OpenVZ and docker - Which providers support Docker?

jeromeza

My HostUS VPS can't seem to run a docker image:

WARN[0000] You are running linux kernel version 2.6.32-042stab108.8, which might be unstable running docker. Please upgrade your kernel to 3.10.0. 
ERRO[0000] 'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded. 
INFO[0000] Listening for HTTP on unix (/var/run/docker.sock) 
WARN[0000] Running modprobe bridge nf_nat failed with message: , error: exit status 1 
FATA[0000] Error starting daemon: Error initializing network controller: Error creating default "bridge" network: inappropriate ioctl for device 

Is there any way to determine which hosts support docker?

jeromeza

Hmmm - actually it may be available here:

https://my.hostus.us/announcements.php?id=23

Let me test and see. Wonder how this gets around the kernel versioning issue? Especially since i'm still obviously on a node with an old kernel version.

martinandrino

Your provider needs to enable some special options on the host node to get docker working in the container, it's unlikely to find any leb provider willing to do the effort.

Get a KVM box instead if you need to use Docker.

PetaByet

@jeromeza Docker is supported with kernel 042stab105.4 or later version

MarkTurner

Why do you want OpenVZ with docker, why not docker on KVM or CoreOS with Docker?

jeromeza

@MarkTurner said:
Why do you want OpenVZ with docker, why not docker on KVM or CoreOS with Docker?

Good question , not sure why I insist on limiting myself! I was just curious if there's a way to determine (without purchasing) if a provider supports Docker or not, but I guess the only way is to contact them.

deadbeef

@MarkTurner said:
Why do you want OpenVZ with docker, why not docker on KVM or CoreOS with Docker?

OpenVZ is cheaper, no?

vimalware

Just get a large(2gb for LET) KVM with additional IPs( if you want to re-use same port numbers) and run multiple Docker CTs inside it .

I recommend @dediserve for dedicated resource KVMs.
They have ~$6.6/m promo going for the next 10 days.

You can even split that bundle into 2 VMs (with an additional IP) , if true isolation floats your boat.

I run gitlab in a docker CT on dediserve.

Docker on OpenVZ is kind of a fool's errand right now. (not to mention eliminating all the OpenVZ memory edge-cases, for some classes of software)

Jacob

What's the point, both will run exactly the same, as long as the dependancy requirements are met.

@MarkTurner said:
Why do you want OpenVZ with docker, why not docker on KVM or CoreOS with Docker?

AlexanderM

@jeromeza said:
My HostUS VPS can't seem to run a docker image:

> WARN[0000] You are running linux kernel version 2.6.32-042stab108.8, which might be unstable running docker. Please upgrade your kernel to 3.10.0. 
> ERRO[0000] 'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded. 
> INFO[0000] Listening for HTTP on unix (/var/run/docker.sock) 
> WARN[0000] Running modprobe bridge nf_nat failed with message: , error: exit status 1 
> FATA[0000] Error starting daemon: Error initializing network controller: Error creating default "bridge" network: inappropriate ioctl for device 
> 

Is there any way to determine which hosts support docker?

§

If you open a ticket we can fix this for you

Alexander

Ikoula

Check the available images if there is an OS like core OS available the provider might be able to support docker.

Check the minimum requirements on Docker website.

You can also open a ticket to the provider's support and ask them.

elgs

Docker is not designed for use like a vm, as docker's storage image is layered that if you want to write a big file in the readonly layer, it has to be copied to the rw layer for write. Docker is probably designed for massive quick deployment of apps.

deadbeef

@elgs said:
Docker is not designed for use like a vm, as docker's storage image is layered that if you want to write a big file in the readonly layer, it has to be copied to the rw layer for write.

Docker has the concept of "volumes" - you mark directories as volumes and they don't get stored in layered fs

MarkTurner

Jacob said: What's the point, both will run exactly the same, as long as the dependancy requirements are met.

Thats not 100% true, OpenVZ doesn't support in Docker in-container bridging properly and things like full overlay filesystems are missing.

ValdikSS

Docker is a problem in OpenVZ, but the actual namespaces, cgroups are not. You can use other solutions like firejail, systemd-nspawn (with machinectl), rkt and it should work.

To run fresh versions of systemd, make sure your host uses kernel 042stab111.1 or newer.

To check namespaces support, I use this:

unshare -muinpf --mount-proc echo works

If should print "works". Just ask to run this command before buying.

deadbeef

@ValdikSS said:
To check namespaces support, I use this:

unshare: invalid option -- 'p'


Usage:
unshare [options] [args...]
Options:
-h, --help usage information (this)
-m, --mount unshare mounts namespace
-u, --uts unshare UTS namespace (hostname etc)
-i, --ipc unshare System V IPC namespace
-n, --net unshare network namespace


ValdikSS

@deadbeef said:
unshare: invalid option -- 'p'

You're probably trying this on a way outdated or 'stable' system like CentOS.

dedicados

You can use DigitalOcean or Vultr, they support Docker with Ubuntu.

just deploy an instance, and download the app your need and run it.