set sslmode paramater and other connection options to be configurable (#4840)

Author: DaMandal0rian

docker/Dockerfile

@@ -63,6 +63,7 @@ ENV postgres_host ""
 ENV postgres_user ""
 ENV postgres_pass ""
 ENV postgres_db ""
+ENV postgres_args "sslmode=prefer"
 # The full URL to the IPFS node
 ENV ipfs ""
 # The etherum network(s) to connect to. Set this to a space-separated

docker/start

@@ -65,7 +65,7 @@ run_graph_node() {
     else
         unset GRAPH_NODE_CONFIG
         postgres_port=${postgres_port:-5432}
-        postgres_url="postgresql://$postgres_user:$postgres_pass@$postgres_host:$postgres_port/$postgres_db?sslmode=prefer"
+        postgres_url="postgresql://$postgres_user:$postgres_pass@$postgres_host:$postgres_port/$postgres_db?$postgres_args"
 
         wait_for_ipfs "$ipfs"
         echo "Waiting for Postgres ($postgres_host:$postgres_port)"