Suggested edit to "What does the double-hyphen do in `lxc exec`"

Question

I'd like to ask for reconsideration on an edit I suggested; based on this meta question, I believe Meta is where such a request belongs.

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The post in question is an answer to a question I asked, What does the double-hyphen do in `lxc exec`.

I thought PeterVanHeusden's answer was precise and thorough (also kind, since as he said, there's an argument to be made that my question was a duplicate, only I haven't realized what's actually behind the behavior I was seeing), but it did have some formatting issues.

muru corrected those, but in so doing s/he also made a change which I feel needs to be rolled back:

1. The question dealt with LXD; PeterVanHeusden made an example involving a shell in both the host and the container, and used the shell prompt to distinguish the two (in a container, typically one gets a root@container:~# prompt). muru felt it was "unnecessarily long", and edited it to a simple $ prompt. Also note that, as KazWolfe mentions below, PeterVanHeusden specified in the text which part works in which context. However, I object to the edit on two grounds: (a) it makes the example less clear, rather than more so (a graphic cue really helps there), and (b) the $ prompt doesn't appear inside a container, because by default one executes commands as root in it (including bash, to get a shell into it); this just adds to the confusion, and the space saved by shrinking the prompt does't help in this case (there's more than enough space in the answer).

Additionally, (something I mistakenly thought muru changed, but was in the original)

2. A sudo call was used in the example to run the LXD command-line tool lxc, which is redundant. From LinuxContainers.org:

   The package creates a new "lxd" group which contains all users allowed to talk to lxd over the local unix socket. All members of the "admin" and "sudoers" groups are automatically added. If your user isn't a member of one of these groups, you'll need to manually add your user to the "lxd" group.

   This implies that any user able to escalate sudo should already be able to call lxc; moreover, the preferred way of gaining privileges is to add a user to the "lxd" group, rather than using sudo.

   Keep in mind the following two points: (a) using sudo for tasks which don't require it is a bad habit to encourage. (b) A user following this example has already installed LXD and launched a container. All tutorials I've seen, including those on Ubuntu Insights written by Stéphane Graber (project head), use unprivileged containers that don't require sudo. If for some reason users find themselves in a situation where sudo is required to manage LXD, they quite surly already know why and how that happened.

   Hence, I contend that almost everyone, and most particularly novices, are safe to remove the sudo call from the example, and therefore it's better not to include it.

I believe the two reviewers who rejected my edit (to roll these changes back, while keeping the changes to format) might not have looked at the edit history, nor realized that it's (now, partially) a roll-back. I might be wrong, but I believe the answer is better with the two changes I suggested. (To me it is, in any case.)

Answer 1

I'm the other one who rejected your suggested edit.

In my opinion:

The first part of your edit was unnecessary, because the answer clearly states:

The following commands were run in the container

And $ is just a sign that we use to show a comamnd, so muru's edit was fine to me.

For the second part you're somewhat right (about the concept of not using sudo), however the sudo was part of the original answer, and also it was too minor to me.

I rejected your edit mostly because of the first part.

Answer 2

I'm one of the people who rejected the review. Hello. Let me try to rationalize my decision based on the data I had at the time I clicked the button according to my own opinion.

And, for the sake of having everything in one thread, here is the suggested edit we are discussing.

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Regarding point 1:

To me, it was clear what was and wasn't supposed to run in the container. The context of the commands (in the answer itself) shows that the first block of commands are meant to be run inside the container (emphasis mine):

Consider the following: I created a file /tmp/bar containing the line --foo. The following commands were run in the container:

$ ...

We can usually (safely) assume that anyone reading the answer will actually read it thoroughly. It's the same reason we don't use bold to emphasize things like Ubuntu 14.04. Therefore, the transition from regular-land to container-land is already well-defined.

This concept of "prompt compression" (so, turning user@host:~$ into $) is pretty common, as the additional information is almost always excessive. We don't need to know your username or hostname, we just need to know that we're typing this into a prompt somewhere.

Now, I am fully aware that lxc internally is root and will have a # prompt. This is where clarity becomes important -- # can mean a comment just as easily as it means a root shell. In this case, it really doesn't matter. You enter a container, you get a root shell automatically, no other actions required. And, as we've already entered the container, it doesn't matter much.

We can change it to # (although that may still cause some confusion whether it's a comment or not), but we shouldn't include the username/hostname, just for the sake of brevity. It's often a good writing practice to say what you need to say as clearly as possible, using as few words as possible.

However, I do agree that the transition out of the container should be made more clear. I can edit that in, or let you do it. It doesn't really matter. Just some blurb somewhere saying that the grep command is meant to be run on the host machine.

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Regarding point 2:

I checked the edit history of the post in question, and did not see muru add sudo. It was present in the original post.

However, even if it was not, it would have still been a sensible addition. Not every user automatically has permission to manage lxc (see here), and we can't make that assumption. It's safer to add sudo to the command and let someone take it out on execution if they feel is unnecessary.

Ok, I was wrong here. Turns out, I don't know how lxc and lxd usually work with permissions. Therefore, I (and I think most editors) will tend to defer to the OP's knowledge being correct unless they know otherwise. Actually doing the research into lxc and doing recon with this shows that your edit is technically accurate (and should have been approved, at least on that front). With that in mind, sorry. I screwed up here.

That said, removing sudo from the OP's post does change the post's intent (something edits typically shouldn't do), and therefore should be discussed (at least briefly) in the comments section about whether sudo is (or isn't) necessary instead of leaving it up to the editors to know. See Zanna's answer on editing code. Personally, I'd consider removing sudo to fall under the "simplification" category as opposed to an error correction.