feat(elbv2): Supports new types of listener rule conditions

packages/@aws-cdk/aws-elasticloadbalancingv2/README.md

@@ -64,16 +64,17 @@ updated to allow the network traffic.
 #### Conditions
 
 It's possible to route traffic to targets based on conditions in the incoming
-HTTP request. Path- and host-based conditions are supported. For example, the
-following will route requests to the indicated AutoScalingGroup only if the
-requested host in the request is either for `example.com/ok` or
-`example.com/path`:
+HTTP request. For example, the following will route requests to the indicated
+AutoScalingGroup only if the requested host in the request is either for
+`example.com/ok` or `example.com/path`:
 
 ```ts
 listener.addTargets('Example.Com Fleet', {
   priority: 10,
-  pathPatterns: ['/ok', '/path'],
-  hostHeader: 'example.com',
+  conditions: [
+    ListenerCondition.hostHeaders(['example.com']),
+    ListenerCondition.pathPatterns(['/ok', '/path']),
+  ],
   port: 8080,
   targets: [asg]
 });
@@ -126,8 +127,10 @@ Here's an example of serving a fixed response at the `/ok` URL:
 
 ```ts
 listener.addAction('Fixed', {
-  pathPatterns: ['/ok'],
   priority: 10,
+  conditions: [
+    ListenerCondition.pathPatterns(['/ok']),
+  ],
   action: ListenerAction.fixedResponse(200, {
     contentType: elbv2.ContentType.TEXT_PLAIN,
     messageBody: 'OK',

packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener-rule.ts

@@ -4,6 +4,7 @@ import { IListenerAction } from '../shared/listener-action';
 import { IApplicationListener } from './application-listener';
 import { ListenerAction } from './application-listener-action';
 import { IApplicationTargetGroup } from './application-target-group';
+import { ListenerCondition } from './conditions';
 
 /**
  * Basic properties for defining a rule on a listener
@@ -58,6 +59,15 @@ export interface BaseApplicationListenerRuleProps {
    */
   readonly redirectResponse?: RedirectResponse;
 
+  /**
+   * Rule applies if matches the conditions.
+   *
+   * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html
+   *
+   * @default - No conditions.
+   */
+  readonly conditions?: ListenerCondition[];
+
   /**
    * Rule applies if the requested host matches the indicated host
    *
@@ -66,6 +76,7 @@ export interface BaseApplicationListenerRuleProps {
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#host-conditions
    *
    * @default - No host condition.
+   * @deprecated Use `conditions` instead.
    */
   readonly hostHeader?: string;
 
@@ -74,7 +85,7 @@ export interface BaseApplicationListenerRuleProps {
    *
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#path-conditions
    * @default - No path condition.
-   * @deprecated Use `pathPatterns` instead.
+   * @deprecated Use `conditions` instead.
    */
   readonly pathPattern?: string;
 
@@ -85,6 +96,7 @@ export interface BaseApplicationListenerRuleProps {
    *
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#path-conditions
    * @default - No path conditions.
+   * @deprecated Use `conditions` instead.
    */
   readonly pathPatterns?: string[];
 }
@@ -187,17 +199,20 @@ export class ApplicationListenerRule extends cdk.Construct {
    */
   public readonly listenerRuleArn: string;
 
-  private readonly conditions: {[key: string]: string[] | undefined} = {};
+  private readonly conditions: ListenerCondition[];
+  private readonly legacyConditions: {[key: string]: string[]} = {};
 
   private readonly listener: IApplicationListener;
   private action?: IListenerAction;
 
   constructor(scope: cdk.Construct, id: string, props: ApplicationListenerRuleProps) {
     super(scope, id);
 
+    this.conditions = props.conditions || [];
+
     const hasPathPatterns = props.pathPatterns || props.pathPattern;
-    if (!props.hostHeader && !hasPathPatterns) {
-      throw new Error('At least one of \'hostHeader\', \'pathPattern\' or \'pathPatterns\' is required when defining a load balancing rule.');
+    if (this.conditions.length === 0 && !props.hostHeader && !hasPathPatterns) {
+      throw new Error('At least one of \'conditions\', \'hostHeader\', \'pathPattern\' or \'pathPatterns\' is required when defining a load balancing rule.');
     }
 
     const possibleActions: Array<keyof ApplicationListenerRuleProps> = ['action', 'targetGroups', 'fixedResponse', 'redirectResponse'];
@@ -248,9 +263,25 @@ export class ApplicationListenerRule extends cdk.Construct {
 
   /**
    * Add a non-standard condition to this rule
+   *
+   * If the condition conflicts with an already set condition, it will be overwritten by the one you specified.
+   *
+   * @deprecated use `addCondition` instead.
    */
   public setCondition(field: string, values: string[] | undefined) {
-    this.conditions[field] = values;
+    if (values === undefined) {
+      delete this.legacyConditions[field];
+      return;
+    }
+
+    this.legacyConditions[field] = values;
+  }
+
+  /**
+   * Add a non-standard condition to this rule
+   */
+  public addCondition(condition: ListenerCondition) {
+    this.conditions.push(condition);
   }
 
   /**
@@ -322,20 +353,28 @@ export class ApplicationListenerRule extends cdk.Construct {
     if (this.action === undefined) {
       return ['Listener rule needs at least one action'];
     }
+
+    const legacyConditionFields = Object.keys(this.legacyConditions);
+    if (legacyConditionFields.length === 0 && this.conditions.length === 0) {
+      return ['Listener rule needs at least one condition'];
+    }
+
     return [];
   }
 
   /**
    * Render the conditions for this rule
    */
-  private renderConditions() {
-    const ret = new Array<{ field: string, values: string[] }>();
-    for (const [field, values] of Object.entries(this.conditions)) {
-      if (values !== undefined) {
-        ret.push({ field, values });
-      }
-    }
-    return ret;
+  private renderConditions(): any {
+    const legacyConditions = Object.entries(this.legacyConditions).map(([field, values]) => {
+      return { field, values };
+    });
+    const conditions = this.conditions.map(condition => condition.renderRawCondition());
+
+    return [
+      ...legacyConditions,
+      ...conditions,
+    ];
   }
 }
 

packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-listener.ts

@@ -10,6 +10,7 @@ import { ApplicationListenerCertificate } from './application-listener-certifica
 import { ApplicationListenerRule, FixedResponse, RedirectResponse, validateFixedResponse, validateRedirectResponse } from './application-listener-rule';
 import { IApplicationLoadBalancer } from './application-load-balancer';
 import { ApplicationTargetGroup, IApplicationLoadBalancerTarget, IApplicationTargetGroup } from './application-target-group';
+import { ListenerCondition } from './conditions';
 
 /**
  * Basic properties for an ApplicationListener
@@ -274,6 +275,7 @@ export class ApplicationListener extends BaseListener implements IApplicationLis
       // TargetGroup.registerListener is called inside ApplicationListenerRule.
       new ApplicationListenerRule(this, id + 'Rule', {
         listener: this,
+        conditions: props.conditions,
         hostHeader: props.hostHeader,
         pathPattern: props.pathPattern,
         pathPatterns: props.pathPatterns,
@@ -319,6 +321,7 @@ export class ApplicationListener extends BaseListener implements IApplicationLis
     });
 
     this.addTargetGroups(id, {
+      conditions: props.conditions,
       hostHeader: props.hostHeader,
       pathPattern: props.pathPattern,
       pathPatterns: props.pathPatterns,
@@ -618,6 +621,15 @@ export interface AddRuleProps {
    */
   readonly priority?: number;
 
+  /**
+   * Rule applies if matches the conditions.
+   *
+   * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html
+   *
+   * @default - No conditions.
+   */
+  readonly conditions?: ListenerCondition[];
+
   /**
    * Rule applies if the requested host matches the indicated host
    *
@@ -628,6 +640,7 @@ export interface AddRuleProps {
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#host-conditions
    *
    * @default No host condition
+   * @deprecated Use `conditions` instead.
    */
   readonly hostHeader?: string;
 
@@ -640,7 +653,7 @@ export interface AddRuleProps {
    *
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#path-conditions
    * @default No path condition
-   * @deprecated Use `pathPatterns` instead.
+   * @deprecated Use `conditions` instead.
    */
   readonly pathPattern?: string;
 
@@ -653,6 +666,7 @@ export interface AddRuleProps {
    *
    * @see https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#path-conditions
    * @default - No path condition.
+   * @deprecated Use `conditions` instead.
    */
   readonly pathPatterns?: string[];
 }
@@ -770,7 +784,11 @@ export interface AddRedirectResponseProps extends AddRuleProps, RedirectResponse
 }
 
 function checkAddRuleProps(props: AddRuleProps) {
-  if ((props.hostHeader !== undefined || props.pathPattern !== undefined || props.pathPatterns !== undefined) !== (props.priority !== undefined)) {
-    throw new Error('Setting \'pathPattern\' or \'hostHeader\' also requires \'priority\', and vice versa');
+  const conditionsCount = props.conditions?.length || 0;
+  const hasAnyConditions = conditionsCount !== 0 ||
+    props.hostHeader !== undefined || props.pathPattern !== undefined || props.pathPatterns !== undefined;
+  const hasPriority = props.priority !== undefined;
+  if (hasAnyConditions !== hasPriority) {
+    throw new Error('Setting \'conditions\', \'pathPattern\' or \'hostHeader\' also requires \'priority\', and vice versa');
   }
 }