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Goodbye Docker on CentOS, Hello Ubuntu

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31–40 of 42 posts

Re: Goodbye Docker on CentOS, Hello Ubuntu

#31
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

>I can't figure out how to manage dependencies for a given OS

It's actually: "Distro-provided dependencies are two-three years old and I don't want to deal with backports, ppas or whatever to get a fresh stable version of Python, Node or anything else."

Re: Goodbye Docker on CentOS, Hello Ubuntu

#32
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

"It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use."

Either you're doing something wrong or everybody's extremely lucky. If you've used Docker for 30 minutes I would bet on the former :)

Re: Goodbye Docker on CentOS, Hello Ubuntu

#33
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

Well... that might be a reason why it's popular. I think the very snappy boot up process for a container is also very appealing. For example, t2.micro's on AWS seem to take at least 30 seconds which is frustratingly slow if you're changing stuff often but only touching application/service dependencies.

It's not "docker or VMs", it's "docker or other container frameworks". Compared to those, Docker seems to come with a ludicrous list of caveats and workarounds.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#34
post #32
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

"It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use." Either you're doing something wrong or everybody's extremely lucky. If you've used Docker for 30 minutes I would bet on the former :)

Or everyone got used to it and don't consider it being an issue.

I believe that the filesystem layering feature in Docker is an anti-feature. It depends on unstable kernel features to work properly and doesn't really address the caching issues properly. Dependencies are usually in a tree, not linear like presented in a Dockerfile.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#35
post #13
post #9

From the op: "I enjoyed its minimal install to create a light environment, intuitive installation process, and it’s package manager." CentOS is neither minimal nor light. Ubuntu also isn't either of these things. Both of these distributions are more targeted towards convenience and ease of use, which means a lot of features/services that are generally unnecessary are enabled by default. The main reasons to use CentOS…

The minimal CentOS install is pretty lightweight. It's not a tiny distro by any means, but for keeping w/in the RHEL/CentOS realm, it's really pretty good. It's the only version that I install on servers, just to keep the excess cruft out (no X, no Gnome, no extra services, etc...).

Ubuntu has "Ubuntu server" which is Ubuntu without X, GNOME and other desktop services.

In addition, there is Ubuntu Minimal (https://help.ubuntu.com/community/Installation/MinimalCD) which is the most minimal you can get in Ubuntu.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#36
post #32
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

"It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use." Either you're doing something wrong or everybody's extremely lucky. If you've used Docker for 30 minutes I would bet on the former :)

Exactly!

My company is extensively using docker. It has made deployment and maintaining different versions too smooth.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#37
post #16

I would rather say "goodbye docker", period. Having used it a bit, I have concluded that it is just not a very good or mature tool. Once you scratch under the surface, things cease to be easy or stop working at all. It makes you wonder how it's been this long and nobody stumbled upon an issue that you uncover 30 minutes into tool's use. Docker does have it's uses, but in the majority of cases you are better off using…

Having worked for some time with configuration management and backend development and seeing the growing pains that happen after any "non-trivial" use case of it like: obscure declarative languages/DSLs, tangled messes of declarative vs scripted configurations, inter-dependencies that are not so obvious until you hit a corner case, etc., I can say that Docker has been a breeze, even when I encounter a breaking bug in a new release that breaks it somehow.

It's easier to get our devs wrapping all of their dependencies in a container, it's easier to just deploy the container, it's easier to separate what's "state" and "data" that should be maintained from the application and what's throwable.

Docker helps a lot to get away from the snowflake-machine mentality, everything is ephemeral so think carefully what you really need not to be like that and treat those cases like they should.

I do understand a lot of criticism about Docker but having worked with almost every mainstream configuration management tool (CFEngine, Puppet, Chef and Ansible) I can say I truly prefer to only have to care about Docker (or containers, I'm taking a look at other solutions atm) than the tangled mess that every single of them become later on.

And I'm sorry, only using "package managers" don't cut for the vast majority of deployments, you still have to manage configuration files, env vars and all of the other ugly mess.

How long have you worked with a scale of hundreds to thousands of automated servers?

Re: Goodbye Docker on CentOS, Hello Ubuntu

#38
post #33

Earlier quoted context omitted.

Well... that might be a reason why it's popular. I think the very snappy boot up process for a container is also very appealing. For example, t2.micro's on AWS seem to take at least 30 seconds which is frustratingly slow if you're changing stuff often but only touching application/service dependencies.

It's not "docker or VMs", it's "docker or other container frameworks ". Compared to those, Docker seems to come with a ludicrous list of caveats and workarounds.

Good point. I haven't kept up with the maturity status of other container frameworks though so I'm not sure how prevalent stuff like Rocket is in the wild.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#39

By default, Docker will use the AUFS storage backend if available, and then fall back to devicemapper on loopback. RHEL, CentOS, and Fedora do not ship the AUFS kernel module because it is not part of the mainline Linux kernel and is unlikely to be included in future, and these distros have an "upstream first, no out-of-tree bits" policy. Instead, they recommend using devicemapper on LVM [1][2]. The same advice is pr…

The author of the original blog is confusing the issue of base-image of a Docker image and the host OS on which the Docker daemon is running. They are completely orthogonal issues. Yes, there've been plenty of complaints about DM performance and space reclamation issues. By all means, switch the host OS from CentOS/Fedora to Ubuntu if it alleviates the problems. The base-image is a completely different matter. There is no reason to switch from CentOS/Fedora to Ubuntu just because you changed the host OS. This is point of the filesystem isolation Docker provides.

Re: Goodbye Docker on CentOS, Hello Ubuntu

#40
post #39

By default, Docker will use the AUFS storage backend if available, and then fall back to devicemapper on loopback. RHEL, CentOS, and Fedora do not ship the AUFS kernel module because it is not part of the mainline Linux kernel and is unlikely to be included in future, and these distros have an "upstream first, no out-of-tree bits" policy. Instead, they recommend using devicemapper on LVM [1][2]. The same advice is pr…

The author of the original blog is confusing the issue of base-image of a Docker image and the host OS on which the Docker daemon is running. They are completely orthogonal issues. Yes, there've been plenty of complaints about DM performance and space reclamation issues. By all means, switch the host OS from CentOS/Fedora to Ubuntu if it alleviates the problems. The base-image is a completely different matter. There…

The base-image is a completely different matter. There is no reason to switch from CentOS/Fedora to Ubuntu just because you changed the host OS

>> Yes, there is. There is a known issue using AUFS(Which Ubuntu uses for Docker) with CentOS/Fedora images:

https://github.com/docker/docker/issues/6980

To make it easier, I just changed the base image from CentOS/Fedora to Ubuntu so I do not have to worry about it.

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