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Transitioning from Docker to Podman

developers.redhat.com

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Re: Transitioning from Docker to Podman

#211

Post by crummy »

yjftsjthsd-h wrote: post #45
choeger wrote: post #29

Earlier quoted context omitted.

Maybe you are just too far into docker. I noticed that a lot of default workflows (needlessly) depended on docker running with privileges. One big reason for that seem to be Mac users that only know docker from inside a VM. However, if you think about what you're really needing for CI you will easily see that docker-in-docker gains you nothing. You can as well use plain docker (or podman). The same holds for privileg…

Okay, I want to build a container image using gitlab CI, which runs builds in docker. How would you like me to build an image without using docker in docker, or buildah in docker?

Lots of folks recommending kaniko, which we use. But it seems quite slow compared to docker build. Is this not an issue for others?

Re: Transitioning from Docker to Podman

#212

Post by ownagefool »

yjftsjthsd-h wrote: post #45
choeger wrote: post #29

Earlier quoted context omitted.

Maybe you are just too far into docker. I noticed that a lot of default workflows (needlessly) depended on docker running with privileges. One big reason for that seem to be Mac users that only know docker from inside a VM. However, if you think about what you're really needing for CI you will easily see that docker-in-docker gains you nothing. You can as well use plain docker (or podman). The same holds for privileg…

Okay, I want to build a container image using gitlab CI, which runs builds in docker. How would you like me to build an image without using docker in docker, or buildah in docker?

https://github.com/GoogleContainerTools/kaniko can do it but I just use podman / buildah with storage driver as vfs, and then neither requires root / high privileges.

I'm not sure why it doesn't do this by default. Performance I guess.

Re: Transitioning from Docker to Podman

#213

Post by spijdar »

tannhaeuser wrote: post #191
zelly wrote: post #126

It's compatible with cgroups v2 unlike the standard Docker. If you're using Fedora, you have to add a kernel parameter to Grub to use cgroups v1 instead. RedHat seems to be pushing a standard ecosystem for Linux: systemd, Wayland, SELinux, GNOME, and now maybe podman. I've been on Linux for a while; it's a welcome change from all the fragmentation I'm used to. Whereas others try to work around the kernel and implemen…

> RedHat just goes with what Linux already has More like, Redhat/IBM defines what Linux has simply by paying most Linux devs, and of course they take advantage of it in userspace and sys management. cgroups/namespaces, systemd, gnome (and it's integration with systemd) plus others are two-sided swords: one one hand they create new functionality, but on the other hand the price to pay is concentrating Linux know-how i…

As a 23 y/old younger (well, young-ish) dev, it strikes me that this isn't anything new. Old commercial solutions since nearly the beginning have been predicated on proprietary solutions specific to some vendor's UNIX based OS. HP-UX, AIX, even back to the really early commercial releases of v7 all seem to have a common theme of having that unix core but with a lot of nice features added on, typically with pretty insane and convoluted frameworks. Tru64's clustering, AIX's management interface, all the competing UIs and management interfaces. All nice features deeply integrated into a proprietary solution as a form of vendor lock-in.

To your point, it seems like eventually this ends poorly for the incumbents, when they become too bloated and too difficult to extend or modify, since you have to work around some over-engineered high-availability process clustering to touch anything.

In Linux's case, I think the kernel itself is actually fine, but the user land is increasingly tightly glued to an increasingly convoluted set of RedHat stacks.

I mean, it always has -- RedHat made the modern posix threads library, Linux's PAM, and several other core parts, but at least those were pretty modular and "unixy", by comparison to the monolith being developed now.

Re: Transitioning from Docker to Podman

#214

Post by Narretz »

nrk7doh wrote: post #130
yjftsjthsd-h wrote: post #45

Earlier quoted context omitted.

Okay, I want to build a container image using gitlab CI, which runs builds in docker. How would you like me to build an image without using docker in docker, or buildah in docker?

Our org just adopted Makisu[1] which works beautifully in our GitLab CI pipelines. After a week of setup and fiddling with the settings, we were able to migrate all our build jobs to Makisu and haven’t looked back. Build times are great too, especially if you set it up with a Redis cache. [1]: https://github.com/uber/makisu

Have you used / considered kaniko before? If so, what are the advantages of Makisu?

Re: Transitioning from Docker to Podman

#215

Post by sofixa »

ryan29 wrote: post #161
tikkabhuna wrote: post #56

Earlier quoted context omitted.

We use kaniko[1] in Gitlab CI and it’s working great for us. It’s annoying the kaniko image requires us to specify the entrypoint. There’s some peculiarities with Dive [2], but otherwise it’s been a very easy migration. [1] https://github.com/GoogleContainerTools/kaniko [2] https://github.com/wagoodman/dive/issues/318

I tried kaniko and didn't like it. Having build and push as part of the same job is frustrating and I view it as a sign that a CI system is built with the expectation of having everything happen post commit by shoveling money into a CI auto-scaler. I know there's `--no-push`, but that's a poor substitute for independent `build`, `tag`, `push` build steps IMO. Do you have any way of running / debugging locally with Gi…

> Having build and push as part of the same job is frustrating and I view it as a sign that a CI system is built with the expectation of having everything happen post commit by shoveling money into a CI auto-scaler

No, the idea is to build and push images you can test directly afterwards in the same conditions. With cache and such, build times shouldn't be too long

Gitlab CI just runs shell commands, it's pretty trivial to pull the same image its using in the job, and run the same commands locally.

If you have long CI times, that can hinder development productivity and should be improved as much as possible, or a local replica of the CI needs to be created.

Re: Transitioning from Docker to Podman

#216

Post by 8fingerlouie »

IceWreck wrote: post #200

For anyone not using Podman just because lack of docker compose like functionality, there are multiple alternatives. * Podman's official stance is to use Kubernetes YAML. The provide tools to generate this as well as convert docker-compose to kubeyaml * podman-compose is not official, but it works well. you have to note that its not 100% compatible with dc but a lot of dc files run out of the box without modification…

podman-compose works really well IMO.

For my stacks, the only thing i can't get working is routing a specific container through a host defined network (not a container). I'm certain podman can do it, i just haven't had the time to "fiddle" with it.

With docker (compose) i just define an ipam network (external) matching the host adapters network, and connect the containers to that network, and the spice begins to flow.

Re: Transitioning from Docker to Podman

#217

Post by bserge »

SEJeff wrote: post #148
zer0nka wrote: post #136

Earlier quoted context omitted.

btrfs is depreciated in redhat distribution

They just made it the default in fedora. It is likely not deprecated for unreleased RHEL versions

I just installed Fedora yesterday and was pretty confused at that part, after reading many articles and posts about RH dropping btrfs.

Re: Transitioning from Docker to Podman

#218

Post by Iolaum »

weikju wrote: post #138
zer0nka wrote: post #136

Earlier quoted context omitted.

btrfs is depreciated in redhat distribution

*deprecated On the other hand isn’t btrfs becoming the default in Fedora 33, thus eventually making a comeback in RHEL?

Yes that may well happen.

It's also noteworthy that the BTRFS change was driven by community members, mainly from Facebook.

Re: Transitioning from Docker to Podman

#220

Post by pjmlp »

tannhaeuser wrote: post #191
zelly wrote: post #126

It's compatible with cgroups v2 unlike the standard Docker. If you're using Fedora, you have to add a kernel parameter to Grub to use cgroups v1 instead. RedHat seems to be pushing a standard ecosystem for Linux: systemd, Wayland, SELinux, GNOME, and now maybe podman. I've been on Linux for a while; it's a welcome change from all the fragmentation I'm used to. Whereas others try to work around the kernel and implemen…

> RedHat just goes with what Linux already has More like, Redhat/IBM defines what Linux has simply by paying most Linux devs, and of course they take advantage of it in userspace and sys management. cgroups/namespaces, systemd, gnome (and it's integration with systemd) plus others are two-sided swords: one one hand they create new functionality, but on the other hand the price to pay is concentrating Linux know-how i…

Having used several UNIX flavours since 1992, I can't relate to what is simple in UNIX, unless you are speaking about V6.
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