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docker image tags and force pull image clarification of behavior in docs

Open daluu opened this issue 8 years ago • 2 comments

It's not quite clear reading the chronos doc:

https://mesos.github.io/chronos/docs/api.html#adding-a-docker-job

Mesos 0.22.0 added support for forcibly pulling the latest version of your Docker image before launching the task, and this behavior can be enabled in Chronos by adding the forcePullImage boolean to your container configuration.

Chronos will default to not doing a docker pull if the image is already found on the executing node. The alternative approach is to use versions/tags for your images.

Regarding these statements:

  1. What happens if one specifies a tag along with the image and sets forcePullImage true? It pulls for latest version of that tagged image, or ignores the tag and goes for "latest" tag version? I assume one generally uses forcePullImage with no tags specified or use tags and not forcePullImage but not both?
  2. What does the above Chronos "default" statement mean? Does it mean behavior when forcePullImage is false? Or does it mean even with that setting true, if an (older) "latest" tag of the image is found on the executing node locally, then it will not force pull a more recent latest tagged image?

It would be nice to better clarify/reword the statements that a novice beginner understands this "crystal" clear.

daluu avatar Oct 13 '16 23:10 daluu

I have a similar question. I have multiple tagged docker images. However, chronos seem to be ignoring the tag and always fetching the "latest" tag version. My setup has Mesos 1.0.1 and Chronos 2.4.0.

systemhalted avatar Jun 16 '17 03:06 systemhalted

+1

julienlau avatar Jun 19 '17 16:06 julienlau