feat: add support for retry strategies (#830)

packages/cli/src/constructs/check-group.ts

@@ -14,6 +14,7 @@ import { ApiCheckDefaultConfig } from './api-check'
 import { pathToPosix } from '../services/util'
 import type { Region } from '..'
 import type { Frequency } from './frequency'
+import type { RetryStrategy } from './retry-strategy'
 
 const defaultApiCheckDefaults: ApiCheckDefaultConfig = {
   headers: [],
@@ -93,6 +94,10 @@ export interface CheckGroupProps {
    */
   localTearDownScript?: string
   apiCheckDefaults?: ApiCheckDefaultConfig
+  /**
+   * Sets a retry policy for the group. Use RetryStrategyBuilder to create a retry policy.
+   */
+  retryStrategy?: RetryStrategy
 }
 
 /**
@@ -119,6 +124,7 @@ export class CheckGroup extends Construct {
   localTearDownScript?: string
   apiCheckDefaults: ApiCheckDefaultConfig
   browserChecks?: BrowserCheckConfig
+  retryStrategy?: RetryStrategy
 
   static readonly __checklyType = 'check-group'
 
@@ -156,6 +162,7 @@ export class CheckGroup extends Construct {
     this.alertChannels = props.alertChannels ?? []
     this.localSetupScript = props.localSetupScript
     this.localTearDownScript = props.localTearDownScript
+    this.retryStrategy = props.retryStrategy
     // `browserChecks` is not a CheckGroup resource property. Not present in synthesize()
     this.browserChecks = props.browserChecks
     const fileAbsolutePath = Session.checkFileAbsolutePath!
@@ -247,6 +254,7 @@ export class CheckGroup extends Construct {
       localTearDownScript: this.localTearDownScript,
       apiCheckDefaults: this.apiCheckDefaults,
       environmentVariables: this.environmentVariables,
+      retryStrategy: this.retryStrategy,
     }
   }
 }

packages/cli/src/constructs/check.ts

@@ -10,6 +10,7 @@ import type { Region } from '..'
 import type { CheckGroup } from './check-group'
 import { PrivateLocation } from './private-location'
 import { PrivateLocationCheckAssignment } from './private-location-check-assignment'
+import { RetryStrategy } from './retry-strategy'
 
 export interface CheckProps {
   /**
@@ -80,6 +81,10 @@ export interface CheckProps {
    * Determines if the check is available only when 'test' runs (not included when 'deploy' is executed).
    */
   testOnly?: boolean
+  /**
+   * Sets a retry policy for the check. Use RetryStrategyBuilder to create a retry policy.
+   */
+  retryStrategy?: RetryStrategy
 }
 
 // This is an abstract class. It shouldn't be used directly.
@@ -99,6 +104,7 @@ export abstract class Check extends Construct {
   groupId?: Ref
   alertChannels?: Array<AlertChannel>
   testOnly?: boolean
+  retryStrategy?: RetryStrategy
   __checkFilePath?: string // internal variable to filter by check file name from the CLI
 
   static readonly __checklyType = 'check'
@@ -134,6 +140,7 @@ export abstract class Check extends Construct {
     // alertSettings, useGlobalAlertSettings, groupId, groupOrder
 
     this.testOnly = props.testOnly ?? false
+    this.retryStrategy = props.retryStrategy
     this.__checkFilePath = Session.checkFilePath
   }
 
@@ -209,6 +216,7 @@ export abstract class Check extends Construct {
       frequencyOffset: this.frequencyOffset,
       groupId: this.groupId,
       environmentVariables: this.environmentVariables,
+      retryStrategy: this.retryStrategy,
     }
   }
 }

packages/cli/src/constructs/index.ts

@@ -22,3 +22,4 @@ export * from './private-location-group-assignment'
 export * from './check'
 export * from './dashboard'
 export * from './phone-call-alert-channel'
+export * from './retry-strategy'

packages/cli/src/constructs/retry-strategy.ts

@@ -0,0 +1,67 @@
+export type RetryStrategyType = 'LINEAR' | 'EXPONENTIAL' | 'FIXED'
+
+export interface RetryStrategy {
+  type: RetryStrategyType,
+  /**
+  * The number of seconds to wait before the first retry attempt.
+  */
+  baseBackoffSeconds?: number,
+  /**
+  * The maximum number of attempts to retry the check. Value must be between 1 and 10.
+  */
+  maxAttempts?: number,
+  /**
+  * The total amount of time to continue retrying the check (maximum 600 seconds).
+  */
+  maxDurationSeconds?: number,
+  /**
+  * Whether retries should be run in the same region as the initial check run.
+  */
+  sameRegion?: boolean,
+}
+
+export type RetryStrategyOptions = Pick<RetryStrategy, 'baseBackoffSeconds' | 'maxAttempts' | 'maxDurationSeconds' | 'sameRegion'>
+
+export class RetryStrategyBuilder {
+  private static readonly DEFAULT_BASE_BACKOFF_SECONDS = 60
+  private static readonly DEFAULT_MAX_ATTEMPTS = 2
+  private static readonly DEFAULT_MAX_DURATION_SECONDS = 60 * 10
+  private static readonly DEFAULT_SAME_REGION = false
+
+  /**
+   * Each retry is run with the same backoff between attempts.
+   */
+  static fixedStrategy (options: RetryStrategyOptions): RetryStrategy {
+    return RetryStrategyBuilder.retryStrategy('FIXED', options)
+  }
+
+  /**
+   * The delay between retries increases linearly
+   *
+   * The delay between retries is calculated using `baseBackoffSeconds * attempt`.
+   * For example, retries will be run with a backoff of 10s, 20s, 30s, and so on.
+   */
+  static linearStrategy (options: RetryStrategyOptions): RetryStrategy {
+    return RetryStrategyBuilder.retryStrategy('LINEAR', options)
+  }
+
+  /**
+   * The delay between retries increases exponentially
+   *
+   * The delay between retries is calculated using `baseBackoffSeconds ^ attempt`.
+   * For example, retries will be run with a backoff of 10s, 100s, 1000s, and so on.
+   */
+  static exponentialStrategy (options: RetryStrategyOptions): RetryStrategy {
+    return RetryStrategyBuilder.retryStrategy('EXPONENTIAL', options)
+  }
+
+  private static retryStrategy (type: RetryStrategyType, options: RetryStrategyOptions): RetryStrategy {
+    return {
+      type,
+      baseBackoffSeconds: options.baseBackoffSeconds ?? RetryStrategyBuilder.DEFAULT_BASE_BACKOFF_SECONDS,
+      maxAttempts: options.maxAttempts ?? RetryStrategyBuilder.DEFAULT_MAX_ATTEMPTS,
+      maxDurationSeconds: options.maxDurationSeconds ?? RetryStrategyBuilder.DEFAULT_MAX_DURATION_SECONDS,
+      sameRegion: options.sameRegion ?? RetryStrategyBuilder.DEFAULT_SAME_REGION,
+    }
+  }
+}