Add container CreateOpt for setting port forwards

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

Author: cpuguy83

container/create.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 
@@ -34,6 +34,56 @@ func WithCreatePlatform(platform string) CreateOption {
 	}
 }
 
+// WithCreateHostConfigOpt allows you to set a function that modifies the
+// HostConfig of the container being created.
+func WithCreateHostConfigOpt(f func(*containerapi.HostConfig)) CreateOption {
+	return func(cfg *CreateConfig) {
+		f(&cfg.Spec.HostConfig)
+	}
+}
+
+// WithCreateNetworkConfigOpt allows you to set a function that modifies the
+// NetworkingConfig of the container being created.
+func WithCreateNetworkConfigOpt(f func(*containerapi.NetworkingConfig)) CreateOption {
+	return func(cfg *CreateConfig) {
+		f(&cfg.Spec.NetworkConfig)
+	}
+}
+
+// WithCreateConfigOpt allows you to set a function that modifies the
+// Config of the container being created.
+func WithCreateConfigOpt(f func(*containerapi.Config)) CreateOption {
+	return func(cfg *CreateConfig) {
+		f(&cfg.Spec.Config)
+	}
+}
+
+// WithCreatePortForwarding adds the specified port forward to the container's
+// configuration.
+// In this case the 'port' is the container port to forward to the host.
+func WithCreatePortForwarding(proto string, port int, hostBindings ...containerapi.PortBinding) CreateOption {
+	return func(cfg *CreateConfig) {
+		portSpec := fmt.Sprintf("%d/%s", port, proto)
+
+		WithCreateConfigOpt(func(c *containerapi.Config) {
+			if c.ExposedPorts == nil {
+				c.ExposedPorts = map[string]struct{}{}
+			}
+			c.ExposedPorts[portSpec] = struct{}{}
+		})(cfg)
+
+		WithCreateHostConfigOpt(func(hc *containerapi.HostConfig) {
+			bindings := hc.PortBindings
+			if bindings == nil {
+				bindings = containerapi.PortMap{}
+			}
+
+			bindings[fmt.Sprintf("%d/%s", port, proto)] = hostBindings
+			hc.PortBindings = bindings
+		})(cfg)
+	}
+}
+
 // Create creates a container using the provided image.
 func (s *Service) Create(ctx context.Context, img string, opts ...CreateOption) (*Container, error) {
 	c := CreateConfig{
@@ -78,7 +128,7 @@ func (s *Service) Create(ctx context.Context, img string, opts ...CreateOption)
 	}
 	defer resp.Body.Close()
 
-	data, err := ioutil.ReadAll(resp.Body)
+	data, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, errdefs.Wrap(err, "error reading response body")
 	}

container/create_test.go

@@ -5,9 +5,11 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/cpuguy83/go-docker/container/containerapi"
 	"github.com/cpuguy83/go-docker/errdefs"
 	"github.com/cpuguy83/go-docker/testutils"
 	"gotest.tools/v3/assert"
+	"gotest.tools/v3/assert/cmp"
 )
 
 func TestCreate(t *testing.T) {
@@ -36,4 +38,56 @@ func TestCreate(t *testing.T) {
 	inspect, err := c.Inspect(ctx)
 	assert.NilError(t, err)
 	assert.Equal(t, name, strings.TrimPrefix(inspect.Name, "/"))
+
+	t.Run("port bindings", func(t *testing.T) {
+		t.Parallel()
+
+		c, err := s.Create(ctx, "busybox:latest",
+			WithCreateName(name),
+			WithCreatePortForwarding("tcp", 80),
+			WithCreatePortForwarding("udp", 81),
+			WithCreatePortForwarding("udp", 82, containerapi.PortBinding{HostIP: "127.0.0.1"}),
+			WithCreateCmd("top"),
+		)
+		assert.NilError(t, err)
+		defer func() {
+			assert.Check(t, s.Remove(ctx, c.ID(), WithRemoveForce))
+		}()
+
+		assert.Assert(t, c.ID() != "")
+		assert.NilError(t, c.Start(ctx))
+
+		inspect, err := c.Inspect(ctx)
+		assert.NilError(t, err)
+		assert.Check(t, cmp.Equal(inspect.Config.ExposedPorts["80/tcp"], struct{}{}))
+
+		port80, ok := inspect.NetworkSettings.Ports["80/tcp"]
+		assert.Check(t, ok)
+		port81, ok := inspect.NetworkSettings.Ports["81/udp"]
+		assert.Check(t, ok)
+
+		port82, ok := inspect.NetworkSettings.Ports["82/udp"]
+		assert.Check(t, ok)
+		assert.Check(t, cmp.Equal(port82[0].HostIP, "127.0.0.1"))
+
+		// Depending on the version of docker (and ipv6 support), there maybe be one
+		// or two bindings.
+		var hostPort string
+		for _, bind := range port80 {
+			if bind.HostPort != "" {
+				hostPort = bind.HostPort
+				break
+			}
+		}
+		assert.Check(t, hostPort != "", "expected a host port binding for 80/tcp")
+
+		hostPort = ""
+		for _, bind := range port81 {
+			if bind.HostPort != "" {
+				hostPort = bind.HostPort
+				break
+			}
+		}
+		assert.Check(t, hostPort != "", "expected a host port binding for 81/udp")
+	})
 }