From 19b0797ae2b792cf14b507f393cd2d0bc39e395d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucas=20Serv=C3=A9n=20Mar=C3=ADn?= <lserven@gmail.com>
Date: Tue, 6 Jul 2021 20:48:18 +0200
Subject: [PATCH] e2e: test multi-cluster connectivity
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This commit adds a new test suite to the e2e tests that validates
multi-cluster connectivity in Kilo. This is really just an extension of
the testing of the Peers CRD and related tooling that also exercises the
`--allowed-ips` flag of the `kgctl` tool.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
---
 .gitignore           |  2 +-
 Makefile             |  2 +-
 e2e/multi-cluster.sh | 66 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100755 e2e/multi-cluster.sh

diff --git a/.gitignore b/.gitignore
index 1e8d72c..adc7929 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,4 @@
 .push*
 bin/
 tmp/
-e2e/kind.yaml
+e2e/kind.yaml*
diff --git a/Makefile b/Makefile
index 741cfb1..f7d02f2 100644
--- a/Makefile
+++ b/Makefile
@@ -209,7 +209,7 @@ $(BASH_UNIT):
 	chmod +x $@
 
 e2e: container $(KIND_BINARY) $(KUBECTL_BINARY) $(BASH_UNIT) bin/$(OS)/$(ARCH)/kgctl
-	KILO_IMAGE=$(IMAGE):$(ARCH)-$(VERSION) KIND_BINARY=$(KIND_BINARY) KUBECTL_BINARY=$(KUBECTL_BINARY) KGCTL_BINARY=$(shell pwd)/bin/$(OS)/$(ARCH)/kgctl $(BASH_UNIT) $(BASH_UNIT_FLAGS) ./e2e/setup.sh ./e2e/full-mesh.sh ./e2e/location-mesh.sh ./e2e/teardown.sh
+	KILO_IMAGE=$(IMAGE):$(ARCH)-$(VERSION) KIND_BINARY=$(KIND_BINARY) KUBECTL_BINARY=$(KUBECTL_BINARY) KGCTL_BINARY=$(shell pwd)/bin/$(OS)/$(ARCH)/kgctl $(BASH_UNIT) $(BASH_UNIT_FLAGS) ./e2e/setup.sh ./e2e/full-mesh.sh ./e2e/location-mesh.sh ./e2e/multi-cluster.sh ./e2e/teardown.sh
 
 header: .header
 	@HEADER=$$(cat .header); \
diff --git a/e2e/multi-cluster.sh b/e2e/multi-cluster.sh
new file mode 100755
index 0000000..6eb58ce
--- /dev/null
+++ b/e2e/multi-cluster.sh
@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC1091
+. lib.sh
+
+# shellcheck disable=SC2153
+KUBECONFIG2="$KUBECONFIG"2
+# shellcheck disable=SC2153
+KIND_CLUSTER2="$KIND_CLUSTER"2
+
+setup_suite() {
+	KUBECONFIG=$KUBECONFIG2 KIND_CLUSTER=$KIND_CLUSTER2 create_cluster "$(build_kind_config 1 6444 10.44.0.0/16 10.45.0.0/16)"
+	# shellcheck disable=SC2016
+	KUBECONFIG=$KUBECONFIG2 _kubectl patch ds -n kube-system kilo -p '{"spec": {"template":{"spec":{"containers":[{"name":"kilo","args":["--hostname=$(NODE_NAME)","--create-interface=false","--kubeconfig=/etc/kubernetes/kubeconfig","--mesh-granularity=full","--subnet=10.6.0.0/16"]}]}}}}'
+	KUBECONFIG=$KUBECONFIG2 block_until_ready_by_name kube-system kilo-userspace 
+	# Register the nodes in cluster1 as peers of cluster2.
+	for n in $(_kubectl get no -o name | cut -d'/' -f2); do
+		# Specify the service CIDR as an extra IP range that should be routable.
+		$KGCTL_BINARY --kubeconfig "$KUBECONFIG" showconf node "$n" --as-peer -o yaml --allowed-ips 10.43.0.0/16 | $KUBECTL_BINARY --kubeconfig "$KUBECONFIG2" apply -f -
+	done
+	# Register the nodes in cluster2 as peers of cluster1.
+	for n in $(KUBECONFIG=$KUBECONFIG2 _kubectl get no -o name | cut -d'/' -f2); do
+		# Specify the service CIDR as an extra IP range that should be routable.
+		$KGCTL_BINARY --kubeconfig "$KUBECONFIG2" showconf node "$n" --as-peer -o yaml --allowed-ips 10.45.0.0/16 | $KUBECTL_BINARY --kubeconfig "$KUBECONFIG" apply -f -
+	done
+}
+
+test_multi_cluster_pod_connectivity() {
+	for ip in $(KUBECONFIG=$KUBECONFIG2 _kubectl get pods -l app.kubernetes.io/name=adjacency -o jsonpath='{.items[*].status.podIP}'); do
+		assert_equals pong "$(retry 10 5 "$ip is not yet routable" curl_pod -m 1 -s http://"$ip":8080/ping)" "should be able to make HTTP request from cluster 1 to Pod in cluster 2"
+	done
+	for ip in $(_kubectl get pods -l app.kubernetes.io/name=adjacency -o jsonpath='{.items[*].status.podIP}'); do
+		assert_equals pong "$(KUBECONFIG="$KUBECONFIG2" retry 10 5 "$ip is not yet routable" curl_pod -m 1 -s http://"$ip":8080/ping)" "should be able to make HTTP request from cluster 2 to Pod in cluster 1"
+	done
+}
+
+test_multi_cluster_service_connectivity() {
+	# Mirror the Kubernetes API service from cluster1 into cluster2.
+	cat <<EOF | $KUBECTL_BINARY --kubeconfig "$KUBECONFIG2" apply -f -
+apiVersion: v1
+kind: Service
+metadata:
+  name: mirrored-kubernetes
+spec:
+  ports:
+    - port: 443
+---
+apiVersion: v1
+kind: Endpoints
+metadata:
+    name: mirrored-kubernetes
+subsets:
+  - addresses:
+      - ip: $(_kubectl get service kubernetes -o jsonpath='{.spec.clusterIP}') # The cluster IP of the Kubernetes API service on cluster1.
+    ports:
+      - port: 443
+EOF
+        assert_equals ok "$(KUBECONFIG="$KUBECONFIG2" retry 10 5 "service is not yet routable" curl_pod -m 1 -s -k https://mirrored-kubernetes/readyz)" "should be able to make HTTP request from cluster 2 to service in cluster 1"
+}
+
+teardown_suite () {
+	# Remove the nodes in cluster2 as peers of cluster1.
+	for n in $(KUBECONFIG=$KUBECONFIG2 _kubectl get no -o name | cut -d'/' -f2); do
+		_kubectl delete peer "$n"
+	done
+	KUBECONFIG=$KUBECONFIG2 KIND_CLUSTER=$KIND_CLUSTER2 delete_cluster
+}