Add password protection support to docker image

Dockerfile

@@ -1,10 +1,10 @@
 FROM debian:stretch
 
-ADD ./init.sh /init
-RUN chmod +x /init && apt-get update && apt-get install -y ca-certificates && rm -rf /var/lib/apt/lists/*
+ADD ./init.sh /init.sh
+RUN chmod +x /init.sh && apt-get update && apt-get install -y ca-certificates && rm -rf /var/lib/apt/lists/*
 
 ADD build/trafficmirror /trafficmirror
 
-CMD ["/init"]
+CMD ["/init.sh"]
 
 EXPOSE 8080

init.sh

@@ -1,8 +1,22 @@
 #!/bin/sh
 
-LISTEN_PORT=${LISTEN_PORT:-7077}
-MAIN=${MAIN:-localhost:8888}
-EXTRA_PARAMS=$1
+# Takes these environment variables:
+#
+# LISTEN_PORT: port to listen on (defaults to 7077)
+# MAIN: reverse proxy to this address (defaults to localhost:8888)
+# USERNAME & PASSWORD: if USERNAME is set protect targets endpoint with basic auth (default to empty)
 
-echo /trafficmirror /trafficmirror -listen ":${LISTEN_PORT}" -main=${MAIN} $EXTRA_PARAMS
-/trafficmirror -listen ":${LISTEN_PORT}" -main=${MAIN} $EXTRA_PARAMS
+listen_port=${LISTEN_PORT:-7077}
+main=${MAIN:-localhost:8888}
+extra_params=$1
+
+if [ ! -z "${USERNAME}" ]
+then
+  printf "${USERNAME}:${PASSWORD}" > /password.file
+  extra_params="${extra_params} -password /password.file"
+fi
+
+cmd="/trafficmirror -listen ":${listen_port}" -main=${main} $extra_params"
+
+echo "$cmd"
+eval "$cmd"