Propgate GOPROXY value to build-image/Dockerfile

[alvinlin123]

What this PR does:

Propagate configured GOPROXY value to build-image/Dockerfile so that we can build the code inside network that disallow access to default Go proxy server.

Which issue(s) this PR fixes:
Fixes #2740

Checklist

• [Not applicable ] Tests updated
  • I have tested the build still works on a vanilla Ubuntu box.
  • I have tested my change works behind my company's network.
• [ Not applicable] Documentation added
• [ Done] CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[pstibrany]

Thank you. Alternatively, since we have updated build image with go1.14, we can also update go.mod file, which will then automatically use vendor directory instead of using modules. This is the direction we plan to go. Do you want to give it a try and update PR with this change? (To clarify: I am suggesting changing go directive in go.mod to 1.14, which then triggers this behaviour)

[alvinlin123]

HI @pstibrany thanks for the comment. I just tried to change go.mod to 1.14, but still got the GOPROXY problem. I guess this is because the problem is still there because when building hugo it runs some go get command? Sorry I am new to Go ecosystem and is not really familiar with the build system :)

The error I am getting is

Step 7/23 : RUN git clone https://github.com/gohugoio/hugo.git --branch ${HUGO_VERSION} --depth 1 &&    cd hugo  && go install --tags extended && cd ../ &&     rm -rf hugo/ && rm -rf /go/pkg /go/src
 ---> Running in 774a1944d764
Cloning into 'hugo'...
Note: checking out '8a7ef3cf4ee3c65d4edba17b1608c770b6da1673'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

go: github.com/BurntSushi/locker@v0.0.0-20171006230638-a6e239ea1c69: Get "https://proxy.golang.org/github.com/%21burnt%21sushi/locker/@v/v0.0.0-20171006230638-a6e239ea1c69.mod": x509: certificate is valid for chalupa-dns-sinkhole.corp.amazon.com, not proxy.golang.org

The certificate does not match error is because my company's internal network redirect proxy.golang.org to some blackhole server.

[pstibrany]

I see, yes you're right that building the build-image needs to access the proxy as well. Propagating GOPROXY setting seems like best option then.

[pstibrany]

Thanks!

[alvinlin123]

What is the process of getting the PR merged? I don't believe I can, nor should merge it myself right?

[pstibrany]

What is the process of getting the PR merged? I don't believe I can, nor should merge it myself right?

No, you cannot merge it yourself. In Cortex, we have a rule that 2 maintainers need to approve the PR before merging. One more approval is needed, I'm sure someone will take a look at it very soon.

[pracucci]

LGTM