How can nomad' job from local docker images

Question

nomad docker image will be fetched from Docker Hub.But I have want use some local images.How can I use theme.(I dont want to use private repo)

Example I want to use local image test


> docker images
REPOSITORY                         TAG                 IMAGE ID            CREATED             SIZE
test                        latest              da795ca8a32f        36 minutes ago      567MB

job "test" {
  datacenters = ["dc1"]

  group "example" {
    task "test" {
      driver = "docker"

      config {
        image = "test"
      }

      resources {
        cpu = 500
        memory = 256 
      }
    }
  }
}

It's wrong !

score 6 · Answer 1 · answered Dec 31 '20 at 10:07

6

I'm not sure if this can be treated as an answer or a "hack".

But if you want Nomad to use docker image that is already present on a node the image MUST NOT be tagged latest.

For testing I tag my images as IMAGE:local. This way Nomad uses it if present, pulls it from remote if not.

answered Dec 31 '20 at 10:07

titus

377
4
16

Note that, by default, Nomad will delete this image after use and you'll have to rebuild it https://www.nomadproject.io/docs/drivers/docker#gc – Andrew Jun 27 '22 at 17:31
@Andrew Did not happen to me yet. config.gc.image=false – titus Jun 28 '22 at 18:38

JamesJJ · Accepted Answer · 2019-05-29T01:43:44.897

Looking at Nomad's source code here and here, it seems that using machine local images is not supported. That would make sense, as in a cluster environment with several nodes, the scheduler needs to be able to get the image irrespective of which machine the job is allocated to.

(One possible workaround would be to run a registry service within the Nomad cluster, and use whichever storage backend is most convenient for you)

score 3 · Answer 3 · answered Nov 08 '19 at 17:34

3

Nomad now supports tar docker images.

here is an example

artifact {
  source = "http://path.to/redis.tar"
}
config {
  load = "redis.tar"
  image = "redis"
}

However, the tar size may be too large to be resiliently transport and provisioned.

answered Nov 08 '19 at 17:34

Miao1007

944
6
22

score 0 · Answer 4 · answered Feb 09 '22 at 16:01

While @Miao1007 s answer works, you need to be aware of one thing. It seems that you you cannot use the tag latest or omit the tag altogether ( see the discussion here). You need to tag your docker build with some version number like

sudo docker build --tag dokr:1.0.0 .
sudo docker save dokr:1.0.0 > dokr-1.0.0.tar

then use the following in the job file
artifact {
    source = "http://localhost:8000/dokr-1.0.0.tar"
}
config {
    load = "go-docker-dokr-1.0.0.tar"
    image = "go-docker-dokr:1.0.0"
}

score 0 · Answer 5 · answered Jan 31 '23 at 05:40

Starting from version 0.9.0, Nomad checking whether the image has already been loaded.

Source code

Contributor comment

 // We're going to check whether the image is already downloaded. If the tag
 // is "latest", or ForcePull is set, we have to check for a new version every time so we don't
 // bother to check and cache the id here. We'll download first, then cache.

score 0 · Answer 6 · answered May 08 '23 at 05:49

0

If the tag of the image is :latest, which is the default, nomad will try to pull it.

Use a different tag for local images, for example :local, and it will be fine.

  config {
    image = "test:local"
  }

answered May 08 '23 at 05:49

KamilCuk

120,984
8
59
111

How can nomad' job from local docker images

6 Answers6