add tmux shell terminal multiplexer

Dockerfile

@@ -34,7 +34,7 @@ RUN mkdir -p "/root/.cache/crontab"
 # Install packages
 RUN pacman-key --init
 RUN pacman -Syu --noconfirm sudo bash-completion openssh neofetch \
-    borgbackup dateutils prometheus-node-exporter wget git base-devel cron net-tools inetutils
+    borgbackup dateutils prometheus-node-exporter wget git base-devel cron net-tools inetutils tmux
 
 # Make Build User
 RUN useradd builduser -m

bash-config/.bashrc

@@ -1,3 +1,5 @@
+[ ! -z "$USE_TMUX_SHELL"  ] && [[ -t 0 ]] && [ -z "$TMUX"  ] && (exec tmux attach || exec tmux new-session && exit)
+
 alias update='sudo pacman -Syu --noconfirm'
 
 export HISTTIMEFORMAT="%d/%m/%y %T "