Clean up certbot-auto docs (#8532)

Fixes https://github.com/certbot/certbot/issues/8519.

I left the `certbot-auto` docs in `install.rst` to avoid breaking links and to help propagate information about our changes there. I moved it closer to the bottom of the doc though since I think our documentation about OS packages and Docker is more helpful to most people.

* clean up certbot-auto docs

* add more info to changelog

* remove more certbot-auto references

4 files changed, 34 insertions, 85 deletions

diff --git a/certbot/CHANGELOG.md b/certbot/CHANGELOG.md
index c3480a3b0..e4f4eda51 100644
--- a/certbot/CHANGELOG.md
+++ b/certbot/CHANGELOG.md
@@ -12,7 +12,9 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 
 * We deprecated support for Python 2 in Certbot and its ACME library.
   Support for Python 2 will be removed in the next planned release of Certbot.
-* certbot-auto was deprecated on all systems.
+* certbot-auto was deprecated on all systems. For more information about this
+  change, see
+  https://community.letsencrypt.org/t/certbot-auto-no-longer-works-on-debian-based-systems/139702/7.
 * We deprecated support for Apache 2.2 in the certbot-apache plugin and it will
   be removed in a future release of Certbot.
 
diff --git a/certbot/docs/compatibility.rst b/certbot/docs/compatibility.rst
index a511f36a2..a4f33c281 100644
--- a/certbot/docs/compatibility.rst
+++ b/certbot/docs/compatibility.rst
@@ -9,7 +9,7 @@ application itself. This means that we will not change behavior in a backwards
 incompatible way except in a new major version of the project.
 
 .. note:: None of this applies to the behavior of Certbot distribution
-    mechanisms such as :ref:`certbot-auto <certbot-auto>` or OS packages whose
+    mechanisms such as :ref:`our snaps <snap-install>` or OS packages whose
     behavior may change at any time. Semantic versioning only applies to the
     common Certbot components that are installed by various distribution
     methods.
diff --git a/certbot/docs/install.rst b/certbot/docs/install.rst
index 4a5a18fc2..df32bb60e 100644
--- a/certbot/docs/install.rst
+++ b/certbot/docs/install.rst
@@ -44,17 +44,6 @@ supports
 <https://github.com/certbot/certbot/blob/master/certbot-apache/certbot_apache/_internal/constants.py>`_
 modern OSes based on Debian, Ubuntu, Fedora, SUSE, Gentoo and Darwin.
 
-
-Additional integrity verification of certbot-auto script can be done by verifying its digital signature.
-This requires a local installation of gpg2, which comes packaged in many Linux distributions under name gnupg or gnupg2.
-
-
-Installing with ``certbot-auto`` requires 512MB of RAM in order to build some
-of the dependencies. Installing from pre-built OS packages avoids this
-requirement. You can also temporarily set a swap file. See "Problems with
-Python virtual environment" below for details.
-
-
 Alternate installation methods
 ================================
 
@@ -78,74 +67,6 @@ choosing "snapd" in the "System" dropdown menu. (You should select "snapd"
 regardless of your operating system, as our instructions are the same across
 all systems.)
 
-.. _certbot-auto:
-
-Certbot-Auto
-------------
-
-The ``certbot-auto`` wrapper script installs Certbot, obtaining some dependencies
-from your web server OS and putting others in a python virtual environment. You can
-download and run it as follows::
-
-  wget https://dl.eff.org/certbot-auto
-  sudo mv certbot-auto /usr/local/bin/certbot-auto
-  sudo chown root /usr/local/bin/certbot-auto
-  sudo chmod 0755 /usr/local/bin/certbot-auto
-  /usr/local/bin/certbot-auto --help
-
-To remove certbot-auto, just delete it and the files it places under /opt/eff.org, along with any cronjob or systemd timer you may have created.
-
-To check the integrity of the ``certbot-auto`` script,
-you can use these steps::
-
-
-	    user@webserver:~$ wget -N https://dl.eff.org/certbot-auto.asc
-	    user@webserver:~$ gpg2 --keyserver pool.sks-keyservers.net --recv-key A2CFB51FA275A7286234E7B24D17C995CD9775F2
-	    user@webserver:~$ gpg2 --trusted-key 4D17C995CD9775F2 --verify certbot-auto.asc /usr/local/bin/certbot-auto
-
-
-
-The output of the last command should look something like::
-
-
-	    gpg: Signature made Wed 02 May 2018 05:29:12 AM IST
-	    gpg:                using RSA key A2CFB51FA275A7286234E7B24D17C995CD9775F2
-	    gpg: key 4D17C995CD9775F2 marked as ultimately trusted
-	    gpg: checking the trustdb
-	    gpg: marginals needed: 3  completes needed: 1  trust model: pgp
-	    gpg: depth: 0  valid:   2  signed:   2  trust: 0-, 0q, 0n, 0m, 0f, 2u
-	    gpg: depth: 1  valid:   2  signed:   0  trust: 2-, 0q, 0n, 0m, 0f, 0u
-	    gpg: next trustdb check due at 2027-11-22
-	    gpg: Good signature from "Let's Encrypt Client Team <letsencrypt-client@eff.org>" [ultimate]
-
-
-
-The ``certbot-auto`` command updates to the latest client release automatically.
-Since ``certbot-auto`` is a wrapper to ``certbot``, it accepts exactly
-the same command line flags and arguments. For more information, see
-`Certbot command-line options <https://certbot.eff.org/docs/using.html#command-line-options>`_.
-
-For full command line help, you can type::
-
-  /usr/local/bin/certbot-auto --help all
-
-Problems with Python virtual environment
-----------------------------------------
-
-On a low memory system such as VPS with less than 512MB of RAM, the required dependencies of Certbot will fail to build.
-This can be identified if the pip outputs contains something like ``internal compiler error: Killed (program cc1)``.
-You can workaround this restriction by creating a temporary swapfile::
-
-  user@webserver:~$ sudo fallocate -l 1G /tmp/swapfile
-  user@webserver:~$ sudo chmod 600 /tmp/swapfile
-  user@webserver:~$ sudo mkswap /tmp/swapfile
-  user@webserver:~$ sudo swapon /tmp/swapfile
-
-Disable and remove the swapfile once the virtual environment is constructed::
-
-  user@webserver:~$ sudo swapoff /tmp/swapfile
-  user@webserver:~$ sudo rm /tmp/swapfile
-
 .. _docker-user:
 
 Running with Docker
@@ -315,6 +236,33 @@ OS packaging is an ongoing effort. If you'd like to package
 Certbot for your distribution of choice please have a
 look at the :doc:`packaging`.
 
+.. _certbot-auto:
+
+Certbot-Auto
+------------
+
+We used to have a shell script named ``certbot-auto`` to help people install
+Certbot on UNIX operating systems, however, this script is no longer supported.
+
+Problems with Python virtual environment
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When using ``certbot-auto`` on a low memory system such as VPS with less than
+512MB of RAM, the required dependencies of Certbot may fail to build.  This can
+be identified if the pip outputs contains something like ``internal compiler
+error: Killed (program cc1)``.  You can workaround this restriction by creating
+a temporary swapfile::
+
+  user@webserver:~$ sudo fallocate -l 1G /tmp/swapfile
+  user@webserver:~$ sudo chmod 600 /tmp/swapfile
+  user@webserver:~$ sudo mkswap /tmp/swapfile
+  user@webserver:~$ sudo swapon /tmp/swapfile
+
+Disable and remove the swapfile once the virtual environment is constructed::
+
+  user@webserver:~$ sudo swapoff /tmp/swapfile
+  user@webserver:~$ sudo rm /tmp/swapfile
+
 Installing from source
 ----------------------
 
diff --git a/certbot/docs/using.rst b/certbot/docs/using.rst
index 1912dafa4..50f5b13fd 100644
--- a/certbot/docs/using.rst
+++ b/certbot/docs/using.rst
@@ -179,10 +179,9 @@ If you'd like to obtain a wildcard certificate from Let's Encrypt or run
 Certbot's DNS plugins.
 
 These plugins are not included in a default Certbot installation and must be
-installed separately. While the DNS plugins cannot currently be used with
-``certbot-auto``, they are available in many OS package managers, as Docker
-images, and as snaps. Visit https://certbot.eff.org to learn the best way to use
-the DNS plugins on your system.
+installed separately. They are available in many OS package managers, as Docker
+images, and as snaps. Visit https://certbot.eff.org to learn the best way to
+use the DNS plugins on your system.
 
 Once installed, you can find documentation on how to use each plugin at: