Docker Registry local error: No such image: localhost:5000

Question

Good morning to all,

I’ve had a problem for two days that I haven’t been able to solve. I built an environment with 3 machines, with Docker swarm, one machine manager and two nodes.

The problem, when I start a service in the manager, I get the error: No such image: localhost:5000/integration-toa

I tried to create the local Registry on the machine manager in two ways:

1 - as a service

docker service create --name registry --publish published=5000,target=5000,mode=host registry:2

As a service, I can’t push the image:

[root@tslxdocker-hlg docker]# docker service create --name registry --publish published=5000,target=5000,mode=host registry:2
1z0a64ulmdvu6f2k08omgg3fj
overall progress: 1 out of 1 tasks
1/1: running   [==================================================>]
verify: Service converged
[root@tslxdocker-hlg docker]# docker push localhost:5000/integracao-toa
The push refers to repository [localhost:5000/integracao-toa]
Get http://localhost:5000/v2/: dial tcp 127.0.0.1:5000: connect: connection refused

As a service, I have refused Connection error. However, on the two other host machines, I can connect to Registry:

curl localhost:5000/v2/_catalog
{"repositories":[]}

created the file /etc/Docker/daemon.json and restarted the Docker service

[root@tslxdocker-hlg docker]# cat /etc/docker/daemon.json
{
    "insecure-registries":[
        "localhost:5000",
        "127.0.0.1:5000"
    ]
}

I also tried to comment on the "localhost" line on /etc/hosts The error persists

2 - as a container

docker run -d -p 5000:5000 --restart=always --name registry registry:2

As a simple container, I can push the image in Registry, but the other nodes cannot connect to the registry:

push the image successfully:

[root@tslxdocker-hlg docker]# docker run -d -p 5000:5000 --restart=always --name registry registry:2
397f6fe083da78d5d0f08be3dfa336c01e328d8bbd46637dd52ac5b479a48c11
[root@tslxdocker-hlg docker]# docker push localhost:5000/integracao-toa
The push refers to repository [localhost:5000/integracao-toa]
82c687db4923: Pushed
fe849f218079: Pushed
bd029db62750: Pushed
03861ebeff3b: Pushed
286ab5bbe85e: Pushed
de2051a29c4c: Pushed
bac22f4e2b6a: Pushed
538ca12fd712: Pushed
f75e64f96dbc: Pushed
8f7ee6d76fd9: Pushed
c23711a84ad4: Pushed
90d1009ce6fe: Pushed
latest: digest: sha256:a6adadccfc2914d4a88f74cd8fba58105d223596e5b32ef7f71754056817e3f4 size: 2849

Failed to add service to swarm:

 docker service create --name integracao-toa --constraint node.labels.group==group01 --replicas 2 -p 3000:80 localhost:5000/integracao-toa
u1fwfqjs1vn1ml8665vbprzov
overall progress: 0 out of 2 tasks
1/2: No such image: localhost:5000/integracao-toa:latest@sha256:a6adadccfc2914d…
2/2: No such image: localhost:5000/integracao-toa:latest@sha256:a6adadccfc2914d…

interesting also that, as container, the nodes also fail to connect in the Registry:

curl localhost:5000/v2/_catalog
curl: (7) Failed connect to localhost:5000; Connection refused

So, I don’t know what else to do and I still have a question, what is the most correct way to run the local Registry? as a service or with Docker run?

Edit 1 In Docker info returns me the list of unsafe records (insecure-registries)

Insecure Registries:
 127.0.0.1:5000
 localhost:5000
 10.0.0.77:5000
 127.0.0.0/8

Answer 1

I managed to solve.

Solution:

The daemon.json file should also be configured in the Workers and not only in the manager.

I also changed the name of the localhost image:5000 to 10.0.0.77:5000 (manager ip)

/etc/Docker/daemon.json

{
    "insecure-registries":[
        "10.0.0.77:5000"
    ]
}

In short

In Workers, I created the daemon.json file with insecure-registries and restarted Docker

In the manager, I ran Registry as a container.

docker run -d -p 5000:5000 registry:2

I created a new image tag (I didn’t use Atest because I want to know which version exactly is running, by Portainer) Docker tag integration-toa:14 10.0.0.77:5000/integration-toa:14

I pushed the image to the local Registry:

docker push 10.0.0.77:5000/integracao-toa:14

I ran the service of my application and used the "contraint" so that it was only published in the Workers (I added a label called group=group01 in the two Workers, so I can control by the manager on which machines my application will deploy)

docker service create --name integracao-toa --constraint node.labels.group==group01 --replicas 2 -p 3000:80 10.0.0.77:5000/integracao-toa:14

and again, I ran with the specific tag of version 14, instead of Latest, so I can more consistently visualize the version running on each node