Adding wildcard support (#190)

* Commenting out unused functions. TODO: remove when it is not needed

* Update README with namespace and template example

* Adding note about changing the record name format via a template

* Adding test scripts to automate k8s startup

* Automating k8s namespace creation

* Adding automation to start 4 k8s services

* Updating documentation for k8s tests

* Avoid downloading kubectl if already exists

* Adding debug statement when namespace is not exposed.

* Adding basic kubernetes integration tests

* Makefile now contains a "testk8s" target. This target requires k8s to
  be running.
* Adding test/kubernetes_test.go file with a couple of basic A record
  tests.

* Updating k8s integration tests to only run k8s integration tests

* Adding support for namespace wildcards

* Refactoring to move filtering logic to kubernetes.go file

* go fmt fixes

* Adding wildcard support for namespaces and service names

* Kubernetes integration tests updated for A records.
* Expanded record name assembly for answer section not yet implemented.
* Refactoring to focus k8sclient code just on accessing k8s API.
 Filtering now handled in kubernetes.go

* Adding wildcard test cases

* Adding skydns startup script. (To allow side by side testing of wildcards.)
* Commenting out record name assmebly based on NameTemplate. Need to improve template before this makes sense.

* Adding basic SRV integration tests

* Need to add verification for additional answer section

* Fixing comments and formatting

* Moving wildcard constants to vars

* Travis test execution appears to be failing on access to these
 constants

* Fixing access to util package

* Trying to work around Travis test bug

* Reverting to access kubernetes/util as "util"

Travis breakage is due to "Infoblox-CTO" in src path

middleware/kubernetes/test/00_run_k8s.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# Based on instructions at: http://kubernetes.io/docs/getting-started-guides/docker/
+
+#K8S_VERSION=$(curl -sS https://storage.googleapis.com/kubernetes-release/release/latest.txt)
+K8S_VERSION="v1.2.4"
+
+ARCH="amd64"
+
+
+export K8S_VERSION
+export ARCH
+
+#RUN_SKYDNS="yes"
+RUN_SKYDNS="no"
+
+if [ "${RUN_SKYDNS}" = "yes" ]; then
+	DNS_ARGUMENTS="--cluster-dns=10.0.0.10 --cluster-domain=cluster.local"
+else
+	DNS_ARGUMENTS=""
+fi
+
+docker run -d \
+    --volume=/:/rootfs:ro \
+    --volume=/sys:/sys:ro \
+    --volume=/var/lib/docker/:/var/lib/docker:rw \
+    --volume=/var/lib/kubelet/:/var/lib/kubelet:rw \
+    --volume=/var/run:/var/run:rw \
+    --net=host \
+    --pid=host \
+    --privileged \
+    gcr.io/google_containers/hyperkube-${ARCH}:${K8S_VERSION} \
+    /hyperkube kubelet \
+    --containerized \
+    --hostname-override=127.0.0.1 \
+    --api-servers=http://localhost:8080 \
+    --config=/etc/kubernetes/manifests \
+    ${DNS_ARGUMENTS} \
+    --allow-privileged --v=2

middleware/kubernetes/test/10_setup_kubectl.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+PWD=`pwd`
+BASEDIR=`realpath $(dirname ${0})`
+
+cd ${BASEDIR}
+if [ ! -e kubectl ]; then
+	curl -O http://storage.googleapis.com/kubernetes-release/release/v1.2.4/bin/linux/amd64/kubectl
+	chmod u+x kubectl
+fi
+
+${BASEDIR}/kubectl config set-cluster test-doc --server=http://localhost:8080
+${BASEDIR}/kubectl config set-context test-doc --cluster=test-doc
+${BASEDIR}/kubectl config use-context test-doc
+
+cd ${PWD}
+
+alias kubctl="${BASEDIR}/kubectl"

middleware/kubernetes/test/15_run_skydns.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# Running skydns based on instructions at: https://testdatamanagement.wordpress.com/2015/09/01/running-kubernetes-in-docker-with-dns-on-a-single-node/
+
+KUBECTL='./kubectl'
+
+#RUN_SKYDNS="yes"
+RUN_SKYDNS="no"
+
+wait_until_k8s_ready() {
+	# Wait until kubernetes is up and fully responsive
+	while :
+	do
+   	 ${KUBECTL} get nodes 2>/dev/null | grep -q '127.0.0.1'
+		if [ "${?}" = "0" ]; then
+			break
+		else
+			echo "sleeping for 5 seconds"
+			sleep 5
+		fi
+	done
+	echo "kubernetes nodes:"
+	${KUBECTL} get nodes
+}
+
+
+if [ "${RUN_SKYDNS}" = "yes" ]; then
+	wait_until_k8s_ready
+
+	echo "Launch kube2sky..."
+	docker run -d --net=host gcr.io/google_containers/kube2sky:1.11 --kube_master_url=http://127.0.0.1:8080 --domain=cluster.local
+
+	echo ""
+
+	echo "Launch SkyDNS..."
+	docker run -d --net=host gcr.io/google_containers/skydns:2015-03-11-001 --machines=http://localhost:4001 --addr=0.0.0.0:53 --domain=cluster.local
+else
+	true
+fi

middleware/kubernetes/test/20_setup_k8s_services.sh

@@ -0,0 +1,80 @@
+#!/bin/bash
+
+KUBECTL='./kubectl'
+
+wait_until_k8s_ready() {
+	# Wait until kubernetes is up and fully responsive
+	while :
+	do
+   	 ${KUBECTL} get nodes 2>/dev/null | grep -q '127.0.0.1'
+		if [ "${?}" = "0" ]; then
+			break
+		else
+			echo "sleeping for 5 seconds"
+			sleep 5
+		fi
+	done
+	echo "kubernetes nodes:"
+	${KUBECTL} get nodes
+}
+
+create_namespaces() {
+	for n in ${NAMESPACES};
+	do
+			echo "Creating namespace: ${n}"
+			${KUBECTL} get namespaces --no-headers 2>/dev/null | grep -q ${n}
+			if [ "${?}" != "0" ]; then
+				${KUBECTL} create namespace ${n}
+			fi
+	done
+
+	echo "kubernetes namespaces:"
+	${KUBECTL} get namespaces
+}
+
+# run_and_expose_service <servicename> <namespace> <image> <port>
+run_and_expose_service() {
+
+    if [ "${#}" != "4" ]; then
+        return -1
+    fi
+
+    service="${1}"
+    namespace="${2}"
+    image="${3}"
+    port="${4}"
+
+    echo "   starting service '${service}' in namespace '${namespace}"
+
+    ${KUBECTL} get deployment --namespace=${namespace} --no-headers 2>/dev/null | grep -q ${service}
+    if [ "${?}" != "0" ]; then
+        ${KUBECTL} run ${service} --namespace=${namespace} --image=${image}
+    else
+        echo "warn: service '${service}' already running in namespace '${namespace}'"
+    fi
+
+    ${KUBECTL} get service --namespace=${namespace} --no-headers 2>/dev/null | grep -q ${service}
+    if [ "${?}" != "0" ]; then
+        ${KUBECTL} expose deployment ${service} --namespace=${namespace} --port=${port}
+    else
+        echo "warn: service '${service}' already exposed in namespace '${namespace}'"
+    fi
+}
+
+
+wait_until_k8s_ready
+
+NAMESPACES="demo test"
+create_namespaces
+
+echo ""
+echo "Starting services:"
+
+run_and_expose_service mynginx demo nginx 80
+run_and_expose_service webserver demo nginx 80
+run_and_expose_service mynginx test nginx 80
+run_and_expose_service webserver test nginx 80
+
+echo ""
+echo "Services exposed:"
+${KUBECTL} get services --all-namespaces

middleware/kubernetes/test/README.md

@@ -0,0 +1,35 @@
+## Test scripts to automate kubernetes startup
+
+Requirements:
+	docker
+	curl
+
+The scripts in this directory startup kubernetes with docker as the container runtime.
+After starting kubernetes, a couple of kubernetes services are started to allow automatic
+testing of CoreDNS with kubernetes.
+
+To use, run the scripts as:
+
+~~~
+$ ./00_run_k8s.sh && ./10_setup_kubectl.sh && ./20_setup_k8s_services.sh
+~~~
+
+After running the above scripts, kubernetes will be running on the localhost with the following services
+exposed:
+
+~~
+NAMESPACE   NAME         CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
+default     kubernetes   10.0.0.1     <none>        443/TCP   48m
+demo        mynginx      10.0.0.168   <none>        80/TCP    9m
+demo        webserver    10.0.0.28    <none>        80/TCP    2m
+test        mynginx      10.0.0.4     <none>        80/TCP    2m
+test        webserver    10.0.0.39    <none>        80/TCP    2m
+~~
+
+
+Kubernetes and all running containers can be uncerimoniously stopped by
+running the `kill_all_containers.sh` script.
+
+~~~
+$ ./kill_all_containers.sh
+~~~

middleware/kubernetes/test/kill_all_containers.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+docker rm -f $(docker ps -a -q)
+sleep 1
+docker rm -f $(docker ps -a -q)