Exposing Docker port 2375

[pelifix]

When trying to expose the docker port 2375, as described here: #2304 (comment)
I get the following error:

Unable to find image 'rancher/socat-docker:latest' locally
docker: Error response from daemon: missing signature key.

When trying to pull the image directly, I get a more detailed error message:

docker pull rancher/socat-docker
Using default tag: latest
latest: Pulling from rancher/socat-docker
[DEPRECATION NOTICE] Docker Image Format v1 and Docker Image manifest version 2, schema 1 support is disabled by default and will be removed in an upcoming release. Suggest the author of docker.io/rancher/socat-docker:latest to upgrade the image to the OCI Format or Docker Image manifest v2, schema 2. More information at https://docs.docker.com/go/deprecated-image-specs/

Anyone have a workaround?

[jandubois]

It is an ancient image that hasn't been updated in 10 years and isn't being used anymore.

You can easily build it yourself:

$ git clone https://github.com/rancher/socat-test
Cloning into 'socat-test'...
remote: Enumerating objects: 21, done.
remote: Total 21 (delta 0), reused 0 (delta 0), pack-reused 21 (from 1)
Receiving objects: 100% (21/21), done.
Resolving deltas: 100% (2/2), done.

$ cd socat-test

$ docker build -t rancher/socat-test .
[+] Building 9.4s (10/10) FINISHED                                                                                                   docker:rancher-desktop
 => [internal] load build definition from Dockerfile                                                                                                   0.0s
 => => transferring dockerfile: 173B                                                                                                                   0.0s
 => [internal] load metadata for docker.io/library/alpine:3.1                                                                                          5.3s
 => [auth] library/alpine:pull token for registry-1.docker.io                                                                                          0.0s
 => [internal] load .dockerignore                                                                                                                      0.0s
 => => transferring context: 2B                                                                                                                        0.0s
 => [1/4] FROM docker.io/library/alpine:3.1@sha256:4dfc68bc95af5c1beb5e307133ce91546874dcd0d880736b25ddbe6f483c65b4                                    0.8s
 => => resolve docker.io/library/alpine:3.1@sha256:4dfc68bc95af5c1beb5e307133ce91546874dcd0d880736b25ddbe6f483c65b4                                    0.0s
 => => sha256:4dfc68bc95af5c1beb5e307133ce91546874dcd0d880736b25ddbe6f483c65b4 433B / 433B                                                             0.0s
 => => sha256:25fd8fc1aefcc8ae46aae23daefcd7dcb97f676fa0bc72bb0bf7cfb75df4f22e 528B / 528B                                                             0.0s
 => => sha256:a1038a41fe2b75d8c53d0a4d22207e4e7f72e95a11da4d20424f0062b239b67f 1.51kB / 1.51kB                                                         0.0s
 => => sha256:0f253aa151d797195fd887f4d3bf2794bfead4f61f5ba1d455cab177fdcb0511 2.30MB / 2.30MB                                                         0.6s
 => => extracting sha256:0f253aa151d797195fd887f4d3bf2794bfead4f61f5ba1d455cab177fdcb0511                                                              0.2s
 => [internal] load build context                                                                                                                      0.0s
 => => transferring context: 99B                                                                                                                       0.0s
 => [2/4] RUN apk add --update socat bash &&     rm -rf /var/cache/apk/*                                                                               2.6s
 => [3/4] COPY ./run.sh /                                                                                                                              0.1s
 => [4/4] RUN chmod +x /run.sh                                                                                                                         0.3s
 => exporting to image                                                                                                                                 0.1s
 => => exporting layers                                                                                                                                0.0s
 => => writing image sha256:349bd115fcaaea75eb21b1c07d100cee5f4f7d8097c5774d101a3ff30fa0cee4                                                           0.0s
 => => naming to docker.io/rancher/socat-test                                                                                                          0.0s

$ docker images
REPOSITORY                                          TAG       IMAGE ID       CREATED          SIZE
rancher/socat-test                                  latest    349bd115fcaa   14 seconds ago   7.09MB
ghcr.io/rancher-sandbox/rancher-desktop/rdx-proxy   latest    3568caf58a2c   54 years ago     5.3MB

[pelifix]

Yes, we ended up building it our self.
But I feel there should be "better" support in Rancher Desktop for enabling the docker port 2375, maybe even a checkbox in the GUI.
If you search for "how to enable docker port 2375 on Rancher Desktop" you will get multiple suggestion on using the /rancher/socat-test container, but now even that one no longer works.
There are stil many (legacy) build systems that depend on port 2375 being available.