Comment 6 for bug 1671713

I am concerned about below case exception

2017-03-08 15:55:26.950 ERROR zun.compute.manager [^[[01;36mreq-e719322a-67a4-4f4e-abe1-f656a9670a25 ^[[00;36madmin admin] ^[[01;35mError occurred while calling Docker start API: Docker internal error: 409 Client Error: Conflict ("cannot join network of a non running container: 33a59b411a165a4e061612c9da13e5383a6277b4cb0cd72ffd8626057541a656").

I reproduce this error by using below steps:
1) Created a container by 'zun run'
2) restarted the docker daemon
3) Checked the status of all containers, sandbox as well as user containers both were stopped.
4) tried to start the container by 'zun start', and got the above exception in compute logs.

Reason is 'zun start' is not starting the sandbox container, that's why we are getting the error 'cannot join network of a non running container'.

Possible Solutions:
1) Use restart policy for sandbox container in the nova-docker driver
2) Start the sandbox container before starting the user container if sandbox container is in stopped state. Now how to check the status of sandbox container using nova apis or using docker apis. Since calling nova APIs may add more performance overhead as compared to docker API.

@Hongbin, @Shunli,

What do you guys think?