Comment on What is Docker?

• possiblylinux127@lemmy.zip ⁨3⁩ ⁨weeks⁩ ago

  No, chroot is kind of its own thing

  It is just a kernel namespace

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  • fishpen0@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    Yes, technically chroot and jails are wrappers around kernel namespaces / cgroups and so is docker.

    But containers were born in a post chroot era as an attempt at making the same functionality much more user friendly and focused more on bundling cgroups and namespaces into a single superset, where chroot on its own is only namespaces. This is super visible in early docker where you could not individually dial those settings. It’s still a useful way to explain containers in general in the sense that comparing two similar things helps you define both of them.

    Also cgroups have evolved alongside containers at this point and work rather differently now compared to 18 years ago when cgroups were invented and this differentiation mattered more than now. We’re at the point where differentiation between VMs and Containers is getting really hard since both more and more often rely on the same kernel features that were developed in recent years on top of cgroups

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  • pupbiru@aussie.zone ⁨3⁩ ⁨weeks⁩ ago

    a chroot is different, but it’s an easy way to get an idea of what docker is:

    it also contains all the libraries and binaries that reference each other, such that if you call commands they use the structure of the chroot

    this is far more relevant to a basic understanding of what docker does than explaining kernel namespaces. once you have the knowledge of “shipping around applications including dependencies”, then you can delve into isolation and other kinds of virtualisation

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• grue@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  I’m aware of that, but OP requested “explain like I’m stupid” so I omitted that detail.

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