Add miniflux deployment

Contains default credentials but these should be overwritten with
group or host -destined variables.

Add default credentials

Hide real credential files from git

roles/miniflux/templates/docker-stack.yml.j2

@@ -0,0 +1,48 @@
+version: '3.7'
+
+services:
+  app:
+    image: {{ stack_image }}:{{ miniflux_version }}
+    networks:
+      - "{{ docker_swarm_public_network_name }}"
+      - backend
+    healthcheck:
+        test: ["CMD", "/usr/bin/miniflux", "-healthcheck", "auto"]
+        interval: 1m
+        timeout: 10s
+        retries: 3
+        start_period: 1m
+    environment:
+      - DATABASE_URL=postgres://{{ miniflux_postgres_user }}:{{ miniflux_postgres_password }}@db/miniflux?sslmode=disable
+      - RUN_MIGRATIONS=1
+      - CREATE_ADMIN=1
+      - ADMIN_USERNAME={{ miniflux_admin_username }}
+      - ADMIN_PASSWORD={{ miniflux_admin_password }}
+      - DEBUG=1
+{% if server_domain is not undefined and not none %}   
+      - "BASE_URL={{ (miniflux_use_https == True) | ternary('https', 'http') }}://{{ (subdomain_alias is not undefined and not none) | ternary(subdomain_alias, stack_name) }}.{{server_domain}}"
+{% else %}
+      - "BASE_URL={{ (miniflux_use_https == True) | ternary('https', 'http') }}://localhost/{{ (subdomain_alias is not undefined and not none) | ternary(subdomain_alias, stack_name) }}"
+{% endif %}
+
+  db:
+    image: postgres:11
+    networks:
+      - backend
+    healthcheck:
+      test: ["CMD", "pg_isready", "-U", "miniflux"]
+      interval: 1m
+      start_period: 30s
+    environment:
+      - POSTGRES_USER={{ miniflux_postgres_user }}
+      - POSTGRES_PASSWORD={{ miniflux_postgres_password }}
+    volumes:
+      - db:/var/lib/postgresql/data
+
+volumes:
+  db:
+
+networks:
+  "{{ docker_swarm_public_network_name }}":
+    external: true
+  backend: