Merge pull request #5328 from mcornella/ssh-agent-refactor

Refactor of ssh-agent plugin

plugins/ssh-agent/README.md

+# ssh-agent plugin
+
+This plugin starts automatically `ssh-agent` to set up and load whichever
+credentials you want for ssh connections.
+
+To enable it, add `ssh-agent` to your plugins:
+
+```zsh
+plugins=(... ssh-agent)
+```
+
+## Instructions
+
+To enable **agent forwarding support** add the following to your zshrc file:
+
+```zsh
+zstyle :omz:plugins:ssh-agent agent-forwarding on
+```
+
+To **load multiple identities** use the `identities` style, For example:
+
+```zsh
+zstyle :omz:plugins:ssh-agent identities id_rsa id_rsa2 id_github
+```
+
+To **set the maximum lifetime of the identities**, use the `lifetime` style.
+The lifetime may be specified in seconds or as described in sshd_config(5)
+(see _TIME FORMATS_). If left unspecified, the default lifetime is forever.
+
+```zsh
+zstyle :omz:plugins:ssh-agent lifetime 4h
+```
+
+## Credits
+
+Based on code from Joseph M. Reagle: http://www.cygwin.com/ml/cygwin/2001-06/msg00537.html
+
+Agent-forwarding support based on ideas from Florent Thoumie and Jonas Pfenniger

plugins/ssh-agent/ssh-agent.plugin.zsh

-#
-# INSTRUCTIONS
-#
-#   To enable agent forwarding support add the following to
-#   your .zshrc file:
-#
-#     zstyle :omz:plugins:ssh-agent agent-forwarding on
-#
-#   To load multiple identities use the identities style, For
-#   example:
-#
-#     zstyle :omz:plugins:ssh-agent identities id_rsa id_rsa2 id_github
-#
-#   To set the maximum lifetime of the identities, use the
-#   lifetime style. The lifetime may be specified in seconds
-#   or as described in sshd_config(5) (see TIME FORMATS)
-#   If left unspecified, the default lifetime is forever.
-#
-#     zstyle :omz:plugins:ssh-agent lifetime 4h
-#
-# CREDITS
-#
-#   Based on code from Joseph M. Reagle
-#   http://www.cygwin.com/ml/cygwin/2001-06/msg00537.html
-#
-#   Agent forwarding support based on ideas from
-#   Florent Thoumie and Jonas Pfenniger
-#
+typeset _agent_forwarding _ssh_env_cache
 
-local _plugin__ssh_env
-local _plugin__forwarding
-
-function _plugin__start_agent()
-{
-  local -a identities
+function _start_agent() {
 	local lifetime
-  zstyle -s :omz:plugins:ssh-agent lifetime lifetime
+	local -a identities
 
 	# start ssh-agent and setup environment
-  /usr/bin/env ssh-agent ${lifetime:+-t} ${lifetime} | sed 's/^echo/#echo/' >! ${_plugin__ssh_env}
-  chmod 600 ${_plugin__ssh_env}
-  . ${_plugin__ssh_env} > /dev/null
+	zstyle -s :omz:plugins:ssh-agent lifetime lifetime
+
+	ssh-agent -s ${lifetime:+-t} ${lifetime} | sed 's/^echo/#echo/' >! $_ssh_env_cache
+	chmod 600 $_ssh_env_cache
+	. $_ssh_env_cache > /dev/null
 
 	# load identies
 	zstyle -a :omz:plugins:ssh-agent identities identities
-  echo starting ssh-agent...
 
-  /usr/bin/ssh-add $HOME/.ssh/${^identities}
+	echo starting ssh-agent...
+	ssh-add $HOME/.ssh/${^identities}
 }
 
 # Get the filename to store/lookup the environment from
-if (( $+commands[scutil] )); then
-  # It's OS X!
-  _plugin__ssh_env="$HOME/.ssh/environment-$(scutil --get ComputerName)"
-else
-  _plugin__ssh_env="$HOME/.ssh/environment-$HOST"
-fi
+_ssh_env_cache="$HOME/.ssh/environment-$SHORT_HOST"
 
 # test if agent-forwarding is enabled
-zstyle -b :omz:plugins:ssh-agent agent-forwarding _plugin__forwarding
-if [[ ${_plugin__forwarding} == "yes" && -n "$SSH_AUTH_SOCK" ]]; then
+zstyle -b :omz:plugins:ssh-agent agent-forwarding _agent_forwarding
+
+if [[ $_agent_forwarding == "yes" && -n "$SSH_AUTH_SOCK" ]]; then
 	# Add a nifty symlink for screen/tmux if agent forwarding
 	[[ -L $SSH_AUTH_SOCK ]] || ln -sf "$SSH_AUTH_SOCK" /tmp/ssh-agent-$USER-screen
-
-elif [ -f "${_plugin__ssh_env}" ]; then
+elif [[ -f "$_ssh_env_cache" ]]; then
 	# Source SSH settings, if applicable
-  . ${_plugin__ssh_env} > /dev/null
-  ps x | grep ${SSH_AGENT_PID} | grep ssh-agent > /dev/null || {
-    _plugin__start_agent;
+	. $_ssh_env_cache > /dev/null
+	ps -o cmd -p $SSH_AGENT_PID | grep -q ssh-agent || {
+		_start_agent
 	}
 else
-  _plugin__start_agent;
+	_start_agent
 fi
 
 # tidy up after ourselves
-unfunction _plugin__start_agent
-unset _plugin__forwarding
-unset _plugin__ssh_env
-
+unset _agent_forwarding _ssh_env_cache
+unfunction _start_agent