Some ikiwiki plugins make outgoing HTTP requests from the web server:

• aggregate (to download Atom and RSS feeds)
• blogspam (to check whether a comment or edit is spam)
• openid (to authenticate users)
• pinger (to ping other ikiwiki installations)

If your ikiwiki installation cannot contact the Internet without going through a proxy, you can configure this in the setup file by setting environment variables:

ENV:
    http_proxy: "http://proxy.example.com:8080"
    https_proxy: "http://proxy.example.com:8080"
    # optional
    no_proxy: ".example.com,www.example.org"

Note that some plugins will use the configured proxy for all destinations, even if they are listed in no_proxy.

To avoid server-side request forgery attacks, ensure that your proxy does not allow requests to addresses that are considered to be internal.