Name or service not known [tcp://redis-slave:6379] - kubernetes

Question

Running the Guestbook Kubernetes app with the Kube-Sky add-on. On the guestbook app page I get this error in the JavaScript console:
Fatal error: Uncaught exception 'Predis\Connection\ConnectionException' with message 'php_network_getaddresses: getaddrinfo failed: Name or service not known [tcp://redis-slave:6379]' in /vendor/predis/predis/lib/Predis/Connection/AbstractConnection.php:141
The following are the all the changes (vs. the provided templates) relating to DNS I can find in my setup:
diff -r sample-configs/unmodified/cloud-init/node.yaml sample-configs/defaults/cloud-init/node.yaml
88a91,92
> --cluster_dns=10.100.88.88 \
> --cluster_domain=cluster.local \
diff -r sample-configs/unmodified/skydns-controller.yaml sample-configs/defaults/skydns-controller.yaml
11c11
< replicas: {{ pillar['dns_replicas'] }}
---
> replicas: 3
50c50,51
< - -domain={{ pillar['dns_domain'] }}
---
> - -domain=cluster.local
> - -kube_master_url=http://$(KUBERNETES_MASTER_IPV4):8080
62c63
< - -domain={{ pillar['dns_domain'] }}.
---
> - -domain=cluster.local.
91c92
< - -cmd=nslookup kubernetes.default.svc.{{ pillar['dns_domain'] }} 127.0.0.1 >/dev/null
---
> - -cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1 >/dev/null
diff -r sample-configs/unmodified/skydns-service.yaml sample-configs/defaults/skydns-service.yaml
13c13,14
< clusterIP: {{ pillar['dns_server'] }}
---
> clusterIP: 10.100.88.88
> type: NodePort
17a19
> nodePort:
20a23
> nodePort:
\ No newline at end of file
./sample-configs/unmodified/cloud-init/master.yaml: --service-cluster-ip-range=10.100.0.0/16 \
NAMESPACE NAME READY STATUS RESTARTS AGE NODE
default frontend-jw0ud 1/1 Running 0 48m $publicip.23
default frontend-mwu18 1/1 Running 0 48m $publicip.23
default frontend-o33ei 1/1 Running 0 48m $publicip.26
default redis-master-ubpga 1/1 Running 0 46m $publicip.23
default redis-slave-7aqp9 1/1 Running 0 46m $publicip.97
default redis-slave-w6rn3 1/1 Running 0 46m $publicip.26
default redis-slave-wny9v 1/1 Running 0 46m $publicip.26
kube-system kube-dns-v9-jek26 4/4 Running 0 50m $publicip.23
kube-system kube-dns-v9-ua150 4/4 Running 0 50m $publicip.26
kube-system kube-dns-v9-ycloq 4/4 Running 0 50m $publicip.97
NAMESPACE NAME CLUSTER_IP EXTERNAL_IP PORT(S) SELECTOR AGE
default frontend 10.100.221.197 nodes 80/TCP name=frontend 46m
default kubernetes 10.100.0.1 <none> 443/TCP <none> 1h
default redis-master 10.100.151.114 <none> 6379/TCP name=redis-master 46m
default redis-slave 10.100.223.227 nodes 6379/TCP name=redis-slave 46m
kube-system kube-dns 10.100.88.88 nodes 53/UDP,53/TCP k8s-app=kube-dns 46m
NAMESPACE CONTROLLER CONTAINER(S) IMAGE(S) SELECTOR REPLICAS AGE
default frontend php-redis kubernetes/example-guestbook-php-redis:v2 name=frontend 3 48m
default redis-master master redis name=redis-master 1 46m
default redis-slave worker kubernetes/redis-slave:v2 name=redis-slave 3 46m
kube-system kube-dns-v9 etcd gcr.io/google_containers/etcd:2.0.9 k8s-app=kube-dns 3 50m
kube2sky gcr.io/google_containers/kube2sky:1.11
skydns gcr.io/google_containers/skydns:2015-10-13-8c72f8c
healthz gcr.io/google_containers/exechealthz:1.0
$ rkubectl exec busybox -- nslookup kubernetes
Server: 10.100.88.88
Address 1: 10.100.88.88
nslookup: can't resolve 'kubernetes'
error: error executing remote command: Error executing command in container: Error executing in Docker Container: 1
$ rkubectl exec busybox -- ping -w 1 10.100.88.88
PING 10.100.88.88 (10.100.88.88): 56 data bytes
--- 10.100.88.88 ping statistics ---
1 packets transmitted, 0 packets received, 100% packet loss
error: error executing remote command: Error executing command in container: Error executing in Docker Container: 1
$ rkubectl exec busybox -- route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.17.42.1 0.0.0.0 UG 0 0 0 eth0
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
$ rkubectl exec busybox -- ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:11:00:1A
inet addr:172.17.0.26 Bcast:0.0.0.0 Mask:255.255.0.0
$ rkubectl exec busybox -- cat /etc/resolv.conf
nameserver 10.100.88.88
nameserver 8.8.8.8
nameserver 8.8.4.4
search default.svc.cluster.local svc.cluster.local cluster.local
options ndots:5