helios-solo: skydns workaround to allow DNS responses up to 32768 bytes

docs/helios_solo.md

@@ -181,3 +181,8 @@ $ docker logs helios-solo-container
 
 $ helios-up && docker exec -it helios-solo-container bash
 ```
+
+Known issues
+------------
+
+ * SkyDNS does not handle DNS TCP responses well. We have a workaround in place to use UDP for responses up to 32768 bytes in size. Any response larger than that will cause a `SERVFAIL`. When this happens SkyDns will log `skydns: failure to forward request "dns: failed to unpack truncated message"`. See https://github.com/spotify/helios/pull/900 and https://github.com/spotify/helios/pull/1081 for more information.

solo/base/unbound-skydns.conf

@@ -8,6 +8,8 @@ server:
     outgoing-num-tcp: 256
     access-control: 0.0.0.0/0 allow
     do-not-query-localhost: no
+    max-udp-size: 32768
+    edns-buffer-size: 32768
 
 forward-zone:
     name: "."

solo/base/version.txt

@@ -1 +1 @@
-0.6
+0.7

solo/docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM spotify/helios-solo-base:0.6
+FROM spotify/helios-solo-base:0.7
 
 EXPOSE 5801