Improve systemd-resolved detection
When 127.0.0.53 is the only nameserver in /etc/resolv.conf assume
systemd-resolved is used. This is better because /etc/resolv.conf does
not have to be symlinked to /run/systemd/resolve/stub-resolv.conf in
order to use systemd-resolved.
[NO TESTS NEEDED]
Fixes:
@@ -1650,22 +1650,20 @@ func (c *Container) generateResolvConf() (string, error) {
}
}
- // Determine the endpoint for resolv.conf in case it is a symlink
- resolvPath, err := filepath.EvalSymlinks(resolvConf)
+ contents, err := ioutil.ReadFile(resolvConf)
// resolv.conf doesn't have to exists
if err != nil && !os.IsNotExist(err) {
return "", err
}
- // Determine if symlink points to any of the systemd-resolved files
- if strings.HasPrefix(resolvPath, "/run/systemd/resolve/") {
- resolvPath = "/run/systemd/resolve/resolv.conf"
+ ns := resolvconf.GetNameservers(contents)
+ // check if systemd-resolved is used, assume it is used when 127.0.0.53 is the only nameserver
+ if len(ns) == 1 && ns[0] == "127.0.0.53" {
+ // read the actual resolv.conf file for systemd-resolved
+ contents, err = ioutil.ReadFile("/run/systemd/resolve/resolv.conf")
+ if err != nil {
+ return "", errors.Wrapf(err, "detected that systemd-resolved is in use, but could not locate real resolv.conf")
}
-
- contents, err := ioutil.ReadFile(resolvPath)
- // resolv.conf doesn't have to exists
- if err != nil && !os.IsNotExist(err) {
- return "", err
}
ipv6 := false
