azagrebin commented on a change in pull request #12131: URL: https://github.com/apache/flink/pull/12131#discussion_r425777456
########## File path: docs/ops/deployment/docker.md ########## @@ -24,119 +24,490 @@ under the License. --> [Docker](https://www.docker.com) is a popular container runtime. -There are Docker images for Apache Flink available on Docker Hub which can be used to deploy a session cluster. -The Flink repository also contains tooling to create container images to deploy a job cluster. +There are Docker images for Apache Flink available [on Docker Hub](https://hub.docker.com/_/flink). +You can use the docker images to deploy a *Session* or *Job cluster* in a containerized environment, e.g., +[standalone Kubernetes](kubernetes.html) or [native Kubernetes](native_kubernetes.html). * This will be replaced by the TOC {:toc} -## Flink session cluster - -A Flink session cluster can be used to run multiple jobs. -Each job needs to be submitted to the cluster after it has been deployed. - -### Docker images +## Docker Hub Flink images The [Flink Docker repository](https://hub.docker.com/_/flink/) is hosted on Docker Hub and serves images of Flink version 1.2.1 and later. -Images for each supported combination of Hadoop and Scala are available, and tag aliases are provided for convenience. +### Image tags -Beginning with Flink 1.5, image tags that omit a Hadoop version (e.g. -`-hadoop28`) correspond to Hadoop-free releases of Flink that do not include a -bundled Hadoop distribution. +Images for each supported combination of Flink and Scala versions are available, and +[tag aliases](https://hub.docker.com/_/flink?tab=tags) are provided for convenience. -For example, the following aliases can be used: *(`1.5.y` indicates the latest -release of Flink 1.5)* +For example, you can use the following aliases: *(`1.11.y` indicates the latest release of Flink 1.11)* * `flink:latest` → `flink:<latest-flink>-scala_<latest-scala>` -* `flink:1.5` → `flink:1.5.y-scala_2.11` -* `flink:1.5-hadoop27` → `flink:1.5.y-hadoop27-scala_2.11` +* `flink:1.11` → `flink:1.11.y-scala_2.11` + +<span class="label label-info">Note</span> Prio to Flink 1.5 version, Hadoop dependencies were always bundled with Flink. +You can see that certain tags include the version of Hadoop, e.g. (e.g. `-hadoop28`). +Beginning with Flink 1.5, image tags that omit the Hadoop version correspond to Hadoop-free releases of Flink +that do not include a bundled Hadoop distribution. + +## How to run Flink image + +The Flink image contains a regular Flink distribution with its default configuration and a standard entry point script. +You can run its entry point in the following modes: +* *Flink Master* for [a Session cluster](#start-a-session-cluster) +* *Flink Master* for [a Single Job cluster](#start-a-single-job-cluster) +* *TaskManager* for any cluster + +This allows you to deploy a standalone cluster (Session or Single Job) in any containerised environment, for example: +* manually in a local docker setup, +* [in a Kubernetes cluster](kubernetes.html), +* [with Docker Compose](#flink-with-docker-compose), +* [with Docker swarm](#flink-with-docker-swarm). + +<span class="label label-info">Note</span> [The native Kubernetes](native_kubernetes.html) also runs the same image by default +and deploys *TaskManagers* on demand so that you do not have to do it manually. + +The next chapters describe how to start a single Flink docker container for various purposes. + +### Start a Session Cluster + +A *Flink Session cluster* can be used to run multiple jobs. Each job needs to be submitted to the cluster after it has been deployed. +To deploy a *Flink Session cluster* with docker, you need to start a *Flink Master* container: + +```sh +docker run flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} jobmanager +``` + +and one or more *TaskManager* containers: + +```sh +docker run flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} taskmanager +``` + +### Start a Job Cluster + +A *Flink Job cluster* is a dedicated cluster which runs a single job. +In this case, you deploy the cluster with the job as one step, thus, there is no extra job submission needed. +Therefore, the *job artifacts* should be already available locally in the container. + +The *job artifacts* are included into the class path of Flink's JVM process within the container and consist of: +* your job jar, which you would normally submit to a *Session cluster* and +* all other necessary dependencies or resources, not included into Flink. + +To deploy a cluster for a single job with docker, you need to +* make *job artifacts* available locally *in all containers* under `/opt/flink/usrlib`, +* start a *Flink Master* container in the *Job Cluster* mode +* start the required number of *TaskManager* containers. + +To make the **job artifacts available** locally in the container, you can + +* **either mount a volume** (or multiple volumes) with the artifacts to `/opt/flink/usrlib` when you start +the *Flink Master* and *TaskManagers*: + + ```sh + docker run \ + --mount type=bind,src=/host/path/to/job/artifacts1,target=/opt/flink/usrlib/artifacts1 \ + --mount type=bind,src=/host/path/to/job/artifacts2,target=/opt/flink/usrlib/artifacts2 \ + flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} standalone-job \ + --job-classname com.job.ClassName \ + --job-id <job id> \ + [--fromSavepoint /path/to/savepoint [--allowNonRestoredState]] \ + [job arguments] + + docker run \ + --mount type=bind,src=/host/path/to/job/artifacts1,target=/opt/flink/usrlib/artifacts1 \ + --mount type=bind,src=/host/path/to/job/artifacts2,target=/opt/flink/usrlib/artifacts2 \ + flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} taskmanager + ``` + +* **or extend the Flink image** by writing a custom `Dockerfile`, build it and use it for starting the *Flink Master* and *TaskManagers*: + + ```dockerfile + FROM flink + ADD /host/path/to/job/artifacts/1 /opt/flink/usrlib/artifacts/1 + ADD /host/path/to/job/artifacts/2 /opt/flink/usrlib/artifacts/2 + ``` + + ```sh + docker build -t flink_with_job_artifacts . + docker run \ + flink_with_job_artifacts standalone-job \ + --job-classname com.job.ClassName \ + --job-id <job id> \ + [--fromSavepoint /path/to/savepoint [--allowNonRestoredState]] \ + [job arguments] + + docker run flink_with_job_artifacts taskmanager + ``` + +The `standalone-job` argument starts a *Flink Master* container in the *Job Cluster* mode. + +#### Flink Master additional command line arguments + +You can provide the following additional command line arguments to the cluster entrypoint: + +* `--job-classname <job class name>`: Class name of the job to run. + + By default, Flink scans its class path for a JAR with a Main-Class or program-class manifest entry and chooses it as the job class. + Use this command line argument to manually set the job class. + This argument is required in case that no or more than one JAR with such a manifest entry is available on the class path. + +* `--job-id <job id>` (optional): Manually set a Flink job ID for the job (default: 00000000000000000000000000000000) + +* `--fromSavepoint /path/to/savepoint` (optional): Restore from a savepoint + + In order to resume from a savepoint, you also need to pass the savepoint path. + Note that `/path/to/savepoint` needs to be accessible in all docker containers of the cluster + (e.g. storing it on a DFS or from the mounted volume or adding it to the image). + +* `--allowNonRestoredState` (optional): Skip broken savepoint state + + Additionally you can specify this argument to allow that savepoint state is skipped which cannot be restored. -**Note:** The Docker images are provided as a community project by individuals -on a best-effort basis. They are not official releases by the Apache Flink PMC. +If the main function of the user job main class accepts arguments, you can also pass them at the end of the `docker run` command. -## Flink job cluster +## Customize Flink image -A Flink job cluster is a dedicated cluster which runs a single job. -The job is part of the image and, thus, there is no extra job submission needed. +When you run the Flink containers, there may be a need to customize them. +The next chapters describe some how-tos of what you can usually customize. -### Docker images +### Configure options -The Flink job cluster image needs to contain the user code jars of the job for which the cluster is started. -Therefore, one needs to build a dedicated container image for every job. -The `flink-container` module contains a `build.sh` script which can be used to create such an image. -Please see the [instructions](https://github.com/apache/flink/blob/{{ site.github_branch }}/flink-container/docker/README.md) for more details. +When you run Flink image, you can also change its configuration options by setting the environment variable `FLINK_PROPERTIES`: + +```sh +FLINK_PROPERTIES="jobmanager.rpc.address: host +taskmanager.numberOfTaskSlots: 3 +blob.server.port: 6124 +" +docker run --env FLINK_PROPERTIES=${FLINK_PROPERTIES} flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} <jobmanager|standalone-job|taskmanager> +``` + +The environment variable `FLINK_PROPERTIES` should contain a list of Flink cluster configuration options separated by new line, +the same way as in the `flink-conf.yaml`. + +### Provide custom configuration + +The configuration files (`flink-conf.yaml`, logging, hosts etc) are located in the `/opt/flink/conf` directory in the Flink image. +To provide a custom location for the Flink configuration files, you can + +* **either mount a volume** with the custom configuration files to this path `/opt/flink/conf` when you run the Flink image: + + ```sh + docker run \ + --mount type=bind,src=/host/path/to/custom/conf,target=/opt/flink/conf \ + flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} <jobmanager|standalone-job|taskmanager> + ``` + +* or add them to your **custom Flink image**, build and run it: + + ```dockerfile + FROM flink + ADD /host/path/to/flink-conf.yaml /opt/flink/conf/flink-conf.yaml + ADD /host/path/to/log4j.properties /opt/flink/conf/log4j.properties + ``` + +<span class="label label-warning">Warning!</span> The mounted volume must contain all necessary configuration files. +The `flink-conf.yaml` file must have write permission so that the docker entry point script can modify it in certain cases. + +### Using plugins -## Using plugins As described in the [plugins]({{ site.baseurl }}/ops/plugins.html) documentation page: in order to use plugins they must be copied to the correct location in the Flink installation for them to work. -When running Flink from one of the provided Docker images by default no plugins have been activated. -The simplest way to enable plugins is to modify the provided official Flink docker images by adding -an additional layer. This does however assume you have a docker registry available where you can push images to and -that is accessible by your cluster. +If you want to enable plugins provided with Flink, you can pass the environment variable `ENABLE_BUILT_IN_PLUGINS` +when you run the Flink image. +The `ENABLE_BUILT_IN_PLUGINS` should contain a list of plugin jar file names separated by `;`. -As an example assume you want to enable the [S3]({{ site.baseurl }}/ops/filesystems/s3.html) plugins in your installation. + ```sh + docker run \ + --env ENABLE_BUILT_IN_PLUGINS=flink-plugin1.jar;flink-plugin2.jar \ + flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} <jobmanager|standalone-job|taskmanager> + ``` -Create a Dockerfile with a content something like this: {% highlight dockerfile %} -# On which specific version of Flink is this based? -# Check https://hub.docker.com/_/flink?tab=tags for current options -FROM flink:{{ site.version }}-scala_2.12 +Otherwise you can use other [advanced methods](#advanced-customization). -# Install Flink S3 FS Presto plugin -RUN mkdir /opt/flink/plugins/s3-fs-presto && cp /opt/flink/opt/flink-s3-fs-presto* /opt/flink/plugins/s3-fs-presto +### Advanced customization -# Install Flink S3 FS Hadoop plugin -RUN mkdir /opt/flink/plugins/s3-fs-hadoop && cp /opt/flink/opt/flink-s3-fs-hadoop* /opt/flink/plugins/s3-fs-hadoop -{% endhighlight %} +If you want to further customize the Flink image, for example, for the following purposes: -Then build and push that image to your registry -{% highlight bash %} -docker build -t docker.example.nl/flink:{{ site.version }}-scala_2.12-s3 . -docker push docker.example.nl/flink:{{ site.version }}-scala_2.12-s3 -{% endhighlight %} +* install custom software (e.g. python) +* enable (symlink) optional libraries or plugins from `/opt/flink/opt` into `/opt/flink/lib` or `/opt/flink/plugins` +* add other libraries to `/opt/flink/lib` (e.g. [hadoop](hadoop.html#adding-hadoop-to-lib)) +* add other plugins to `/opt/flink/plugins` +* override configuration files -Now you can reference this image in your cluster deployment and the installed plugins are available for use. +you can achieve this in several ways: -## Flink with Docker Compose +* **override the container entry point** with a custom script where you can run any bootstrap actions. +At the end you can call the standard `/docker-entrypoint.sh` script of the Flink image with its usual arguments. + + The following example creates a custom entry point script which enables more libraries and plugins. + The custom script, custom library and plugin are provided from a mounted volume. + Then it runs the standard entry point script of the Flink image: + + ```sh + # create custom_lib.jar + # create custom_plugin.jar + + echo " + ln -fs /opt/flink/opt/flink-queryable-state-runtime-*.jar /opt/flink/lib/. # enable an optional library + ln -fs /mnt/custom_lib.jar /opt/flink/lib/. # enable a custom library + + mkdir -p /opt/flink/plugins/flink-s3-fs-hadoop + ln -fs /opt/flink/opt/flink-s3-fs-hadoop-*.jar /opt/flink/plugins/flink-s3-fs-hadoop/. # enable an optional plugin + + mkdir -p /opt/flink/plugins/custom_plugin + ln -fs /mnt/custom_plugin.jar /opt/flink/plugins/custom_plugin/. # enable a custom plugin + + /docker-entrypoint.sh <jobmanager|standalone-job|taskmanager> + " > custom_entry_point_script.sh + + chmod 755 custom_entry_point_script.sh -[Docker Compose](https://docs.docker.com/compose/) is a convenient way to run a -group of Docker containers locally. + docker run \ + --mount type=bind,src=$(pwd),target=/mnt + flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} /mnt/custom_entry_point_script.sh + ``` -Example config files for a [session cluster](https://github.com/docker-flink/examples/blob/master/docker-compose.yml) and a [job cluster](https://github.com/apache/flink/blob/{{ site.github_branch }}/flink-container/docker/docker-compose.yml) -are available on GitHub. +* **extend the Flink image** by writing a custom `Dockerfile` and build a custom image: + + ```dockerfile + FROM flink + + RUN set -ex; apt-get update; apt-get -y install python + + ADD /host/path/to/flink-conf.yaml /container/local/path/to/custom/conf/flink-conf.yaml + ADD /host/path/to/log4j.properties /container/local/path/to/custom/conf/log4j.properties + + RUN ln -fs /opt/flink/opt/flink-queryable-state-runtime-*.jar /opt/flink/lib/. + + RUN mkdir -p /opt/flink/plugins/flink-s3-fs-hadoop + RUN ln -fs /opt/flink/opt/flink-s3-fs-hadoop-*.jar /opt/flink/plugins/flink-s3-fs-hadoop/. + + ENV VAR_NAME value + ``` + + ```sh + docker build -t custom_flink_image . + # optional push to your docker image registry if you have it, + # e.g. to distribute the custom image to your cluster + docker push custom_flink_image + ``` + +{% top %} + +## Flink with Docker Compose + +[Docker Compose](https://docs.docker.com/compose/) is a way to run a group of Docker containers locally. +The next chapters show examples of configuration files to run Flink. ### Usage +* Create the `yaml` files with the container configuration, check examples for: + * [Session cluster](#session-cluster-with-docker-compose) + * [Single Job](#single-job-cluster-with-docker-compose) + + See also [the Flink docker image tags](#image-tags) and [how to customize the Flink docker image](#advanced-customization) + for usage in the configuration files. + * Launch a cluster in the foreground - docker-compose up + ```sh + docker-compose up + ``` * Launch a cluster in the background - docker-compose up -d + ```sh + docker-compose up -d + ``` -* Scale the cluster up or down to *N* TaskManagers +* Scale the cluster up or down to *N TaskManagers* - docker-compose scale taskmanager=<N> + ```sh + docker-compose scale taskmanager=<N> + ``` -* Kill the cluster +* Access the *Flink Master* container - docker-compose kill + ```sh + docker exec -it $(docker ps --filter name=jobmanager --format={{.ID}}) /bin/sh + ``` -When the cluster is running, you can visit the web UI at [http://localhost:8081](http://localhost:8081). -You can also use the web UI to submit a job to a session cluster. +* Kill the cluster -To submit a job to a session cluster via the command line, you must copy the JAR to the JobManager -container and submit the job from there. + ```sh + docker-compose kill + ``` + +* Access Web UI + + When the cluster is running, you can visit the web UI at [http://localhost:8081](http://localhost:8081). + You can also use the web UI to submit a job to a *Session cluster*. + +* To submit a job to a *Session cluster* via the command line, you must copy the JAR to the *Flink Master* container and +submit the job from there. For example: + + ```sh + JOB_CLASS_NAME="com.job.ClassName" + MASTER_CONTAINER=$(docker ps --filter name=jobmanager --format={{.ID}}) + docker cp path/to/jar "${MASTER_CONTAINER}":/job.jar + docker exec -t -i "${MASTER_CONTAINER}" flink run -d -c ${JOB_CLASS_NAME} /job.jar + ``` + +### Session Cluster with Docker Compose + +```yaml +version: "2.2" +services: + jobmanager: + image: flink:{% if site.is_stable %}{{site.version}}-scala{{site.scala_version_suffix}}{% else %}latest{% endif %} + ports: + - "8081:8081" + command: jobmanager + environment: + - | + FLINK_PROPERTIES= + jobmanager.rpc.address: jobmanager + taskmanager.numberOfTaskSlots: 2 Review comment: asaik, it only matters for active integrations atm, not for standalone, but it does not hurt and who knows future. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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