Define simple healthchecks for simulators

- currently containers are healthy if they have successfully started
their Http servers thus simple endpoint at /healthcheck is sufficient
- to enable docker healthcheck we need to add `curl` to docker images
- http_proxy needs to be provided for docker to be able to build images
behind proxy

Closes ONAP-695

Change-Id: I02f0b8cc2732713b5307dbc34ba604d8185b74fc
Signed-off-by: fkrzywka <filip.krzywka@nokia.com>
Issue-ID: DCAEGEN2-601
diff --git a/hv-collector-dcae-app-simulator/Dockerfile b/hv-collector-dcae-app-simulator/Dockerfile
index 39bd878..55bf645 100644
--- a/hv-collector-dcae-app-simulator/Dockerfile
+++ b/hv-collector-dcae-app-simulator/Dockerfile
@@ -5,6 +5,10 @@
 LABEL license.url="http://www.apache.org/licenses/LICENSE-2.0"
 LABEL maintainer="Nokia Wroclaw ONAP Team"
 
+RUN apt-get update \
+        && apt-get install -y --no-install-recommends curl  \
+        && apt-get clean
+
 WORKDIR /opt/ves-hv-dcae-app-simulator
 ENTRYPOINT ["java", "-cp", "*:", "org.onap.dcae.collectors.veshv.simulators.dcaeapp.MainKt"]
 COPY target/libs/external/* ./