Build latest/main branch of rust-synapse-compress-state for non-amd64 users

The latest tagged release (v0.1.3) does not pin any versions in its
Dockerfile and as such fails to build right now.

The `main` branch of rust-synapse-compress-state has already addressed
this and is buildable, but there's no tagged release yet.

Reported here: https://github.com/matrix-org/rust-synapse-compress-state/issues/134

roles/custom/matrix-synapse-auto-compressor/defaults/main.yml

@@ -6,7 +6,7 @@
 matrix_synapse_auto_compressor_enabled: true
 
 # renovate: datasource=docker depName=registry.gitlab.com/etke.cc/rust-synapse-compress-state
-matrix_synapse_auto_compressor_version: v0.1.3
+matrix_synapse_auto_compressor_version: "{{ 'latest' if matrix_synapse_auto_compressor_container_image_self_build else 'v0.1.3' }}"
 
 matrix_synapse_auto_compressor_base_path: "{{ matrix_base_data_path }}/synapse-auto-compressor"
 matrix_synapse_auto_compressor_container_src_files_path: "{{ matrix_synapse_auto_compressor_base_path }}/container-src"

roles/custom/matrix-synapse-auto-compressor/tasks/install.yml

@@ -34,28 +34,39 @@
   delay: "{{ devture_playbook_help_container_retries_delay }}"
   until: result is not failed
 
-- name: Ensure synapse-auto-compressor repository is present on self-build
-  ansible.builtin.git:
-    repo: "{{ matrix_synapse_auto_compressor_container_image_self_build_repo }}"
-    version: "{{ matrix_synapse_auto_compressor_container_image_self_build_version }}"
-    dest: "{{ matrix_synapse_auto_compressor_container_src_files_path }}"
-    force: "yes"
-  become: true
-  become_user: "{{ matrix_user_username }}"
-  register: matrix_synapse_auto_compressor_git_pull_results
-  when: "matrix_synapse_auto_compressor_container_image_self_build | bool"
 
-- name: Ensure synapse-auto-compressor image is built
-  community.docker.docker_image:
-    name: "{{ matrix_synapse_auto_compressor_container_image }}"
-    source: build
-    force_source: "{{ matrix_synapse_auto_compressor_git_pull_results.changed if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mailer_git_pull_results.changed }}"
-    build:
-      dockerfile: Dockerfile
-      path: "{{ matrix_synapse_auto_compressor_container_src_files_path }}"
-      pull: true
-  when: "matrix_synapse_auto_compressor_container_image_self_build | bool"
+- when: "matrix_synapse_auto_compressor_container_image_self_build | bool"
+  block:
+    - name: Ensure synapse-auto-compressor repository is present on self-build
+      ansible.builtin.git:
+        repo: "{{ matrix_synapse_auto_compressor_container_image_self_build_repo }}"
+        version: "{{ matrix_synapse_auto_compressor_container_image_self_build_version }}"
+        dest: "{{ matrix_synapse_auto_compressor_container_src_files_path }}"
+        force: "yes"
+      become: true
+      become_user: "{{ matrix_user_username }}"
+      register: matrix_synapse_auto_compressor_git_pull_results
+
+    - name: Check if synapse-auto-compressor image exists
+      ansible.builtin.command: "{{ devture_systemd_docker_base_host_command_docker }} images --quiet --filter 'reference={{ matrix_synapse_auto_compressor_container_image }}'"
+      register: matrix_synapse_auto_compressor_container_image_check_result
+      changed_when: false
+
+    # Invoking the `docker build` command here, instead of calling the `docker_image` Ansible module,
+    # because the latter does not support BuildKit.
+    # See: https://github.com/ansible-collections/community.general/issues/514
+    - name: Ensure synapse-auto-compressor image is built
+      ansible.builtin.shell:
+        chdir: "{{ matrix_synapse_auto_compressor_container_src_files_path }}"
+        cmd: |
+          {{ devture_systemd_docker_base_host_command_docker }} build \
+          -t "{{ matrix_synapse_auto_compressor_container_image }}" \
+          -f Dockerfile \
+          .
+      environment:
+        DOCKER_BUILDKIT: 1
+      changed_when: true
+      when: "matrix_synapse_auto_compressor_git_pull_results.changed | bool or matrix_synapse_auto_compressor_container_image_check_result.stdout == ''"
 
 - name: Ensure matrix-synapse-auto-compressor container network is created
   community.general.docker_network: