net: run.sh: support tmux as terminal

Create one tmux session, with each Osmocom program in one window, if
tmux is chosen as "terminal". This allows using osmo-dev's run.sh over
ssh without X forwarding. Also the existing supported terminals
automatically scroll to the bottom as soon as there is new output,
making it hard to read logs.

Change-Id: Iaef08fb3cb3c6f58cd8490a631e177a03af9c974

net/config_2g3g

@@ -1,5 +1,5 @@
 # Terminal for launching Osmocom programs
-# Supported: urxvt, xterm
+# Supported: urxvt, xterm, tmux
 TERMINAL="urxvt"
 
 ETH_DEV=eth0

net/templates/run.sh

@@ -1,5 +1,13 @@
 #!/usr/bin/env bash
 
+# tmux: start this script inside a new session
+tmux_session="CN"
+if [ "${TERMINAL}" = "tmux" ] && [ "$1" != "inside-tmux" ]; then
+  echo "Starting tmux session '$tmux_session'"
+  unset TMUX
+  exec tmux new-session -s "$tmux_session" -n "RUN" "$0" "inside-tmux"
+fi
+
 if ! ../fill_config.py --check-stale; then
 	echo
 	echo "WARNING: STALE CONFIGS - your net configs are older than the templates they should be based on!"
@@ -46,7 +54,7 @@ mkdir -p "$logdir" "$piddir" "$launcherdir"
 
 find_term() {
   # Find a terminal program and write to the global "terminal" variable
-  local programs="urxvt xterm"
+  local programs="urxvt xterm tmux"
 
   if [ -z "${TERMINAL}" ]; then
     echo "ERROR: TERMINAL is not defined in your osmo-dev net config file. Please add it."
@@ -118,12 +126,19 @@ done
 EOF
   chmod +x "$launcher"
 
-  $terminal \
-    -title "CN:$title" \
-    -e sh -c "$launcher" \
-    &
+  case "$terminal" in
+    tmux)
+      tmux new-window -d -n "$title" "$launcher &; echo \$! > $pidfile_term; fg; wait"
+      ;;
+    *)
+      $terminal \
+        -title "CN:$title" \
+        -e sh -c "$launcher" \
+        &
 
-  echo "$!" > "$pidfile_term"
+      echo "$!" > "$pidfile_term"
+      ;;
+  esac
 }
 
 kill_pids() {