Refactor docker-compose.yml for better compatibility with new version (#1641)

The newest versions of docker-compose want to have some values double-quoted in the env file while old versions failing to process such files.
The solution is simple, move some of the parameters to the `docker-compose.yml` and rely on anchors for inheritance.
Since the main idea behind env files was to keep "secret" information off the main YAML we also get rid of any non-secret stuff, mainly located in the etcd.env.

docker-compose.yml

@@ -9,53 +9,39 @@ services:
     etcd1:
         image: patroni
         networks: [ demo ]
-        env_file: docker/etcd.env
         container_name: demo-etcd1
         hostname: etcd1
         command: etcd -name etcd1 -initial-advertise-peer-urls http://etcd1:2380
+        environment: &etcd_env
+            ETCD_LISTEN_PEER_URLS: http://0.0.0.0:2380
+            ETCD_LISTEN_CLIENT_URLS: http://0.0.0.0:2379
+            ETCD_INITIAL_CLUSTER: etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
+            ETCD_INITIAL_CLUSTER_STATE: new
+            ETCD_INITIAL_CLUSTER_TOKEN: tutorial
+            ETCD_NAME: etcd1
+            ETCD_INITIAL_ADVERTISE_PEER_URLS: http://etcd1:2380
 
     etcd2:
         image: patroni
         networks: [ demo ]
-        env_file: docker/etcd.env
         container_name: demo-etcd2
         hostname: etcd2
         command: etcd -name etcd2 -initial-advertise-peer-urls http://etcd2:2380
+        environment:
+            <<: *etcd_env
+            ETCD_NAME: etcd2
+            ETCD_INITIAL_ADVERTISE_PEER_URLS: http://etcd2:2380
 
     etcd3:
         image: patroni
         networks: [ demo ]
-        env_file: docker/etcd.env
         container_name: demo-etcd3
         hostname: etcd3
         command: etcd -name etcd3 -initial-advertise-peer-urls http://etcd3:2380
-
-    patroni1:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni1
-        container_name: demo-patroni1
         environment:
-            PATRONI_NAME: patroni1
+            <<: *etcd_env
-
+            ETCD_NAME: etcd3
-    patroni2:
+            ETCD_INITIAL_ADVERTISE_PEER_URLS: http://etcd3:2380
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni2
-        container_name: demo-patroni2
-        environment:
-            PATRONI_NAME: patroni2
-
-    patroni3:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni3
-        container_name: demo-patroni3
-        environment:
-            PATRONI_NAME: patroni3
 
     haproxy:
         image: patroni
@@ -67,3 +53,37 @@ services:
             - "5000:5000"
             - "5001:5001"
         command: haproxy
+        environment: &haproxy_env
+            ETCDCTL_ENDPOINTS: http://etcd1:2379,http://etcd2:2379,http://etcd3:2379
+            PATRONI_ETCD3_HOSTS: "'etcd1:2379','etcd2:2379','etcd3:2379'"
+            PATRONI_SCOPE: demo
+
+    patroni1:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni1
+        container_name: demo-patroni1
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni1
+
+    patroni2:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni2
+        container_name: demo-patroni2
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni2
+
+    patroni3:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni3
+        container_name: demo-patroni3
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni3

docker/etcd.env

@@ -1,5 +0,0 @@
-ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
-ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
-ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
-ETCD_INITIAL_CLUSTER_STATE=new
-ETCD_INITIAL_CLUSTER_TOKEN=tutorial

docker/patroni.env

@@ -1,6 +1,3 @@
-PATRONI_SCOPE=demo
-PATRONI_ETCD3_HOSTS='etcd1:2379','etcd2:2379','etcd3:2379'
-
 PATRONI_RESTAPI_USERNAME=admin
 PATRONI_RESTAPI_PASSWORD=admin
 PATRONI_SUPERUSER_USERNAME=postgres
@@ -9,6 +6,3 @@ PATRONI_REPLICATION_USERNAME=replicator
 PATRONI_REPLICATION_PASSWORD=replicate
 PATRONI_admin_PASSWORD=admin
 PATRONI_admin_OPTIONS=createdb,createrole
-
-# for etcdctl
-ETCDCTL_ENDPOINTS=http://etcd1:2379,http://etcd2:2379,http://etcd3:2379