[frontend] Add docker-compose file for HAProxy setup

as testing ground for a production HA setup.

* Loadbalancing by HAProxy is now available via localhost:8080
* First frontend node can be accessed via localhost:3000
* Second frontend node can be accessed via localhost:3001

contrib/Procfile.ha

@@ -0,0 +1,5 @@
+web: bundle exec rails server -P tmp/pids/server$NODE_NUMBER.pid
+delayed: bundle exec script/delayed_job.api.rb run
+clock: bundle exec clockworkd --log-dir=log -l -c config/clock.rb run 
+search: bundle exec rake ts:rebuild NODETACH=true
+mailcatcher: mailcatcher --ip 0.0.0.0 -f --no-quit -v

contrib/haproxy.cfg

@@ -0,0 +1,26 @@
+defaults
+  log     global
+  mode    http
+  option  httplog
+  option  dontlognull
+  timeout connect 5000
+  timeout client  50000
+  timeout server  50000
+
+resolvers dockerdns
+  nameserver dns 127.0.0.11:53
+
+frontend localnodes
+  bind *:80
+  mode http
+  default_backend nodes
+
+backend nodes
+  mode http
+  balance roundrobin
+  option forwardfor
+  http-request set-header X-Forwarded-Port %[dst_port]
+  http-request add-header X-Forwarded-Proto https if { ssl_fc }
+  option httpchk HEAD /about HTTP/1.1\r\nHost:localhost
+  server web01 frontend:3000 check resolvers dockerdns resolve-prefer ipv4
+  server web02 frontend_node_2:3000 check resolvers dockerdns resolve-prefer ipv4

contrib/thinking_sphinx.yml.ha

@@ -0,0 +1,24 @@
+development:
+  mysql41: 9312
+  bin_path: /usr/bin
+  mem_limit: 512M
+  charset_table: "0..9, a..z, A..Z->a..z, U+410..U+42F->U+430..U+44F, U+430..U+44F"
+  mysql41: <%= 9313 + ENV['NODE_NUMBER'].to_i %>
+  indices_location: <%= File.join(Rails.root, "db", "sphinx", "development#{ENV['NODE_NUMBER']}") %>
+  configuration_file: <%= File.join(Rails.root, "config", "development#{ENV['NODE_NUMBER']}.sphinx.conf")%>
+  log: <%= File.join(Rails.root, "log", "development#{ENV['NODE_NUMBER']}.searchd.log") %>
+  query_log: <%= File.join(Rails.root, "log", "development#{ENV['NODE_NUMBER']}.searchd.query.log") %>
+  binlog_path: <%= File.join(Rails.root, "tmp", "binlog", "development#{ENV['NODE_NUMBER']}") %>
+  pid_file: <%= File.join(Rails.root, "tmp", "pids", "development#{ENV['NODE_NUMBER']}.sphinx.pid") %>
+test:
+  mysql41: 9313
+  bin_path: /usr/bin
+  mem_limit: 512M
+  charset_table: "0..9, a..z, A..Z->a..z, U+410..U+42F->U+430..U+44F, U+430..U+44F"
+  # To efficiently deal with large ids generated by fixtures
+  sql_range_step: 10000000
+production:
+  mysql41: 9314
+  bin_path: /usr/bin
+  mem_limit: 512M
+  charset_table: "0..9, a..z, A..Z->a..z, U+410..U+42F->U+430..U+44F, U+430..U+44F"

docker-compose.ha.yml

@@ -0,0 +1,27 @@
+version: "2.1"
+services:
+  proxy:
+    image: haproxy:1.7
+    volumes:
+      - ./contrib/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
+    ports:
+      - "8080:80"
+    depends_on:
+      - frontend
+      - frontend_node_2
+  frontend_node_2:
+    image: openbuildservice/frontend
+    environment:
+      - NODE_NUMBER=2
+    volumes:
+      - .:/obs
+      - ./contrib/thinking_sphinx.yml.ha:/obs/src/api/config/thinking_sphinx.yml:ro
+      - ./contrib/Procfile.ha:/obs/src/api/Procfile
+    ports:
+      - "3001:3000"
+      - "1081:1080"
+    depends_on:
+      - db
+      - cache
+      - backend
+      - worker