Merge branch 'remove-omnibus-gitlab-centos6' into 'master'

Remove omnibus-gitlab-centos6 Dockerfile

See merge request gitlab-org/gitlab-build-images!340

.gitlab-ci.yml

@@ -108,7 +108,6 @@ gitlab-qa-alpine-ruby-2.6 test: *test_build
 gitlab-qa-alpine-ruby-2.7 test: *test_build
 gitlab-puppeteer test: *test_build
 omnibus-gitlab-bionic test: *test_build
-omnibus-gitlab-centos6 test: *test_build
 omnibus-gitlab-centos7 test: *test_build
 omnibus-gitlab-centos8 test: *test_build
 omnibus-gitlab-jessie test: *test_build
@@ -189,7 +188,6 @@ gitlab-qa-alpine-ruby-2.6: *build_and_deploy
 gitlab-qa-alpine-ruby-2.7: *build_and_deploy
 gitlab-puppeteer: *build_and_deploy
 omnibus-gitlab-bionic: *build_and_deploy
-omnibus-gitlab-centos6: *build_and_deploy
 omnibus-gitlab-centos7: *build_and_deploy
 omnibus-gitlab-centos8: *build_and_deploy
 omnibus-gitlab-jessie: *build_and_deploy

Dockerfile.omnibus-gitlab-centos6

@@ -1,22 +0,0 @@
-FROM centos:centos6
-
-RUN yum update -y -q \
-  && yum groupinstall -y Development Tools \
-  && yum install -y \
-        gcc gcc-c++ git make curl zlib-devel openssl-devel \
-  && yum clean all
-
-ENV LANG en_US.UTF-8
-ENV LC_ALL en_US.UTF-8
-RUN localedef -c -f UTF-8 -i en_US en_US.UTF-8
-
-ENV RUBY_VERSION 2.6.5
-RUN curl -fsSL "https://cache.ruby-lang.org/pub/ruby/2.6/ruby-${RUBY_VERSION}.tar.gz" \
-  | tar -xzC /tmp \
-  && cd "/tmp/ruby-${RUBY_VERSION}" \
-  && ./configure --disable-install-rdoc --disable-install-doc --disable-install-capi\
-  && make \
-  && make install \
-  && cd / \
-  && rm -rf "/tmp/ruby-${RUBY_VERSION}" \
-  && gem install bundler --no-document