Release Synapse v1.27.0 to ARM32 via self-building

Related to: https://matrix.org/blog/2021/02/18/synapse-1-27-0-released#dropping-armv7-docker-images

group_vars/matrix_servers

@@ -1269,7 +1269,7 @@ matrix_client_element_jitsi_preferredDomain: "{{ matrix_server_fqn_jitsi if matr
 #
 ######################################################################
 
-matrix_synapse_container_image_self_build: "{{ matrix_architecture not in ['arm32', 'arm64', 'amd64'] }}"
+matrix_synapse_container_image_self_build: "{{ matrix_architecture not in ['arm64', 'amd64'] }}"
 
 # When ma1sd is enabled, we can use it to validate email addresses and phone numbers.
 # Synapse can validate email addresses by itself as well, but it's probably not what we want by default when we have an identity server.

roles/matrix-synapse/defaults/main.yml

@@ -11,7 +11,11 @@ matrix_synapse_docker_image_name_prefix: "{{ 'localhost/' if matrix_synapse_cont
 # The if statement below may look silly at times (leading to the same version being returned),
 # but ARM-compatible container images are only released 1-7 hours after a release,
 # so we may often be on different versions for different architectures when new Synapse releases come out.
-matrix_synapse_docker_image_tag: "{{ 'v1.27.0' if matrix_architecture == 'amd64' else 'v1.26.0' }}"
+#
+# amd64 gets released first.
+# arm32 relies on self-building, so the same version can be built immediately.
+# arm64 users need to wait for a prebuilt image to become available.
+matrix_synapse_docker_image_tag: "{{ 'v1.27.0' if matrix_architecture in ['arm32', 'amd64'] else 'v1.26.0' }}"
 matrix_synapse_docker_image_force_pull: "{{ matrix_synapse_docker_image.endswith(':latest') }}"
 
 matrix_synapse_base_path: "{{ matrix_base_data_path }}/synapse"