cannot write valid mount path for docker container in go

I'm trying to start a test container to test my database. I'm using test containers.
Here is a piece of code how I setup a container:

func createContainer(ctx context.Context) (testcontainers.Container, *pgxpool.Pool, string, error) {
var env = map[string]string{
		"POSTGRES_PASSWORD": DbPass,
		"POSTGRES_USER":     DbUser,
		"POSTGRES_DB":       DbName,
	}
	var port = "5432/tcp"

	// /Users/<path>:/<container path> 
	path := `/c/Users/pizhlo21/Desktop/Folder/golang/TgBotReminder/internal/db/postgresql/migration:/usr/app`

	req := testcontainers.GenericContainerRequest{
		ContainerRequest: testcontainers.ContainerRequest{
			Image:        "postgres:latest",
			ExposedPorts: []string{port},
			Env:          env,
			WaitingFor:   wait.ForLog("database system is ready to accept connections"),
			VolumeMounts: map[string]string{"/docker-entrypoint-initdb.d": path},
			SkipReaper: true,
		},
		Started: true,
	}
	container, err := testcontainers.GenericContainer(ctx, req)
	if err != nil {
		return container, nil, "", fmt.Errorf("unable to start container: %v", err)
	}
...

but I got an error from Docker: failed to setup testunable to start container: failed to create container: Error response from daemon: create /docker-entrypoint-initdb.d: "/docker-entrypoint-initdb.d" includes invalid characters for a local volume name, only "[a-zA-Z0-9][a-zA-Z0-9_.-]" are allowed. If you intended to pass a host directory, use absolute path.
<br><Br>Sometimes this error looks like: failed to setup testfailed to start container: failed to create container: Error response from daemon: invalid mount config for type "volume": invalid mount path:
'"c/Desktop/Folder/golang/TgBotReminder/internal/db/postgresql/migration/000001_init_schema.up"' mount path must be absolute

I've tried many variations of my path such as:<br>
//c/Users/...
c/Users/...
/%cd%/Desktop/...
$HOME/Desktop/Folder/...<br>
but nothing helped me.

How to do it correct?

TL;DR

Replace

VolumeMounts: map[string]string{"/docker-entrypoint-initdb.d": path},

with

BindMounts: map[string]string{"/docker-entrypoint-initdb.d": path},

Issue 1

> "/docker-entrypoint-initdb.d" includes invalid characters for a local volume name, only "[a-zA-Z0-9][a-zA-Z0-9_.-]" are allowed.

It's important to know that there are three types of mounts:

• Volumes are stored in a part of the host filesystem which is managed by Docker (/var/lib/docker/volumes/ on Linux). Non-Docker processes should not modify this part of the filesystem. Volumes are the best way to persist data in Docker.
• Bind mounts may be stored anywhere on the host system. They may even be important system files or directories. Non-Docker processes on the Docker host or a Docker container can modify them at any time.
• tmpfs mounts are stored in the host system’s memory only, and are never written to the host system’s filesystem.

VolumeMounts is for specifying the volume mounts. As of github.com/testcontainers/testcontainers-go@v0.12.0, the value of an entry in VolumeMounts stores the volume name, which only allows [a-zA-Z0-9][a-zA-Z0-9_.-], that's why you see the error message. BTW, to see the error message above, your code must be something like this (note that /docker-entrypoint-initdb.d is the value instead of the key):

VolumeMounts: map[string]string{path: "/docker-entrypoint-initdb.d"},

Issue 2

> invalid mount config for type "volume": invalid mount path: '"c/Desktop/Folder/golang/TgBotReminder/internal/db/postgresql/migration/000001_init_schema.up"' mount path must be absolute

To see this error message, your code must be something like this:

VolumeMounts: map[string]string{`"/c/Desktop/Folder/golang/TgBotReminder/internal/db/postgresql/migration/000001_init_schema.up"`: "/docker-entrypoint-initdb.d"},

As of github.com/testcontainers/testcontainers-go@v0.12.0, the key of an entry in VolumeMounts stores the mount path. Since the mount path contains the double quotes ("), it's invalid. The docker daemon verifies the mount path first. That's why you see the error message.

Consider upgrading github.com/testcontainers/testcontainers-go

In release v0.13.0, ContainerRequest.BindMounts and ContainerRequest.VolumeMounts are replaced with ContainerRequest.Mounts. That's because "the map based data structure is somehow confusing. This change avoids confusion by introducing dedicated types for all components to get help by IDEs and the compiler". (see PR#386).

After upgrading to github.com/testcontainers/testcontainers-go@v0.21.0, the bind mounts can be specified with:

Mounts: testcontainers.Mounts(
	testcontainers.BindMount(path, "/docker-entrypoint-initdb.d"),
),