Add single-stack IPv6 support

docs/release-notes.md

@@ -11,6 +11,7 @@ nav_order: 9
 ### Features
 
 - Support partitioning disk with mounted partitions
+- Support IPv6 for single-stack OpenStack
 
 ### Changes
 

internal/providers/openstack/openstack.go

@@ -22,6 +22,7 @@ package openstack
 import (
  "context"
  "fmt"
+ "net"
  "net/url"
  "os"
  "os/exec"
@@ -43,14 +44,6 @@ const (
  configDriveUserdataPath = "/openstack/latest/user_data"
 )
 
-var (
- metadataServiceUrl = url.URL{
- Scheme: "http",
- Host: "169.254.169.254",
- Path: "openstack/latest/user_data",
- }
-)
-
 func init() {
  platform.Register(platform.Provider{
  Name: "openstack",
@@ -166,14 +159,86 @@ func fetchConfigFromDevice(logger *log.Logger, ctx context.Context, path string)
  return os.ReadFile(filepath.Join(mnt, configDriveUserdataPath))
 }
 
+func FindIPv6InterfaceName() (string, error) {
+ interfaces, err := net.Interfaces()
+ if err != nil {
+ return "", err
+ }
+
+ for _, iface := range interfaces {
+ // Check if the interface is up and not loopback
+ if iface.Flags&net.FlagUp != 0 && iface.Flags&net.FlagLoopback == 0 {
+ addrs, err := iface.Addrs()
+ if err != nil {
+ continue
+ }
+
+ for _, addr := range addrs {
+ // Check if the address is an IPv6
+ if ipnet, ok := addr.(*net.IPNet); ok && ipnet.IP.To4() == nil && !ipnet.IP.IsLinkLocalUnicast() {
+ return iface.Name, nil
+ }
+ }
+ }
+ }
+
+ return "", fmt.Errorf("no IPv6 interface name found")
+}
+
 func fetchConfigFromMetadataService(f *resource.Fetcher) ([]byte, error) {
- res, err := f.FetchToBuffer(metadataServiceUrl, resource.FetchOptions{})
 
- // the metadata server exists but doesn't contain any actual metadata,
- // assume that there is no config specified
- if err == resource.ErrNotFound {
- return nil, nil
+ // Find IPv6 name
+ iface, err := FindIPv6InterfaceName()
+ if err != nil {
+ return nil, err
+ }
+
+ // Construct URL
+ var (
+ ipv4MetadataServiceUrl = url.URL{
+ Scheme: "http",
+ Host: "169.254.169.254",
+ Path: "openstack/latest/user_data",
+ }
+ ipv6MetadataServiceUrl = url.URL{
+ Scheme: "http",
+ Host: fmt.Sprintf("[fe80::a9fe:a9fe%%%s]", url.PathEscape(iface)),
+ Path: "openstack/latest/user_data",
+ }
+ )
+
+ var resIPv4, resIPv6 []byte
+ var errIPv4, errIPv6 error
+
+ // Try IPv4 endpoint
+ resIPv4, errIPv4 = f.FetchToBuffer(ipv4MetadataServiceUrl, resource.FetchOptions{})
+ if errIPv4 != nil && errIPv4 != resource.ErrNotFound {
+ f.Logger.Err("Failed to fetch config from IPv4: %v", errIPv4)
+ }
+
+ // Try IPv6 endpoint
+ resIPv6, errIPv6 = f.FetchToBuffer(ipv6MetadataServiceUrl, resource.FetchOptions{})
+ if errIPv6 != nil && errIPv6 != resource.ErrNotFound {
+ f.Logger.Err("Failed to fetch config from IPv6: %v", errIPv6)
+ }
+
+ // If both IPv4 and IPv6 have valid data, combine them
+ if resIPv4 != nil && resIPv6 != nil {
+ return append(resIPv4, resIPv6...), nil
+ } else if resIPv4 != nil {
+ return resIPv4, nil
+ } else if resIPv6 != nil {
+ return resIPv6, nil
+ }
+
+ // If both endpoints fail, return the appropriate error
+ if errIPv4 != nil {
+ return nil, errIPv4
+ }
+ if errIPv6 != nil {
+ return nil, errIPv6
  }
 
- return res, err
+ // If both endpoints return ErrNotFound
+ return nil, nil
 }