restructured the project to comply community guideline, for others check release note

internal/docker/client.go

@@ -0,0 +1,153 @@
+package docker
+
+import (
+	"net/http"
+	"sync"
+	"sync/atomic"
+
+	"github.com/docker/cli/cli/connhelper"
+	"github.com/docker/docker/client"
+	"github.com/sirupsen/logrus"
+	"github.com/yusing/go-proxy/internal/common"
+	E "github.com/yusing/go-proxy/internal/error"
+	F "github.com/yusing/go-proxy/internal/utils/functional"
+)
+
+type Client struct {
+	key      string
+	refCount *atomic.Int32
+	*client.Client
+
+	l logrus.FieldLogger
+}
+
+func ParseDockerHostname(host string) (string, E.NestedError) {
+	switch host {
+	case common.DockerHostFromEnv, "":
+		return "localhost", nil
+	}
+	url, err := E.Check(client.ParseHostURL(host))
+	if err != nil {
+		return "", E.Invalid("host", host).With(err)
+	}
+	return url.Hostname(), nil
+}
+
+func (c Client) DaemonHostname() string {
+	// DaemonHost should always return a valid host
+	hostname, _ := ParseDockerHostname(c.DaemonHost())
+	return hostname
+}
+
+func (c Client) Connected() bool {
+	return c.Client != nil
+}
+
+// if the client is still referenced, this is no-op
+func (c *Client) Close() error {
+	if c.refCount.Add(-1) > 0 {
+		return nil
+	}
+
+	clientMap.Delete(c.key)
+
+	client := c.Client
+	c.Client = nil
+
+	c.l.Debugf("client closed")
+
+	if client != nil {
+		return client.Close()
+	}
+	return nil
+}
+
+// ConnectClient creates a new Docker client connection to the specified host.
+//
+// Returns existing client if available.
+//
+// Parameters:
+//   - host: the host to connect to (either a URL or common.DockerHostFromEnv).
+//
+// Returns:
+//   - Client: the Docker client connection.
+//   - error: an error if the connection failed.
+func ConnectClient(host string) (Client, E.NestedError) {
+	clientMapMu.Lock()
+	defer clientMapMu.Unlock()
+
+	// check if client exists
+	if client, ok := clientMap.Load(host); ok {
+		client.refCount.Add(1)
+		return client, nil
+	}
+
+	// create client
+	var opt []client.Opt
+
+	switch host {
+	case common.DockerHostFromEnv:
+		opt = clientOptEnvHost
+	default:
+		helper, err := E.Check(connhelper.GetConnectionHelper(host))
+		if err.HasError() {
+			return Client{}, E.UnexpectedError(err.Error())
+		}
+		if helper != nil {
+			httpClient := &http.Client{
+				Transport: &http.Transport{
+					DialContext: helper.Dialer,
+				},
+			}
+			opt = []client.Opt{
+				client.WithHTTPClient(httpClient),
+				client.WithHost(helper.Host),
+				client.WithAPIVersionNegotiation(),
+				client.WithDialContext(helper.Dialer),
+			}
+		} else {
+			opt = []client.Opt{
+				client.WithHost(host),
+				client.WithAPIVersionNegotiation(),
+			}
+		}
+	}
+
+	client, err := E.Check(client.NewClientWithOpts(opt...))
+
+	if err.HasError() {
+		return Client{}, err
+	}
+
+	c := Client{
+		Client:   client,
+		key:      host,
+		refCount: &atomic.Int32{},
+		l:        logger.WithField("docker_client", client.DaemonHost()),
+	}
+	c.refCount.Add(1)
+	c.l.Debugf("client connected")
+
+	clientMap.Store(host, c)
+	return c, nil
+}
+
+func CloseAllClients() {
+	clientMap.RangeAll(func(_ string, c Client) {
+		c.Client.Close()
+	})
+	clientMap.Clear()
+	logger.Debug("closed all clients")
+}
+
+var (
+	clientMap   F.Map[string, Client] = F.NewMapOf[string, Client]()
+	clientMapMu sync.Mutex
+
+	clientOptEnvHost = []client.Opt{
+		client.WithHostFromEnv(),
+		client.WithAPIVersionNegotiation(),
+	}
+
+	logger = logrus.WithField("module", "docker")
+)