Ability to make container configuration changes on (running) containers

[jorisvddonk]

I'd like to be able to make configuration changes to a container (running or stopped). Specifically, any setting that can be set when starting a container with docker run should be able to be changed after-the-fact easily.

Rationale:
When working with containers, it's inevitable that at one point you find yourself in a situation where you've spent an hour fiddling with a running container so that you can start using it (e.g. setting up a job system in a Jenkins container), only to realize that you forgot to make a certain configuration change way back when you ran the container using docker run. This tends to happen a lot with badly-documented images on the Index; if the image documentation doesn't tell me that I need to expose port 443 on my host system, I'm probably going to forget that.

In such cases, it would be great if I could make container configuration changes whilst the container is running, or after I've stopped the container manually.

Unfortunately, docker doesn't currently seem to support this. Since you can't re-run a stopped container with docker run, you would need to commit the container to an image and then re-run it.

Unfortunately, docker commit clears the container's configuration, so you need to explicitly set a startup configuration using the -run commandline argument, unless you don't mind manually specifying the entrypoint/cmd et cetera each time you run this new image with docker run (which I don't think is very user friendly). As a workaround, you can inspect the container, copy the Config, and paste the config into the -run parameter of docker commit, but this isn't really user-friendly either.

[bfirsh]

Related to #2733. What we probably need is an "update" command that takes similar options to "run" along with a container ID/name.

[reberhardt7]

For those needing a quick fix for port mapping/binding: http://stackoverflow.com/questions/19897743/exposing-a-port-on-a-live-docker-container

[nivance]

iptables can't work.

[jerng]

+1(!)

[Mulkave]

+1
Some of the things I needed most is to re-import the --env-file and --link to a newly run container without having to restart.

[muddflappz]

+100

[JasCodes]

+1

[nazar-pc]

Even changing ports binding without need to create intermediate image and start new container would be great.

[pjincz]

+1

I want to change a container's base image. And keep all other settings.
It will be very very useful. When you have an new image.
But, I have to recreate container with all arguments I used.
That's very dangerous.

[thaJeztah]

@jinchizhong changing the base-image of a (running) container is not possible (even if this proposal is implemented). This proposal is only for changing a limited number of settings of a running container (for example, rename the container, expose/publish ports, add a link to a container)

[JasCodes]

@thaJeztah Would also like to have a flag while commit to copy settings of running container and bake it to image

[o0x2a]

+1
Need to add new volume and publish new ports after running a container

[windlessuser]

+1
Common guy's it's been 2 years. It is a real pain when trying to setup a group of containers that need to talk to each other.

[IanWizard]

I think it's safe to stop with the +1s. I too find myself wanting this almost daily, but am some how able to divine the strength and serenity to not pollute the internet with yet another +1. There's no doubt it's a desired and useful feature. If you're not contributing to the conversation, please keep it to yourself.

[Mulkave]

@IanWizard totally agree, the Subscribe button is right there for this specific reason.

[toby-griffiths]

Thank you @IanWizard Was getting a little frustrated with all the email (he says, triggering another one)

[IanWizard]

I will slap the next person to +1 this...

[nijikokun]

+1....

[isanych]

container renaming would be nice

[cpuguy83]

@isanych container renaming was introduced in docker 1.5

[isanych]

@cpuguy83, thanks, will ask to upgrade docker on server

[keshy]

+1!!

[sinchb]

＋1

[IanWizard]

Even the political threads don't hurt this much.

On 07/29/2015 11:24 AM, Charles Ferreira Gonçalves wrote:

+1

—
Reply to this email directly or view it on GitHub
#3285 (comment).

[charlesfg]

I agree with @bradleypeabody .... The requirement of 'running' could be removed if this would make the implementation easier. Would not be a great deal to stop the container.

[cnaize]

Hello!
What about progress in this issue?
Can I help to implement this?

[cpuguy83]

There is an implementation here: #15078

[f3l1x]

👍

[GordonTheTurtle]

USER POLL

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[omerh]

+1
This command will be great: docker remove -p 443:443 container_id

[cpuguy83]

@omerh see docker update command in docker 1.10
It currently only supports modifying container resource constraints.
I'm not sure it will be expanded to support changing exposed ports... probably best to open as a specific issue.

I believe we should close this generic issue since docker update exists now for this purpose and anything it doesn't specifically support yet should be opened as separate issues.

ping @thaJeztah Do you agree?

[thaJeztah]

I agree, each property that's added to docker update should be looked at separately, so there's no reason to keep a "general" issue open now that docker update is there.

[carloscarcamo]

+1

[b1zzu]

+1

[p0liper]

+1
Are you think this configuration commands will enough for make changes?
I would like to change volume settings (such as "-v" arg), but I doesn't find it.
For make this change, I will create new persistent container, move all volumes to new container, and remove old.

Usage: docker update CONTAINER [CONTAINER...]

Update configuration of one or more containers

--blkio-weight Block IO (relative weight), between 10 and 1000
-c, --cpu-shares CPU shares (relative weight)
--cpu-period Limit CPU CFS (Completely Fair Scheduler) period
--cpu-quota Limit CPU CFS (Completely Fair Scheduler) quota
--cpuset-cpus CPUs in which to allow execution (0-3, 0,1)
--cpuset-mems MEMs in which to allow execution (0-3, 0,1)
--help Print usage
--kernel-memory Kernel memory limit
-m, --memory Memory limit
--memory-reservation Memory soft limit
--memory-swap Swap limit equal to memory plus swap: '-1' to enable unlimited swap
--restart Restart policy to apply when a container exits

Addressed for @cpuguy83 also for all Docker contributors. I think you fix this. Thanks :)

[thaJeztah]

@yanislavb no -v is not supported on docker update. See my comment before this issue was closed; #3285 (comment)

w.r.t -v, chances are little that that would be implemented; swapping a volume in a container, at runtime can have quite some side-effects, and creating a new container with a new volume / different volume is likely the best approach.

[p0liper]

Can I modify container configuration file?
If yes, where are these files located?

[thaJeztah]

The container configuration file is in /var/lib/docker/containers/<container-id>, but I discourage editing those, as they are really designed as "internal" to docker. Updating the configuration will have no effect on a running container, and not sure what'll happen after updating those files.

If your container itself does not contain any stateful data, replacing a container is really the way to go (instead of updating the existing one).

[p0liper]

On my way, that's not really

[ngtuna]

Hi there, I am curious if we can support docker update command to update the mapped ports to the running container. That would be really helpful.

[thaJeztah]

@ngtuna see #21282

[thaJeztah]

I am going to lock the conversation on this issue, to repeat my earlier comment #3285 (comment);

A docker update command has been implemented, but additional options that can be updated on a running container should be looked at separately. If you think something should be added to the docker update command, please open a separate issue if it doesn't exist, and explain the use case (this is important to understand the reason why it's needed, and recreating the container is not an option).

Also note that docker services (in swarm mode) allow you to update service definitions, but mechanics are slightly different, because updating a service recreates containers.