feat: Support special IP host-gateway in --add-host flag (runfinch#216)

Issue #, if available:
runfinch#209

*Description of changes:*
Support special IP `host-gateway` in `--add-host` flag. Finch will
resolve to the IP that can be used to access host from containers. It is
not configurable for now. See
[issue](runfinch#209) for more details.

*Testing done:*
unit tests and e2e tests
runfinch/common-tests#29

- [ X ] I've reviewed the guidance in CONTRIBUTING.md


#### License Acceptance

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

---------

Signed-off-by: Ziwen Ning <ningziwe@amazon.com>

cmd/finch/nerdctl.go

@@ -9,6 +9,9 @@ import (
 	"path/filepath"
 	"strings"
 
+	dockerops "github.com/docker/docker/opts"
+	"github.com/lima-vm/lima/pkg/networks"
+
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
 
@@ -102,14 +105,16 @@ func (nc *nerdctlCommand) run(cmdName string, args []string) error {
 			if addEnv != "" {
 				envs = append(envs, addEnv)
 			}
-
 		case strings.HasPrefix(arg, "--env-file"):
 			shouldSkip, addEnvs, err := handleEnvFile(nc.fs, nc.systemDeps, arg, args[i+1])
 			if err != nil {
 				return err
 			}
 			skip = shouldSkip
 			fileEnvs = append(fileEnvs, addEnvs...)
+		case arg == "--add-host":
+			args[i+1] = resolveIP(args[i+1], nc.logger)
+			nerdctlArgs = append(nerdctlArgs, arg)
 		default:
 			nerdctlArgs = append(nerdctlArgs, arg)
 		}
@@ -273,6 +278,19 @@ func handleEnvFile(fs afero.Fs, systemDeps NerdctlCommandSystemDeps, arg, arg2 s
 	return skip, envs, nil
 }
 
+func resolveIP(host string, logger flog.Logger) string {
+	parts := strings.SplitN(host, ":", 2)
+	// If the IP Address is a string called "host-gateway", replace this value with the IP address that can be used to
+	// access host from the containers.
+	// TODO: make the host gateway ip configurable.
+	if parts[1] == dockerops.HostGatewayName {
+		resolvedIP := networks.SlirpGateway
+		logger.Debugf(`Resolving special IP "host-gateway" to %q for host %q`, resolvedIP, parts[0])
+		return fmt.Sprintf("%s:%s", parts[0], resolvedIP)
+	}
+	return host
+}
+
 var nerdctlCmds = map[string]string{
 	"build":     "Build an image from Dockerfile",
 	"builder":   "Manage builds",

cmd/finch/nerdctl_test.go

@@ -336,6 +336,76 @@ func TestNerdctlCommand_run(t *testing.T) {
 				logger.EXPECT().Debugf("Status of virtual machine: %s", "Running")
 			},
 		},
+		{
+			name:    "with --add-host flag and special IP",
+			cmdName: "run",
+			args:    []string{"--rm", "--add-host", "name:host-gateway", "alpine:latest"},
+			wantErr: nil,
+			mockSvc: func(
+				t *testing.T,
+				lcc *mocks.LimaCmdCreator,
+				ncsd *mocks.NerdctlCommandSystemDeps,
+				logger *mocks.Logger,
+				ctrl *gomock.Controller,
+				fs afero.Fs,
+			) {
+				getVMStatusC := mocks.NewCommand(ctrl)
+				lcc.EXPECT().CreateWithoutStdio("ls", "-f", "{{.Status}}", limaInstanceName).Return(getVMStatusC)
+				getVMStatusC.EXPECT().Output().Return([]byte("Running"), nil)
+				logger.EXPECT().Debugf("Status of virtual machine: %s", "Running")
+				logger.EXPECT().Debugf(`Resolving special IP "host-gateway" to %q for host %q`, "192.168.5.2", "name")
+				c := mocks.NewCommand(ctrl)
+				lcc.EXPECT().Create("shell", limaInstanceName, nerdctlCmdName, "run",
+					"--rm", "--add-host", "name:192.168.5.2", "alpine:latest").Return(c)
+				c.EXPECT().Run()
+			},
+		},
+		{
+			name:    "with --add-host flag but without using special IP",
+			cmdName: "run",
+			args:    []string{"--rm", "--add-host", "name:0.0.0.0", "alpine:latest"},
+			wantErr: nil,
+			mockSvc: func(
+				t *testing.T,
+				lcc *mocks.LimaCmdCreator,
+				ncsd *mocks.NerdctlCommandSystemDeps,
+				logger *mocks.Logger,
+				ctrl *gomock.Controller,
+				fs afero.Fs,
+			) {
+				getVMStatusC := mocks.NewCommand(ctrl)
+				lcc.EXPECT().CreateWithoutStdio("ls", "-f", "{{.Status}}", limaInstanceName).Return(getVMStatusC)
+				getVMStatusC.EXPECT().Output().Return([]byte("Running"), nil)
+				logger.EXPECT().Debugf("Status of virtual machine: %s", "Running")
+				c := mocks.NewCommand(ctrl)
+				lcc.EXPECT().Create("shell", limaInstanceName, nerdctlCmdName, "run",
+					"--rm", "--add-host", "name:0.0.0.0", "alpine:latest").Return(c)
+				c.EXPECT().Run()
+			},
+		},
+		{
+			name:    "with --add-host flag but without subsequent arg",
+			cmdName: "run",
+			args:    []string{"--rm", "--add-host", "alpine:latest"},
+			wantErr: errors.New("run cmd error"),
+			mockSvc: func(
+				t *testing.T,
+				lcc *mocks.LimaCmdCreator,
+				ncsd *mocks.NerdctlCommandSystemDeps,
+				logger *mocks.Logger,
+				ctrl *gomock.Controller,
+				fs afero.Fs,
+			) {
+				getVMStatusC := mocks.NewCommand(ctrl)
+				lcc.EXPECT().CreateWithoutStdio("ls", "-f", "{{.Status}}", limaInstanceName).Return(getVMStatusC)
+				getVMStatusC.EXPECT().Output().Return([]byte("Running"), nil)
+				logger.EXPECT().Debugf("Status of virtual machine: %s", "Running")
+				c := mocks.NewCommand(ctrl)
+				lcc.EXPECT().Create("shell", limaInstanceName, nerdctlCmdName, "run",
+					"--rm", "--add-host", "alpine:latest").Return(c)
+				c.EXPECT().Run().Return(errors.New("run cmd error"))
+			},
+		},
 		{
 			name:    "with --help flag",
 			cmdName: "pull",

e2e/container/container_test.go

@@ -39,7 +39,7 @@ func TestContainer(t *testing.T) {
 		tests.Pull(o)
 		tests.Rm(o)
 		tests.Rmi(o)
-		tests.Run(&tests.RunOption{BaseOpt: o, CGMode: tests.Unified})
+		tests.Run(&tests.RunOption{BaseOpt: o, CGMode: tests.Unified, DefaultHostGatewayIP: "192.168.5.2"})
 		tests.Start(o)
 		tests.Stop(o)
 		tests.Cp(o)

go.mod

@@ -3,14 +3,15 @@ module github.com/runfinch/finch
 go 1.18
 
 require (
+	github.com/docker/docker v23.0.1+incompatible
 	github.com/golang/mock v1.6.0
 	github.com/google/go-licenses v1.6.0
 	github.com/lima-vm/lima v0.14.2
 	github.com/onsi/ginkgo/v2 v2.8.0
 	github.com/onsi/gomega v1.26.0
 	github.com/pelletier/go-toml v1.9.5
 	github.com/pkg/sftp v1.13.5
-	github.com/runfinch/common-tests v0.4.0
+	github.com/runfinch/common-tests v0.5.0
 	github.com/sirupsen/logrus v1.9.0
 	github.com/spf13/afero v1.9.3
 	github.com/spf13/cobra v1.6.1
@@ -27,11 +28,14 @@ require (
 	github.com/apparentlymart/go-cidr v1.1.0 // indirect
 	github.com/containerd/containerd v1.6.14 // indirect
 	github.com/containers/gvisor-tap-vsock v0.4.1-0.20220920072955-5b1aff8ba743 // indirect
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/btree v1.0.1 // indirect
 	github.com/google/gopacket v1.1.19 // indirect
 	github.com/insomniacslk/dhcp v0.0.0-20220504074936-1ca156eafb9f // indirect
 	github.com/miekg/dns v1.1.50 // indirect
+	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/u-root/uio v0.0.0-20210528114334-82958018845c // indirect
 	golang.org/x/sync v0.1.0 // indirect

go.sum

@@ -155,6 +155,10 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/docker/docker v23.0.1+incompatible h1:vjgvJZxprTTE1A37nm+CLNAdwu6xZekyoiVlUZEINcY=
+github.com/docker/docker v23.0.1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/go-connections v0.4.0 h1:El9xVISelRB7BuFusrZozjnkIM5YnzCViNKohAFqRJQ=
+github.com/docker/go-connections v0.4.0/go.mod h1:Gbd7IOopHjR8Iph03tsViu4nIes5XhDvyHbTtUxmeec=
 github.com/docker/go-units v0.4.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
 github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
@@ -220,6 +224,7 @@ github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7a
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
 github.com/gogo/protobuf v1.2.2-0.20190723190241-65acae22fc9d/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
 github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
+github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20160516000752-02826c3e7903/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
@@ -458,6 +463,8 @@ github.com/onsi/gomega v1.26.0/go.mod h1:r+zV744Re+DiYCIPRlYOTxn0YkOLcAnW8k1xXdM
 github.com/opencontainers/go-digest v0.0.0-20180430190053-c9281466c8b2/go.mod h1:cMLVZDEM3+U2I4VmLI6N8jQYUd2OVphdqWwCJHrFt2s=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
+github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 h1:rc3tiVYb5z54aKaDfakKn0dDjIyPpTtszkjuMzyt7ec=
+github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
 github.com/opencontainers/runc v0.0.0-20190115041553-12f6a991201f/go.mod h1:qT5XzbpPznkRYVz/mWwUaVBUv2rmF59PVA73FjuZG0U=
 github.com/opencontainers/runc v1.0.0-rc90/go.mod h1:qT5XzbpPznkRYVz/mWwUaVBUv2rmF59PVA73FjuZG0U=
 github.com/opencontainers/runtime-spec v1.0.2/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
@@ -502,8 +509,8 @@ github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40T
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
-github.com/runfinch/common-tests v0.4.0 h1:MOtkY/Wcg3hEILDWcaA4cK/NXmk9vUS4y0yOdlIm2Cw=
-github.com/runfinch/common-tests v0.4.0/go.mod h1:8Kjz5W85nbSzFCI0NEnwoPMDvTeCm/JutQAEVFMJP/I=
+github.com/runfinch/common-tests v0.5.0 h1:ihYdYKLuXEZR0aYT2hbgfUffn5x2IgSRjItDUhyTj1I=
+github.com/runfinch/common-tests v0.5.0/go.mod h1:8Kjz5W85nbSzFCI0NEnwoPMDvTeCm/JutQAEVFMJP/I=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=