We lose intermediate layers, but win on complexity

REPOSITORY                                                   TAG                                IMAGE ID            CREATED             SIZE
centos_7_builder_slim                                        latest                             33a57d4eb3db        6 minutes ago       1.67GB
dev.gitlab.org:5005/cookbooks/gitlab-omnibus-builder         centos_7-0.0.9                     9476567a1c71        4 days ago          2.27GB

From:
REPOSITORY                                                   TAG                                IMAGE ID            CREATED                  SIZE
registry.gitlab.com/gitlab-org/gitlab-omnibus-builder        debian_7-0.0.9                     8c5847961e76        4 days ago               1.63GB
debian_7_builder_slim                                        latest                             12aabbb863dd        Less than a second ago   979MB

Looking at the history, we have a few fat layers.

I remember a technique for making the layers smaller, which is basically
to delete any working files you make during the process, by making the
RUN steps big and long and have a rm or cache clean or whatever.

  $ docker history dev.gitlab.org:5005/cookbooks/gitlab-omnibus-builder:centos_6-0.0.9
  IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
  f62741de2a6e        4 days ago          /bin/sh -c rm -rf /tmp/*                        0B
  <missing>           4 days ago          /bin/sh -c git config --global user.name "...   56B
  <missing>           4 days ago          /bin/sh -c git config --global user.email ...   36B
  <missing>           4 days ago          /bin/sh -c mkdir -p /opt/gitlab /var/cache...   0B
  <missing>           4 days ago          /bin/sh -c mkdir /usr/local/yarn   && curl...   13.8MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV YARN_VERSION=0.20.3      0B
  <missing>           4 days ago          /bin/sh -c curl -fsSL "https://nodejs.org/...   42.5MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV NODE_VERSION=6.9.5       0B
  <missing>           4 days ago          /bin/sh -c /usr/local/bin/gem install bund...   1.4MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV BUNDLER_VERSION=1.13.6   0B
  <missing>           4 days ago          /bin/sh -c /usr/local/bin/gem update --sys...   16.8MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV RUBYGEMS_VERSION=2....   0B
  <missing>           4 days ago          /bin/sh -c curl -fsSL "https://cache.ruby-...   412MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV RUBY_VERSION=2.3.5       0B
  <missing>           4 days ago          /bin/sh -c curl -fsSL "https://storage.goo...   273MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV GO_VERSION=1.8.1         0B
  <missing>           4 days ago          /bin/sh -c curl -fsSL "https://www.kernel....   302MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV GIT_VERSION=2.7.4        0B
  <missing>           4 days ago          /bin/sh -c pip install awscli                   46.1MB
  <missing>           4 days ago          /bin/sh -c curl -fsSL "http://python.org/f...   214MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV PYTHON_VERSION=2.7.14    0B
  <missing>           4 days ago          /bin/sh -c localedef -c -f UTF-8 -i en_US ...   1.53MB
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV LC_ALL=en_US.UTF-8       0B
  <missing>           4 days ago          /bin/sh -c #(nop)  ENV LANG=en_US.UTF-8         0B
  <missing>           4 days ago          /bin/sh -c yum install -y -q       gcc    ...   166MB
  <missing>           4 days ago          /bin/sh -c yum install -y epel-release          30.4MB
  <missing>           4 days ago          /bin/sh -c yum groupinstall -y Development...   358MB
  <missing>           4 days ago          /bin/sh -c yum update -y -q                     52.1MB
  <missing>           4 days ago          /bin/sh -c #(nop)  MAINTAINER GitLab Inc. ...   0B
  <missing>           2 weeks ago         /bin/sh -c #(nop)  CMD ["/bin/bash"]            0B
  <missing>           2 weeks ago         /bin/sh -c #(nop)  LABEL name=CentOS Base ...   0B
  <missing>           2 weeks ago         /bin/sh -c #(nop) ADD file:c32955e5fd79dfa...   194MB

This might slim this down.

Build python without tk

See merge request gitlab-org/gitlab-omnibus-builder!66

This reverts merge request !65

Create all-in-one image with public images also

Closes gitlab-org/build/team-tasks#66

See merge request gitlab-org/gitlab-omnibus-builder!65

Create all-in-one image using packer

Closes gitlab-org/build/team-tasks#25

See merge request gitlab-org/gitlab-omnibus-builder!60

Build SLES image only on master on dev

See merge request gitlab-org/gitlab-omnibus-builder!63

Install latest pip in Debian 7 and CentOS 6

Closes gitlab-org/build/team-tasks#60

See merge request gitlab-org/gitlab-omnibus-builder!62

Fix arm docker images

Closes #12

See merge request gitlab-org/gitlab-omnibus-builder!59

`qemu-arm-static` and the other scripts inside the `/docker/arm` folder
are already provided by the base image.

Update rubygems and ruby to their latest security patches

See merge request gitlab-org/gitlab-omnibus-builder!57

Resolve "Omnibus Builder does not work with Chef 13"

Closes #8

See merge request !56

Add GNUPG to Debian 9

See merge request !55

Debian 9 appear to be the only builder image that didn't have GnuPG (`gpg`) installed.

Correct that

Docker: SLES: Lock nodejs version to matching

Closes omnibus-gitlab#2569

See merge request !54

Bring SLES container in-line with the rest of the containers, in regards to the version of nodejs.

```
$ docker run -ti 8770c06f4636 /bin/bash -l
Directory: /
Mon Jul 10 16:13:40 UTC 2017
0c97a4876845:/ # which node
/usr/local/bin/node
0c97a4876845:/ # node --version
v6.9.5
0c97a4876845:/ # which npm
/usr/local/bin/npm
0c97a4876845:/ # npm version
{ npm: '3.10.10',
  ares: '1.10.1-DEV',
  http_parser: '2.7.0',
  icu: '57.1',
  modules: '48',
  node: '6.9.5',
  openssl: '1.0.2k',
  uv: '1.9.1',
  v8: '5.1.281.89',
  zlib: '1.2.8' }
```

This was an oversight, and should not have been in the previous method.

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/issues/2569

SLES: add missing openssh

Closes #10

See merge request !52

We somehow managed to miss the the container didn't contain `openssh` package.
Fix this, as it is blocking the final move to shared runners.

Closes #10

Use official docker package in ruby_docker image

See merge request !51

Add SLES/SMT documentation, update platforms in README

See merge request !50

Move to dynamic builders for SLES

See merge request !49

Builder image for Debian 9

See merge request !48

Use IMAGE_VERSION content as image tag

See merge request !46