Massive architectural rework

This commit massively overhauls the project's structure to simplify
development. Most parts are now correctly compartmentalized and
dependencies are passed in a sane way rather than global variables
galore xd.

internal/docker/volume.go

@@ -0,0 +1,37 @@
+package docker
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/docker/docker/api/types/volume"
+	"go.uber.org/zap"
+)
+
+type DockerVolume struct {
+	VolumeID   string
+	Mountpoint string
+}
+
+func (d *DockerClient) CreateDockerVolume(ctx context.Context) (vol *DockerVolume, err error) {
+	dockerVolume, err := d.client.VolumeCreate(ctx, volume.CreateOptions{
+		Driver:     "local",
+		DriverOpts: map[string]string{},
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to create volume: %v", err)
+	}
+
+	d.logger.Debugw("Volume created", zap.String("volume_id", dockerVolume.Name), zap.String("mountpoint", dockerVolume.Mountpoint))
+
+	vol = &DockerVolume{
+		VolumeID: dockerVolume.Name,
+	}
+
+	return vol, nil
+}
+
+func (d *DockerClient) DeleteDockerVolume(ctx context.Context, volumeID string) error {
+	d.logger.Debugw("Removing volume", zap.String("volume_id", volumeID))
+	return d.client.VolumeRemove(ctx, volumeID, true)
+}