podman network exists

Add podman network exists command with remote support.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

cmd/podman/networks/exists.go

@@ -0,0 +1,40 @@
+package network
+
+import (
+	"github.com/containers/podman/v2/cmd/podman/common"
+	"github.com/containers/podman/v2/cmd/podman/registry"
+	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/spf13/cobra"
+)
+
+var (
+	networkExistsDescription = `If the named network exists, podman network exists exits with 0, otherwise the exit code will be 1.`
+	networkExistsCommand     = &cobra.Command{
+		Use:               "exists NETWORK",
+		Short:             "network exists",
+		Long:              networkExistsDescription,
+		RunE:              networkExists,
+		Example:           `podman network exists net1`,
+		Args:              cobra.ExactArgs(1),
+		ValidArgsFunction: common.AutocompleteNetworks,
+	}
+)
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
+		Command: networkExistsCommand,
+		Parent:  networkCmd,
+	})
+}
+
+func networkExists(cmd *cobra.Command, args []string) error {
+	response, err := registry.ContainerEngine().NetworkExists(registry.GetContext(), args[0])
+	if err != nil {
+		return err
+	}
+	if !response.Value {
+		registry.SetExitCode(1)
+	}
+	return nil
+}

docs/source/markdown/podman-network-exists.1.md

@@ -0,0 +1,44 @@
+% podman-network-exists(1)
+
+## NAME
+podman\-network\-exists - Check if the given network exists
+
+## SYNOPSIS
+**podman network exists** *network*
+
+## DESCRIPTION
+**podman network exists** checks if a network exists. The **Name** or **ID**
+of the network may be used as input.  Podman will return an exit code
+of `0` when the network is found.  A `1` will be returned otherwise. An exit code of
+`125` indicates there was an other issue.
+
+
+## OPTIONS
+
+#### **--help**, **-h**
+
+Print usage statement
+
+## EXAMPLE
+
+Check if a network called `net1` exists (the network does actually exist).
+```
+$ podman network exists net1
+$ echo $?
+0
+$
+```
+
+Check if an network called `webbackend` exists (the network does not actually exist).
+```
+$ podman network exists webbackend
+$ echo $?
+1
+$
+```
+
+## SEE ALSO
+podman(1), podman-network-create(1), podman-network-rm(1)
+
+## HISTORY
+January 2021, Originally compiled by Paul Holzinger <paul.holzinger@web.de>

docs/source/markdown/podman-network.1.md

@@ -16,6 +16,7 @@ The network command manages CNI networks for Podman.
 | connect    | [podman-network-connect(1)](podman-network-connect.1.md)       | Connect a container to a network                                    |
 | create     | [podman-network-create(1)](podman-network-create.1.md)         | Create a Podman CNI network                                         |
 | disconnect | [podman-network-disconnect(1)](podman-network-disconnect.1.md) | Disconnect a container from a network                               |
+| exists     | [podman-network-exists(1)](podman-network-exists.1.md)         | Check if the given network exists                                   |
 | inspect    | [podman-network-inspect(1)](podman-network-inspect.1.md)       | Displays the raw CNI network configuration for one or more networks |
 | ls         | [podman-network-ls(1)](podman-network-ls.1.md)                 | Display a summary of CNI networks                                   |
 | reload     | [podman-network-reload(1)](podman-network-reload.1.md)         | Reload network configuration for containers                         |

docs/source/network.rst

@@ -7,6 +7,8 @@ Network
 
 :doc:`disconnect <markdown/podman-network-disconnect.1>` network disconnect
 
+:doc:`exists <markdown/podman-network-exists.1>` network exists
+
 :doc:`inspect <markdown/podman-network-inspect.1>` network inspect
 
 :doc:`ls <markdown/podman-network-ls.1>` network list

pkg/api/handlers/libpod/networks.go

@@ -157,3 +157,21 @@ func Connect(w http.ResponseWriter, r *http.Request) {
 	}
 	utils.WriteResponse(w, http.StatusOK, "OK")
 }
+
+// ExistsNetwork check if a network exists
+func ExistsNetwork(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	name := utils.GetName(r)
+
+	ic := abi.ContainerEngine{Libpod: runtime}
+	report, err := ic.NetworkExists(r.Context(), name)
+	if err != nil {
+		utils.Error(w, "Something went wrong.", http.StatusInternalServerError, err)
+		return
+	}
+	if !report.Value {
+		utils.Error(w, "network not found", http.StatusNotFound, define.ErrNoSuchNetwork)
+		return
+	}
+	utils.WriteResponse(w, http.StatusNoContent, "")
+}

pkg/api/server/register_networks.go

@@ -226,6 +226,28 @@ func (s *APIServer) registerNetworkHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/networks/{name}/json"), s.APIHandler(libpod.InspectNetwork)).Methods(http.MethodGet)
+	// swagger:operation GET /libpod/networks/{name}/exists libpod libpodExistsNetwork
+	// ---
+	// tags:
+	//  - networks
+	// summary: Network exists
+	// description: Check if network exists
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or ID of the network
+	// produces:
+	// - application/json
+	// responses:
+	//   204:
+	//     description: network exists
+	//   404:
+	//     $ref: '#/responses/NoSuchNetwork'
+	//   500:
+	//     $ref: '#/responses/InternalError'
+	r.Handle(VersionedPath("/libpod/networks/{name}/exists"), s.APIHandler(libpod.ExistsNetwork)).Methods(http.MethodGet)
 	// swagger:operation GET /libpod/networks/json libpod libpodListNetwork
 	// ---
 	// tags:

pkg/bindings/network/network.go

@@ -167,3 +167,16 @@ func Connect(ctx context.Context, networkName string, ContainerNameOrId string,
 	}
 	return response.Process(nil)
 }
+
+// Exists returns true if a given network exists
+func Exists(ctx context.Context, nameOrID string, options *ExistsOptions) (bool, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return false, err
+	}
+	response, err := conn.DoRequest(nil, http.MethodGet, "/networks/%s/exists", nil, nil, nameOrID)
+	if err != nil {
+		return false, err
+	}
+	return response.IsSuccess(), nil
+}

pkg/bindings/network/types.go

@@ -68,3 +68,9 @@ type ConnectOptions struct {
 	// when using the dns plugin
 	Aliases *[]string
 }
+
+//go:generate go run ../generator/generator.go ExistsOptions
+// ExistsOptions are optional options for checking
+// if a network exists
+type ExistsOptions struct {
+}

pkg/bindings/network/types_exists_options.go

@@ -0,0 +1,88 @@
+package network
+
+import (
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+
+	jsoniter "github.com/json-iterator/go"
+	"github.com/pkg/errors"
+)
+
+/*
+This file is generated automatically by go generate.  Do not edit.
+*/
+
+// Changed
+func (o *ExistsOptions) Changed(fieldName string) bool {
+	r := reflect.ValueOf(o)
+	value := reflect.Indirect(r).FieldByName(fieldName)
+	return !value.IsNil()
+}
+
+// ToParams
+func (o *ExistsOptions) ToParams() (url.Values, error) {
+	params := url.Values{}
+	if o == nil {
+		return params, nil
+	}
+	json := jsoniter.ConfigCompatibleWithStandardLibrary
+	s := reflect.ValueOf(o)
+	if reflect.Ptr == s.Kind() {
+		s = s.Elem()
+	}
+	sType := s.Type()
+	for i := 0; i < s.NumField(); i++ {
+		fieldName := sType.Field(i).Name
+		if !o.Changed(fieldName) {
+			continue
+		}
+		fieldName = strings.ToLower(fieldName)
+		f := s.Field(i)
+		if reflect.Ptr == f.Kind() {
+			f = f.Elem()
+		}
+		switch f.Kind() {
+		case reflect.Bool:
+			params.Set(fieldName, strconv.FormatBool(f.Bool()))
+		case reflect.String:
+			params.Set(fieldName, f.String())
+		case reflect.Int, reflect.Int64:
+			// f.Int() is always an int64
+			params.Set(fieldName, strconv.FormatInt(f.Int(), 10))
+		case reflect.Uint, reflect.Uint64:
+			// f.Uint() is always an uint64
+			params.Set(fieldName, strconv.FormatUint(f.Uint(), 10))
+		case reflect.Slice:
+			typ := reflect.TypeOf(f.Interface()).Elem()
+			switch typ.Kind() {
+			case reflect.String:
+				sl := f.Slice(0, f.Len())
+				s, ok := sl.Interface().([]string)
+				if !ok {
+					return nil, errors.New("failed to convert to string slice")
+				}
+				for _, val := range s {
+					params.Add(fieldName, val)
+				}
+			default:
+				return nil, errors.Errorf("unknown slice type %s", f.Kind().String())
+			}
+		case reflect.Map:
+			lowerCaseKeys := make(map[string][]string)
+			iter := f.MapRange()
+			for iter.Next() {
+				lowerCaseKeys[iter.Key().Interface().(string)] = iter.Value().Interface().([]string)
+
+			}
+			s, err := json.MarshalToString(lowerCaseKeys)
+			if err != nil {
+				return nil, err
+			}
+
+			params.Set(fieldName, s)
+		}
+	}
+	return params, nil
+}

pkg/domain/entities/engine_container.go

@@ -60,6 +60,7 @@ type ContainerEngine interface {
 	NetworkConnect(ctx context.Context, networkname string, options NetworkConnectOptions) error
 	NetworkCreate(ctx context.Context, name string, options NetworkCreateOptions) (*NetworkCreateReport, error)
 	NetworkDisconnect(ctx context.Context, networkname string, options NetworkDisconnectOptions) error
+	NetworkExists(ctx context.Context, networkname string) (*BoolReport, error)
 	NetworkInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]NetworkInspectReport, []error, error)
 	NetworkList(ctx context.Context, options NetworkListOptions) ([]*NetworkListReport, error)
 	NetworkReload(ctx context.Context, names []string, options NetworkReloadOptions) ([]*NetworkReloadReport, error)

pkg/domain/infra/abi/network.go

@@ -140,3 +140,18 @@ func (ic *ContainerEngine) NetworkDisconnect(ctx context.Context, networkname st
 func (ic *ContainerEngine) NetworkConnect(ctx context.Context, networkname string, options entities.NetworkConnectOptions) error {
 	return ic.Libpod.ConnectContainerToNetwork(options.Container, networkname, options.Aliases)
 }
+
+// NetworkExists checks if the given network exists
+func (ic *ContainerEngine) NetworkExists(ctx context.Context, networkname string) (*entities.BoolReport, error) {
+	config, err := ic.Libpod.GetConfig()
+	if err != nil {
+		return nil, err
+	}
+	exists, err := network.Exists(config, networkname)
+	if err != nil {
+		return nil, err
+	}
+	return &entities.BoolReport{
+		Value: exists,
+	}, nil
+}

pkg/domain/infra/tunnel/network.go

@@ -78,3 +78,14 @@ func (ic *ContainerEngine) NetworkConnect(ctx context.Context, networkname strin
 	options := new(network.ConnectOptions).WithAliases(opts.Aliases)
 	return network.Connect(ic.ClientCtx, networkname, opts.Container, options)
 }
+
+// NetworkExists checks if the given network exists
+func (ic *ContainerEngine) NetworkExists(ctx context.Context, networkname string) (*entities.BoolReport, error) {
+	exists, err := network.Exists(ic.ClientCtx, networkname, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &entities.BoolReport{
+		Value: exists,
+	}, nil
+}

test/e2e/network_test.go

@@ -456,4 +456,20 @@ var _ = Describe("Podman network", func() {
 		nc.WaitWithDefaultTimeout()
 		Expect(nc.ExitCode()).To(Equal(0))
 	})
+
+	It("podman network exists", func() {
+		net := "net" + stringid.GenerateNonCryptoID()
+		session := podmanTest.Podman([]string{"network", "create", net})
+		session.WaitWithDefaultTimeout()
+		defer podmanTest.removeCNINetwork(net)
+		Expect(session.ExitCode()).To(BeZero())
+
+		session = podmanTest.Podman([]string{"network", "exists", net})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		session = podmanTest.Podman([]string{"network", "exists", stringid.GenerateNonCryptoID()})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(1))
+	})
 })