Add docker files for running an Elasticsearch instance alongside the plugin

 because of gradle 'run' task removal here: elastic/elasticsearch@36d018c

Author: Bapt Abl

docker-compose.yml

@@ -0,0 +1,17 @@
+version: "3.7"
+
+services:
+  elasticsearch-plugin-debug:
+    build:
+      context: .
+      dockerfile: docker/Dockerfile
+      target: elasticsearch-plugin-debug
+    environment:
+      - discovery.type=single-node
+      # NO DEBUG
+      - ES_JAVA_OPTS=-Xms512m -Xmx512m
+      # DEBUG
+      # - ES_JAVA_OPTS=-Xms512m -Xmx512m -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=*:5005
+    ports:
+      - "9200:9200"
+      - "5005:5005"  # DEBUG

docker/Dockerfile

@@ -0,0 +1,4 @@
+FROM docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2 AS elasticsearch-plugin-debug
+
+COPY /build/distributions/geopoint-clustering-aggregation-7.10.2.0.zip /tmp/geopoint-clustering-aggregation-7.10.2.0.zip
+RUN ./bin/elasticsearch-plugin install file:/tmp/geopoint-clustering-aggregation-7.10.2.0.zip