Proposal: expand dockerfile command "ENV" to be able to unset environment variables

[liusdu]

problem on unsetting environment variables

In Dockerfile, we use "ENV" command to export environment variables. But we can not unset variables. While in linux shell we can do that using "export -n" or "unset". It is very inconvenient. Think about below:

• variables while useful duiring image-building but useless when finishing. (such as https_proxy). So I think we need this improvement.
• number of en variables can only grow

RFC thoughts to solve this.

Allow ENV to allow one argument. Look at these cases:

• ENV VAR 1 #set VAR to 1
• ENV VAR #unset VAR
• ENV VAR=1 #set VAR to 1
• ENV VAR= #unset VAR

RFC patches you can see here ##11921

Lable

We can expend lable command just as what ENV does.

[thaJeztah]

I think this is a dup of #3465, which is implemented in #8177

Unfortunately it didn't make it in the 1.6 release, but is scheduled for docker 1.7

[erikh]

Yes, I prefer this approach over the proposed one here. Sorry.

-Erik

On Mar 30, 2015, at 2:31 AM, Sebastiaan van Stijn notifications@github.com wrote:

I think this is a dup of #3465 #3465, which is implemented in #8177 #8177
Unfortunately it didn't make it in the 1.6 release, but is scheduled for docker 1.7

—
Reply to this email directly or view it on GitHub #11922 (comment).

[liusdu]

Yes, I have not seen it . I will cose this issue

[thaJeztah]

@liusdu thanks! Thanks you for your contribution (even though it won't be merged). I fully agree that something like this is needed, so hope that #8177 will be merged soon.

Please don't let this stop you from contributing to the project; it is really appreciated!