network aliases for container creation

podman can now support adding network aliases when running containers
(--network-alias).  It requires an updated dnsname plugin as well as an
updated ocicni to work properly.

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 31 insertions, 1 deletions

diff --git a/cmd/podman/common/create_opts.go b/cmd/podman/common/create_opts.go
index 8b2efc988..4b52663c3 100644
--- a/cmd/podman/common/create_opts.go
+++ b/cmd/podman/common/create_opts.go
@@ -133,6 +133,7 @@ func stringMaptoArray(m map[string]string) []string {
 // a specgen spec.
 func ContainerCreateToContainerCLIOpts(cc handlers.CreateContainerConfig, cgroupsManager string) (*ContainerCLIOpts, []string, error) {
 	var (
+		aliases    []string
 		capAdd     []string
 		cappDrop   []string
 		entrypoint string
@@ -242,8 +243,11 @@ func ContainerCreateToContainerCLIOpts(cc handlers.CreateContainerConfig, cgroup
 	// network names
 	endpointsConfig := cc.NetworkingConfig.EndpointsConfig
 	cniNetworks := make([]string, 0, len(endpointsConfig))
-	for netName := range endpointsConfig {
+	for netName, endpoint := range endpointsConfig {
 		cniNetworks = append(cniNetworks, netName)
+		if len(endpoint.Aliases) > 0 {
+			aliases = append(aliases, endpoint.Aliases...)
+		}
 	}
 
 	// netMode
@@ -262,6 +266,7 @@ func ContainerCreateToContainerCLIOpts(cc handlers.CreateContainerConfig, cgroup
 	// defined when there is only one network.
 	netInfo := entities.NetOptions{
 		AddHosts:     cc.HostConfig.ExtraHosts,
+		Aliases:      aliases,
 		CNINetworks:  cniNetworks,
 		DNSOptions:   cc.HostConfig.DNSOptions,
 		DNSSearch:    cc.HostConfig.DNSSearch,
diff --git a/cmd/podman/common/netflags.go b/cmd/podman/common/netflags.go
index 1b8297c36..935a5f7b9 100644
--- a/cmd/podman/common/netflags.go
+++ b/cmd/podman/common/netflags.go
@@ -43,6 +43,10 @@ func GetNetFlags() *pflag.FlagSet {
 		"network", containerConfig.NetNS(),
 		"Connect a container to a network",
 	)
+	netFlags.StringSlice(
+		"network-alias", []string{},
+		"Add network-scoped alias for the container",
+	)
 	netFlags.StringSliceP(
 		"publish", "p", []string{},
 		"Publish a container's port, or a range of ports, to the host (default [])",
@@ -158,6 +162,9 @@ func NetFlagsToNetOptions(cmd *cobra.Command) (*entities.NetOptions, error) {
 	}
 
 	opts.NoHosts, err = cmd.Flags().GetBool("no-hosts")
+	if err != nil {
+		return nil, err
+	}
 
 	if cmd.Flags().Changed("network") {
 		network, err := cmd.Flags().GetString("network")
@@ -181,5 +188,12 @@ func NetFlagsToNetOptions(cmd *cobra.Command) (*entities.NetOptions, error) {
 		opts.CNINetworks = cniNets
 	}
 
+	aliases, err := cmd.Flags().GetStringSlice("network-alias")
+	if err != nil {
+		return nil, err
+	}
+	if len(aliases) > 0 {
+		opts.Aliases = aliases
+	}
 	return &opts, err
 }
diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go
index ca1e25be1..39ff02857 100644
--- a/cmd/podman/common/specgen.go
+++ b/cmd/podman/common/specgen.go
@@ -396,6 +396,17 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string
 		s.ShmSize = &shmSize
 	}
 	s.CNINetworks = c.Net.CNINetworks
+
+	// Network aliases
+	if len(c.Net.Aliases) > 0 {
+		// build a map of aliases where key=cniName
+		aliases := make(map[string][]string, len(s.CNINetworks))
+		for _, cniNetwork := range s.CNINetworks {
+			aliases[cniNetwork] = c.Net.Aliases
+		}
+		s.Aliases = aliases
+	}
+
 	s.HostAdd = c.Net.AddHosts
 	s.UseImageResolvConf = c.Net.UseImageResolvConf
 	s.DNSServers = c.Net.DNSServers