Allow disabling compression of uploaded images

This may not be required for openstack, but let's maintain parity
between the swift and s3 upload roles.

Change-Id: I3740528d90b27ca36d742b6069014a395252a1f3
Co-Authored-By: Simon Westphahl <simon.westphahl@bmw.de>

roles/upload-image-swift/README.rst

@@ -4,7 +4,8 @@ This uploads a filesystem image (for example, one built by diskimage
 builder) to an OpenStack Object Store (Swift) container.  The role
 returns an artifact to Zuul suitable for use by the zuul-launcher.
 
-If a `raw` or `vhd` image is provided and the `zstd` command is
+If a `raw` or `vhd` image is provided,
+`upload_image_swift_compress_image` is true and the `zstd` command is
 available, it will be compressed in the way that zuul-launcher
 expects.
 
@@ -61,6 +62,15 @@ expects.
 
    The object name to use when uploading.
 
+.. zuul:rolevar:: upload_image_swift_compress_image
+   :default: true
+
+   Whether to compress the image using zstd before upload.
+
+   Some providers may require the image to be in raw format when
+   importing directly from object storage. In those cases the flag
+   should be set to `false`.
+
 .. zuul:rolevar:: upload_image_swift_hash_timeout
     :default: 600
 

roles/upload-image-swift/defaults/main.yaml

@@ -3,4 +3,5 @@ upload_image_swift_delete_after: 0
 upload_image_swift_filename: '{{ build_diskimage_image_root }}/{{ build_diskimage_image_name }}.{{ upload_image_swift_extension }}'
 upload_image_swift_name: '{{ zuul.build }}-{{ build_diskimage_image_name }}.{{ upload_image_swift_extension }}'
 upload_image_swift_extension: '{{ upload_image_swift_format }}'
+upload_image_swift_compress_image: true
 upload_image_swift_hash_timeout: 600

roles/upload-image-swift/tasks/main.yaml

@@ -15,27 +15,31 @@
   poll: 0
   register: md5_task
 
-- name: Check if zstd is installed
-  shell: "command -v zstd || exit 1"
-  register: zstd_installed
-  failed_when: false
-
-- name: Compress image
-  when:
-    - "zstd_installed.rc == 0"
-    - "upload_image_swift_format in ['raw', 'vhd']"
-  command: zstd '{{ upload_image_swift_filename }}'
-
 - name: Set extension
   set_fact:
     zj_upload_image_swift_extension: ''
 
-- name: Set extension
+- name: Compress image
   when:
-    - "zstd_installed.rc == 0"
-    - "upload_image_swift_format in ['raw', 'vhd']"
-  set_fact:
-    zj_upload_image_swift_extension: '.zst'
+    - "upload_image_swift_compress_image"
+  block:
+    - name: Check if zstd is installed
+      shell: "command -v zstd || exit 1"
+      register: zstd_installed
+      failed_when: false
+
+    - name: Compress image
+      when:
+        - "zstd_installed.rc == 0"
+        - "upload_image_swift_format in ['raw', 'vhd']"
+      command: zstd '{{ upload_image_swift_filename }}'
+
+    - name: Set extension
+      when:
+        - "zstd_installed.rc == 0"
+        - "upload_image_swift_format in ['raw', 'vhd']"
+      set_fact:
+        zj_upload_image_swift_extension: '.zst'
 
 - name: Upload image to swift
   upload_image_swift: