istio

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// Copyright Istio Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package helmreconciler
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import (
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	"io"
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	"strings"
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	"istio.io/istio/operator/pkg/name"
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	"istio.io/istio/pkg/log"
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)
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const (
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	// MetadataNamespace is the namespace for mesh metadata (labels, annotations)
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	MetadataNamespace = "install.operator.istio.io"
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	// OwningResourceName represents the name of the owner to which the resource relates
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	OwningResourceName = MetadataNamespace + "/owning-resource"
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	// OwningResourceNamespace represents the namespace of the owner to which the resource relates
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	OwningResourceNamespace = MetadataNamespace + "/owning-resource-namespace"
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	// OwningResourceNotPruned indicates that the resource should not be pruned during reconciliation cycles,
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	// note this will not prevent the resource from being deleted if the owning resource is deleted.
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	OwningResourceNotPruned = MetadataNamespace + "/owning-resource-not-pruned"
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	// operatorLabelStr indicates Istio operator is managing this resource.
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	operatorLabelStr = name.OperatorAPINamespace + "/managed"
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	// operatorReconcileStr indicates that the operator will reconcile the resource.
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	operatorReconcileStr = "Reconcile"
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	// IstioComponentLabelStr indicates which Istio component a resource belongs to.
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	IstioComponentLabelStr = name.OperatorAPINamespace + "/component"
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	// istioVersionLabelStr indicates the Istio version of the installation.
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	istioVersionLabelStr = name.OperatorAPINamespace + "/version"
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)
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var (
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	// TestMode sets the controller into test mode. Used for unit tests to bypass things like waiting on resources.
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	TestMode = false
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	scope = log.RegisterScope("installer", "installer")
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)
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func init() {
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	// Tree representation and wait channels are an inversion of ComponentDependencies and are constructed from it.
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	buildInstallTree()
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}
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// ComponentTree represents a tree of component dependencies.
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type (
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	ComponentTree          map[name.ComponentName]any
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	componentNameToListMap map[name.ComponentName][]name.ComponentName
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)
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var (
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	// ComponentDependencies is a tree of component dependencies. The semantics are ComponentDependencies[cname] gives
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	// the subtree of components that must wait for cname to be installed before starting installation themselves.
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	ComponentDependencies = componentNameToListMap{
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		name.PilotComponentName: {
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			name.CNIComponentName,
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			name.IngressComponentName,
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			name.EgressComponentName,
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		},
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		name.IstioBaseComponentName: {
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			name.PilotComponentName,
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		},
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		name.CNIComponentName: {
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			name.ZtunnelComponentName,
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		},
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	}
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	// InstallTree is a top down hierarchy tree of dependencies where children must wait for the parent to complete
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	// before starting installation.
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	InstallTree = make(ComponentTree)
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)
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// buildInstallTree builds a tree from buildInstallTree where parents are the root of each subtree.
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func buildInstallTree() {
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	// Starting with root, recursively insert each first level child into each node.
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	insertChildrenRecursive(name.IstioBaseComponentName, InstallTree, ComponentDependencies)
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}
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func insertChildrenRecursive(componentName name.ComponentName, tree ComponentTree, children componentNameToListMap) {
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	tree[componentName] = make(ComponentTree)
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	for _, child := range children[componentName] {
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		insertChildrenRecursive(child, tree[componentName].(ComponentTree), children)
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	}
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}
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// InstallTreeString returns a string representation of the dependency tree.
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func InstallTreeString() string {
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	var sb strings.Builder
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	buildInstallTreeString(name.IstioBaseComponentName, "", &sb)
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	return sb.String()
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}
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func buildInstallTreeString(componentName name.ComponentName, prefix string, sb io.StringWriter) {
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	_, _ = sb.WriteString(prefix + string(componentName) + "\n")
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	if _, ok := InstallTree[componentName].(ComponentTree); !ok {
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		return
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	}
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	for k := range InstallTree[componentName].(ComponentTree) {
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		buildInstallTreeString(k, prefix+"  ", sb)
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	}
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}
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