Use buildah commands for yum update to improve speed

This allows directly mounting directories instead of copying them
twice. Also the resulting image has only one extra layer instead of
one per Dockerfile directive.

Change-Id: I8a3769c0b55572ba05cc29ecd28a131cc94e8c4d

tasks/modify_image.yml

@@ -8,11 +8,6 @@
       - modify_dir_path is defined
       - modify_dir_path | length > 0
 
-- name: Set default modified_append_tag
-  set_fact:
-    modified_append_tag: "{{ lookup('pipe','date +-modified-%Y%m%d%H%M%S') }}"
-  when: modified_append_tag is undefined
-
 - name: Create Dockerfile tempfile name
   tempfile:
     path: "{{ modify_dir_path }}"

tasks/precheck.yml

@@ -7,3 +7,8 @@
 - name: Ensure that container_build_tool is correctly set
   fail: msg="{{ container_build_tool }} is not a valid value for container_build_tool. Pick docker or buildah."
   when: container_build_tool not in ['docker', 'buildah']
+
+- name: Set default modified_append_tag
+  set_fact:
+    modified_append_tag: "{{ lookup('pipe','date +-modified-%Y%m%d%H%M%S') }}"
+  when: modified_append_tag is undefined

tasks/yum_update.yml

@@ -2,55 +2,8 @@
   tags:
     - always
 
-- import_tasks: get_original_user.yml
+- import_tasks: yum_update_buildah.yml
+  when: container_build_tool == 'buildah'
 
-- name: Create image build context directory
-  tempfile:
-    state: directory
-    prefix: tripleo-modify-image
-  register: context_dir
-
-- name: Set modify_dir_path
-  set_fact:
-    modify_dir_path: "{{ context_dir.path }}"
-
-- name: Copy local file repos to context directory
-  shell: |
-    #!/bin/sh
-    set -ex
-
-    cp -a {{ yum_repos_dir_path }} {{ modify_dir_path }}/yum.repos.d
-
-    # discover repos with local packages
-    repos=$(sed -n 's/baseurl=file:\/\///p' {{ yum_repos_dir_path }}/*.repo)
-
-    mkdir repos
-    for repo in $repos ; do
-        if [ -d $repo ]; then
-            target_dir=repos$repo
-            echo "copying $repo to $target_dir"
-            mkdir -p $target_dir
-            cp -a $repo/* $target_dir
-        fi
-    done
-  args:
-    chdir: "{{ modify_dir_path }}"
-  when: yum_repos_dir_path is defined
-
-- name: Write Dockerfile to {{ modify_dir_path }}
-  template:
-    src: Dockerfile-yum.j2
-    dest: "{{ modify_dir_path }}/Dockerfile"
-
-- name: Write yum_update.sh
-  copy:
-    src: yum_update.sh
-    dest: "{{ modify_dir_path }}/yum_update.sh"
-    mode: '0555'
-
-- include_tasks: modify_image.yml
-
-- name: Clean modify directory
-  file:
-    state: absent
-    path: "{{ modify_dir_path }}"
+- import_tasks: yum_update_docker.yml
+  when: container_build_tool == 'docker'

tasks/yum_update_buildah.yml

@@ -0,0 +1,49 @@
+- import_tasks: precheck.yml
+  tags:
+    - always
+
+- name: From image {{ source_image }}
+  command: buildah from {{ source_image }}
+  register: from_image_cmd
+
+- name: Set from_image
+  set_fact:
+    from_image: "{{ from_image_cmd.stdout }}"
+
+- name: Run buildah config
+  command: >
+    buildah config
+      --label modified_append_tag={{ modified_append_tag }}
+      --workingdir / {{ from_image }}
+
+- name: Copy yum_update.sh
+  command: >
+    buildah copy
+      {{ from_image }}
+      files/yum_update.sh /tmp/yum_update.sh
+
+- name: List file repos
+  shell: sed -n 's|baseurl=file://||p' *.repo
+  args:
+    chdir: "{{ yum_repos_dir_path }}"
+  register: file_repos
+
+- name: Run yum_update.sh
+  command: >
+    buildah run
+      --volume {{ yum_repos_dir_path }}:/etc/yum.repos.d
+      {% for repo in file_repos.stdout_lines %}
+        {% if repo|exists %}
+          --volume {{ repo }}:{{ repo }}
+        {% endif %}
+      {% endfor %}
+      --user root
+      --net host
+      {{ from_image }}
+      /tmp/yum_update.sh "{{ update_repo }}"
+
+- name: Commit changes to image {{ target_image | default(source_image) }}
+  command: >
+    buildah commit
+      {{ from_image }}
+      {{ target_image | default(source_image) }}

tasks/yum_update_docker.yml

@@ -0,0 +1,56 @@
+- import_tasks: precheck.yml
+  tags:
+    - always
+
+- import_tasks: get_original_user.yml
+
+- name: Create image build context directory
+  tempfile:
+    state: directory
+    prefix: tripleo-modify-image
+  register: context_dir
+
+- name: Set modify_dir_path
+  set_fact:
+    modify_dir_path: "{{ context_dir.path }}"
+
+- name: Copy local file repos to context directory
+  shell: |
+    #!/bin/sh
+    set -ex
+
+    cp -a {{ yum_repos_dir_path }} {{ modify_dir_path }}/yum.repos.d
+
+    # discover repos with local packages
+    repos=$(sed -n 's/baseurl=file:\/\///p' {{ yum_repos_dir_path }}/*.repo)
+
+    mkdir repos
+    for repo in $repos ; do
+        if [ -d $repo ]; then
+            target_dir=repos$repo
+            echo "copying $repo to $target_dir"
+            mkdir -p $target_dir
+            cp -a $repo/* $target_dir
+        fi
+    done
+  args:
+    chdir: "{{ modify_dir_path }}"
+  when: yum_repos_dir_path is defined
+
+- name: Write Dockerfile to {{ modify_dir_path }}
+  template:
+    src: Dockerfile-yum.j2
+    dest: "{{ modify_dir_path }}/Dockerfile"
+
+- name: Write yum_update.sh
+  copy:
+    src: yum_update.sh
+    dest: "{{ modify_dir_path }}/yum_update.sh"
+    mode: '0555'
+
+- include_tasks: modify_image.yml
+
+- name: Clean modify directory
+  file:
+    state: absent
+    path: "{{ modify_dir_path }}"