@ThomasWard Fully agree with locking the ranting in Meta, but just a thought on your comment, "if you've been reading the site for as long as you claim you'll have learned that 'link only' answers or answers that don't actually give any context or solutions themselves are deleted" ...

From the perspective of those who haven't contributed yet, it's really not apparent that this happens, because for the casual reader, they'll never see all the NAAs. They'll already have been deleted! They just get the benefit of a cleaner site, without knowing the why and process behind it.

@StoneThrow Welcome to AUGR!

@NotTheDr01ds - lol -- you noticed me join! I've been on various stack exchange sites for years, but never really made use of the chat rooms, so forgive me in advance as I get my bearings, and any lack of awareness of prevailing conventions. Do we need to create a dedicated room to continue our discussion about WSL and Docker, or do we chat right here, as-is?

@StoneThrow No worries. Yeah, I just happened to see your name pop up as you joined. Feel free to chat right here. It's a general chat, so anything goes. It can be quiet in here, but some other folks might chime in on the discussion or be interested in it.

For context for others, (to over-summarize) we were having a "comment chat" on why sudo service docker start works on WSL, and the Docker package installs both a legacy SysV scripts as well as the modern Systemd unit files. And that Docker doesn't get started by the install script due to lack of Systemd on WSL.

And for others, if anyone prefers that we take our "WSL" talk elsewhere, just let us know and we can set up a separate chat. ;-)

@NotTheDr01ds -- (digesting your most recent comment at superuser.com/questions/1734044/… think I get the gist: the "process" that runs in response to one of the apt-get statements (that I ran to install Docker Engine) tries to do systemctl enable docker on the assumption that the Ubuntu instance boots with SysD (because that's "normal" for "real" (non-WSL) Ubuntu)....

@NotTheDr01ds ...And it does not try to do the "equivalent" command that would create a SysV init script for Docker. Is that a correct description?

@StoneThrow Exactly.

Many distros (as mentioned, mainly RPM based) have simply removed the old SysVInit scripts from the packages. Debian/Ubuntu still provides the legacy scripts, at least, but since Ubuntu is a Systemd-based distro, it (the package install script) assumes that it can enable/start Docker using systemctl. That's a fair assumption, except on (a) WSL, and (b) when Ubuntu is running in a container without Systemd.

@NotTheDr01ds (thank you...digesting your answer...there is so much intermingling software, and my poor old brain is slow to grok all the connections...but you've helped me understand the original question/answer)

@NotTheDr01ds You also mentioned that installing Docker Desktop (for Windows) is the preferred solution over installing Docker Engine in the Ubuntu WSL instance. Here, again, I have only a tenuous understanding of what all's involved...my naive understanding is that Docker Engine "talks to an OS that natively supports containers" (which I think is only Linux) -- is that accurate?

@NotTheDr01ds ...and Docker Desktop installs a virtual machine that natively supports containers, which therefore then allows Docker Engine to "talk to" that virtual machine's OS, which then enables Docker...is that all correct?

@StoneThrow Yes, to the first part. What Docker Desktop does, though, is set up "managed" docker-desktop and docker-desktop-data WSL2 distributions for you. It then integrates itself into each of your WSL2 distributions (like Ubuntu) as well as PowerShell and CMD. So you can use the same Docker images/containers/resources from Ubuntu, PowerShell, Arch (on WSL2 as well), whereever.

It has the (again, legacy) option of running as a Hyper-V VM itself, but when WSL2 came out 2 years ago, the Docker team transitioned to using it instead, as it is much more resource-friendly.

@NotTheDr01ds -- oh, are you saying WSL (and/or WSL2) is a virtual machine?

@StoneThrow Oh there's a topic ;-). Let me find an answer I've written up on that.

@StoneThrow superuser.com/a/1731103/1210833

Yes, WSL2 (the feature itself) is a "managed" (as in, we can't see it) virtual machine. But the WSL2 "distributions" (or "instances" or "containers") running in it are namespace containers.

in it (big difference), got the edit in

@NotTheDr01ds "But the WSL2 "distributions" (or "instances" or "containers") running in it" -- so WSL2 is a "managed VM", and what I've been calling the "Ubuntu WSL" or "Ubuntu instance" is a "'namespace container' running in the 'managed VM'"?

@NotTheDr01ds - Thank you: I've occupied a lot of your time, and I could easily occupy much more, building my understanding by continuing to pick your brain. But I'll stop myself short and try to use our discussion as a jumping-off point for further directed learning. Thank you, again, for the time you spent helping me 1:1!