Add additional logic to entrypoint to handle more subcommands. (#1350)

CHANGELOG.md

@@ -47,6 +47,8 @@ Boundary) but it's worth repeating.
   causing an error when the scheduler attempts to run jobs
   ([issue](https://github.com/hashicorp/boundary/issues/1309),
   [PR](https://github.com/hashicorp/boundary/pull/1310)).
+* Docker: update entrypoint script to handle more Boundary subcommands for 
+  better UX
 
 ## 0.3.0 (2021/06/08)
 

docker/docker-entrypoint.sh

@@ -19,6 +19,10 @@ if [ "$1" = 'server' ]; then
     shift
     set -- boundary server \
         "$@"
+elif boundary --help "$1" 2>&1 | grep -q "boundary $1"; then
+    # We can't use the return code to check for the existence of a subcommand, so
+    # we have to use grep to look for a pattern in the help output.
+    set -- boundary "$@"
 fi
 
 # If we are running Boundary, make sure it executes as the proper user.