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Sync Pod host ports back to GameServer in GCP (#2782)
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This is the start of the implementation for #2777:

* Most of this is mechanical and implements a thin cloud product
abstraction layer in pkg/cloud, instantiated with New(product). The
product abstraction provides a single function so far:
SyncPodPortsToGameServer.

* SyncPodPortsToGameServer is inserted as a hook while syncing
IP/ports, to let different cloud providers handle port allocation
slightly differently (in this case, GKE Autopilot)

* In GKE Autopilot, we look for a JSON string like
`{"min":7000,"max":8000,"portsAssigned":{"7001":7737,"7002":7738}}`
as an indication that the host ports were reassigned (per policy).
As a side note to anyone watching, this is currently an unreleased
feature. If we see this, we use the provided mapping to map the
host ports in the GameServer.Spec.

With this change, it's possible to launch a GameServer and get a
healthy GameServer Pod by adding the following annotation:

```
annotations:
  cluster-autoscaler.kubernetes.io/safe-to-evict: "true"
  autopilot.gke.io/host-port-assignment: '{"min": 7000, "max": 8000}'
```

If this PR causes any issues, the cloud product auto detection can
be disabled by setting `agones.cloudProduct=generic`, or forced to
GKE Autopilot using `agones.cloudProduct=gke-autopilot`.

In a future PR, I will add the host-port-assignment annotation
automatically on Autopilot

Co-authored-by: Mark Mandel <[email protected]>
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zmerlynn and markmandel authored Nov 3, 2022
1 parent 352617b commit 3c38876
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Showing 18 changed files with 448 additions and 30 deletions.
17 changes: 14 additions & 3 deletions cmd/controller/main.go
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,7 @@ import (
agonesv1 "agones.dev/agones/pkg/apis/agones/v1"
"agones.dev/agones/pkg/client/clientset/versioned"
"agones.dev/agones/pkg/client/informers/externalversions"
"agones.dev/agones/pkg/cloudproduct"
"agones.dev/agones/pkg/fleetautoscalers"
"agones.dev/agones/pkg/fleets"
"agones.dev/agones/pkg/gameserverallocations"
Expand Down Expand Up @@ -78,6 +79,7 @@ const (
logSizeLimitMBFlag = "log-size-limit-mb"
kubeconfigFlag = "kubeconfig"
allocationBatchWaitTime = "allocation-batch-wait-time"
cloudProductFlag = "cloud-product"
defaultResync = 30 * time.Second
)

Expand Down Expand Up @@ -105,6 +107,7 @@ func setupLogging(logDir string, logSizeLimitMB int) {

// main starts the operator for the gameserver CRD
func main() {
ctx := signals.NewSigKillContext()
ctlConf := parseEnvFlags()

if ctlConf.LogDir != "" {
Expand Down Expand Up @@ -154,6 +157,11 @@ func main() {
logger.WithError(err).Fatal("Could not create the agones api clientset")
}

cloudProduct, err := cloudproduct.New(ctx, ctlConf.CloudProduct, kubeClient)
if err != nil {
logger.WithError(err).Fatal("Could not initialize cloud provider")
}

// https server and the items that share the Mux for routing
httpsServer := https.NewServer(ctlConf.CertFile, ctlConf.KeyFile)
wh := webhooks.NewWebHook(httpsServer.Mux)
Expand Down Expand Up @@ -207,7 +215,7 @@ func main() {
ctlConf.MinPort, ctlConf.MaxPort, ctlConf.SidecarImage, ctlConf.AlwaysPullSidecar,
ctlConf.SidecarCPURequest, ctlConf.SidecarCPULimit,
ctlConf.SidecarMemoryRequest, ctlConf.SidecarMemoryLimit, ctlConf.SdkServiceAccount,
kubeClient, kubeInformerFactory, extClient, agonesClient, agonesInformerFactory)
kubeClient, kubeInformerFactory, extClient, agonesClient, agonesInformerFactory, cloudProduct)
gsSetController := gameserversets.NewController(wh, health, gsCounter,
kubeClient, extClient, agonesClient, agonesInformerFactory)
fleetController := fleets.NewController(wh, health, kubeClient, extClient, agonesClient, agonesInformerFactory)
Expand All @@ -219,8 +227,6 @@ func main() {
rs = append(rs,
httpsServer, gsCounter, gsController, gsSetController, fleetController, fasController, gasController, server)

ctx := signals.NewSigKillContext()

kubeInformerFactory.Start(ctx.Done())
agonesInformerFactory.Start(ctx.Done())

Expand Down Expand Up @@ -264,6 +270,7 @@ func parseEnvFlags() config {
viper.SetDefault(logDirFlag, "")
viper.SetDefault(logLevelFlag, "Info")
viper.SetDefault(logSizeLimitMBFlag, 10000) // 10 GB, will be split into 100 MB chunks
viper.SetDefault(cloudProductFlag, cloudproduct.AutoDetect)

pflag.String(sidecarImageFlag, viper.GetString(sidecarImageFlag), "Flag to overwrite the GameServer sidecar image that is used. Can also use SIDECAR env variable")
pflag.String(sidecarCPULimitFlag, viper.GetString(sidecarCPULimitFlag), "Flag to overwrite the GameServer sidecar container's cpu limit. Can also use SIDECAR_CPU_LIMIT env variable")
Expand All @@ -288,6 +295,7 @@ func parseEnvFlags() config {
pflag.Int32(logSizeLimitMBFlag, 1000, "Log file size limit in MB")
pflag.String(logLevelFlag, viper.GetString(logLevelFlag), "Agones Log level")
pflag.Duration(allocationBatchWaitTime, viper.GetDuration(allocationBatchWaitTime), "Flag to configure the waiting period between allocations batches")
pflag.String(cloudProductFlag, viper.GetString(cloudProductFlag), "Cloud product. Set to 'auto' to auto-detect, set to 'generic' to force generic behavior, set to 'gke-autopilot' for GKE Autopilot. Can also use CLOUD_PRODUCT env variable.")
runtime.FeaturesBindFlags()
pflag.Parse()

Expand Down Expand Up @@ -315,6 +323,7 @@ func parseEnvFlags() config {
runtime.Must(viper.BindEnv(logDirFlag))
runtime.Must(viper.BindEnv(logSizeLimitMBFlag))
runtime.Must(viper.BindEnv(allocationBatchWaitTime))
runtime.Must(viper.BindEnv(cloudProductFlag))
runtime.Must(viper.BindPFlags(pflag.CommandLine))
runtime.Must(runtime.FeaturesBindEnv())

Expand Down Expand Up @@ -364,6 +373,7 @@ func parseEnvFlags() config {
LogSizeLimitMB: int(viper.GetInt32(logSizeLimitMBFlag)),
StackdriverLabels: viper.GetString(stackdriverLabels),
AllocationBatchWaitTime: viper.GetDuration(allocationBatchWaitTime),
CloudProduct: viper.GetString(cloudProductFlag),
}
}

Expand Down Expand Up @@ -392,6 +402,7 @@ type config struct {
LogLevel string
LogSizeLimitMB int
AllocationBatchWaitTime time.Duration
CloudProduct string
}

// validate ensures the ctlConfig data is valid.
Expand Down
2 changes: 2 additions & 0 deletions install/helm/agones/templates/controller.yaml
Original file line number Diff line number Diff line change
Expand Up @@ -115,6 +115,8 @@ spec:
value: {{ .Values.agones.featureGates | quote }}
- name: ALLOCATION_BATCH_WAIT_TIME
value: {{ .Values.agones.controller.allocationBatchWaitTime | quote }}
- name: CLOUD_PRODUCT
value: {{ .Values.agones.cloudProduct | quote }}
{{- if .Values.agones.controller.persistentLogs }}
- name: LOG_DIR
value: "/home/agones/logs"
Expand Down
5 changes: 5 additions & 0 deletions install/helm/agones/templates/serviceaccounts/controller.yaml
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,11 @@ rules:
- apiGroups: [""]
resources: ["nodes", "secrets"]
verbs: ["list", "watch"]
{{- if eq .Values.agones.cloudProduct "auto" }}
- apiGroups: ["admissionregistration.k8s.io"] # only needed for cloudProduct detection
resources: ["mutatingwebhookconfigurations"]
verbs: ["get"]
{{- end}}
- apiGroups: ["apiextensions.k8s.io"]
resources: ["customresourcedefinitions"]
verbs: ["get"]
Expand Down
1 change: 1 addition & 0 deletions install/helm/agones/values.yaml
Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,7 @@ agones:
annotations: {}
createPriorityClass: true
priorityClassName: agones-system
cloudProduct: "auto"
controller:
resources: {}
# requests:
Expand Down
5 changes: 5 additions & 0 deletions install/yaml/install.yaml
Original file line number Diff line number Diff line change
Expand Up @@ -14342,6 +14342,9 @@ rules:
- apiGroups: [""]
resources: ["nodes", "secrets"]
verbs: ["list", "watch"]
- apiGroups: ["admissionregistration.k8s.io"] # only needed for cloudProduct detection
resources: ["mutatingwebhookconfigurations"]
verbs: ["get"]
- apiGroups: ["apiextensions.k8s.io"]
resources: ["customresourcedefinitions"]
verbs: ["get"]
Expand Down Expand Up @@ -14726,6 +14729,8 @@ spec:
value: ""
- name: ALLOCATION_BATCH_WAIT_TIME
value: "500ms"
- name: CLOUD_PRODUCT
value: "auto"
- name: LOG_DIR
value: "/home/agones/logs"
- name: LOG_SIZE_LIMIT_MB
Expand Down
84 changes: 84 additions & 0 deletions pkg/cloudproduct/cloudproduct.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,84 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package cloudproduct

import (
"context"
"fmt"

agonesv1 "agones.dev/agones/pkg/apis/agones/v1"
"agones.dev/agones/pkg/cloudproduct/generic"
"agones.dev/agones/pkg/cloudproduct/gke"
"agones.dev/agones/pkg/util/runtime"
corev1 "k8s.io/api/core/v1"
"k8s.io/client-go/kubernetes"
)

// CloudProduct provides a generic interface that abstracts cloud product
// specific functionality. Users should call New() to instantiate a
// specific cloud product interface.
type CloudProduct interface {
// SyncPodPortsToGameServer runs after a Pod has been assigned to a Node and before we sync
// Pod host ports to the GameServer status.
SyncPodPortsToGameServer(*agonesv1.GameServer, *corev1.Pod) error
}

const (
// If --cloud-product=auto, auto-detect
AutoDetect = "auto"

genericProduct = "generic"
)

var (
logger = runtime.NewLoggerWithSource("cloudproduct")
productDetectors = []func(context.Context, *kubernetes.Clientset) string{gke.Detect}
)

// New instantiates a new CloudProduct interface by product name.
func New(ctx context.Context, product string, kc *kubernetes.Clientset) (CloudProduct, error) {
product = autoDetect(ctx, product, kc)

switch product {
case "gke-autopilot":
return gke.Autopilot()
case genericProduct:
return generic.New()
}
return nil, fmt.Errorf("unknown cloud product: %q", product)
}

func autoDetect(ctx context.Context, product string, kc *kubernetes.Clientset) string {
if product != AutoDetect {
logger.Infof("Cloud product forced to %q, skipping auto-detection", product)
return product
}
for _, detect := range productDetectors {
product = detect(ctx, kc)
if product != "" {
logger.Infof("Cloud product detected as %q", product)
return product
}
}
logger.Infof("Cloud product defaulted to %q", genericProduct)
return genericProduct
}

// MustNewGeneric returns the "generic" cloud product, panicking if an error is encountered.
func MustNewGeneric(ctx context.Context) CloudProduct {
c, err := New(ctx, genericProduct, nil)
runtime.Must(err)
return c
}
16 changes: 16 additions & 0 deletions pkg/cloudproduct/doc.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,16 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package cloudproduct provides an abstraction layer to product specific functionality
package cloudproduct
17 changes: 17 additions & 0 deletions pkg/cloudproduct/generic/doc.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package generic provides the generic cloud provider. The generic cloud provider
// should be usable on all clouds, but provides no special functionality.
package generic
25 changes: 25 additions & 0 deletions pkg/cloudproduct/generic/generic.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package generic

import (
agonesv1 "agones.dev/agones/pkg/apis/agones/v1"
corev1 "k8s.io/api/core/v1"
)

func New() (*generic, error) { return &generic{}, nil }

type generic struct{}

func (*generic) SyncPodPortsToGameServer(*agonesv1.GameServer, *corev1.Pod) error { return nil }
16 changes: 16 additions & 0 deletions pkg/cloudproduct/gke/doc.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,16 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package gke provides the GKE cloud product interfaces for GKE Standard and Autopilot
package gke
84 changes: 84 additions & 0 deletions pkg/cloudproduct/gke/gke.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,84 @@
// Copyright 2022 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package gke

import (
"context"
"encoding/json"

agonesv1 "agones.dev/agones/pkg/apis/agones/v1"
"agones.dev/agones/pkg/util/runtime"
"cloud.google.com/go/compute/metadata"
"github.com/pkg/errors"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
)

const (
workloadDefaulterWebhook = "workload-defaulter.config.common-webhooks.networking.gke.io"
noWorkloadDefaulter = "failed to get MutatingWebhookConfigurations/workload-defaulter.config.common-webhooks.networking.gke.io (error expected if not on GKE Autopilot)"
hostPortAssignmentAnnotation = "autopilot.gke.io/host-port-assignment"
)

var logger = runtime.NewLoggerWithSource("gke")

type gkeAutopilot struct{}

// hostPortAssignment is the JSON structure of the `host-port-assignment` annotation
type hostPortAssignment struct {
Min int32 `json:"min,omitempty"`
Max int32 `json:"max,omitempty"`
PortsAssigned map[int32]int32 `json:"portsAssigned,omitempty"` // old -> new
}

func Detect(ctx context.Context, kc *kubernetes.Clientset) string {
if !metadata.OnGCE() {
return ""
}
// Look for the workload defaulter - this is the current best method to detect Autopilot
if _, err := kc.AdmissionregistrationV1().MutatingWebhookConfigurations().Get(
ctx, workloadDefaulterWebhook, metav1.GetOptions{}); err != nil {
logger.WithError(err).WithField("reason", noWorkloadDefaulter).Info(
"Assuming GKE Standard and defaulting to generic provider")
return "" // GKE standard, but we don't need an interface for it just yet.
}
logger.Info("Running on GKE Autopilot (skip detection with --cloud-product=gke-autopilot)")
return "gke-autopilot"
}

func Autopilot() (*gkeAutopilot, error) { return &gkeAutopilot{}, nil }

func (*gkeAutopilot) SyncPodPortsToGameServer(gs *agonesv1.GameServer, pod *corev1.Pod) error {
// If applyGameServerAddressAndPort has already filled in Status, SyncPodPortsToGameServer
// has already run. Skip syncing from the Pod again - this avoids having to reason
// about whether we're re-applying the old->new mapping.
if len(gs.Status.Ports) == len(gs.Spec.Ports) {
return nil
}
annotation, ok := pod.ObjectMeta.Annotations[hostPortAssignmentAnnotation]
if !ok {
return nil
}
var hpa hostPortAssignment
if err := json.Unmarshal([]byte(annotation), &hpa); err != nil {
return errors.Wrapf(err, "could not unmarshal annotation %s (value %q)", hostPortAssignmentAnnotation, annotation)
}
for i, p := range gs.Spec.Ports {
if newPort, ok := hpa.PortsAssigned[p.HostPort]; ok {
gs.Spec.Ports[i].HostPort = newPort
}
}
return nil
}
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