was setting up the flink taskworker(s) to run docker. This >> requires running docker-in-docker as the taskworker itself is a docker >> container in k8s. >> >> First create a custom flink container with docker: >> >> # docker-flink Dockerfile >> >> FROM flink:1.10 >> # install docker >> RUN apt-get ... >> >> Then setup the taskmanager deployment to use a sidecar docker-in-docker >> service. This dind service is where the python sdk harness container >> actually runs. >> >> kind: Deployment >> ... >> containers: >> - name: docker >> image: docker:19.03.5-dind >> ... >> - name: taskmanger >> image: myregistry:5000/docker-flink:1.10 >> env: >> - name: DOCKER_HOST >> value: tcp://localhost:2375 >> ... >> >> I quickly threw all these pieces together in a repo here: >> https://github.com/sambvfx/beam-flink-k8s >> >> I added a working (via minikube) step-by-step in the README to prove to >> myself that I didn’t miss anything, but feel free to submit any PRs if you >> want to add anything useful. >> >> The documents you linked are very informative. It would be great to >> aggregate all this into digestible documentation. Let me know if you have >> any further questions! >> >> Cheers, >> Sam >> >> On Thu, Aug 27, 2020 at 10:25 AM Eugene Kirpichov <ekirpic...@gmail.com> >> wrote: >> >>> Hi Kyle, >>> >>> Thanks for the response! >>> >>> On Wed, Aug 26, 2020 at 5:28 PM Kyle Weaver <kcwea...@google.com> wrote: >>> >>>> > - With the Flink operator, I was able to submit a Beam job, but hit >>>> the issue that I need Docker installed on my Flink nodes. I haven't yet >>>> tried changing the operator's yaml files to add Docker inside them. >>>> >>>> Running Beam workers via Docker on the Flink nodes is not recommended >>>> (and probably not even possible), since the Flink nodes are themselves >>>> already running inside Docker containers. Running workers as sidecars >>>> avoids that problem. For example: >>>> https://github.com/GoogleCloudPlatform/flink-on-k8s-operator/blob/master/examples/beam/with_job_server/beam_flink_cluster.yaml#L17-L20 >>>> >>>> The main problem with the sidecar approach is that I can't use the >>> Flink cluster as a "service" for anybody to submit their jobs with custom >>> containers - the container version is fixed. >>> Do I understand it correctly? >>> Seems like the Docker-in-Docker approach is viable, and is mentioned in >>> the Beam Flink K8s design doc >>> <https://docs.google.com/document/d/1z3LNrRtr8kkiFHonZ5JJM_L4NWNBBNcqRc_yAf6G0VI/edit#heading=h.dtj1gnks47dq> >>> . >>> >>> >>>> > I also haven't tried this >>>> <https://github.com/GoogleCloudPlatform/flink-on-k8s-operator/blob/master/docs/beam_guide.md> >>>> yet >>>> because it implies submitting jobs using "kubectl apply" which is weird - >>>> why not just submit it through the Flink job server? >>>> >>>> I'm guessing it goes through k8s for monitoring purposes. I see no >>>> reason it shouldn't be possible to submit to the job server directly >>>> through Python, network permitting, though I haven't tried this. >>>> >>>> >>>> >>>> On Wed, Aug 26, 2020 at 4:10 PM Eugene Kirpichov <ekirpic...@gmail.com> >>>> wrote: >>>> >>>>> Hi folks, >>>>> >>>>> I'm still working with Pachama <https://pachama.com/> right now; we >>>>> have a Kubernetes Engine cluster on GCP and want to run Beam Python batch >>>>> pipelines with custom containers against it. >>>>> Flink and Cloud Dataflow are the two options; Cloud Dataflow doesn't >>>>> support custom containers for batch pipelines yes so we're going with >>>>> Flink. >>>>> >>>>> I'm struggling to find complete documentation on how to do this. There >>>>> seems to be lots of conflicting or incomplete information: several ways to >>>>> deploy Flink, several ways to get Beam working with it, bizarre >>>>> StackOverflow questions, and no documentation explaining a complete >>>>> working >>>>> example. >>>>> >>>>> == My requests == >>>>> * Could people briefly share their working setup? Would be good to >>>>> know which directions are promising. >>>>> * It would be particularly helpful if someone could volunteer an hour >>>>> of their time to talk to me about their working Beam/Flink/k8s setup. It's >>>>> for a good cause (fixing the planet :) ) and on my side I volunteer to >>>>> write up the findings to share with the community so others suffer less. >>>>> >>>>> == Appendix: My findings so far == >>>>> There are multiple ways to deploy Flink on k8s: >>>>> - The GCP marketplace Flink operator >>>>> <https://cloud.google.com/blog/products/data-analytics/open-source-processing-engines-for-kubernetes> >>>>> (couldn't >>>>> get it to work) and the respective CLI version >>>>> <https://github.com/GoogleCloudPlatform/flink-on-k8s-operator> (buggy, >>>>> but I got it working) >>>>> - https://github.com/lyft/flinkk8soperator (haven't tried) >>>>> - Flink's native k8s support >>>>> <https://ci.apache.org/projects/flink/flink-docs-release-1.10/ops/deployment/native_kubernetes.html> >>>>> (super >>>>> easy to get working) >>>>> <https://ci.apache.org/projects/flink/flink-docs-release-1.10/ops/deployment/native_kubernetes.html> >>>>> >>>>> I confirmed that my Flink cluster was operational by running a simple >>>>> Wordcount job, initiated from my machine. However I wasn't yet able to get >>>>> Beam working: >>>>> >>>>> - With the Flink operator, I was able to submit a Beam job, but hit >>>>> the issue that I need Docker installed on my Flink nodes. I haven't yet >>>>> tried changing the operator's yaml files to add Docker inside them. I also >>>>> haven't tried this >>>>> <https://github.com/GoogleCloudPlatform/flink-on-k8s-operator/blob/master/docs/beam_guide.md> >>>>> yet because it implies submitting jobs using "kubectl apply" which is >>>>> weird - why not just submit it through the Flink job server? >>>>> >>>>> - With Flink's native k8s support, I tried two things: >>>>> - Creating a fat portable jar using --output_executable_path. The >>>>> jar is huge (200+MB) and takes forever to upload to my Flink cluster - >>>>> this >>>>> is a non-starter. But if I actually upload it, then I hit the same issue >>>>> with lacking Docker. Haven't tried fixing it yet. >>>>> - Simply running my pipeline --runner=FlinkRunner >>>>> --environment_type=DOCKER --flink_master=$PUBLIC_IP:8081. The Java process >>>>> appears to send 1+GB of data to somewhere, but the job never even starts. >>>>> >>>>> I looked at a few conference talks: >>>>> - >>>>> https://www.cncf.io/wp-content/uploads/2020/02/CNCF-Webinar_-Apache-Flink-on-Kubernetes-Operator-1.pdf >>>>> - seems to imply that I need to add a Beam worker "sidecar" to the Flink >>>>> workers; and that I need to submit my job using "kubectl apply". >>>>> - https://www.youtube.com/watch?v=8k1iezoc5Sc which also mentions the >>>>> sidecar, but also mentions the fat jar option >>>>> >>>>> -- >>>>> Eugene Kirpichov >>>>> http://www.linkedin.com/in/eugenekirpichov >>>>> >>>> >>> >>> -- >>> Eugene Kirpichov >>> http://www.linkedin.com/in/eugenekirpichov >>> >> > > -- > Eugene Kirpichov > http://www.linkedin.com/in/eugenekirpichov > -- Eugene Kirpichov http://www.linkedin.com/in/eugenekirpichov
