fix(init): use /proc/net/pnp as resolv.conf (#87)

initramfs/cmd/init/pkg/etc/etc.go

@@ -11,7 +11,6 @@ import (
 	"strings"
 	"text/template"
 
-	"github.com/autonomy/dianemo/initramfs/pkg/userdata"
 	"github.com/autonomy/dianemo/initramfs/pkg/version"
 )
 
@@ -24,12 +23,6 @@ ff02::1         ip6-allnodes
 ff02::2         ip6-allrouters
 `
 
-const resolvConfTemplate = `
-{{- range $_, $ip := . -}}
-nameserver {{ $ip }}
-{{- end -}}
-`
-
 const osReleaseTemplate = `
 NAME="{{ .Name }}"
 ID={{ .ID }}
@@ -67,30 +60,12 @@ func Hosts(s, hostname, ip string) (err error) {
 	return nil
 }
 
-// ResolvConf renders a valid /etc/resolv.conf file and writes it to disk.
+// ResolvConf symlinks /proc/net/pnp to /etc/resolv.conf. See
-func ResolvConf(s string, userdata userdata.UserData) (err error) {
+// https://www.kernel.org/doc/Documentation/filesystems/nfs/nfsroot.txt.
-	tmpl, err := template.New("").Parse(resolvConfTemplate)
+func ResolvConf(s string) (err error) {
-	if err != nil {
+	if err = os.Symlink("/proc/net/pnp", path.Join(s, "/etc/resolv.conf")); err != nil {
 		return
 	}
-	var buf []byte
-	writer := bytes.NewBuffer(buf)
-	ip, err := DefaultGateway()
-	if err != nil {
-		return
-	}
-	nameservers := []string{ip}
-	if userdata.OS.Network != nil {
-		nameservers = append(nameservers, userdata.OS.Network.Nameservers...)
-	}
-	err = tmpl.Execute(writer, nameservers)
-	if err != nil {
-		return
-	}
-
-	if err := ioutil.WriteFile(path.Join(s, "/etc/resolv.conf"), writer.Bytes(), 0644); err != nil {
-		return fmt.Errorf("write /etc/resolv.conf: %v", err)
-	}
 
 	return nil
 }

initramfs/cmd/init/pkg/rootfs/rootfs.go

@@ -40,7 +40,7 @@ func Prepare(s string, userdata userdata.UserData) (err error) {
 		return
 	}
 	// Create /etc/resolv.conf.
-	if err = etc.ResolvConf(s, userdata); err != nil {
+	if err = etc.ResolvConf(s); err != nil {
 		return
 	}
 	// Create /etc/os-release.

initramfs/pkg/userdata/userdata.go

@@ -57,9 +57,7 @@ type OS struct {
 
 // Network represents the operating system networking specific configuration
 // options.
-type Network struct {
+type Network struct{}
-	Nameservers []string `yaml:"nameservers,omitempty"`
-}
 
 // Security represents the operating system security specific configuration
 // options.