Merge pull request #418 from klihub/devel/agent-runtime-configuration

[podresapi 1/3] agent,config,helm: make agent runtime configurable.

config/crd/bases/config.nri_balloonspolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: BalloonsPolicySpec describes a balloons policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               allocatorTopologyBalancing:
                 description: |-
                   If AllocatorTopologyBalancing is true, balloons are

config/crd/bases/config.nri_templatepolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: TemplatePolicySpec describes a template policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               availableResources:
                 additionalProperties:
                   type: string

config/crd/bases/config.nri_topologyawarepolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: TopologyAwarePolicySpec describes a topology-aware policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               availableResources:
                 additionalProperties:
                   type: string

deployment/helm/balloons/crds/config.nri_balloonspolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: BalloonsPolicySpec describes a balloons policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               allocatorTopologyBalancing:
                 description: |-
                   If AllocatorTopologyBalancing is true, balloons are

deployment/helm/template/crds/config.nri_templatepolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: TemplatePolicySpec describes a template policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               availableResources:
                 additionalProperties:
                   type: string

deployment/helm/topology-aware/crds/config.nri_topologyawarepolicies.yaml

@@ -40,6 +40,18 @@ spec:
           spec:
             description: TopologyAwarePolicySpec describes a topology-aware policy.
             properties:
+              agent:
+                default:
+                  nodeResourceTopology: true
+                description: AgentConfig provides access to configuration data for
+                  the agent.
+                properties:
+                  nodeResourceTopology:
+                    description: |-
+                      NodeResourceTopology enables support for exporting resource usage using
+                      NodeResourceTopology Custom Resources.
+                    type: boolean
+                type: object
               availableResources:
                 additionalProperties:
                   type: string

pkg/agent/agent.go

@@ -268,37 +268,39 @@ func (a *Agent) hasLocalConfig() bool {
 
 func (a *Agent) setupClients() error {
 	if a.hasLocalConfig() {
+		log.Warn("running with local configuration, skipping cluster access client setup...")
 		return nil
 	}
 
-	cfg, err := a.getRESTConfig()
-	if err != nil {
-		return err
-	}
+	// Create HTTP/REST client and K8s client on initial startup. Any failure
+	// to create these is a failure start up.
+	if a.httpCli == nil {
+		log.Info("setting up HTTP/REST client...")
+		restCfg, err := a.getRESTConfig()
+		if err != nil {
+			return err
+		}
 
-	a.httpCli, err = rest.HTTPClientFor(cfg)
-	if err != nil {
-		return fmt.Errorf("failed to setup kubernetes HTTP client: %w", err)
-	}
+		a.httpCli, err = rest.HTTPClientFor(restCfg)
+		if err != nil {
+			return fmt.Errorf("failed to setup kubernetes HTTP client: %w", err)
+		}
 
-	a.k8sCli, err = k8sclient.NewForConfigAndClient(cfg, a.httpCli)
-	if err != nil {
-		a.cleanupClients()
-		return fmt.Errorf("failed to setup kubernetes client: %w", err)
-	}
+		log.Info("setting up K8s client...")
+		a.k8sCli, err = k8sclient.NewForConfigAndClient(restCfg, a.httpCli)
+		if err != nil {
+			a.cleanupClients()
+			return fmt.Errorf("failed to setup kubernetes client: %w", err)
+		}
 
-	restCfg := *cfg
-	a.nrtCli, err = nrtapi.NewForConfigAndClient(&restCfg, a.httpCli)
-	if err != nil {
-		a.cleanupClients()
-		return fmt.Errorf("failed to setup NRT client: %w", err)
+		kubeCfg := *restCfg
+		err = a.cfgIf.SetKubeClient(a.httpCli, &kubeCfg)
+		if err != nil {
+			return fmt.Errorf("failed to setup kubernetes config resource client: %w", err)
+		}
 	}
 
-	restCfg = *cfg
-	err = a.cfgIf.SetKubeClient(a.httpCli, &restCfg)
-	if err != nil {
-		return fmt.Errorf("failed to setup kubernetes config resource client: %w", err)
-	}
+	a.configure(a.currentCfg)
 
 	return nil
 }
@@ -312,6 +314,51 @@ func (a *Agent) cleanupClients() {
 	a.nrtCli = nil
 }
 
+var (
+	defaultConfig = &cfgapi.AgentConfig{
+		NodeResourceTopology: true,
+	}
+)
+
+func getAgentConfig(newConfig metav1.Object) *cfgapi.AgentConfig {
+	cfg := cfgapi.GetAgentConfig(newConfig)
+	if cfg == nil {
+		return defaultConfig
+	}
+	return cfg
+}
+
+func (a *Agent) configure(newConfig metav1.Object) {
+	if a.hasLocalConfig() {
+		log.Warn("running with local configuration, skipping client setup...")
+		return
+	}
+
+	cfg := getAgentConfig(newConfig)
+
+	// Reconfigure NRT client, both on initial startup and reconfiguration.
+	// Failure to create a client is not a fatal error.
+	switch {
+	case cfg.NodeResourceTopology && a.nrtCli == nil:
+		log.Info("enabling NRT client")
+		cfg, err := a.getRESTConfig()
+		if err != nil {
+			log.Error("failed to setup NRT client: %w", err)
+			break
+		}
+		cli, err := nrtapi.NewForConfigAndClient(cfg, a.httpCli)
+		if err != nil {
+			log.Error("failed to setup NRT client: %w", err)
+			break
+		}
+		a.nrtCli = cli
+
+	case !cfg.NodeResourceTopology && a.nrtCli != nil:
+		log.Info("disabling NRT client")
+		a.nrtCli = nil
+	}
+}
+
 func (a *Agent) getRESTConfig() (*rest.Config, error) {
 	var (
 		cfg *rest.Config
@@ -556,6 +603,7 @@ func (a *Agent) updateConfig(cfg metav1.Object) {
 	}
 
 	a.currentCfg = cfg
+	a.configure(cfg)
 }
 
 func (a *Agent) patchConfigStatus(prev, curr metav1.Object, errors error) {

pkg/apis/config/v1alpha1/agent.go

@@ -0,0 +1,31 @@
+// Copyright The NRI Plugins Authors. 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 v1alpha1
+
+// AgentConfig provides access to configuration data for the agent.
+type AgentConfig struct {
+	// NodeResourceTopology enables support for exporting resource usage using
+	// NodeResourceTopology Custom Resources.
+	// +optional
+	NodeResourceTopology bool `json:"nodeResourceTopology,omitempty"`
+}
+
+// GetAgentConfig returns the agent-specific configuration if we have one.
+func GetAgentConfig(cfg interface{}) *AgentConfig {
+	if ac, ok := cfg.(interface{ AgentConfig() *AgentConfig }); ok {
+		return ac.AgentConfig()
+	}
+	return nil
+}

pkg/apis/config/v1alpha1/balloons-policy.go

@@ -18,6 +18,16 @@ var (
 	_ ResmgrConfig = &BalloonsPolicy{}
 )
 
+func (c *BalloonsPolicy) AgentConfig() *AgentConfig {
+	if c == nil {
+		return nil
+	}
+
+	a := c.Spec.Agent
+
+	return &a
+}
+
 func (c *BalloonsPolicy) CommonConfig() *CommonConfig {
 	if c == nil {
 		return nil

pkg/apis/config/v1alpha1/resmgr.go

@@ -29,6 +29,7 @@ import (
 // +kubebuilder:object:generate=false
 type ResmgrConfig interface {
 	metav1.ObjectMetaAccessor
+	AgentConfig() *AgentConfig
 	CommonConfig() *CommonConfig
 	PolicyConfig() interface{}
 }

pkg/apis/config/v1alpha1/template-policy.go

@@ -18,6 +18,16 @@ var (
 	_ ResmgrConfig = &TemplatePolicy{}
 )
 
+func (c *TemplatePolicy) AgentConfig() *AgentConfig {
+	if c == nil {
+		return nil
+	}
+
+	a := c.Spec.Agent
+
+	return &a
+}
+
 func (c *TemplatePolicy) CommonConfig() *CommonConfig {
 	if c == nil {
 		return nil

pkg/apis/config/v1alpha1/topology-aware-policy.go

@@ -18,6 +18,16 @@ var (
 	_ ResmgrConfig = &TopologyAwarePolicy{}
 )
 
+func (c *TopologyAwarePolicy) AgentConfig() *AgentConfig {
+	if c == nil {
+		return nil
+	}
+
+	a := c.Spec.Agent
+
+	return &a
+}
+
 func (c *TopologyAwarePolicy) CommonConfig() *CommonConfig {
 	if c == nil {
 		return nil

pkg/apis/config/v1alpha1/types.go

@@ -46,6 +46,9 @@ type TopologyAwarePolicySpec struct {
 	Log log.Config `json:"log,omitempty"`
 	// +optional
 	Instrumentation instrumentation.Config `json:"instrumentation,omitempty"`
+	// +optional
+	// +kubebuilder:default={"nodeResourceTopology": true }
+	Agent AgentConfig `json:"agent,omitempty"`
 }
 
 // TopologyAwarePolicyList represents a list of TopologyAwarePolicies.
@@ -78,6 +81,9 @@ type BalloonsPolicySpec struct {
 	Log log.Config `json:"log,omitempty"`
 	// +optional
 	Instrumentation instrumentation.Config `json:"instrumentation,omitempty"`
+	// +optional
+	// +kubebuilder:default={"nodeResourceTopology": true }
+	Agent AgentConfig `json:"agent,omitempty"`
 }
 
 // BalloonsPolicyList represents a list of BalloonsPolicies.
@@ -110,6 +116,9 @@ type TemplatePolicySpec struct {
 	Log log.Config `json:"log,omitempty"`
 	// +optional
 	Instrumentation instrumentation.Config `json:"instrumentation,omitempty"`
+	// +optional
+	// +kubebuilder:default={"nodeResourceTopology": true }
+	Agent AgentConfig `json:"agent,omitempty"`
 }
 
 // TemplatePolicyList represents a list of TemplatePolicies.