Configure host with --host (#74)

* Configure host with --host

e.g. using --host 127.0.0.1 restricts incoming connections to those
from localhost

* fix

* nix variables, use defaults

app/src/entry-point.lisp

@@ -34,9 +34,16 @@
      :optional t
      :documentation "start a QVM server")
 
+    (("host")
+     :type string
+     :optional t
+     :initial-value "0.0.0.0"
+     :documentation "host on which to start the QVM server")
+
     (("port" #\p)
      :type integer
      :optional t
+     :initial-value 5000
      :documentation "port to start the QVM server on")
 
     (("qubits" #\q)
@@ -190,18 +197,13 @@ Copyright (c) 2016-2019 Rigetti Computing.~2%")
           (or *num-workers* (max 1 (qvm:count-logical-cores))))
   nil)
 
-(defparameter *host-address* "0.0.0.0")
-(defparameter *default-host-port* 5000)
-
-(defun start-server-app (port)
+(defun start-server-app (host port)
   (check-type port (or null (integer 0 65535))
               "The port must be between 0 and 65535.")
-  (when (null port)
-    (setf port *default-host-port*))
   (format-log "Starting server on port ~D." port)
   (unless (null *qubit-limit*)
     (format-log "Server is limited to ~D qubit~:P." *qubit-limit*))
-  (start-server port)
+  (start-server host port)
   ;; TODO? Make this join the thread, instead of spinning in a loop.
   (loop (sleep 1)))
 
@@ -332,6 +334,7 @@ Copyright (c) 2016-2019 Rigetti Computing.~2%")
                           help
                           memory-limit
                           server
+                          host
                           port
                           #-forest-sdk swank-port
                           num-workers
@@ -493,7 +496,7 @@ Version ~A is available from downloads.rigetti.com/qcs-sdk/forest-sdk.dmg~%"
 
        (format-log "Created persistent memory for ~D qubits" qubits))
      ;; Start the server
-     (start-server-app port))
+     (start-server-app host port))
 
     ;; Batch mode.
     (t
@@ -614,7 +617,7 @@ Version ~A is available from downloads.rigetti.com/qcs-sdk/forest-sdk.dmg~%"
 (defun asdf-entry-point ()
   (%main (list* "qvm-app" (uiop:command-line-arguments))))
 
-(defun start-server (port)
+(defun start-server (host port)
   #+forest-sdk
   (setq tbnl:*log-lisp-backtraces-p* nil
         tbnl:*log-lisp-errors-p* nil)
@@ -625,7 +628,7 @@ Version ~A is available from downloads.rigetti.com/qcs-sdk/forest-sdk.dmg~%"
         tbnl:*catch-errors-p* (not *debug*))
   (setq *app* (make-instance
                'vhost
-               :address *host-address*
+               :address host
                :port port
                :taskmaster (make-instance 'tbnl:one-thread-per-connection-taskmaster)))
   (when (null (dispatch-table *app*))