unixPB: Install Python2.7 on C6; Use it to install JDKs

ansible/Dockerfile.CentOS6

@@ -14,6 +14,7 @@ RUN sed -i -e 's!mirrorlist!#mirrorlist!g' /etc/yum.repos.d/CentOS-Base.repo; \
     ./configure --enable-optimizations; \
     make install; \
     rm /usr/src/Python-3.6.10.tgz; \
+    pip3 install --upgrade pip; \
     pip3 install ansible
 
 COPY . /ansible

ansible/playbooks/AdoptOpenJDK_Unix_Playbook/main.yml

@@ -25,6 +25,7 @@
     - Version
     - adopt_etc
     - Common
+    - Python2.7                   # CentOS6
     - Providers                   # AdoptOpenJDK Infrastructure
     - autoconf
     - curl

ansible/playbooks/AdoptOpenJDK_Unix_Playbook/roles/Python2.7/tasks/main.yml

@@ -0,0 +1,32 @@
+---
+####################
+# Python Bootstrap #
+####################
+
+# Check if Python is installed, and its version. If Python isn't installed, or it's at a version below 2.7.18, install Python 2.7.18.
+# Currently only for CentOS6. See: https://github.com/AdoptOpenJDK/openjdk-infrastructure/issues/1877
+
+- name: Check for Python 2's version
+  shell: python -V 2>&1 | grep -Po '(?<=Python )(.+)'
+  register: python_version
+  ignore_errors: yes
+  when:
+    - (ansible_distribution == "CentOS") and (ansible_distribution_major_version == "6")
+  tags:
+    - python2.7
+
+- name: Install Python2.7 to /usr/local/python2
+  unarchive:
+    src: https://ci.adoptopenjdk.net/userContent/usrlocalPython27.tar.xz
+    dest: /usr/local/
+    remote_src: yes
+    mode: 0755
+  retries: 3
+  delay: 5
+  register: python_download
+  until: python_download is not failed
+  when:
+    - (ansible_distribution == "CentOS") and (ansible_distribution_major_version == "6")
+    - (python_version.rc != 0) or (python_version.rc == 0 and python_version.stdout is version_compare('2.7.18', operator='lt'))
+  tags:
+    - python2.7

ansible/playbooks/AdoptOpenJDK_Unix_Playbook/roles/adoptopenjdk_install/tasks/main.yml

@@ -101,10 +101,29 @@
   until: adoptopenjdk_download is not failed
   when:
     - ansible_distribution != "MacOSX"
+    - not (ansible_distribution == "CentOS" and ansible_distribution_major_version == "6")
     - ansible_os_family != "Solaris"
     - adoptopenjdk_installed.rc != 0
   tags: adoptopenjdk_install
 
+# CentOS6 needs it's own task so it can use a different python interpreter.
+# See: https://github.com/AdoptOpenJDK/openjdk-infrastructure/issues/1877
+- name: Install latest release if not already installed (CentOS6)
+  unarchive:
+    src: https://api.adoptopenjdk.net/v3/binary/latest/{{ jdk_version }}/ga/linux/{{ api_architecture }}/jdk/{{ bootjdk }}/normal/adoptopenjdk?project=jdk
+    dest: /usr/lib/jvm
+    remote_src: yes
+  vars:
+    - ansible_python_interpreter: /usr/local/python2/bin/python2.7
+  retries: 3
+  delay: 5
+  register: adoptopenjdk_download
+  until: adoptopenjdk_download is not failed
+  when:
+    - ansible_distribution == "CentOS" and ansible_distribution_major_version == "6"
+    - adoptopenjdk_installed.rc != 0
+  tags: adoptopenjdk_install
+
 - name: Install latest release if one not already installed (macOS)
   get_url:
     url: https://api.adoptopenjdk.net/v3/installer/latest/{{ jdk_version }}/ga/mac/{{ api_architecture }}/jdk/{{ bootjdk }}/normal/adoptopenjdk?project=jdk