Move beat specific logic to docker-compose

Dockerfile

@@ -17,22 +17,10 @@ RUN set -x \
 
 COPY scripts/docker-entrypoint.sh /entrypoint.sh
 
-# Setup work environment
-ENV LIBBEAT_PATH /go/src/github.com/elastic/beats/libbeat
 ENV GO15VENDOREXPERIMENT=1
-RUN mkdir -p $LIBBEAT_PATH/coverage
-WORKDIR $LIBBEAT_PATH
 
 RUN mkdir -p /etc/pki/tls/certs
 COPY scripts/docker/logstash/pki/tls/certs/logstash.crt /etc/pki/tls/certs/logstash.crt
 
 # Create a copy of the respository inside the container.
 COPY . /go/src/github.com/elastic/beats/
-
-# It is expected that libbeat from the host is mounted
-# within the container at the WORKDIR location.
-ENTRYPOINT ["/entrypoint.sh"]
-
-# Build libbeat inside of the container so that it is ready
-# for testing.
-RUN make

libbeat/docker-compose.yml

@@ -12,8 +12,13 @@ libbeat:
     - LS_TLS_PORT=5055
     - ES_USER=beats
     - ES_PASS=testing
+    # Setup work environment
+    - LIBBEAT_PATH=/go/src/github.com/elastic/beats/libbeat
   env_file:
     - build/test.env
+  working_dir: /go/src/github.com/elastic/beats/libbeat
+  command: make
+  entrypoint: /entrypoint.sh
 elasticsearch:
   build: ../scripts/docker/elasticsearch
   dockerfile: Dockerfile-2.2.0