Add docker_container_copy_into module (#545)

* Move copying functionality to module_utils.

* Add docker_container_copy_into module.

* Use new module in other tests.

* Fix copyright and attributes.

* Improve idempotency, improve stat code.

* Document and test when a stopped container works.

* Improve owner/group detection error handling when container is stopped.

* Fix formulation.

Co-authored-by: Brian Scholer <1260690+briantist@users.noreply.github.com>

* Improve file comparison.

* Avoid reading whole file at once.

* Stream when fetching files from daemon.

* Fix comment.

* Use read() instead of read1().

* Stream files when copying into container.

* Linting.

* Add force parameter.

* Simplify library code.

* Linting.

* Add content and content_is_b64 options.

* Make force=false work as for copy module: only copy if the destination does not exist.

* Improve docs.

* content should be no_log.

* Implement diff mode.

* Improve error handling.

* Lint and improve.

* Set owner/group ID to avoid ID lookup (which fails in paused containers).

* Apply suggestions from code review

Co-authored-by: Brian Scholer <1260690+briantist@users.noreply.github.com>

Co-authored-by: Brian Scholer <1260690+briantist@users.noreply.github.com>

tests/integration/targets/generic_connection_tests/tasks/main.yml

@@ -43,7 +43,12 @@
     - nginx.conf
 
   - name: Copy static files into volume
-    command: docker cp {{ remote_tmp_dir }}/{{ item }} {{ daemon_nginx_frontend }}:/etc/nginx/{{ item }}
+    docker_container_copy_into:
+      container: '{{ daemon_nginx_frontend }}'
+      path: '{{ remote_tmp_dir }}/{{ item }}'
+      container_path: '/etc/nginx/{{ item }}'
+      owner_id: 0
+      group_id: 0
     loop:
     - nginx.conf
     register: can_copy_files
@@ -94,7 +99,12 @@
         provider: ownca
 
     - name: Copy dynamic files into volume
-      command: docker cp {{ remote_tmp_dir }}/{{ item }} {{ daemon_nginx_frontend }}:/etc/nginx/{{ item }}
+      docker_container_copy_into:
+        container: '{{ daemon_nginx_frontend }}'
+        path: '{{ remote_tmp_dir }}/{{ item }}'
+        container_path: '/etc/nginx/{{ item }}'
+        owner_id: 0
+        group_id: 0
       loop:
       - ca.pem
       - cert.pem