Use ssh multiplexing

startvnc.sh

@@ -14,8 +14,9 @@
 # The vncviewer client has to support the -via option. TurboVNC,
 # TigerVNC and TightVNC are known to work.
 #
-# You really should use publickey authentication. Otherwise you
-# have to type your password many times.
+# Set SSH_MUX=true to share one ssh connection. This can speed up the
+# script if ssh login is slow. If you have to use password
+# authentication, you will only have to give your password twice.
 
 set -e
 
@@ -28,8 +29,9 @@ readonly GEOMETRY="1920x1200"           # resolution of remote desktop window
 readonly VNCVIEWER=/usr/bin/vncviewer   # path to local vncviewer
 readonly PASSWORD=true                  # copy vncpassword temporarily to
                                         # the local workstation
-
-#readonly OPTIONS="-extssh"              # uncomment this if you use
+readonly SSH_MUX=true                   # use sharing of multiple ssh sessions
+                                        # over a single network connection
+#readonly OPTIONS="-extssh"             # uncomment this if you use
                                         # TurboVNC as vncviewer
 
 clean_up () {
@@ -55,6 +57,10 @@ clean_up () {
         ${ssh_mistral} "cd .startvnc && rm -f ${tmp_files}"
     fi
 
+    if [[ ${SSH_MUX} = true ]]; then
+        ssh ${ssh_options} -O exit ${mistral}
+    fi
+
     # Remove local vnc PasswordFile
     if [[ ${copy_password} = true ]]; then
         rm -f ${HOME}/vnc_passwd
@@ -83,7 +89,7 @@ do
            ;;
         v) vncviewer="$OPTARG"
            ;;
-        x) options="$OPTARG"
+        x) vnc_options="$OPTARG"
            ;;
         ?) usage
         exit 2
@@ -97,10 +103,15 @@ qos=${qos:-${QOS}}
 runtime=${runtime:-${TIME}}
 username=${username:-${USERNAME}}
 vncviewer=${vncviewer:-${VNCVIEWER}}
-options=${options:-${OPTIONS}}
-mistral="${username}@mistral.dkrz.de"
-ssh_mistral_options="-x"
-ssh_mistral="ssh ${ssh_mistral_options} ${mistral}"
+vnc_options=${vnc_options:-${OPTIONS}}
+mistral="${username}@mistral00.dkrz.de"
+ssh_options="-o ForwardX11=no"
+
+if [[ ${SSH_MUX} = true ]]; then
+    ssh_options+=" -o ControlPath=~/.ssh/control:%h:%p:%r"
+fi
+
+ssh_mistral="ssh ${ssh_options} ${mistral}"
 
 if [[ -z ${acctcode} ]] || [[ -z ${username} ]]; then
     printf "ERROR: Please specify at least username and acctcode.\n\n" >&2
@@ -108,6 +119,10 @@ if [[ -z ${acctcode} ]] || [[ -z ${username} ]]; then
     exit 2
 fi
 
+if [[ ${SSH_MUX} = true ]]; then
+    ssh -MNf ${ssh_options} ${mistral}
+fi
+
 if ! ${ssh_mistral} "test -s .vnc/passwd"; then
     echo "No VNC password found. Please set now."
     ${ssh_mistral} -t "salloc -Q -n1 -pgpu -A${acctcode} -- /bin/bash -c \
@@ -154,12 +169,12 @@ host_and_display=$(${ssh_mistral} "/bin/bash .startvnc/gethost.${job_id}")
 
 vnc_host=${host_and_display%:*}
 vnc_display=${host_and_display#*:}
-options+=" -via ${username}@${vnc_host}.dkrz.de"
+vnc_options+=" -via ${username}@${vnc_host}.dkrz.de"
 
 if [[ ${PASSWORD} = true ]]; then
-    scp -q -o "ForwardX11=no" ${mistral}:.vnc/passwd ${HOME}/vnc_passwd
-    options+=" -passwd ${HOME}/vnc_passwd"
+    scp -q ${ssh_options} ${mistral}:.vnc/passwd ${HOME}/vnc_passwd
+    vnc_options+=" -passwd ${HOME}/vnc_passwd"
 fi
 
 # Start VNC viewer
-${vncviewer} ${options} :${vnc_display}
+${vncviewer} ${vnc_options} :${vnc_display}