lxc/completion: Add completions for network forward port target addre…

…sses

Closes #14697.

This commit adds `cmpNetworkForwardPortTargetAddresses` to provide
target address completions for `lxc network forward port add`.

Signed-off-by: Kadin Sayani <[email protected]>

lxc/completion.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"net"
 	"regexp"
 	"strings"
 
@@ -844,6 +845,48 @@ func (g *cmdGlobal) cmpNetworkForwards(networkName string) ([]string, cobra.Shel
 	return results, cmpDirectives
 }
 
+// cmpNetworkForwardPortTargetAddresses provides shell completion for network forward port target addresses.
+// It takes a network name and listen address to determine whether to return ipv4 or ipv6 target addresses and returns a list of target addresses.
+func (g *cmdGlobal) cmpNetworkForwardPortTargetAddresses(networkName string, listenAddress string) ([]string, cobra.ShellCompDirective) {
+	cmpDirectives := cobra.ShellCompDirectiveNoFileComp
+
+	resources, _ := g.ParseServers(networkName)
+	if len(resources) <= 0 {
+		return nil, cobra.ShellCompDirectiveError
+	}
+
+	resource := resources[0]
+	instances, err := resource.server.GetInstancesFull(api.InstanceTypeAny)
+	if err != nil {
+		return nil, cobra.ShellCompDirectiveError
+	}
+
+	results := []string{}
+	listenAddressIsIP4 := net.ParseIP(listenAddress).To4() != nil
+	for _, instance := range instances {
+		if instance.IsActive() && instance.State != nil && instance.State.Network != nil {
+			for _, network := range instance.State.Network {
+				if network.Type == "loopback" {
+					continue
+				}
+
+				results = make([]string, 0, len(network.Addresses))
+				for _, address := range network.Addresses {
+					if shared.ValueInSlice(address.Scope, []string{"link", "local"}) {
+						continue
+					}
+
+					if (listenAddressIsIP4 && address.Family == "inet") || (!listenAddressIsIP4 && address.Family == "inet6") {
+						results = append(results, address.Address)
+					}
+				}
+			}
+		}
+	}
+
+	return results, cmpDirectives
+}
+
 // cmpNetworkLoadBalancers provides shell completion for network load balancers.
 // It takes a network name and returns a list of network load balancers along with a shell completion directive.
 func (g *cmdGlobal) cmpNetworkLoadBalancers(networkName string) ([]string, cobra.ShellCompDirective) {

lxc/network_forward.go

@@ -904,6 +904,10 @@ func (c *cmdNetworkForwardPort) commandAdd() *cobra.Command {
 			return []string{"tcp", "udp"}, cobra.ShellCompDirectiveNoFileComp
 		}
 
+		if len(args) == 4 {
+			return c.global.cmpNetworkForwardPortTargetAddresses(args[0], args[1])
+		}
+
 		return nil, cobra.ShellCompDirectiveNoFileComp
 	}
 
@@ -986,6 +990,10 @@ func (c *cmdNetworkForwardPort) commandRemove() *cobra.Command {
 			return []string{"tcp", "udp"}, cobra.ShellCompDirectiveNoFileComp
 		}
 
+		if len(args) == 4 {
+			return c.global.cmpNetworkForwardPortTargetAddresses(args[0], args[1])
+		}
+
 		return nil, cobra.ShellCompDirectiveNoFileComp
 	}