[MSB] Make consul run as non-root

[oom.git] / kubernetes / msb / charts / msb-consul / resources / docker-entrypoint.sh

diff --git a/kubernetes/msb/charts/msb-consul/resources/docker-entrypoint.sh b/kubernetes/msb/charts/msb-consul/resources/docker-entrypoint.sh
new file mode 100755 (executable)
index 0000000..0cd4616
--- /dev/null
+++ b/kubernetes/msb/charts/msb-consul/resources/docker-entrypoint.sh
@@ -0,0 +1,100 @@
+#!/usr/bin/dumb-init /bin/sh
+set -e
+set -x
+
+# Note above that we run dumb-init as PID 1 in order to reap zombie processes
+# as well as forward signals to all processes in its session. Normally, sh
+# wouldn't do either of these functions so we'd leak zombies as well as do
+# unclean termination of all our sub-processes.
+# As of docker 1.13, using docker run --init achieves the same outcome.
+
+# You can set CONSUL_BIND_INTERFACE to the name of the interface you'd like to
+# bind to and this will look up the IP and pass the proper -bind= option along
+# to Consul.
+CONSUL_BIND=
+if [ -n "$CONSUL_BIND_INTERFACE" ]; then
+  CONSUL_BIND_ADDRESS=$(ip -o -4 addr list $CONSUL_BIND_INTERFACE | head -n1 | awk '{print $4}' | cut -d/ -f1)
+  if [ -z "$CONSUL_BIND_ADDRESS" ]; then
+    echo "Could not find IP for interface '$CONSUL_BIND_INTERFACE', exiting"
+    exit 1
+  fi
+
+  CONSUL_BIND="-bind=$CONSUL_BIND_ADDRESS"
+  echo "==> Found address '$CONSUL_BIND_ADDRESS' for interface '$CONSUL_BIND_INTERFACE', setting bind option..."
+fi
+
+# You can set CONSUL_CLIENT_INTERFACE to the name of the interface you'd like to
+# bind client intefaces (HTTP, DNS, and RPC) to and this will look up the IP and
+# pass the proper -client= option along to Consul.
+CONSUL_CLIENT=
+if [ -n "$CONSUL_CLIENT_INTERFACE" ]; then
+  CONSUL_CLIENT_ADDRESS=$(ip -o -4 addr list $CONSUL_CLIENT_INTERFACE | head -n1 | awk '{print $4}' | cut -d/ -f1)
+  if [ -z "$CONSUL_CLIENT_ADDRESS" ]; then
+    echo "Could not find IP for interface '$CONSUL_CLIENT_INTERFACE', exiting"
+    exit 1
+  fi
+
+  CONSUL_CLIENT="-client=$CONSUL_CLIENT_ADDRESS"
+  echo "==> Found address '$CONSUL_CLIENT_ADDRESS' for interface '$CONSUL_CLIENT_INTERFACE', setting client option..."
+fi
+
+# CONSUL_DATA_DIR is exposed as a volume for possible persistent storage. The
+# CONSUL_CONFIG_DIR isn't exposed as a volume but you can compose additional
+# config files in there if you use this image as a base, or use CONSUL_LOCAL_CONFIG
+# below.
+CONSUL_DATA_DIR=/consul/data
+CONSUL_CONFIG_DIR=/consul/config
+
+# You can also set the CONSUL_LOCAL_CONFIG environemnt variable to pass some
+# Consul configuration JSON without having to bind any volumes.
+if [ -n "$CONSUL_LOCAL_CONFIG" ]; then
+       echo "$CONSUL_LOCAL_CONFIG" > "$CONSUL_CONFIG_DIR/local.json"
+fi
+
+# If the user is trying to run Consul directly with some arguments, then
+# pass them to Consul.
+if [ "${1:0:1}" = '-' ]; then
+    set -- consul "$@"
+fi
+
+# Look for Consul subcommands.
+if [ "$1" = 'agent' ]; then
+    shift
+    set -- consul agent \
+        -data-dir="$CONSUL_DATA_DIR" \
+        -config-dir="$CONSUL_CONFIG_DIR" \
+        $CONSUL_BIND \
+        $CONSUL_CLIENT \
+        "$@"
+elif [ "$1" = 'version' ]; then
+    # This needs a special case because there's no help output.
+    set -- consul "$@"
+elif consul --help "$1" 2>&1 | grep -q "consul $1"; then
+    # We can't use the return code to check for the existence of a subcommand, so
+    # we have to use grep to look for a pattern in the help output.
+    set -- consul "$@"
+fi
+
+# If we are running Consul, make sure it executes as the proper user.
+if [ "$1" = 'consul' ]; then
+    # If the data or config dirs are bind mounted then chown them.
+    # Note: This checks for root ownership as that's the most common case.
+    if [ "$(stat -c %u /consul/data)" != "$(id -u consul)" ]; then
+        chown consul:consul /consul/data
+    fi
+    if [ "$(stat -c %u /consul/config)" != "$(id -u consul)" ]; then
+        chown consul:consul /consul/config
+    fi
+
+    # If requested, set the capability to bind to privileged ports before
+    # we drop to the non-root user. Note that this doesn't work with all
+    # storage drivers (it won't work with AUFS).
+    if [ ! -z ${CONSUL_ALLOW_PRIVILEGED_PORTS+x} ]; then
+        setcap "cap_net_bind_service=+ep" /bin/consul
+    fi
+
+# Instead of using this we run our pod as a non-root user.
+#    set -- su-exec consul:consul "$@"
+fi
+
+exec "$@"