Set node name for clustering based on ECS metadata

Author: reachfh

rel/env.sh.eex

@@ -18,3 +18,15 @@
 # # RELEASE_DISTRIBUTION must be "sname" (local), "name" (distributed) or "none".
 # export RELEASE_DISTRIBUTION=name
 # export RELEASE_NODE=<%= @release.name %>
+
+# Set node name for clustering based on ECS metadata
+# https://dmblake.com/elixir-clustering-with-libcluster-and-aws-ecs-fargate-in-cdk
+# https://docs.aws.amazon.com/AmazonECS/latest/userguide/task-metadata-endpoint-v4-fargate.html
+if [ ! -z "$ECS_CONTAINER_METADATA_URI_V4" ]; then
+    export RELEASE_DISTRIBUTION=name
+    # HOSTNAME=$(curl -s ${ECS_CONTAINER_METADATA_URI_V4}/task | jq -r '.Containers[0].Networks[0].IPv4Addresses[0]')
+    HOSTNAME=$(wget -q ${ECS_CONTAINER_METADATA_URI_V4}/task -O -| jq -r '.Containers[0].Networks[0].IPv4Addresses[0]')
+    export RELEASE_NODE="${RELEASE_NAME}@${HOSTNAME}"
+fi
+
+# export DISTRIBUTION_PORT=7777