plugin/tls: manage certificates with ACME DNS-01 (#8310)

* plugin/tls: add automatic ACME certificates

Signed-off-by: houyuwushang <liuluoqianqiu@outlook.com>

* chore: add houyuwushang to CODEOWNERS

Signed-off-by: houyuwushang <liuluoqianqiu@outlook.com>

* chore: regenerate maintainer owners

Signed-off-by: houyuwushang <liuluoqianqiu@outlook.com>

---------

Signed-off-by: houyuwushang <liuluoqianqiu@outlook.com>

core/dnsserver/config.go

@@ -171,3 +171,22 @@ func GetConfig(c *caddy.Controller) *Config {
 	ctx.saveConfig(key, &Config{ListenHosts: []string{""}})
 	return GetConfig(c)
 }
+
+// AddPluginToAllServerBlocks adds m once to every server block in c's
+// instance. It is intended for directives that must handle traffic on a
+// listener other than the one where the directive is configured.
+func AddPluginToAllServerBlocks(c *caddy.Controller, m plugin.Plugin) {
+	ctx := c.Context().(*dnsContext)
+	seen := make(map[*Config]struct{})
+	for _, cfg := range ctx.configs {
+		first := cfg.firstConfigInBlock
+		if first == nil {
+			first = cfg
+		}
+		if _, ok := seen[first]; ok {
+			continue
+		}
+		seen[first] = struct{}{}
+		first.AddPlugin(m)
+	}
+}