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https://issues.apache.org/jira/browse/YARN-8523?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16562260#comment-16562260
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Eric Yang commented on YARN-8523:
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There are a couple possible approaches to support docker exec on yarn:
1. System administrator approach:
When system administrator needs to perform same operation on all instances of a
component or service. It is possible to create a YARN cli command to pass
simple docker exec command to targeted components and services. Stdout and
stderr are aggregated, and report back to application master and YARN cli.
This would be similar to kubectl exec on kubernetes. There is no session
persistence to remember the directory, or hot key lookup because there is no
terminal bind to the YARN cli.
2. Developer friendly approach:
The alternative approach is to avoid building this into YARN framework but
depend on docker container to run multi-processes container. This allows sshd
to run inside the docker container. User can use ssh and pdsh to login to the
docker container. Dumb Terminal and hot key can be supported depending on
Linux bits in the docker image.
3. Build a pseudo terminal rewiring to YARN UI:
There are software like [ttyd|https://tsl0922.github.io/ttyd/] that offers
ability to share docker interactive terminal over javascript. It might be
possible to modify the code to interface with container-executor started docker
exec session to provide a full experience.
Option 3 would be fun from research point of view, but it is more practical to
build 1 for diagnosing production problems at scale. Which approach is most
useful to the community?
> Interactive docker shell
> ------------------------
>
> Key: YARN-8523
> URL: https://issues.apache.org/jira/browse/YARN-8523
> Project: Hadoop YARN
> Issue Type: Sub-task
> Reporter: Eric Yang
> Priority: Major
> Labels: Docker
>
> Some application might require interactive unix commands executions to carry
> out operations. Container-executor can interface with docker exec to debug
> or analyze docker containers while the application is running. It would be
> nice to support an API to invoke docker exec to perform unix commands and
> report back the output to application master. Application master can
> distribute and aggregate execution of the commands to record in application
> master log file.
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