network: add support for podman network update and --network-dns-server

* Add support for `podman network update <>`

```console
network update

Description:
  update networks for containers and pods

Usage:
  podman network update [options] NAME

Examples:
  podman network update podman1

Options:
      --dns-add stringArray      add network level nameservers
      --dns-drop stringArray   remove network level nameservers
```

* Add support for `--network-dns-server` to `podman network create`

Extends podman to support recently added features in `netavark` and
`aardvark-dns`

* containers/netavark#497
* containers/aardvark-dns#252
* containers/netavark#503

[NO NEW TESTS NEEDED]
[NO TESTS NEEDED]

Signed-off-by: Aditya R <arajan@redhat.com>

cmd/podman/networks/create.go

@@ -80,6 +80,9 @@ func networkCreateFlags(cmd *cobra.Command) {
 	flags.BoolVar(&networkCreateOptions.DisableDNS, "disable-dns", false, "disable dns plugin")
 
 	flags.BoolVar(&networkCreateOptions.IgnoreIfExists, "ignore", false, "Don't fail if network already exists")
+	dnsserverFlagName := "dns"
+	flags.StringArrayVar(&networkCreateOptions.NetworkDNSServers, dnsserverFlagName, nil, "DNS servers this network will use")
+	_ = cmd.RegisterFlagCompletionFunc(dnsserverFlagName, completion.AutocompleteNone)
 }
 func init() {
 	registry.Commands = append(registry.Commands, registry.CliCommand{
@@ -107,13 +110,14 @@ func networkCreate(cmd *cobra.Command, args []string) error {
 	}
 
 	network := types.Network{
-		Name:        name,
-		Driver:      networkCreateOptions.Driver,
-		Options:     networkCreateOptions.Options,
-		Labels:      networkCreateOptions.Labels,
-		IPv6Enabled: networkCreateOptions.IPv6,
-		DNSEnabled:  !networkCreateOptions.DisableDNS,
-		Internal:    networkCreateOptions.Internal,
+		Name:              name,
+		Driver:            networkCreateOptions.Driver,
+		Options:           networkCreateOptions.Options,
+		Labels:            networkCreateOptions.Labels,
+		IPv6Enabled:       networkCreateOptions.IPv6,
+		DNSEnabled:        !networkCreateOptions.DisableDNS,
+		NetworkDNSServers: networkCreateOptions.NetworkDNSServers,
+		Internal:          networkCreateOptions.Internal,
 	}
 
 	if cmd.Flags().Changed(ipamDriverFlagName) {

cmd/podman/networks/update.go

@@ -0,0 +1,57 @@
+package network
+
+import (
+	"fmt"
+
+	"github.com/containers/common/pkg/completion"
+	"github.com/containers/podman/v4/cmd/podman/common"
+	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/pkg/domain/entities"
+	"github.com/spf13/cobra"
+)
+
+var (
+	networkUpdateDescription = `Update an existing podman network`
+	networkUpdateCommand     = &cobra.Command{
+		Use:               "update [options] NETWORK",
+		Short:             "update an existing podman network",
+		Long:              networkUpdateDescription,
+		RunE:              networkUpdate,
+		Args:              cobra.ExactArgs(1),
+		ValidArgsFunction: common.AutocompleteNetworks,
+		Example:           `podman network update podman1`,
+	}
+)
+
+var (
+	networkUpdateOptions entities.NetworkUpdateOptions
+)
+
+func networkUpdateFlags(cmd *cobra.Command) {
+	flags := cmd.Flags()
+
+	addDNSServerFlagName := "dns-add"
+	flags.StringArrayVar(&networkUpdateOptions.AddDNSServers, addDNSServerFlagName, nil, "add network level nameservers")
+	removeDNSServerFlagName := "dns-drop"
+	flags.StringArrayVar(&networkUpdateOptions.RemoveDNSServers, removeDNSServerFlagName, nil, "remove network level nameservers")
+	_ = cmd.RegisterFlagCompletionFunc(addDNSServerFlagName, completion.AutocompleteNone)
+	_ = cmd.RegisterFlagCompletionFunc(removeDNSServerFlagName, completion.AutocompleteNone)
+}
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Command: networkUpdateCommand,
+		Parent:  networkCmd,
+	})
+	networkUpdateFlags(networkUpdateCommand)
+}
+
+func networkUpdate(cmd *cobra.Command, args []string) error {
+	name := args[0]
+
+	err := registry.ContainerEngine().NetworkUpdate(registry.Context(), name, networkUpdateOptions)
+	if err != nil {
+		return err
+	}
+	fmt.Printf("%s", name)
+	return nil
+}

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

@@ -24,6 +24,10 @@ release because it is used as a special network mode in **podman run/create --ne
 Disables the DNS plugin for this network which if enabled, can perform container to container name
 resolution.
 
+#### **--dns**=*ip*
+
+Set network-scoped DNS resolver/nameserver for containers in this network. If not set, the host servers from `/etc/resolv.conf` will be used.  It can be overwritten on the container level with the `podman run/create --dns` option. This option can be specified multiple times to set more than one IP.
+
 #### **--driver**, **-d**
 
 Driver to manage the network. Currently `bridge`, `macvlan` and `ipvlan` are supported. Defaults to `bridge`.

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

@@ -0,0 +1,37 @@
+% podman-network-update 1
+
+## NAME
+podman\-network\-update - Update an existing podman network
+
+## SYNOPSIS
+**podman network update**  [*options*] *network*
+
+## DESCRIPTION
+Allow changes to existing container networks. At present, only changes to the DNS servers in use by a network is supported.
+
+NOTE: Only supported with the netavark network backend.
+
+
+## OPTIONS
+#### **--dns-add**
+
+Accepts array of DNS resolvers and add it to the existing list of resolvers configured for a network.
+
+#### **--dns-drop**
+
+Accepts array of DNS resolvers and removes them from the existing list of resolvers configured for a network.
+
+## EXAMPLE
+
+Update a network
+```
+$ podman network update network1 --dns-add 8.8.8.8,1.1.1.1
+podman2
+```
+
+Update a network and add/remove dns servers
+```
+$ podman network update network1 --dns-drop 8.8.8.8 --dns-add 3.3.3.3
+```
+## SEE ALSO
+**[podman(1)](podman.1.md)**, **[podman-network(1)](podman-network.1.md)**, **[podman-network-inspect(1)](podman-network-inspect.1.md)**, **[podman-network-ls(1)](podman-network-ls.1.md)**

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

@@ -32,6 +32,7 @@ so networks have to be created again after a backend change.
 | prune      | [podman-network-prune(1)](podman-network-prune.1.md)           | Remove all unused networks                                      |
 | reload     | [podman-network-reload(1)](podman-network-reload.1.md)         | Reload network configuration for containers                     |
 | rm         | [podman-network-rm(1)](podman-network-rm.1.md)                 | Remove one or more networks                                     |
+| update     | [podman-network-upate(1)](podman-network-update.1.md)          | Update an existing Podman network                               |
 
 ## SEE ALSO
 **[podman(1)](podman.1.md)**, **[containers.conf(5)](https://github.com/containers/common/blob/main/docs/containers.conf.5.md)**

pkg/api/handlers/libpod/networks.go

@@ -27,7 +27,7 @@ func CreateNetwork(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
 	network := types.Network{}
 	if err := json.NewDecoder(r.Body).Decode(&network); err != nil {
-		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("failed to decode request JSON payload: %w", err))
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("failed to decode JSON request payload: %w", err))
 		return
 	}
 
@@ -53,6 +53,26 @@ func CreateNetwork(w http.ResponseWriter, r *http.Request) {
 	utils.WriteResponse(w, http.StatusOK, report)
 }
 
+func UpdateNetwork(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
+	ic := abi.ContainerEngine{Libpod: runtime}
+
+	networkUpdateOptions := entities.NetworkUpdateOptions{}
+	if err := json.NewDecoder(r.Body).Decode(&networkUpdateOptions); err != nil {
+		utils.Error(w, http.StatusBadRequest, fmt.Errorf("failed to decode request JSON payload: %w", err))
+		return
+	}
+
+	name := utils.GetName(r)
+
+	err := ic.NetworkUpdate(r.Context(), name, networkUpdateOptions)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, err)
+	}
+
+	utils.WriteResponse(w, http.StatusNoContent, nil)
+}
+
 func ListNetworks(w http.ResponseWriter, r *http.Request) {
 	if v, err := utils.SupportedVersion(r, ">=4.0.0"); err != nil {
 		utils.BadRequest(w, "version", v.String(), err)

pkg/api/handlers/swagger/models.go

@@ -44,3 +44,7 @@ type networkDisconnectRequest types.NetworkDisconnect
 // Network connect
 // swagger:model
 type networkConnectRequestLibpod entities.NetworkConnectOptions
+
+// Network update
+// swagger:model
+type networkUpdateRequestLibpod entities.NetworkUpdateOptions

pkg/api/server/register_networks.go

@@ -234,6 +234,33 @@ func (s *APIServer) registerNetworkHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/internalError"
 	r.HandleFunc(VersionedPath("/libpod/networks/{name}"), s.APIHandler(libpod.RemoveNetwork)).Methods(http.MethodDelete)
+	// swagger:operation POST /libpod/networks/{name}/update libpod NetworkUpdateLibpod
+	// ---
+	// tags:
+	//  - networks
+	// summary: Update exisiting podman network
+	// description: Update exisiting podman network
+	// produces:
+	// - application/json
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or ID of the network
+	//  - in: body
+	//    name: update
+	//    description: attributes for updating a netavark network
+	//    schema:
+	//      $ref: "#/definitions/networkUpdateRequestLibpod"
+	// responses:
+	//   200:
+	//     description: OK
+	//   400:
+	//     $ref: "#/responses/badParamError"
+	//   500:
+	//     $ref: "#/responses/internalError"
+	r.HandleFunc(VersionedPath("/libpod/networks/{name}/update"), s.APIHandler(libpod.UpdateNetwork)).Methods(http.MethodPost)
 	// swagger:operation GET /libpod/networks/{name}/exists libpod NetworkExistsLibpod
 	// ---
 	// tags:

pkg/bindings/network/network.go

@@ -50,6 +50,25 @@ func CreateWithOptions(ctx context.Context, network *types.Network, extraCreateO
 	return report, response.Process(&report)
 }
 
+// Updates an existing netavark network config
+func Update(ctx context.Context, netNameOrID string, options *UpdateOptions) error {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return err
+	}
+	networkConfig, err := jsoniter.MarshalToString(options)
+	if err != nil {
+		return err
+	}
+	reader := strings.NewReader(networkConfig)
+	response, err := conn.DoRequest(ctx, reader, http.MethodPost, "/networks/%s/update", nil, nil, netNameOrID)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	return response.Process(nil)
+}
+
 // Inspect returns information about a network configuration
 func Inspect(ctx context.Context, nameOrID string, _ *InspectOptions) (types.Network, error) {
 	var net types.Network

pkg/bindings/network/types.go

@@ -58,6 +58,14 @@ type ListOptions struct {
 	Filters map[string][]string
 }
 
+// NetworkUpdateOptions describes options to update a network
+//
+//go:generate go run ../generator/generator.go UpdateOptions
+type UpdateOptions struct {
+	AddDNSServers    []string `json:"adddnsservers"`
+	RemoveDNSServers []string `json:"removednsservers"`
+}
+
 // DisconnectOptions are optional options for disconnecting
 // containers from a network
 //

pkg/domain/entities/engine_container.go

@@ -64,6 +64,7 @@ type ContainerEngine interface { //nolint:interfacebloat
 	KubeApply(ctx context.Context, body io.Reader, opts ApplyOptions) error
 	NetworkConnect(ctx context.Context, networkname string, options NetworkConnectOptions) error
 	NetworkCreate(ctx context.Context, network types.Network, createOptions *types.NetworkCreateOptions) (*types.Network, error)
+	NetworkUpdate(ctx context.Context, networkname string, options NetworkUpdateOptions) 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) ([]types.Network, []error, error)

pkg/domain/entities/network.go

@@ -41,21 +41,28 @@ type NetworkRmReport struct {
 
 // NetworkCreateOptions describes options to create a network
 type NetworkCreateOptions struct {
-	DisableDNS bool
-	Driver     string
-	Gateways   []net.IP
-	Internal   bool
-	Labels     map[string]string
-	MacVLAN    string
-	Ranges     []string
-	Subnets    []string
-	IPv6       bool
+	DisableDNS        bool
+	Driver            string
+	Gateways          []net.IP
+	Internal          bool
+	Labels            map[string]string
+	MacVLAN           string
+	NetworkDNSServers []string
+	Ranges            []string
+	Subnets           []string
+	IPv6              bool
 	// Mapping of driver options and values.
 	Options map[string]string
 	// IgnoreIfExists if true, do not fail if the network already exists
 	IgnoreIfExists bool
 }
 
+// NetworkUpdateOptions describes options to update a network
+type NetworkUpdateOptions struct {
+	AddDNSServers    []string `json:"adddnsservers"`
+	RemoveDNSServers []string `json:"removednsservers"`
+}
+
 // NetworkCreateReport describes a created network for the cli
 type NetworkCreateReport struct {
 	Name string

pkg/domain/infra/abi/network.go

@@ -13,6 +13,17 @@ import (
 	"github.com/containers/podman/v4/pkg/domain/entities"
 )
 
+func (ic *ContainerEngine) NetworkUpdate(ctx context.Context, netName string, options entities.NetworkUpdateOptions) error {
+	var networkUpdateOptions types.NetworkUpdateOptions
+	networkUpdateOptions.AddDNSServers = options.AddDNSServers
+	networkUpdateOptions.RemoveDNSServers = options.RemoveDNSServers
+	err := ic.Libpod.Network().NetworkUpdate(netName, networkUpdateOptions)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func (ic *ContainerEngine) NetworkList(ctx context.Context, options entities.NetworkListOptions) ([]types.Network, error) {
 	// dangling filter is not provided by netutil
 	var wantDangling bool

pkg/domain/infra/tunnel/network.go

@@ -12,6 +12,11 @@ import (
 	"github.com/containers/podman/v4/pkg/errorhandling"
 )
 
+func (ic *ContainerEngine) NetworkUpdate(ctx context.Context, netName string, opts entities.NetworkUpdateOptions) error {
+	options := new(network.UpdateOptions).WithAddDNSServers(opts.AddDNSServers).WithRemoveDNSServers(opts.RemoveDNSServers)
+	return network.Update(ic.ClientCtx, netName, options)
+}
+
 func (ic *ContainerEngine) NetworkList(ctx context.Context, opts entities.NetworkListOptions) ([]types.Network, error) {
 	options := new(network.ListOptions).WithFilters(opts.Filters)
 	return network.List(ic.ClientCtx, options)