Docker SDK Go - Create container with PortBindings (error: "cannot use type nat.PortMap as type nat.PortMap")

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1

Hello,

I’m trying to create and run a container with the Docker SDK for GoLang, but I am getting always the same error when I try to set the port bindings. I looked these threads in StackOverflow, but I’m getting the same error:

This is my code:

import (
	"fmt"
	"strings"
	"strconv"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/client"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/go-connections/nat"
	"golang.org/x/net/context"
)

func CreateAndRun(image string, bindings map[string]int) {
	portBinding := nat.PortMap {}
	for port, binding := range bindings {
		portBinding[nat.Port(port)] = []nat.PortBinding{
			nat.PortBinding{
				HostIP: "0.0.0.0",
				HostPort: strconv.Itoa(binding),
			},
		}
	}

	resp, err := client.ContainerCreate(ctx, &container.Config {
		Image: image,
		Labels: map[string]string {DOCKER_CONTAINER_LABEL: ""},
	}, &container.HostConfig{
		PortBindings: portBinding,
		AutoRemove: DOCKER_REMOVE_ON_EXIT,
	}, nil, "")
	if err != nil {
		panic(err)
	}

	if err := client.ContainerStart(ctx, resp.ID, types.ContainerStartOptions{}); err != nil {
		panic(err)
	}

	fmt.Println(resp.ID)
}

And this is the error I’m getting while compiling:

error: incompatible type for field 5 in struct construction (cannot use type nat.PortMap as type nat.PortMap)
      PortBindings: portBinding,

If I cast the variable “portBinding” to “net.PortMap” I am still getting this error.

For installing the libraries I ran:

go get github.com/docker/docker/api/types
go get github.com/docker/docker/client
go get github.com/docker/go-connections/nat
go get golang.org/x/net/context

Does anyone know what is happening?

Thanks,
Xoán

UPDATE: If somehow it matters, I’m using Ubuntu 18.04 LTS, Docker 19.03.4 and Go 1.10.3 (gccgo).

2

I’m going to answer myself:

The problem is that “github.com/docker/docker” imports “github.com/docker/go-connections/nat” as vendor. So when it says cannot use type nat.PortMap as type nat.PortMap, in reality it’s trying to say cannot use type "github.com/docker/docker/vendor/github.com/docker/go-connections/nat.PortMap" as "github.com/docker/go-connections/nat.PortMap".

You can solve this using a package manager (like “dep”), or just deleting the folder “$GOPATH/src/github.com/docker/docker/vendor/github.com/docker/go-connections” (as you are importing that dependency from a different way). However, I think that something could be done in the Docker libraries to prevent this to happen.