change docker image build path (#51)

* change docker image build path

* document image build path param

* align the Dockerfile creation task

* prefer ephemeral directory to build unless specified otherwise

* add a cleanup playbook for custom build context

* fix tests issues

molecule_docker/driver.py

@@ -58,6 +58,7 @@ class Docker(Driver):
             image: image_name:tag
             dockerfile: Dockerfile.j2
             pull: True|False
+            path: /path/to_docker/build/context
             pre_build_image: True|False
             registry:
               url: registry.example.com

molecule_docker/playbooks/cleanup.yml

@@ -0,0 +1,16 @@
+---
+- name: Cleanup
+  hosts: localhost
+  connection: local
+  gather_facts: false
+  no_log: "{{ molecule_no_log }}"
+  vars:
+    molecule_labels:
+      owner: molecule
+  tasks:
+    - name: Cleanup Dockerfiles
+      file:
+        state: absent
+        path: "{{ item.path }}/Dockerfile_{{ item.image | regex_replace('[^a-zA-Z0-9_]', '_') }}"
+      when: item.path is defined
+      loop: "{{ molecule_yml.platforms }}"

molecule_docker/playbooks/create.yml

@@ -40,14 +40,22 @@
           {%- else -%}
           {{ playbook_dir + '/Dockerfile.j2' }}
           {%- endif -%}
-        dest: "{{ molecule_ephemeral_directory }}/Dockerfile_{{ item.image | regex_replace('[^a-zA-Z0-9_]', '_') }}"
+        dest: "{{ item.path | default(molecule_ephemeral_directory) }}/Dockerfile_{{ item.image | regex_replace('[^a-zA-Z0-9_]', '_') }}"
         mode: "0600"
       loop: "{{ molecule_yml.platforms }}"
       loop_control:
         index_var: i
       when: not item.pre_build_image | default(false)
       register: platforms
 
+    - name: Copy files for image building
+      copy:
+        src: "{{ molecule_scenario_directory }}/"
+        dest: "{{ molecule_ephemeral_directory }}"
+        mode: "0600"
+      when: not item.pre_build_image | default(false) and not item.path
+      loop: "{{ molecule_yml.platforms }}"
+
     - name: Discover local Docker images
       docker_image_info:
         name: "molecule_local/{{ item.item.name }}"
@@ -67,7 +75,7 @@
         - not item.item.pre_build_image | default(false)
       docker_image:
         build:
-          path: "{{ molecule_ephemeral_directory }}"
+          path: "{{ item.item.path | default(molecule_ephemeral_directory) }}"
           dockerfile: "{{ item.invocation.module_args.dest }}"
           pull: "{{ item.item.pull | default(true) }}"
           network: "{{ item.item.network_mode | default(omit) }}"