Add first version of the frontend

As of now the only usable functionality is signin in/out and managing
authorized users, and even then there is much room for improvement.

Change-Id: Ib87fc6866f69113a230187710de8644b78391917
diff --git a/docker/envoy-dev/envoy.yaml b/docker/envoy-dev/envoy.yaml
new file mode 100644
index 0000000..be29930
--- /dev/null
+++ b/docker/envoy-dev/envoy.yaml
@@ -0,0 +1,56 @@
+admin:
+  access_log_path: /tmp/admin_access.log
+  address:
+    socket_address: { address: 0.0.0.0, port_value: 9901 }
+
+static_resources:
+  listeners:
+  - name: listener_0
+    address:
+      socket_address: { address: 0.0.0.0, port_value: 8081 }
+    filter_chains:
+    - filters:
+      - name: envoy.filters.network.http_connection_manager
+        typed_config:
+          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+          codec_type: auto
+          stat_prefix: ingress_http
+          route_config:
+            name: local_route
+            virtual_hosts:
+            - name: local_service
+              domains: ["*"]
+              routes:
+              - match: { prefix: "/" }
+                route:
+                  cluster: echo_service
+                  timeout: 0s
+                  max_stream_duration:
+                    grpc_timeout_header_max: 0s
+              cors:
+                allow_origin_string_match:
+                - prefix: "*"
+                allow_methods: GET, PUT, DELETE, POST, OPTIONS
+                allow_headers: keep-alive,user-agent,cache-control,content-type,content-transfer-encoding,custom-header-1,x-accept-content-transfer-encoding,x-accept-response-streaming,x-user-agent,x-grpc-web,grpc-timeout,authorization
+                max_age: "1728000"
+                expose_headers: custom-header-1,grpc-status,grpc-message
+          http_filters:
+          - name: envoy.filters.http.grpc_web
+          - name: envoy.filters.http.cors
+          - name: envoy.filters.http.router
+  clusters:
+  - name: echo_service
+    connect_timeout: 3s
+    type: logical_dns
+    http2_protocol_options: {}
+    lb_policy: round_robin
+    dns_lookup_family: V4_ONLY
+    load_assignment:
+      cluster_name: cluster_0
+      endpoints:
+        - lb_endpoints:
+            - endpoint:
+                address:
+                  socket_address:
+                    address: server
+                    port_value: 10000