Document new Podman support, which is basically the same as Docker fo…

…r Eldev's purposes.

README.adoc

@@ -51,7 +51,8 @@ provides only a brief overview.
   setups.
 * Can run on {uri-documentation}#different-emacs-versions[different
   Emacs version] even on the same machine; can also use
-  {uri-documentation}#docker[Docker] for that.
+  {uri-documentation}#docker[Docker] or
+  {uri-documentation}#podman[Podman] for that.
 * There are {uri-documentation}#setup-procedure[_four_ levels of
   configuration] — you can customize most aspects of Eldev for your
   project needs and personal preferences.

doc/README.adoc

@@ -38,6 +38,7 @@
 :uri-travis: https://travis-ci.org/
 :uri-circle: https://circleci.com/
 :uri-docker: https://www.docker.com/
+:uri-podman: https://podman.io/
 :uri-coveralls: https://coveralls.io/
 :uri-setup-emacs: https://github.com/jcs090218/setup-emacs
 :uri-setup-eldev: https://github.com/emacs-eldev/setup-eldev

doc/emacs-versions.adoc

@@ -38,21 +38,28 @@ Therefore, if you use byte-compilation and switch Emacs versions,
 don’t forget to clean the directory.
 
 [#docker]
-=== Using Docker
+=== Using Docker or Podman
 
 Alternatively, if you are on a Linux or macOS system and have
-{uri-docker}[Docker] installed, you can run arbitrary Eldev commands
-within containers based on the images distributed by
-{uri-docker-emacs}[docker-emacs].  For example:
+{uri-docker}[Docker] or (since 1.10) {uri-podman}[Podman] installed,
+you can run arbitrary Eldev commands within containers based on the
+images distributed by {uri-docker-emacs}[docker-emacs].  For example:
 
     $ eldev docker 27.2 emacs --eval '(insert (format "Emacs version: %s" emacs-version))'
 
 will start an Emacs 27.2 container and run `eldev emacs --eval
 '(insert (format "Emacs version: %s" emacs-version))'` in it.
 
+[#podman]
+{since-1-10} Podman, from Eldev’s point of view, works just the
+same.  There is a special command for it, but it is basically
+indistinguishable (except for the name):
+
+    $ eldev podman 27.2 emacs --eval '(insert (format "Emacs version: %s" emacs-version))'
+
 NOTE: You may have to run `xhost +local:root` which allows the Docker
-container to make connections to the host X server.  However, this
-does come with some security considerations, see `man xhost`.
+(Podman) container to make connections to the host X server.  However,
+this does come with some security considerations, see `man xhost`.
 
 This command can be used not only to start Emacs of given version, but
 to run _any_ Eldev command.  For example, run project’s tests on an
@@ -64,20 +71,21 @@ or evaluate something using project’s functions:
 
     $ eldev docker 26.3 eval "(my-project-read-data \"foo.bin\")"
 
-Docker’s output is forwarded to normal Eldev output, however, because
-of {uri-emacs-forwarding}[Elisp limitations], it all ends up on
-Eldev’s stdout!  There might also be unwieldy delays, so that output
-doesn’t come smoothly as generated by the process inside Docker, but
-instead in larger chunks.  Before Eldev 1.2 the output would instead
-only appear when Docker has exited.
+Docker’s (Podman’s) output is forwarded to normal Eldev output,
+however, because of {uri-emacs-forwarding}[Elisp limitations], it all
+ends up on Eldev’s stdout!  There might also be unwieldy delays, so
+that output doesn’t come smoothly as generated by the process inside
+Docker, but instead in larger chunks.  Before Eldev 1.2 the output
+would instead only appear when Docker has exited.
 
 It is also possible to use a custom image.  For this, replace Emacs
 version argument (26.3 in the last example above) with the full image
 name.  The image must contain a preinstalled Emacs of a version
 supported by Eldev (i.e. 24.4 and up), but not Eldev itself.
 
 Additionally, `docker run` arguments are customisable via the variable
-`eldev-docker-run-extra-args`.  For example, adding the following to
+`eldev-docker-run-extra-args` (and likewise for Podman:
+`eldev-podman-run-extra-args`).  For example, adding the following to
 your project’s `Eldev`:
 
 ....

doc/overview.adoc

@@ -9,7 +9,8 @@ Eldev features:
 * Blends nicely into <<continuous-integration,continuous
   integration>> setups.
 * Can run on <<different-emacs-versions,different Emacs version>> even
-  on the same machine; can also use <<docker,Docker>> for that.
+  on the same machine; can also use <<docker,Docker>> or
+  <<podman,Podman>> for that.
 * There are <<setup-procedure,_four_ levels of configuration>> — you
   can customize most aspects of Eldev for your project needs and
   personal preferences.