This patch uses mdformat to auto-format markdown documentation.
To support \ for line breaks (which is what mdformat uses), mkdocs now
requires the pymdownx.escapeall extension.
Because of incompatibilities between mdformat (which formats to
CommonMark) and mkdocs (which expects Python-Markdown), there are now
some limitations: no nested lists, multi-paragraph list items, or
admonitions support.
These limitations are acceptable for now, although some of the docs had
to be adjusted to meet them.
Today we use the HELO/EHLO domain in a variety of places, which are
informational, but some have specific syntax (like the Received header).
Using the un-sanitized values can lead to some confusing and/or invalid
values. This is not very risky today, but it could be problematic in the
future if these strings are used in other contexts.
To prevent those problems, this patch sanitizes the HELO/EHLO domain
when receiving it.
Hooks used to receive the sanitized and raw variants; now, both are
sanitized (the raw one is kept for backwards compatibility).
If the sanitization leaves the string empty, we use the hard-coded
no-valid-characters.invalid as a placeholder, to make this situation
easier to identify when troubleshooting.
This patch simplifies the internal alias lookup logic, unifying it
across Resolve and Exists.
As part of this, the `alias-exists` hook is removed. It was redundant to
begin with, although it enabled a potential optimization, it isn't worth
the complexity. The timeout for execution of both was the same.
This change should be backwards-compatible because `alias-resolve` is
still used, and the semantics haven't changed.
Some utilities might want to access the EHLO/HELO domain in the
post-data hook (for example, to do additional SPF validations).
This patch implements that support, including sanitizing the EHLO domain
on the environment variable to reduce the risk of problems.
This patch implements two new hooks: alias-resolve and alias-exists.
They are called during the aliases resolution process, to allow for more
complex integration with other systems, such as storing the aliases in a
database.
See the included documentation for more details.
Alberto Bertogli