Unexpected parameter is passed to docker run option --entrypoint

[DanielXiao]

Summary

docker run --entrypoint take unexpected parameters.

Environment information

vSphere and vCenter Server version

vSphere 6.7

VIC version

1.4.3 and 1.5.0

VCH configuration

./bin/vic-machine-linux create --name=v150-photon-2 --target 10.161.93.246 --user 'administrator@vsphere.local' --password 'Admin!23' --image-store=sharedVmfs-0 --compute-resource=/dc1/host/cls/Resources --public-network=management --volume-store sharedVmfs-0/v150-photon-2:default --bridge-network bridge --bridge-network-range 192.168.0.0/16 --container-network vm-network --thumbprint 'BF:68:A6:73:B4:D3:62:A9:21:3E:B0:73:B8:A2:25:2A:31:41:86:C0' --no-tlsverify

Details

When you add --entrypoint to run a container without entrypoint instruction of its Dockerfile, CMD instruction is passed as arguments: docker -H 10.161.90.47:2376 --tls run --entrypoint=/bin/date busybox date: invalid date 'sh'

When you add --entrypoint to overwrite entrypoint instruction of the container 's Dockerfile, image name is passed as arguments: docker -H 10.161.90.159:2376 --tls run -it --entrypoint /bin/sh postgres /bin/sh: 0: Can't open postgres

Steps to reproduce

Run busybox with following command: docker -H :2376 --tls run --entrypoint=/bin/date busybox

Run postgres with following command: docker -H :2376 --tls run -it --entrypoint /bin/sh postgres

Below are results of a docker engine: docker run --entrypoint=/bin/date busybox Mon Oct 29 05:55:02 UTC 2018

docker run -it --entrypoint /bin/sh postgres Enter sh prompt.

Actual behavior

1. date: invalid date 'sh'

2. /bin/sh: 0: Can't open postgres

Expected behavior

1. Show date command output.

2. Enter sh prompt without any parameter.

   Logs

   Troubleshooting attempted

   • [ ] Searched GitHub for existing issues. (Mention any similar issues under "See also", above.)
   • [ ] Searched the documentation for relevant troubleshooting guidance.
   • [ ] Searched for a relevant VMware KB article.

[hickeng]

This is surprising tbh - we'd have to go way back in time to determine if this was always a problem or a change in behavior that we missed. We can easily work around for this case by specifying the CMD values via:

docker run -it --entrypoint /bin/bash postgres -c "exec /bin/bash"

however in some cases this isn't going to be viable as the entry point we want to specify will not accept throwaway arguments and the CMD values are passed as direct argv values.