add initial mas setup

mas.config.yaml.tmpl

@@ -0,0 +1,41 @@
+# Docs: https://element-hq.github.io/matrix-authentication-service/
+
+http:
+  public_base: https://{{ env "DOMAIN" }}/
+  trusted_proxies:
+    - 10.0.0.0/8
+    - 172.16.0.0/12
+    - 192.168.0.0/16
+    - 127.0.0.0/8
+    - fd00::/8
+    - ::1/128
+  listeners:
+    - name: web
+      resources:
+        - name: discovery
+        - name: human
+        - name: oauth
+        - name: compat
+        - name: graphql
+          playground: false
+        - name: assets
+      binds:
+        - address: "[::]:8080"
+
+database:
+  uri: postgresql://synapse:{{ secret "db_password" }}@{{ env "STACK_NAME" }}_db:5432/mas?sslmode=disable
+
+matrix:
+  kind: synapse
+  homeserver: {{ or (env "SERVER_NAME") (env "DOMAIN") }}
+  endpoint: http://{{ env "STACK_NAME" }}_app:8008/
+  secret_file: /run/secrets/mas_synapse_shared
+
+secrets:
+  # Plain hex in file (abra: length=64 charset=hex). See .env.sample modifiers.
+  encryption_file: /run/secrets/mas_encryption
+  keys:
+    - key_file: /run/secrets/mas_signing_rsa
+
+passwords:
+  enabled: true