====== Squid Proxy ======

''squid'' is a popular proxy server, if one wishes to access the outside world pretending to be the droplet in wherever it is... Handy for various things.
  - [[http://etutorials.org/Server+Administration/Squid.+The+definitive+guide/|Squid. The definitive guide - etutorials.org]]

===== Install =====

<code>
apt-get update && apt-get upgrade -y
apt-get install squid3

# Backup original configuration to file named squid.conf.factory
cp -v /etc/squid/squid.conf{,.factory}
</code>

===== Firewall Configuration =====

See notes under: [[server_configuration:firewall|Firewall]]

<code>
ufw status
ufw allow squid
ufw status
</code>


===== Configure Squid =====

View the existing squid conf (with comments/documentation cut out)
<code>
cat /etc/squid/squid.conf | grep -v -e '^\#' -e '^$'
</code>

Configure password store using apache, see docs online... I didn't set this up yet (I limited by IP).
<code>
  400  apt-get install apache2-utils
  401  sudo touch /etc/squid/passwd
  402  sudo chown proxy: /etc/squid/passwd
  403  ls -l /etc/squid/passwd
  405  htpasswd /etc/squid/passwd david
</code>

Toggle blanket allow/deny rule (debugging to see if its your rule, or your application trying to connect which isn't configured properly)
<code>
sed -i 's,http_access deny all,http_access allow all,g' /etc/squid/squid.conf

sed -i 's,http_access allow all,http_access deny all,g' /etc/squid/squid.conf
</code>


<code>
# Add rule (BEFORE line matching sed pattern)
sed -i '/http_access deny all/i http_access allow my_allow_ip' /etc/squid/squid.conf
sed -i '/http_access allow my_allow_ip/i acl my_allow_ip src xxx.xxx.xxx.xxx' /etc/squid/squid.conf

# Delete rule by sed pattern
sed -i '/acl my_allow_ip src xxx.xxx.xxx.xxx/d' /etc/squid/squid.conf
</code>

<code>
# Test config
squid -k parse

# Refresh configuration
squid -k reconfigure
</code>

===== Stopping =====

<code>
# Kill squid
sudo squid -k shutdown

# Restart Daemon: http://etutorials.org/Server+Administration/Squid.+The+definitive+guide/Chapter+5.+Running+Squid/5.5+Running+Squid+as+a+Daemon+Process/
squid -s
</code>

More from: http://etutorials.org/Server+Administration/Squid.+The+definitive+guide/Chapter+5.+Running+Squid/5.8+Stopping+Squid/

<code>
ps aux | grep squid
</code>

Check cache usage:
<code>
sudo du -h /var/spool/
</code>