Change terminal color when SSH from OS-X

My terminal

• Use iTerm2 as my terminal
• zsh as the shell
• oh-my-zsh to manage zsh configurations
• More info - my customised terminal

Background

• In day today developments and deployments we have to ssh into different machines/servers

• For an instance we may have to ssh into

  1. Production servers
  2. Staging servers
  3. Amazon boxes
  4. Local testing servers etc..

• Usual behaviour is open new terminal tab to and starting ssh session

• Sometimes we may have multiple ssh session in different terminal tabs simultaneously

• In these kind of situations its bit confuse to identifies where I am(which host currently I am in)

• To solve this confusing issue we can use different terminal themes(terminal colors) for different ssh sessions

iTerm profiles with oh-my-zsh

• In my scenario I'm using different iTerm profiles with different themes(colors)
• I'm loading these terminal profiles when ssh into different environments
• Its(terminal profile selecting) done by using custom oh-my-zsh command(shell script)

• In my scenario I'm using three different iTerm profiles(with different colors) for ssh session

  1. Production ssh session - dark red color
  2. Staging ssh session - dark purple color
  3. Other ssh session - dark blue color

• You can use different iTerm themes to obtain different terminal colors - iTerm themes

• Following are the steps that need to follow in order to change the terminal color when SSH'ing

1. Create iTerm terminal profiles

• Goto iTerm preferences and create profiles according to your ssh environments
• In my scenario I have 4 iTerm profiles
• Default profile uses in local terminal and other three profiles(Production, Staging and Other) use in different ssh sessions

2. Create custom shell script

• Goto ~/.oh-my-zsh/custom and create a file iTrem2-ssh.zsh

• Put following content into iTrem2-ssh.zsh file

function tabc() {
  NAME=$1; if [ -z "$NAME" ]; then NAME="Default"; fi
  # if you have trouble with this, change
  # "Default" to the name of your default theme
  echo -e "\033]50;SetProfile=$NAME\a"
}

function tab-reset() {
    NAME="Default"
    echo -e "\033]50;SetProfile=$NAME\a"
}

function colorssh() {
    if [[ -n "$ITERM_SESSION_ID" ]]; then
        trap "tab-reset" INT EXIT
        if [[ "$*" =~ "production*" ]]; then
            tabc Production
        elif [[ "$*" =~ "staging*" ]]; then
            tabc Staging
        else
            tabc Other
        fi
    fi
    ssh $*
}
compdef _ssh tabc=ssh

alias ssh="colorssh"

• colorssh() function selecting different terminal profile according to ssh'ing host

• It selects

  1. Production profile when ssh to production server (ssh eranga@production_box)
  2. Staging profile when ssh to staging server(ssh eranga@staging_box)
  3. Other profile when ssh to any other server(local server, amazon box etc)

  Change tabc <profile-name> according to your profile names

• tab-reset() function reset the terminal profile to Default profile when exit from the ssh session

• alias ssh="colorssh" creates an alias to ssh(when execute ssh from the terminal it calls to colorssh function)

• You can get this code from my github

Example terminal session

• Default terminal

• SSH into production (ssh eranga@production_box1)

• SSH into staging (ssh eranga@staging_box1)

• SSH into other server (ssh eranga@10.2.4.201)

Reference

• https://github.com/hectorleiva/iterm2-ssh-color-scheme
• http://www.rngtng.com/2011/01/14/mac-os-x-terminal-visual-indication-for-your-ssh-connection/
• https://gist.github.com/porras/5856906
• https://gist.github.com/wadey/1140259