letsencrypt: Add ACME dns-01 challenge support

This adds support for the ACME dns-01 challenge while keeping http-01
the default. A new --challenge option (default http-01) selects the
challenge type. When dns-01 is selected, --dns-provider names any DNS
provider compiled into the bundled lego binary, and an optional
--dns-additional-opts passthrough forwards extra lego DNS flags (such as
--dns.resolvers or --dns.propagation-disable-ans) for environments where
the authoritative name server propagation check cannot be performed.

Provider credentials are supplied via --env-file: lego DNS providers
read credentials only from environment variables, so the wrapper
exports the file's contents before lego runs. The file is parsed like
docker --env-file: literal KEY=VALUE pairs split on the first '=',
comments and blank lines ignored, values taken verbatim and never
executed as shell. Selecting dns-01 without --dns-provider fails fast.

Co-Authored-By: Premysl Kouril <premysl.kouril@ultimum.io>
Assisted-By: Claude Code

Change-Id: I61dc5e3f399f6eec02475c7b90e0f41c85c6093c
Signed-off-by: Timon Schnell <timon.schnell@btc-it-services.com>
Signed-off-by: Jan Horstmann <horstmann@osism.tech>

0 files changed, 0 insertions, 0 deletions