feat(ssh-agent): add `quiet` option to silence plugin (#9659)

Closes #9659

Co-authored-by: Jeff Warner <jeff@develops.software>

plugins/ssh-agent/README.md

@@ -13,28 +13,24 @@ plugins=(... ssh-agent)
 
 **IMPORTANT: put these settings _before_ the line that sources oh-my-zsh**
 
+### `agent-forwarding`
+
 To enable **agent forwarding support** add the following to your zshrc file:
 
 ```zsh
-zstyle :omz:plugins:ssh-agent agent-forwarding on
+zstyle :omz:plugins:ssh-agent agent-forwarding yes
 ```
 
-----
+### `helper`
 
-To **NOT load any identities on start** use the `lazy` setting. This is particularly
-useful when combined with the `AddKeysToAgent` setting (available since OpenSSH 7.2),
-since it allows to enter the password only on first use. _NOTE: you can know your
-OpenSSH version with `ssh -V`._
+To set an **external helper** to ask for the passwords and possibly store
+them in the system keychain use the `helper` style. For example:
 
 ```zsh
-zstyle :omz:plugins:ssh-agent lazy yes
+zstyle :omz:plugins:ssh-agent helper ksshaskpass
 ```
 
-You can enable `AddKeysToAgent` by passing `-o AddKeysToAgent=yes` to the `ssh` command,
-or by adding `AddKeysToAgent yes` to your `~/.ssh/config` file [1].
-See the [OpenSSH 7.2 Release Notes](http://www.openssh.com/txt/release-7.2).
-
-----
+### `identities`
 
 To **load multiple identities** use the `identities` style (**this has no effect
 if the `lazy` setting is enabled**). For example:
@@ -52,7 +48,22 @@ zstyle :omz:plugins:ssh-agent identities ~/.config/ssh/id_rsa ~/.config/ssh/id_r
 zstyle :omz:plugins:ssh-agent identities ~/.config/ssh/{id_rsa,id_rsa2,id_github}
 ```
 
-----
+### `lazy`
+
+To **NOT load any identities on start** use the `lazy` setting. This is particularly
+useful when combined with the `AddKeysToAgent` setting (available since OpenSSH 7.2),
+since it allows to enter the password only on first use. _NOTE: you can know your
+OpenSSH version with `ssh -V`._
+
+```zsh
+zstyle :omz:plugins:ssh-agent lazy yes
+```
+
+You can enable `AddKeysToAgent` by passing `-o AddKeysToAgent=yes` to the `ssh` command,
+or by adding `AddKeysToAgent yes` to your `~/.ssh/config` file [1].
+See the [OpenSSH 7.2 Release Notes](http://www.openssh.com/txt/release-7.2).
+
+### `lifetime`
 
 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)
@@ -62,7 +73,15 @@ The lifetime may be specified in seconds or as described in sshd_config(5)
 zstyle :omz:plugins:ssh-agent lifetime 4h
 ```
 
-----
+### `quiet`
+
+To silence the plugin, use the following setting:
+
+```zsh
+zstyle :omz:plugins:ssh-agent quiet yes
+```
+
+### `ssh-add-args`
 
 To **pass arguments to the `ssh-add` command** that adds the identities on startup,
 use the `ssh-add-args` setting. You can pass multiple arguments separated by spaces:
@@ -80,15 +99,6 @@ ssh-add -K -c -a /run/user/1000/ssh-auth <identities>
 
 For valid `ssh-add` arguments run `ssh-add --help` or `man ssh-add`.
 
-----
-
-To set an **external helper** to ask for the passwords and possibly store
-them in the system keychain use the `helper` style. For example:
-
-```zsh
-zstyle :omz:plugins:ssh-agent helper ksshaskpass
-```
-
 ## Credits
 
 Based on code from Joseph M. Reagle: https://www.cygwin.com/ml/cygwin/2001-06/msg00537.html

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

@@ -18,7 +18,7 @@ function _start_agent() {
   zstyle -s :omz:plugins:ssh-agent lifetime lifetime
 
   # start ssh-agent and setup environment
-  echo Starting ssh-agent...
+  zstyle -t :omz:plugins:ssh-agent quiet || echo >&2 "Starting ssh-agent ..."
   ssh-agent -s ${lifetime:+-t} ${lifetime} | sed '/^echo/d' >! "$ssh_env_cache"
   chmod 600 "$ssh_env_cache"
   . "$ssh_env_cache" > /dev/null
@@ -78,7 +78,7 @@ function _add_identities() {
 
   if [[ -n "$helper" ]]; then
     if [[ -z "${commands[$helper]}" ]]; then
-      echo "ssh-agent: the helper '$helper' has not been found."
+      echo >&2 "ssh-agent: the helper '$helper' has not been found."
     else
       SSH_ASKPASS="$helper" ssh-add "${args[@]}" ${^not_loaded} < /dev/null
       return $?
@@ -88,11 +88,9 @@ function _add_identities() {
   ssh-add "${args[@]}" ${^not_loaded}
 }
 
-# test if agent-forwarding is enabled
-zstyle -b :omz:plugins:ssh-agent agent-forwarding agent_forwarding
-
-# Add a nifty symlink for screen/tmux if agent forwarding
-if [[ $agent_forwarding = "yes" && -n "$SSH_AUTH_SOCK" && ! -L "$SSH_AUTH_SOCK" ]]; then
+# Add a nifty symlink for screen/tmux if agent forwarding is enabled
+if zstyle -t :omz:plugins:ssh-agent agent-forwarding \
+   && [[ -n "$SSH_AUTH_SOCK" && ! -L "$SSH_AUTH_SOCK" ]]; then
   ln -sf "$SSH_AUTH_SOCK" /tmp/ssh-agent-$USERNAME-screen
 else
   _start_agent