Allow setting build args during porter build

[carolynvs]

Sometimes a bundle needs to configure something during build, for example use a corporate proxy while building the bundle, but it doesn't want those values hard coded into the image because it will be used in many environments.

porter build --arg PROXY=https://example.com/proxy

Then the author can use the argument passed (see below). It is up to the author to define and use the arg in the Dockerfile, this feature should not edit the Dockerfile.

FROM debian

ARG PROXY
# use the proxy when building the invocation image

Related #927

[adelowo]

If no one is working on this, I'd take a crack at it

[carolynvs]

Perfect! All yours, let us know if you have any questions.

[carolynvs]

Here's where we set the build args for docker during the porter build command

https://github.com/deislabs/porter/blob/e644d0093b88a73b1ecb5b36012f071b0b24ace9/pkg/build/provider/docker.go#L44-L46

[adelowo]

Thanks @carolynvs !!

[LvffY]

@carolynvs Do you have any plan to add this feature ?

[carolynvs]

We have an open pull request that adds support for this #1900. In addition #1769 is on the backlog for our v1 release.

[carolynvs]

Closed in #1769