jimblue · March 20, 2021 23:43 · May 29, 2019 · Jun 2, 2018 · Jun 2, 2018 · Jun 2, 2018
diff --git a/ssh--rc b/ssh--rc
@@ -1,5 +1,18 @@
 #! /bin/bash
 # This is ~/.ssh/rc (remote)
+
+# for X11 forwarding - needed, since the rc files hides default behaviour
+if read proto cookie && [ -n "$DISPLAY" ]; then
+    if [ `echo $DISPLAY | cut -c1-10` = 'localhost:' ]; then
+        # X11UseLocalhost=yes
+        echo add unix:`echo $DISPLAY | cut -c11-` $proto $cookie
+    else
+        # X11UseLocalhost=no
+        echo add $DISPLAY $proto $cookie
+    fi | xauth -q -
+fi
+
+# Setup standard ssh socket link
 if [ ! -S $HOME/.ssh/ssh_auth_sock -a -S "$SSH_AUTH_SOCK" ]; then
     ln -sf $SSH_AUTH_SOCK ~/.ssh/ssh_auth_sock
 fi
diff --git a/00-ssh-tmux-iterm.md b/00-ssh-tmux-iterm.md
@@ -38,3 +38,8 @@ You might want to set up two shorthands, one for normal ssh accesses and one for
 
 ## Automatic ssh-agent socket handling and renewal
 
+The socket of the ssh agent to access the unlocked keys changes with every ssh login. You loose access to your ssh keys when you re-attach to your tmux session. To avoid this, we can link the current authentication socket to a well-known name. We use `~/.ssh/ssh-auth-sock`. This link can be set and updated in `~/.ssh/rc`, see the `ssh--rc` example below. To use this name, set the `SSH_AUTH_SOCK` environment variable in your `~/.tmux.conf` file, see the `tmux.conf` example below.
+
+**NB** Your global `sshd` configuration might prohibit the use of the `~/.ssh/rc` file. This is controlled by the administrator of the remote host.
+
+**NB** The `~/.ssh/ssh-auth-sock` gets set if it doesn't point to a valid socket. This means it might not point to the authentication socket of the ssh session running your tmux session if you have an earlier, regular ssh session open. If that is the case, the socket connection will be lost the moment you log out from that session.
diff --git a/00-ssh-tmux-iterm.md b/00-ssh-tmux-iterm.md
@@ -8,27 +8,33 @@ This is a compilation of information I found in different postings on the net.
 
 `tmux` can be invoked in command mode using `tmux -CC`. The simplest way to get a remote tmux session into a window of iterm is to invoke it on the remote host
 ```
-   local> ssh tmhost
+   local> ssh rmhost
    #...
-   remote> tmux -CC
+   rmhost> tmux -CC
 ```
 This will open a new tmux session in a new iterm window.
 
 ### Invoke tmux as the command to ssh
 
 To run `tmux` as the remote command argument to `ssh`, it need a pseudo-terminal attached. This means invoking `ssh` with the `-t` flag:
 ```
-   local> ssh tmhost -t tmux -CC
+   local> ssh rmhost -t tmux -CC
 ```
 
 ### Naming the remote session to be able to re-attach
 
 If you want to re-attach to a remote session, you have to know its name. The easisest way to is to create a session with a well known name and re-attach to that session later. For that, we invoke `tmux` with the command `new -A -s tmux-main`. The session name is set using the `-s` flag, the `-A` flag specifies that `new` behaves like `attach` if the session exists. The command is now
 ```
-   local> ssh tmhost -t tmux -CC new -A -s tmux-main
+   local> ssh rmhost -t tmux -CC new -A -s tmux-main
 ```
 
 ## Setting up a host configuration
 
+The final command we put together above is a much on the fingers if you use it a lot. The solution is either to set up a shell alias or a special `Host` configuration in your `~./.ssh/config` file, as shown below in `ssh--config`. If you do that, the command to invoke becomes
+```
+   local> ssh tmhost
+```
+You might want to set up two shorthands, one for normal ssh accesses and one for ssh with tmux.
+
 ## Automatic ssh-agent socket handling and renewal
 
diff --git a/ssh--config b/ssh--config
@@ -1,7 +1,14 @@
 # This is a fragment of ~/.ssh/config (local)
 
+# regular ssh shorthand for remote host
+Host rmhost
+HostName remote.host.some.where             ### fix host name
+### more ssh options here are needed
+
+# ssh shorthand for remote host with tmux invocation 
 Host tmhost
-HostName remote.host.some.where
+HostName remote.host.some.where             ### fix host name
 ForwardAgent yes
 RemoteCommand tmux -CC new -A -s tmux-main
 RequestTTY yes
+### more ssh options here are needed
diff --git a/00-ssh-tmux-iterm.md b/00-ssh-tmux-iterm.md
@@ -7,7 +7,6 @@ This is a compilation of information I found in different postings on the net.
 ### Basic remote tmux session
 
 `tmux` can be invoked in command mode using `tmux -CC`. The simplest way to get a remote tmux session into a window of iterm is to invoke it on the remote host
-
 ```
    local> ssh tmhost
    #...
@@ -22,6 +21,13 @@ To run `tmux` as the remote command argument to `ssh`, it need a pseudo-terminal
    local> ssh tmhost -t tmux -CC
 ```
 
+### Naming the remote session to be able to re-attach
+
+If you want to re-attach to a remote session, you have to know its name. The easisest way to is to create a session with a well known name and re-attach to that session later. For that, we invoke `tmux` with the command `new -A -s tmux-main`. The session name is set using the `-s` flag, the `-A` flag specifies that `new` behaves like `attach` if the session exists. The command is now
+```
+   local> ssh tmhost -t tmux -CC new -A -s tmux-main
+```
+
 ## Setting up a host configuration
 
 ## Automatic ssh-agent socket handling and renewal

diff --git a/00-ssh-tmux-iterm.md b/00-ssh-tmux-iterm.md
@@ -4,13 +4,23 @@ This is a compilation of information I found in different postings on the net.
 
 ## All manual invocation
 
+### Basic remote tmux session
+
 `tmux` can be invoked in command mode using `tmux -CC`. The simplest way to get a remote tmux session into a window of iterm is to invoke it on the remote host
 
 ```
    local> ssh tmhost
    #...
    remote> tmux -CC
 ```
+This will open a new tmux session in a new iterm window.
+
+### Invoke tmux as the command to ssh
+
+To run `tmux` as the remote command argument to `ssh`, it need a pseudo-terminal attached. This means invoking `ssh` with the `-t` flag:
+```
+   local> ssh tmhost -t tmux -CC
+```
 
 ## Setting up a host configuration
 

diff --git a/00-ssh-tmux-iterm.md b/00-ssh-tmux-iterm.md
@@ -0,0 +1,18 @@
+# Configuration to use remote tmux over ssh in iterm
+
+This is a compilation of information I found in different postings on the net.
+
+## All manual invocation
+
+`tmux` can be invoked in command mode using `tmux -CC`. The simplest way to get a remote tmux session into a window of iterm is to invoke it on the remote host
+
+```
+   local> ssh tmhost
+   #...
+   remote> tmux -CC
+```
+
+## Setting up a host configuration
+
+## Automatic ssh-agent socket handling and renewal
+
diff --git a/README-ssh-tmux-iterm.md b/README-ssh-tmux-iterm.md
@@ -1,2 +0,0 @@
-# Configuration to use remote tmux over ssh in iterm
-

diff --git a/ssh--config b/ssh--config
@@ -1,6 +1,6 @@
 # This is a fragment of ~/.ssh/config (local)
 
-Host tmux
+Host tmhost
 HostName remote.host.some.where
 ForwardAgent yes
 RemoteCommand tmux -CC new -A -s tmux-main

diff --git a/README.md → README-ssh-tmux-iterm.md b/README.md → README-ssh-tmux-iterm.md
diff --git a/.ssh--config → ssh--config b/.ssh--config → ssh--config
diff --git a/.ssh--rc → ssh--rc b/.ssh--rc → ssh--rc
diff --git a/.tmux.conf → tmux.conf b/.tmux.conf → tmux.conf
diff --git a/tmux-iterm2-ssh.md → README.md b/tmux-iterm2-ssh.md → README.md
diff --git a/.ssh--config b/.ssh--config
@@ -0,0 +1,7 @@
+# This is a fragment of ~/.ssh/config (local)
+
+Host tmux
+HostName remote.host.some.where
+ForwardAgent yes
+RemoteCommand tmux -CC new -A -s tmux-main
+RequestTTY yes
diff --git a/.ssh--rc b/.ssh--rc
@@ -0,0 +1,5 @@
+#! /bin/bash
+# This is ~/.ssh/rc (remote)
+if [ ! -S $HOME/.ssh/ssh_auth_sock -a -S "$SSH_AUTH_SOCK" ]; then
+    ln -sf $SSH_AUTH_SOCK ~/.ssh/ssh_auth_sock
+fi
diff --git a/.tmux.conf b/.tmux.conf
@@ -0,0 +1,7 @@
+# This is ~/.tmux.conf (remote)
+set -g update-environment "DISPLAY SSH_ASKPASS SSH_AGENT_PID SSH_CONNECTION WINDOWID XAUTHORITY"
+set-environment -g 'SSH_AUTH_SOCK' $HOME/.ssh/ssh_auth_sock
+set -g set-titles on
+# not all distros have a tmux terminal type
+#set -g default-terminal tmux
+set -g default-terminal xterm-color
diff --git a/tmux-iterm2-ssh.md b/tmux-iterm2-ssh.md
@@ -0,0 +1,2 @@
+# Configuration to use remote tmux over ssh in iterm
+
Original file line number	Diff line number	Diff line change
		@@ -1,2 +0,0 @@
		# Configuration to use remote tmux over ssh in iterm
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		# Configuration to use remote tmux over ssh in iterm