copr/backend: creating a new partition for /var/cache/mock

Fixes: #787 in copr

roles/copr/backend/files/provision/provision_builder_tasks.yml

@@ -141,3 +141,7 @@
   - 204.157.3.70 # https://pagure.io/fedora-infrastructure/issue/8096
   when:
   - prepare_base_image is not defined
+
+- name: mount cache filesystem on /var/cache/mock
+  mount: path=/var/cache/mock state=mounted src=mock_cache_tmpfs fstype=tmpfs opts="size=32G"
+  when: mock_var_cache_tmpfs is defined

roles/copr/backend/templates/provision/aws_cloud_vars.yml

@@ -6,3 +6,5 @@ aws_region: {{ copr_aws_region }}
 builder_images:
   x86_64: "{{ copr_builder_images.aws.x86_64 }}"
   aarch64: "{{ copr_builder_images.aws.aarch64 }}"
+
+mock_var_cache_tmpfs: true