Improve status check for pulling an image through docker-swarm - #337
Improve status check for pulling an image through docker-swarm#337hawky-4s- wants to merge 1 commit into
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This should be possible by inherit |
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I followed your suggestion but only changed the implementation of the PullImageResultCallback. It is now able to differentiate between Docker Swarm and Docker Client and adjust it's behavior accordingly. I did this so it is transparent to the user of the api if he's talking to a swarm or client without knowing it in advance. WDYT? |
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How this should work. The first item that doesn't indicate a succesfull pull will lead to pull error.
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Swarm works like so. When you issue a pull cmd, it returns following responses as PullResponseItem for each node in the swarm:
21:38:57.269 DEBUG c.g.d.c.c.PullImageResultCallback - PullResponseItem[stream=<null>,status=Pulling ci1.camunda.loc:5000/camunda-ci-postgresql:9.4...,progressDetail=ResponseItem.ProgressDetail[current=0,total=0,start=0],progress=<null>,id=ci7.camunda.loc,from=<null>,time=0,errorDetail=<null>,error=<null>]
When a pull is successfully for a swarm node following PullResponseItem is returned:
21:39:04.513 DEBUG c.g.d.c.c.PullImageResultCallback - PullResponseItem[stream=<null>,status=Pulling ci1.camunda.loc:5000/camunda-ci-postgresql:9.4... : downloaded,progressDetail=ResponseItem.ProgressDetail[current=0,total=0,start=0],progress=<null>,id=ci3.camunda.loc,from=<null>,time=0,errorDetail=<null>,error=<null>]
There are only these two responses for each swarm node when a pull request is successfull.
My code will first collect all PullResponseItems ordered by node id as key. So only the latest PullResponseItem of each node will be stored, previous ones overwritten.
When the PullImageCmd is finished and awaitSuccess method continues to evaluate the success of the pull, it will check the last result of each node. When one of those results indicates a failed pull, it will throw an exception with all nodes where the pull failed.
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Ok. Now i got it. Thanks!
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Interesting, how this all can be tested... DinD? |
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Shouldn't it be possible to start a swarm manager and a swarm node as containers at the docker host and handle this single docker host as a swarm? This would be the easiest solution... |
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Doesn't swarm do pull on two hosts at once? |
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You can start a swarm manager and point it to the local docker server like |
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@KostyaSha |
It what i mean about tests complexity. (Just curious) |
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Yes, but you could also just start a single swarm master configured to use the same node where it runs as swarm member with the command I provided above. |
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Example debug output from running the pull cmd against a swarm using docker-java: |
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#711 on the way, then your changes should be picked. |
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Trying to pick into swarm branch. Help is welcome. |
This improves the PullImageCmd for docker-swarm because docker-swarm returns a different status line than the normal docker client.
This fix only checks if the last status line returns successfully when pulling through docker-swarm, which means that the pull on the last node was successful. It does not mean the image pull on all swarm nodes went ok.
I do not know how to check this, because to be fully swarm compatible it would be needed to read the last x lines where x is the number of swarm nodes and check them all if the result is successful.
This change is