Update bootstrap messages

docker-entrypoint.sh

@@ -21,10 +21,13 @@ if ! test -f ${DATA_DIR}/host.crt; then
     cd ${DATA_DIR} || exit 1
     if ! test -d ${DATA_DIR}/host.csr; then
         "${BIN_DIR}/nebula-cert" keygen -out-key host.key -out-pub host.csr
+        # shellcheck disable=SC2016
         echo 'You will need to get the `host.csr` file signed by a cluster admin'
+        echo "Provide them with the hostname (${HOSTNAME}) and the \`host.csr\` file"
         exit 3
     else
-        echo 'Awaiting `host.csr` to be signed'
+        # shellcheck disable=SC2016
+        echo 'Awaiting for `host.csr` to be signed by a cluster admin'
         exit 4
     fi
 fi