enabling using another container's network stack on build process

cmd/skaffold/app/cmd/runner.go

@@ -105,6 +105,10 @@ func runContext(opts config.SkaffoldOptions) (*runcontext.RunContext, *latest.Sk
 		return nil, nil, fmt.Errorf("getting run context: %w", err)
 	}
 
+	if err := validation.ProcessWithRunContext(config, runCtx); err != nil {
+		return nil, nil, fmt.Errorf("invalid skaffold config: %w", err)
+	}
+
 	return runCtx, config, nil
 }
 

cmd/skaffold/app/cmd/runner_test.go

@@ -86,8 +86,11 @@ func TestCreateNewRunner(t *testing.T) {
 	for _, test := range tests {
 		testutil.Run(t, test.description, func(t *testutil.T) {
 			t.Override(&docker.NewAPIClient, func(docker.Config) (docker.LocalDaemon, error) {
-				return nil, nil
+				return docker.NewLocalDaemon(&testutil.FakeAPIClient{
+					ErrVersion: true,
+				}, nil, false, nil), nil
 			})
+
 			t.Override(&update.GetLatestAndCurrentVersion, func() (semver.Version, semver.Version, error) {
 				return semver.Version{}, semver.Version{}, nil
 			})

docs/content/en/schemas/v2beta11.json

@@ -992,11 +992,12 @@
         },
         "network": {
           "type": "string",
-          "description": "passed through to docker and overrides the network configuration of docker builder. If unset, use whatever is configured in the underlying docker daemon. Valid modes are `host`: use the host's networking stack. `bridge`: use the bridged network configuration. `none`: no networking in the container.",
-          "x-intellij-html-description": "passed through to docker and overrides the network configuration of docker builder. If unset, use whatever is configured in the underlying docker daemon. Valid modes are <code>host</code>: use the host's networking stack. <code>bridge</code>: use the bridged network configuration. <code>none</code>: no networking in the container.",
+          "description": "passed through to docker and overrides the network configuration of docker builder. If unset, use whatever is configured in the underlying docker daemon. Valid modes are `host`: use the host's networking stack. `bridge`: use the bridged network configuration. `container:<name|id>`: reuse another container's network stack. `none`: no networking in the container.",
+          "x-intellij-html-description": "passed through to docker and overrides the network configuration of docker builder. If unset, use whatever is configured in the underlying docker daemon. Valid modes are <code>host</code>: use the host's networking stack. <code>bridge</code>: use the bridged network configuration. <code>container:&lt;name|id&gt;</code>: reuse another container's network stack. <code>none</code>: no networking in the container.",
           "enum": [
             "host",
             "bridge",
+            "container:<name|id>",
             "none"
           ]
         },

examples/getting-started/skaffold.yaml

@@ -3,6 +3,11 @@ kind: Config
 build:
   artifacts:
   - image: skaffold-example
+    context: .
+    docker:
+      network: "container:alpine"
+  local:
+    push: false
 deploy:
   kubectl:
     manifests:

go.mod

@@ -35,6 +35,7 @@ require (
 	github.com/go-git/go-git/v5 v5.0.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e
+	github.com/golang/mock v1.4.4
 	github.com/golang/protobuf v1.4.3
 	github.com/google/go-cmp v0.5.2
 	github.com/google/go-containerregistry v0.1.4

go.sum

@@ -405,6 +405,7 @@ github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFU
 github.com/golang/mock v1.4.0/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/mock v1.4.1/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/mock v1.4.3/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
+github.com/golang/mock v1.4.4 h1:l75CXGRSwbaYNpl/Z2X1XIIAMSCquvXgpVZDhwEIJsc=
 github.com/golang/mock v1.4.4/go.mod h1:l3mdAwkq5BuhzHwde/uurv3sEJeZMXNpwsxVWU71h+4=
 github.com/golang/protobuf v0.0.0-20161109072736-4bd1920723d7/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=

pkg/skaffold/schema/latest/config.go

@@ -1115,6 +1115,7 @@ type DockerArtifact struct {
 	// is configured in the underlying docker daemon. Valid modes are
 	// `host`: use the host's networking stack.
 	// `bridge`: use the bridged network configuration.
+	// `container:<name|id>`: reuse another container's network stack.
 	// `none`: no networking in the container.
 	NetworkMode string `yaml:"network,omitempty"`
 

pkg/skaffold/schema/validation/validation.go

@@ -17,13 +17,18 @@ limitations under the License.
 package validation
 
 import (
+	"context"
 	"fmt"
 	"reflect"
 	"regexp"
 	"strings"
+	"time"
+
+	"github.com/docker/docker/api/types"
 
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/build/misc"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/docker"
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/runner/runcontext"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/util"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/yamltags"
@@ -60,6 +65,22 @@ func Process(config *latest.SkaffoldConfig) error {
 	return fmt.Errorf(strings.Join(messages, " | "))
 }
 
+// ProcessWithRunContext checks if the Skaffold pipeline is valid when a RunContext is required.
+// It returns all encountered errors as a concatenated string.
+func ProcessWithRunContext(config *latest.SkaffoldConfig, runCtx *runcontext.RunContext) error {
+	var errs []error
+	errs = append(errs, validateDockerNetworkContainerExists(config.Build.Artifacts, runCtx)...)
+
+	if len(errs) == 0 {
+		return nil
+	}
+	var messages []string
+	for _, err := range errs {
+		messages = append(messages, err.Error())
+	}
+	return fmt.Errorf(strings.Join(messages, " | "))
+}
+
 // validateTaggingPolicy checks that the tagging policy is valid in combination with other options.
 func validateTaggingPolicy(bc latest.BuildConfig) (errs []error) {
 	if bc.LocalBuild != nil {
@@ -179,7 +200,7 @@ func validateUniqueDependencyAliases(artifacts []*latest.Artifact) (errs []error
 	return
 }
 
-// validateDockerNetworkMode makes sure that networkMode is one of `bridge`, `none`, or `host` if set.
+// validateDockerNetworkMode makes sure that networkMode is one of `bridge`, `none`, `container:<name|id>`, or `host` if set.
 func validateDockerNetworkMode(artifacts []*latest.Artifact) (errs []error) {
 	for _, a := range artifacts {
 		if a.DockerArtifact == nil || a.DockerArtifact.NetworkMode == "" {
@@ -189,11 +210,60 @@ func validateDockerNetworkMode(artifacts []*latest.Artifact) (errs []error) {
 		if mode == "none" || mode == "bridge" || mode == "host" {
 			continue
 		}
+		containerRegExp := regexp.MustCompile("^container:[a-zA-Z0-9][a-zA-Z0-9_.-]*$")
+		if containerRegExp.MatchString(mode) {
+			continue
+		}
+
 		errs = append(errs, fmt.Errorf("artifact %s has invalid networkMode '%s'", a.ImageName, mode))
 	}
 	return
 }
 
+// Validates that a Docker Container with a Network Mode "container:<id|name>" points to an actually running container
+func validateDockerNetworkContainerExists(artifacts []*latest.Artifact, runCtx docker.Config) []error {
+	var errs []error
+	apiClient, err := docker.NewAPIClient(runCtx)
+	if err != nil {
+		errs = append(errs, err)
+		return errs
+	}
+
+	client := apiClient.RawClient()
+	ctx, cancel := context.WithDeadline(context.Background(), time.Now().Add(5*time.Second))
+	defer cancel()
+
+	for _, a := range artifacts {
+		if a.DockerArtifact == nil || a.DockerArtifact.NetworkMode == "" {
+			continue
+		}
+		mode := strings.ToLower(a.DockerArtifact.NetworkMode)
+		prefix := "container:"
+		if strings.HasPrefix(mode, prefix) {
+			id := strings.TrimPrefix(mode, prefix)
+			containers, err := client.ContainerList(ctx, types.ContainerListOptions{})
+			if err != nil {
+				errs = append(errs, fmt.Errorf("retrieving docker containers list: %s", err.Error()))
+				return errs
+			}
+			for _, c := range containers {
+				// Comparing ID seeking for <id>
+				if c.ID == id {
+					return errs
+				}
+				for _, name := range c.Names {
+					// c.Names come in form "/<name>"
+					if name == "/"+id {
+						return errs
+					}
+				}
+			}
+			errs = append(errs, fmt.Errorf("container '%s' not found. Required by image '%s' for docker network stack sharing", id, a.ImageName))
+		}
+	}
+	return errs
+}
+
 // validateCustomDependencies makes sure that dependencies.ignore is only used in conjunction with dependencies.paths
 func validateCustomDependencies(artifacts []*latest.Artifact) (errs []error) {
 	for _, a := range artifacts {