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Merge pull request #31 from cloudscale-ch/alain/udp
Add UDP Support
2 parents 26ce829 + 47b4042 commit 74832ba

6 files changed

Lines changed: 744 additions & 50 deletions

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‎examples/dns-dual-protocol.yaml‎

Lines changed: 99 additions & 0 deletions
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@@ -0,0 +1,99 @@
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# Deploys a DNS server container and creates a loadbalancer service for it with both UDP and TCP:
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#
3+
# export KUBECONFIG=path/to/kubeconfig
4+
# kubectl apply -f dns-dual-protocol.yaml
5+
#
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# Wait for `kubectl describe service dns-server` to show "Loadbalancer Ensured",
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# then use the IP address found under "LoadBalancer Ingress" to connect to the
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# service.
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#
10+
# You can test the DNS service with dig:
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#
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# # Test UDP (default)
13+
# dig @$(kubectl get service dns-server -o jsonpath='{.status.loadBalancer.ingress[0].ip}') example.com
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#
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# # Test TCP explicitly
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# dig +tcp @$(kubectl get service dns-server -o jsonpath='{.status.loadBalancer.ingress[0].ip}') example.com
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#
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# To view the logs:
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#
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# kubectl logs -l "app=dns-server"
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#
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---
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apiVersion: v1
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kind: ConfigMap
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metadata:
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name: coredns-config
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data:
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Corefile: |
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.:53 {
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log
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errors
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health
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ready
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whoami
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forward . 8.8.8.8 9.9.9.9
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}
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---
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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name: dns-server
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spec:
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replicas: 2
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selector:
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matchLabels:
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app: dns-server
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template:
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metadata:
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labels:
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app: dns-server
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spec:
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containers:
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- name: coredns
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image: coredns/coredns:1.11.1
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args:
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- -conf
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- /etc/coredns/Corefile
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volumeMounts:
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- name: config
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mountPath: /etc/coredns
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ports:
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- containerPort: 53
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protocol: UDP
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name: dns-udp
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- containerPort: 53
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protocol: TCP
67+
name: dns-tcp
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livenessProbe:
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httpGet:
70+
path: /health
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port: 8080
72+
readinessProbe:
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httpGet:
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path: /ready
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port: 8181
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volumes:
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- name: config
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configMap:
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name: coredns-config
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---
81+
apiVersion: v1
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kind: Service
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metadata:
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labels:
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app: dns-server
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name: dns-server
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spec:
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ports:
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- port: 53
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protocol: UDP
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targetPort: 53
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name: dns-udp
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- port: 53
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protocol: TCP
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targetPort: 53
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name: dns-tcp
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selector:
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app: dns-server
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type: LoadBalancer

‎examples/udp.yaml‎

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@@ -0,0 +1,63 @@
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# Deploys a UDP echo server container and creates a loadbalancer service for it:
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#
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# export KUBECONFIG=path/to/kubeconfig
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# kubectl apply -f udp-echo.yml
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#
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# Wait for `kubectl describe service udp-echo` to show "Loadbalancer Ensured",
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# then use the IP address found under "LoadBalancer Ingress" to connect to the
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# service.
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#
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# You can test the UDP service with netcat:
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#
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# echo "Tell me a joke" | nc -u -w 1 $(kubectl get service udp-echo -o jsonpath='{.status.loadBalancer.ingress[0].ip}') 5000
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#
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# To view the logs:
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#
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# kubectl logs -l "app=udp-echo"
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#
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---
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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name: udp-echo
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spec:
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replicas: 2
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selector:
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matchLabels:
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app: udp-echo
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template:
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metadata:
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labels:
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app: udp-echo
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spec:
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containers:
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- name: udp-echo
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image: docker.io/alpine/socat
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command:
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- socat
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- "-v"
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- "UDP4-RECVFROM:5353,fork"
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- "SYSTEM:echo 'I could tell you a UDP joke, but you might not get it...',pipes"
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ports:
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- containerPort: 5353
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protocol: UDP
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---
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apiVersion: v1
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kind: Service
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metadata:
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annotations:
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k8s.cloudscale.ch/loadbalancer-health-monitor-type: udp-connect
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k8s.cloudscale.ch/loadbalancer-health-monitor-delay-s: "3"
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k8s.cloudscale.ch/loadbalancer-health-monitor-timeout-s: "2"
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labels:
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app: udp-echo
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name: udp-echo
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spec:
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ports:
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- port: 5000
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protocol: UDP
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targetPort: 5353
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name: udp
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selector:
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app: udp-echo
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type: LoadBalancer

‎pkg/cloudscale_ccm/loadbalancer.go‎

Lines changed: 13 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -115,8 +115,14 @@ const (
115115
// as all pools have to be recreated.
116116
LoadBalancerPoolAlgorithm = "k8s.cloudscale.ch/loadbalancer-pool-algorithm"
117117

118-
// LoadBalancerPoolProtocol defines the protocol for all the pools of the
119-
// service. We are technically able to have different protocols for
118+
// LoadBalancerPoolProtocol defines the protocol the pools of a port
119+
// with protocol `TCP` use. Set it to `proxy` and `proxyv2` if TCP
120+
// traffic should be forwarded using these protocols.
121+
//
122+
// When setting the protocol of a port to `UDP`, traffic is always forwarded
123+
// using UDP.
124+
//
125+
// We are technically able to have different protocols for
120126
// different ports in a service, but as our options apart from `tcp` are
121127
// currently `proxy` and `proxyv2`, we go with Kubernetes's recommendation
122128
// to apply these protocols to all incoming connections the same way:
@@ -216,6 +222,8 @@ const (
216222
// LoadBalancerHealthMonitorType defines the approach the monitor takes.
217223
// (ping, tcp, http, https, tls-hello).
218224
//
225+
// Note that the same type is used for all ports in your service.
226+
//
219227
// See https://www.cloudscale.ch/en/api/v1#health-monitor-types
220228
//
221229
// Changing this annotation on an active service may lead to new
@@ -233,6 +241,9 @@ const (
233241
// LoadBalancerListenerProtocol defines the protocol used by the listening
234242
// port on the loadbalancer. Currently, only tcp is supported.
235243
//
244+
// This property is ignored for ports with the protocol `UDP`, where
245+
// we always create udp listeners.
246+
//
236247
// See https://www.cloudscale.ch/en/api/v1#listener-protocols
237248
//
238249
// Changing this annotation on an established service may cause downtime

‎pkg/cloudscale_ccm/reconcile.go‎

Lines changed: 18 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -122,9 +122,10 @@ func desiredLbState(
122122

123123
for _, port := range serviceInfo.Service.Spec.Ports {
124124

125-
if port.Protocol != "TCP" {
125+
if port.Protocol != v1.ProtocolTCP && port.Protocol != v1.ProtocolUDP {
126126
return nil, fmt.Errorf(
127-
"service %s: cannot use %s for %d, only TCP is supported",
127+
"service %s: cannot use %s for %d"+
128+
", only TCP and UDP are supported",
128129
serviceInfo.Service.Name,
129130
port.Protocol,
130131
port.Port)
@@ -145,10 +146,15 @@ func desiredLbState(
145146
}
146147
}
147148

149+
poolProtocol := protocol
150+
if port.Protocol != v1.ProtocolTCP {
151+
poolProtocol = "udp"
152+
}
153+
148154
pool := cloudscale.LoadBalancerPool{
149155
Name: poolName(port.Protocol, port.Name),
150156
Algorithm: algorithm,
151-
Protocol: protocol,
157+
Protocol: poolProtocol,
152158
}
153159
s.pools = append(s.pools, &pool)
154160

@@ -213,7 +219,7 @@ func desiredLbState(
213219
s.monitors[&pool] = append(s.monitors[&pool], *monitor)
214220

215221
// Add a listener for each pool
216-
listener, err := listenerForPort(serviceInfo, int(port.Port))
222+
listener, err := listenerForPort(serviceInfo, port)
217223
if err != nil {
218224
return nil, err
219225
}
@@ -813,16 +819,21 @@ func runActions(
813819
// annotations into consideration.
814820
func listenerForPort(
815821
serviceInfo *serviceInfo,
816-
port int,
822+
port v1.ServicePort,
817823
) (*cloudscale.LoadBalancerListener, error) {
818824

819825
var (
820826
listener = cloudscale.LoadBalancerListener{}
821827
err error
822828
)
823829

824-
listener.Protocol = serviceInfo.annotation(LoadBalancerListenerProtocol)
825-
listener.ProtocolPort = port
830+
listenerProtocol := serviceInfo.annotation(LoadBalancerListenerProtocol)
831+
if port.Protocol != v1.ProtocolTCP {
832+
listenerProtocol = "udp"
833+
}
834+
835+
listener.Protocol = listenerProtocol
836+
listener.ProtocolPort = int(port.Port)
826837
listener.Name = listenerName(listener.Protocol, listener.ProtocolPort)
827838

828839
listener.TimeoutClientDataMS, err = serviceInfo.annotationInt(

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