fix: allow Lambda function config overrides without Lambda: property

README.md

@@ -440,10 +440,9 @@ functions:
       dashboard:
         enabled: false    # No Lambda widgets will be created for this function
       alarms:
-        Lambda:
-          Invocations:
-            Threshold: 2  # The invocation threshold is specific to
-                          # this function's expected invocation count
+        Invocations:
+          Threshold: 2  # The invocation threshold is specific to
+                        # this function's expected invocation count
 ```
 
 To disable all alarms for any given function, use:
@@ -454,8 +453,7 @@ functions:
     handler: basic-handler.hello
     slicWatch:
       alarms:
-        Lambda:
-          enabled: false
+        enabled: false
 ```
 
 #### SAM/CloudFormation function-level configuration
@@ -468,9 +466,8 @@ Resources:
     Metadata:
       slicWatch:
         alarms:
-          Lambda:
-            Invocations:
-              Threshold: 3
+          Invocations:
+            Threshold: 3
         dashboard:
           enabled: true
 ```
@@ -486,8 +483,7 @@ Resources:
     Metadata:
       slicWatch:
         alarms:
-          Lambda:
-            enabled: false
+          enabled: false
 ```
 
 #### CDK function-level configuration
@@ -497,10 +493,8 @@ const cfnFuncHello = hello.node.defaultChild as CfnResource;
 cfnFuncHello.cfnOptions.metadata = {
   slicWatch: {
     alarms: {
-      Lambda: {
-        Invocations: {
-          Threshold: 2
-        }
+      Invocations: {
+        Threshold: 2
       }
     }
   }

core/alarms/lambda.ts

@@ -18,9 +18,9 @@ export type SlicWatchLambdaAlarmsConfig<T extends InputOutput> = T & {
 const lambdaMetrics = ['Errors', 'ThrottlesPc', 'DurationPc', 'Invocations']
 
 /**
- * Add all required Lambda alarms to the provided CloudFormation templatebased on the Lambda resources found within
+ * Add all required Lambda alarms to the provided CloudFormation template based on the Lambda resources found within
  *
- * @param functionAlarmPropertiess The cascaded Lambda alarm configuration with function-specific overrides by function logical ID
+ * @param lambdaAlarmConfig Lambda-specific alarm configuration
  * @param alarmActionsConfig Notification configuration for alarm status change events
  * @compiledTemplate  CloudFormation template object
  *

core/cf-template.ts

@@ -9,7 +9,7 @@ import { cascade } from './inputs/cascading-config'
 import { type SlicWatchMergedConfig } from './alarms/alarm-types'
 import { type WidgetMetricProperties } from './dashboards/dashboard-types'
 import { defaultConfig } from './inputs/default-config'
-import { type ConfigType, cfTypeByConfigType } from './inputs/config-types'
+import { ConfigType, cfTypeByConfigType } from './inputs/config-types'
 
 const logger = getLogger()
 
@@ -69,7 +69,13 @@ export function getResourceAlarmConfigurationsByType<M extends SlicWatchMergedCo
   const alarmConfigurations: Record<string, M> = {}
   const resources = getResourcesByType(cfTypeByConfigType[type], template)
   for (const [funcLogicalId, resource] of Object.entries(resources)) {
-    const resourceConfig = resource?.Metadata?.slicWatch?.alarms // Resource-specific overrides
+    let legacyFallbackResourceConfig
+    if (type === ConfigType.Lambda) {
+      // Older versions only allowed function resource overrides and required the `Lambda` property within the config object
+      // If this is still present in configuration, we take it from here
+      legacyFallbackResourceConfig = resource?.Metadata?.slicWatch?.alarms?.Lambda
+    }
+    const resourceConfig = legacyFallbackResourceConfig ?? resource?.Metadata?.slicWatch?.alarms // Resource-specific overrides
     const defaultResourceConfig = defaultConfig.alarms?.[type] // Default configuration for the type's alarms
     // Cascade the default resource's configuration into the resource-specific overrides
     const cascadedResourceConfig = resourceConfig !== undefined ? cascade(merge({}, defaultResourceConfig, resourceConfig)) : {}
@@ -97,7 +103,13 @@ export function getResourceDashboardConfigurationsByType<T extends WidgetMetricP
   const dashConfigurations: Record<string, T> = {}
   const resources = getResourcesByType(cfTypeByConfigType[type], template)
   for (const [logicalId, resource] of Object.entries(resources)) {
-    const resourceConfig = resource?.Metadata?.slicWatch?.dashboard // Resource-specific overrides
+    let legacyFallbackResourceConfig
+    if (type === ConfigType.Lambda) {
+      // Older versions only allowed function resource overrides and required the `Lambda` property within the config object
+      // If this is still present in configuration, we take it from here
+      legacyFallbackResourceConfig = resource?.Metadata?.slicWatch?.dashboard?.Lambda
+    }
+    const resourceConfig = legacyFallbackResourceConfig ?? resource?.Metadata?.slicWatch?.dashboard // Resource-specific overrides
     const defaultResourceConfig = defaultConfig.dashboard?.widgets?.[type] // Default configuration for the widget
     // Cascade the default resource's configuration into the resource-specific overrides
     const cascadedResourceConfig = resourceConfig !== undefined ? cascade(merge({}, defaultResourceConfig, resourceConfig)) : {}

serverless-plugin/serverless-plugin.ts

@@ -42,8 +42,8 @@ class ServerlessPlugin {
   }
 
   /**
-     * Modify the CloudFormation template before the package is finalized
-     */
+   * Modify the CloudFormation template before the package is finalized
+   */
   createSlicWatchResources () {
     const slicWatchConfig: SlicWatchConfig = this.serverless.service.custom?.slicWatch ?? {}
 
@@ -65,6 +65,7 @@ class ServerlessPlugin {
       // CloudFormation Metadata on the generate AWS::Lambda::Function resource
       const allFunctions = this.serverless.service.getAllFunctions() as string[]
       this.serverless.cli.log(`Setting SLIC Watch configuration for ${allFunctions}`)
+
       for (const funcName of allFunctions) {
         const func = this.serverless.service.getFunction(funcName) as any
         const funcConfig = func.slicWatch ?? {}

serverless-plugin/tests/index.test.ts

@@ -1,10 +1,14 @@
 import { test } from 'tap'
 import _ from 'lodash'
 import ServerlessError from 'serverless/lib/serverless-error'
+import type Template from 'cloudform-types/types/template'
 
 import ServerlessPlugin from '../serverless-plugin'
 import { getLogger } from 'slic-watch-core/logging'
-import { createMockServerless, dummyLogger, pluginUtils, slsYaml } from '../../test-utils/sls-test-utils'
+import { type SlsYaml, createMockServerless, dummyLogger, pluginUtils, slsYaml } from '../../test-utils/sls-test-utils'
+import { type ResourceType } from 'slic-watch-core'
+import { getDashboardFromTemplate, getDashboardWidgetsByTitle } from 'slic-watch-core/tests/testing-utils'
+import { type MetricWidgetProperties } from 'cloudwatch-dashboard-types'
 
 interface TestData {
   schema?
@@ -48,6 +52,134 @@ test('index', t => {
     t.end()
   })
 
+  t.test('function-level overrides in serverless `functions` block take precedence', t => {
+    const compiledTemplate: Template = {
+      Resources: {
+        HelloLambdaFunction: {
+          Type: 'AWS::Lambda::Function',
+          Properties: {
+            FunctionName: 'serverless-test-project-dev-hello'
+          }
+        }
+      }
+    }
+    const slsConfig: SlsYaml = {
+      custom: {
+        slicWatch: {
+          alarms: {
+            Lambda: {
+              Invocations: {
+                enabled: true,
+                Threshold: 10
+              }
+            }
+          },
+          dashboard: {
+            widgets: {
+              Lambda: {
+                Invocations: {
+                  yAxis: 'left'
+                }
+              }
+            }
+          }
+        }
+      },
+      functions: {
+        hello: {
+          slicWatch: {
+            enabled: true
+          }
+        }
+      }
+    }
+
+    t.test('Plugin succeeds without function-level overrides', t => {
+      const sls = createMockServerless(compiledTemplate, slsConfig)
+      const plugin = new ServerlessPlugin(sls, null, pluginUtils)
+      plugin.createSlicWatchResources()
+      const invocationAlarmProperties = (compiledTemplate.Resources as ResourceType).slicWatchLambdaInvocationsAlarmHelloLambdaFunction.Properties
+      t.equal(invocationAlarmProperties?.Threshold, 10)
+
+      const { dashboard } = getDashboardFromTemplate(compiledTemplate)
+      const widgets = getDashboardWidgetsByTitle(dashboard, /Lambda Invocations/)
+      t.equal(widgets.length, 1)
+      t.match((widgets[0].properties as MetricWidgetProperties).metrics, [
+        ['AWS/Lambda', 'Invocations', 'FunctionName', '${HelloLambdaFunction}', { stat: 'Sum', yAxis: 'left' }]
+      ])
+
+      t.end()
+    })
+
+    t.test('Plugin succeeds with function-level overrides', t => {
+      const modifiedSlsConfig = _.cloneDeep(slsConfig)
+      Object.assign(modifiedSlsConfig.functions.hello.slicWatch, {
+        alarms: {
+          Invocations: {
+            Threshold: 3,
+            enabled: true
+          }
+        },
+        dashboard: {
+          Invocations: {
+            yAxis: 'right'
+          }
+        }
+      })
+
+      const sls = createMockServerless(compiledTemplate, modifiedSlsConfig)
+      const plugin = new ServerlessPlugin(sls, null, pluginUtils)
+      plugin.createSlicWatchResources()
+      const invocationAlarmProperties = (compiledTemplate.Resources as ResourceType).slicWatchLambdaInvocationsAlarmHelloLambdaFunction.Properties
+      t.equal(invocationAlarmProperties?.Threshold, 3)
+
+      const { dashboard } = getDashboardFromTemplate(compiledTemplate)
+      const widgets = getDashboardWidgetsByTitle(dashboard, /Lambda Invocations/)
+      t.equal(widgets.length, 1)
+      t.match((widgets[0].properties as MetricWidgetProperties).metrics, [
+        ['AWS/Lambda', 'Invocations', 'FunctionName', '${HelloLambdaFunction}', { stat: 'Sum', yAxis: 'right' }]
+      ])
+      t.end()
+    })
+
+    t.test('Plugin succeeds with legacy function-level overrides', t => {
+      const modifiedSlsConfig = _.cloneDeep(slsConfig)
+      Object.assign(modifiedSlsConfig.functions.hello.slicWatch, {
+        alarms: {
+          Lambda: { // This extra property is the 'legacy' configuration bit
+            Invocations: {
+              Threshold: 4,
+              enabled: true
+            }
+          }
+        },
+        dashboard: {
+          Lambda: { // This extra property is the 'legacy' configuration bit
+            Invocations: {
+              yAxis: 'right'
+            }
+          }
+        }
+      })
+
+      const sls = createMockServerless(compiledTemplate, modifiedSlsConfig)
+      const plugin = new ServerlessPlugin(sls, null, pluginUtils)
+      plugin.createSlicWatchResources()
+      const invocationAlarmProperties = (compiledTemplate.Resources as ResourceType).slicWatchLambdaInvocationsAlarmHelloLambdaFunction.Properties
+      t.equal(invocationAlarmProperties?.Threshold, 4)
+
+      const { dashboard } = getDashboardFromTemplate(compiledTemplate)
+      const widgets = getDashboardWidgetsByTitle(dashboard, /Lambda Invocations/)
+      t.equal(widgets.length, 1)
+      t.match((widgets[0].properties as MetricWidgetProperties).metrics, [
+        ['AWS/Lambda', 'Invocations', 'FunctionName', '${HelloLambdaFunction}', { stat: 'Sum', yAxis: 'right' }]
+      ])
+      t.end()
+    })
+
+    t.end()
+  })
+
   t.test('Plugin succeeds with no custom section', t => {
     const plugin = new ServerlessPlugin({
       ...mockServerless,

test-utils/sls-test-utils.ts

@@ -46,12 +46,7 @@ export function createMockServerless (compiledTemplate: Template, slsConfig = sl
         name: 'aws',
         compiledCloudFormationTemplate: compiledTemplate
       },
-      custom: {
-        slicWatch: {
-          enabled: true,
-          topicArn: 'test-topic'
-        }
-      },
+      custom: slsConfig.custom,
       getAllFunctions: () => Object.keys(slsConfig.functions ?? {}),
       getFunction: (funcRef) => slsConfig.functions[funcRef]
     }