Well, between a good technology with a lot of hype and a better technology with no hype except for a few condescending people, how am I supposed to chose the latter? Tell me.
I just read the ArchWiki page on systemd-nspawn[1] and I fail to see how it is any better by the way. It just looks way harder to use (Docker images vs packages, scripts and per distro instructions ; docker create, docker start, docker ps, docker logs vs pacstrap, systemd-nspawn, machinectl, journalctl) and honestly not very different technically. systemd-nspawn just looks like a less user-friendly Docker to me.
Would you prefer if all those command were prefaced with `systemd`? Because that's all there is to it do docker in your example then.
You're seeing condescension where there is none. I'm just pointing out facts. It's okay, Docker runs on hype, and apparently so do you. But then, I can't expect Red Hat to invest into advertising for a core system component, because developers ought to be aware of it.
nspawn also offers faster startup time, better integration with cgroups and chroot jails, etc.
>Would you prefer if all those command were prefaced with `systemd`?
Well, I'm fine with journalctl and machinectl as they're part of systemd. I'm not really fine with having to install respectively arch-install-script, deboostrap+debian-archive-keyring, debootstrap+ubuntu-archive-keyring to run an Arch, Debian or Ubuntu container. What if I want to run something like CentOS or Alpine?
>But then, I can't expect Red Hat to invest into advertising for a core system component, because developers ought to be aware of it.
That's why Docker has the market. systemd is huge and scary, developers see it as a sysadmin only component. You cannot expect developers to know systemd without explaining it to them in a way they can understand.
>nspawn also offers faster startup time
Is Docker slow? Starting a container is usually instantaneous. Maybe the engine? For me it's managed with systemd and its weird socket binding, it's pretty fast too.. Fast is good but I can't remember thinking "wow docker is slow"
>better integration with cgroups and chroot jails
How? Why do I need this better integration?
- - -
I'm convinced there are not a lot of things Docker cannot do in comparison to systemd-nspawn. On the contrary, with systemd-nspawn:
- how do I spawn a container remotely?
- how do I share my "images"? is there an easy way to bundle the app I want to isolate? something at least kinda portable between Linuxes, so no .deb/.rpm
- can I include a file to my source code and tell my users something like "run docker build, then docker run and you're good to go"?
- my sysadmins just gave me the rights to run the docker command (we configured the user namespace so that I'm not indirectly root on the host), would it be that easy for them with nspawn?
- say I want a specific dependency, redis for example. Can I do something as simple as `docker run -p6379:6379 -v/data/redis:/data --name redis redis` or would I have to manually install the redis in the nspawn?
I just read the ArchWiki page on systemd-nspawn[1] and I fail to see how it is any better by the way. It just looks way harder to use (Docker images vs packages, scripts and per distro instructions ; docker create, docker start, docker ps, docker logs vs pacstrap, systemd-nspawn, machinectl, journalctl) and honestly not very different technically. systemd-nspawn just looks like a less user-friendly Docker to me.
[1]: https://wiki.archlinux.org/index.php/Systemd-nspawn