add comments on rootless docker

Author: Xronophobe

chapter_11_ansible.asciidoc

@@ -401,6 +401,10 @@ PLAY RECAP ********************************************************************
 staging.ottg.co.uk         : ok=3    changed=2    unreachable=0    failed=0
 skipped=0    rescued=0    ignored=0
 ----
+// CSANAD: without rootless docker or adding the server's user to the docker
+//         group, this requires a password for `sudo` on the server. I would add
+// a TIP or something similar to inform the reader it can be done with the `-K` flag:
+// ansible-playbook --user=elspeth -i staging.ottg.co.uk, infra/ansible-provision.yaml -K -vv
 
 I don't know about you, but whenever I make a terminal spew out a stream
 of output, I like to make little _brrp brrp brrp_ noises, a bit like the
@@ -434,6 +438,8 @@ minutes ago             testcontainer
 elspeth@server:$ *docker logs testcontainer*
 hello world
 ----
+// CSANAD: we haven't set up rootless docker and haven't added the user to the
+//         `docker` group either, so `docker ps` would only run with sudo.
 
 TIP: Look out for that `elspeth@server`
     in the command-line listings in this chapter.
@@ -523,6 +529,17 @@ In Ansible config, it looks like this:
 ====
 // CSANAD: I would add `update_cache: true` to the `Install docker` task back,
 //         it's a good practice to update the apt cache before installing.
+//
+// Also because of the `delegate_to` the reader may face permission errors if they
+// have not set up rootless docker or haven't added their user to the docker group
+// on their local (developer) system.
+// TASK [Export container image locally] ****[...]
+// task path: /path/to/goat-book/infra/ansible-provision.yaml:12
+// fatal: [192.168.122.23 -> 127.0.0.1]: FAILED! => {"changed": false, "msg": "Error connecting: Error while fetching server API version: ('Connection aborted.', PermissionError(13, 'Permission denied'))"}
+//
+// They may get away with just using `sudo docker` but `sudo ansible-playbook`
+// will not work.
+//
 
 <1> We export the docker image to a `.tar` file by using the `docker_image` module
   with the `archive_path` set to temp file, and setting the `delegate_to` attribute