feat(tmux): impl ssh host switching

It works by creating a new tmux server on a specific socket (`ssh`)
that runs an additional config to change the prefix key and hide the
status bar. It then uses a hook to reattach to the local session if the
pane, and therefor ssh process, is exited.

3 files changed, 45 insertions, 22 deletions

diff --git a/tmux/.config/tmux/ssh.conf b/tmux/.config/tmux/ssh.conf
new file mode 100644
index 0000000..4bee96b
--- /dev/null
+++ b/tmux/.config/tmux/ssh.conf
@@ -0,0 +1,10 @@
+# vim: ft=tmux
+
+set-option -g remain-on-exit on
+set-option -g prefix C-b
+set-option -g status off
+
+bind-key -n C-a send-prefix
+
+set-hook -g pane-died "detach -E 'tmux -L ssh kill-pane; tmux attach'"
+
diff --git a/tmux/.config/tmux/tmux.conf b/tmux/.config/tmux/tmux.conf
index 5967869..1bcef1f 100644
--- a/tmux/.config/tmux/tmux.conf
+++ b/tmux/.config/tmux/tmux.conf
@@ -15,10 +15,10 @@ set -g base-index 1
 set -g pane-base-index 1
 set -g detach-on-destroy off
 
+bind-key -n C-s run-shell ~/.local/bin/tmux-ssh
+
 bind-key -N "Switch last session" A switch-client -l
 bind-key -N "Clock" T clock-mode
-bind-key -N "Host: new" s run-shell ~/.local/bin/tmux-ssh
-# bind-key -N "Host: switch" S run-shell ~/.local/bin/tmux-ssh
 bind-key -N "Session: new" f run-shell ~/.local/bin/tmux-sessionizer
 bind-key -N "Session: switch" F run-shell ~/.local/bin/tmux-sessions
 bind-key -N "Window: new" t new-window
@@ -45,3 +45,7 @@ if "test ! -d $XDG_CONFIG_HOME/tmux/plugins/tpm" \
   && $XDG_CONFIG_HOME/tmux/plugins/tpm/bin/install_plugins'"
 
 run '$XDG_CONFIG_HOME/tmux/plugins/tpm/tpm'
+
+%if #{m:*ssh,#{socket_path}}
+source "$XDG_CONFIG_HOME/tmux/ssh.conf"
+%endif
diff --git a/tmux/.local/bin/tmux-ssh b/tmux/.local/bin/tmux-ssh
index 335e75c..b1875e2 100755
--- a/tmux/.local/bin/tmux-ssh
+++ b/tmux/.local/bin/tmux-ssh
@@ -4,30 +4,39 @@
 # shellcheck disable=2016,2089
 
 if [ "$#" -eq 0 ]; then
-	ATTACHED=$(tmux display -p '#{session_path}')
+	ATTACHED=$(tmux display -p '#S' 2>/dev/null)
+	HOST=$(tmux display -p '#{host}' 2>/dev/null)
 
-	# shellcheck disable=2046
-	set -- $(
-		grep -P '^[Hh]ost ([^*]+)$' "$HOME/.ssh/config" | grep -Po ' \K(\w+)' |
-			sed "\|^$HOST\$|d" | sed "\|^${ATTACHED#SSH_}\$|d" | sort -u |
-			timestamp.sh --type="ssh" --format="{}:{1}" | sort -r | cut -d':' -f2 |
-			fzf-tmux "$FZF_TMUX_OPTS" -- --multi --print-query -d/ --with-nth -1 |
-			tr -s '\n' ' '
-	) && [ $# -gt 1 ] && shift
+	set -- "$(
+		(
+			tmux display -p '#{?#{m:*ssh,#{socket_path}},localhost,}' 2>/dev/null
+			grep -P '^[Hh]ost ([^*]+)$' "$HOME/.ssh/config" | grep -Po ' \K(\w+)' | sed "\|^$HOST\$|d" |
+				sed "\|^${ATTACHED}\$|d" |
+				sort -u |
+				timestamp.sh --type="ssh" --format="{}:{1}" |
+				sort -r |
+				cut -d':' -f2
+		) |
+			sed '\|^$|d' |
+			fzf-tmux -p20%,20% -- --print-query -d/ --with-nth -1 |
+			tail -1
+	)"
 fi
 
-while [ $# -gt 0 ]; do
-	ssh_host="$1"
-	shift
+if [ -z "$1" ]; then
+	exit 0
+fi
 
-	name="SSH_$ssh_host"
-	if ! tmux has-session -t "$name" 2>/dev/null; then
-		tmux new-session -ds "$name" ssh -t "$ssh_host" # 'tmux new -As $USER'
+if [ "$1" = "localhost" ] || [ "$1" = "$HOST" ]; then
+	tmux detach -E 'tmux attach'
+else
+	if ! tmux -L ssh has-session -t "$1"; then
+		tmux -L ssh new-session -ds "$1" ssh -t "$1" zsh -l -c tmux new -As "$USER"
 	fi
-done
 
-if [ -z "$TMUX" ] && [ -z "$name" ]; then
-	tmux attach-session -t "$name"
-elif tmux has-session -t="$name" 2>/dev/null; then
-	tmux switch-client -t "$name"
+	if [ -z "$TMUX" ]; then
+		tmux -L ssh attach -t "$1"
+	else
+		tmux detach -E "tmux -L ssh attach -t $1"
+	fi
 fi