Alternative fix for #1007

Closed in favour of #1007

@rhatdan I like the reduced complexity using the official golang image - I'll close my PR in favour of this one.

@myback That is why I used ARG and not ENV. :) It won't carry over into another image build like ENV will do. You can even see it when using a multistage Dockerfile.

$ cat Dockerfile
FROM alpine AS test1
ARG KEY=value
RUN echo $KEY

FROM test1
RUN echo $KEY
$ docker build -t test --no-cache .
Sending build context to Docker daemon  3.072kB
Step 1/5 : FROM alpine AS test1
 ---> a24bb4013296
Step 2/5 : ARG KEY=value
 ---> Running in 714bba7751a3
Removing intermediate container 714bba7751a3
 ---> 2833cb022b29
Step 3/5 : RUN echo $KEY
 ---> Running in 9ea4d7148f62
value
Removing intermediate container 9ea4d7148f62
 ---> e11d56b72078
Step 4/5 : FROM test1
 ---> e11d56b72078
Step 5/5 : RUN echo $KEY
 ---> Running in 96d6c6160321

Removing intermediate container 96d6c6160321
 ---> 8848d2fe0555
Successfully built 8848d2fe0555
Successfully tagged test:latest
$

The second echo $KEY does not yield the value as it is only present in the first stage.

To me make is still missing in the install and when using --no-install-recommends a run of make binary fails as gcc can not be found. (I also recommend ARG to provide a temporary environment var, but that is more cosmetic - I'd say why not use ENV?)

Alternative fix for #1007

@lobsterdore do you happen to have an example of how you use it?

Issue #, if available:

Description of changes:

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

https://github.com/aws-samples/aws-batch-using-nice-dcv/blob/75459f56fb9ff1ec426e50a2b89e35cc0c96d6e7/aws-batch-using-nice-dcv.dockerfile#L73

<!--

First of all, please read https://www.chiark.greenend.org.uk/~sgtatham/bugs.html.

If you don't want to read, it's up to you. But don't waste your time continue reporting.

The issue will be closed without any explanation if it does not satisfy any of following requirements:

1. Please speak English, we have forum in 中文: https://discuss.gogs.io/c/getting-help/getting-help-chinese.
2. Please post any questions, configuration or deploy problems on our forum: https://discuss.gogs.io.
3. Please do not end your title with a question mark or period.
4. Please take a moment to search and make sure the issue doesn't already exist.
5. Please give all relevant information below for bug reports; incomplete details are considered invalid report.

-->

Describe the bug <!-- A clear and concise description of what the bug is -->

Gogs version and commit <!-- The version number or the commit SHA of the Gogs instance you use. You can find these information in the admin dashboard ("/admin"). -->

/app/gogs/gogs -v
Gogs version 0.12.0+dev

Operating system <!-- The name and version of your operating system -->

/app/gogs $ cat /etc/os-release
NAME="Alpine Linux"
ID=alpine
VERSION_ID=3.11.6

Database <!-- The database and version you use -->

sqlite3

To Reproduce

When running /app/gogs/gogs backup --verbose I get the following error, even though the user I am running is git.

/app/gogs $ /app/gogs/gogs backup --verbose
2020/07/02 07:53:32 [FATAL] [gogs.io/gogs/gogs.go:40 main()] Failed to start application: init configuration: user configured to run Gogs is "git", but the current user is ""
/app/gogs $ whoami
git
/app/gogs $ id
uid=1000(git) gid=1000(git) groups=1000(git)
/app/gogs $

Can you reproduce the bug at https://try.gogs.io? <!-- If yes, please provide the example URL; if no, please explain why -->

Expected behavior <!-- A clear and concise description of what you expected to happen -->

The backup should be done

Actual behavior <!-- A clear and concise description of what you see instead -->

Seems like gogs is not able to read the user to check against the configured user.

Screenshots <!-- If applicable, add screenshots to help explain your problem -->

Additional context <!-- Please include any error logs found in log/gogs.log -->

I changed the base image to a smaller (220MB) version of the jupyter notebook.

What would be the minimal version of the notebook you would see possible?

Took the freedom to add a Dockerfile and adjusting the readme to have a quick start (#11).