examples: unify apt and cleanup unused installation

examples/cache/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD /usr/local/bin/envoy -c /etc/front-envoy.yaml --service-cluster front-proxy

examples/cors/backend/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c", "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]

examples/cors/frontend/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c", "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]

examples/csrf/crosssite/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c", "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]

examples/csrf/samesite/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c",  "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]

examples/dynamic-config-cp/Dockerfile-control-plane

@@ -1,6 +1,11 @@
 FROM golang
 
-RUN apt-get -y update && apt-get install -y -qq --no-install-recommends netcat
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y netcat \
+    && apt-get autoremove -y \
+    && apt-get clean \
+    && rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/*
+
 RUN git clone https://github.com/envoyproxy/go-control-plane
 ADD ./resource.go /go/go-control-plane/internal/example/resource.go
 RUN cd go-control-plane && make bin/example

examples/dynamic-config-cp/Dockerfile-proxy

@@ -1,6 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get -y update && apt-get install -y -qq --no-install-recommends netcat
 COPY ./envoy.yaml /etc/envoy.yaml
 RUN chmod go+r /etc/envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c /etc/envoy.yaml", "-l", "debug"]

examples/ext_authz/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./config /etc/envoy-config
 COPY ./run_envoy.sh /run_envoy.sh
 RUN chmod go+r -R /etc/envoy-config \

examples/fault-injection/Dockerfile-envoy

@@ -1,6 +1,10 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get install -y curl tree
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y tree curl \
+    && apt-get autoremove -y \
+    && apt-get clean \
+    && rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/*
 COPY ./envoy.yaml /etc/envoy.yaml
 RUN chmod go+r /etc/envoy.yaml
 COPY enable_delay_fault_injection.sh disable_delay_fault_injection.sh enable_abort_fault_injection.sh disable_abort_fault_injection.sh send_request.sh /

examples/front-proxy/Dockerfile-frontenvoy

@@ -1,7 +1,10 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y curl \
+    && apt-get autoremove -y \
+    && apt-get clean \
+    && rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/*
 COPY ./front-envoy.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c", "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]

examples/jaeger-native-tracing/Dockerfile-frontenvoy

@@ -1,7 +1,11 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y curl \
+    && apt-get autoremove -y \
+    && apt-get clean \
+    && rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/*
+
 COPY ./front-envoy-jaeger.yaml /etc/front-envoy.yaml
 #
 # for discussion on jaeger binary compatibility, and the source of the file, see here:

examples/skywalking-tracing/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy-skywalking.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD /usr/local/bin/envoy -c /etc/front-envoy.yaml --service-cluster front-proxy

examples/zipkin-tracing/Dockerfile-frontenvoy

@@ -1,7 +1,5 @@
 FROM envoyproxy/envoy-dev:latest
 
-RUN apt-get update && apt-get -q install -y \
-    curl
 COPY ./front-envoy-zipkin.yaml /etc/front-envoy.yaml
 RUN chmod go+r /etc/front-envoy.yaml
 CMD ["/usr/local/bin/envoy", "-c", "/etc/front-envoy.yaml", "--service-cluster", "front-proxy"]