feat(api): show a user pool's Lambda triggers

packages/api/src/adapter-aws/AwsUserPoolsAdapter.test.ts

@@ -125,9 +125,31 @@ describe('AwsUserPoolsAdapter', () => {
             mfaConfiguration: 'OFF',
             deletionProtection: 'INACTIVE',
             appClients: [{clientId: 'a8e5c7d38d3b4a1a97c9d822de', clientName: 'orders-users-client'}],
+            lambdaTriggers: [],
         })
     })
 
+    test('lists the pool\'s Lambda triggers in sign-in order, with the trigger version when set', async () => {
+        const arn = (name: string) => `arn:aws:lambda:us-east-1:000000000000:function:${name}`
+        const {client} = stubCognito((command) => {
+            if (command instanceof DescribeUserPoolCommand) return {UserPool: {...pool, LambdaConfig: {
+                PreTokenGeneration: arn('claims'),
+                PreTokenGenerationConfig: {LambdaArn: arn('claims'), LambdaVersion: 'V2_0'},
+                PreSignUp: `${arn('signup')}:live`,
+                CustomEmailSender: {LambdaArn: arn('mailer'), LambdaVersion: 'V1_0'},
+                KMSKeyID: 'arn:aws:kms:us-east-1:000000000000:key/1',
+            }}}
+            return {}
+        })
+
+        const resource = await new AwsUserPoolsAdapter(client).get(POOL_ID)
+        expect(resource?.metadata.lambdaTriggers).toEqual([
+            {trigger: 'PreSignUp', label: 'Pre sign-up', functionArn: `${arn('signup')}:live`, functionName: 'signup', version: null},
+            {trigger: 'PreTokenGeneration', label: 'Pre token generation', functionArn: arn('claims'), functionName: 'claims', version: 'V2_0'},
+            {trigger: 'CustomEmailSender', label: 'Custom email sender', functionArn: arn('mailer'), functionName: 'mailer', version: 'V1_0'},
+        ])
+    })
+
     test('counts users itself, since the runtime leaves EstimatedNumberOfUsers at 0', async () => {
         const {client} = stubCognito((command) => {
             if (command instanceof DescribeUserPoolCommand) return {UserPool: {...pool, EstimatedNumberOfUsers: 0}}

packages/api/src/adapter-aws/AwsUserPoolsAdapter.ts

@@ -460,10 +460,43 @@ function toResource(pool: UserPoolType, clients: UserPoolClientDescription[], us
             mfaConfiguration: pool.MfaConfiguration ?? null,
             deletionProtection: pool.DeletionProtection ?? null,
             appClients: clients.map((client) => ({clientId: client.ClientId ?? '', clientName: client.ClientName ?? ''})),
+            lambdaTriggers: lambdaTriggersOf(pool.LambdaConfig),
         },
     }
 }
 
+// Labels as the AWS console names them, in the order a sign-up and sign-in reach them.
+const LAMBDA_TRIGGERS = [
+    ['PreSignUp', 'Pre sign-up'],
+    ['UserMigration', 'User migration'],
+    ['CustomMessage', 'Custom message'],
+    ['PostConfirmation', 'Post confirmation'],
+    ['PreAuthentication', 'Pre authentication'],
+    ['DefineAuthChallenge', 'Define auth challenge'],
+    ['CreateAuthChallenge', 'Create auth challenge'],
+    ['VerifyAuthChallengeResponse', 'Verify auth challenge response'],
+    ['PostAuthentication', 'Post authentication'],
+    ['PreTokenGeneration', 'Pre token generation'],
+    ['CustomEmailSender', 'Custom email sender'],
+    ['CustomSMSSender', 'Custom SMS sender'],
+] as const
+
+type LambdaTrigger = {trigger: string; label: string; functionArn: string; functionName: string; version: string | null}
+
+function lambdaTriggersOf(config: UserPoolType['LambdaConfig']): LambdaTrigger[] {
+    if (!config) return []
+    return LAMBDA_TRIGGERS.flatMap(([trigger, label]) => {
+        // PreTokenGenerationConfig carries the trigger version and supersedes the older PreTokenGeneration field.
+        const versioned = trigger === 'PreTokenGeneration' ? config.PreTokenGenerationConfig
+            : trigger === 'CustomEmailSender' ? config.CustomEmailSender
+                : trigger === 'CustomSMSSender' ? config.CustomSMSSender
+                    : undefined
+        const functionArn = versioned?.LambdaArn ?? config[trigger]
+        if (typeof functionArn !== 'string' || !functionArn) return []
+        return [{trigger, label, functionArn, functionName: functionArn.split(':')[6] ?? functionArn, version: versioned?.LambdaVersion ?? null}]
+    })
+}
+
 function toUserItem(
     username: string | undefined,
     attributes: AttributeType[] | undefined,

packages/frontend/src/components/CognitoTriggersSection.tsx

@@ -0,0 +1,31 @@
+import {ScrollText, Zap} from 'lucide-react'
+import type {CloudResource} from '@/types/resource'
+
+type LambdaTrigger = {trigger: string; label: string; functionArn: string; functionName: string; version: string | null}
+
+export function CognitoTriggersSection({pool}: {pool?: CloudResource}) {
+    const triggers = triggersOf(pool)
+    return <>
+        <div className="input-row resource-table-bar">
+            <div><p className="eyebrow">Lambda triggers</p><span className="muted">Functions Cognito runs during sign-up, sign-in and token issue</span></div>
+        </div>
+        {pool && triggers.length === 0 && <p className="muted padded">This pool runs no Lambda triggers.</p>}
+        {triggers.length > 0 && <div className="cognito-table"><table className="table"><thead><tr><th>Trigger</th><th>Function</th><th>Version</th><th/></tr></thead><tbody>{triggers.map((trigger) => (
+            <tr key={trigger.trigger}>
+                <td>{trigger.label}</td>
+                <td><code title={trigger.functionArn}>{trigger.functionName}</code></td>
+                <td>{trigger.version ? <code>{trigger.version}</code> : '—'}</td>
+                <td className="cognito-row-actions">
+                    <a className="button" href={`/cloud-explorer/aws/serverless?resource=${encodeURIComponent(trigger.functionName)}`} aria-label={`Open function ${trigger.functionName}`}><Zap size={13}/> Function</a>
+                    <a className="button" href={`/cloud-explorer/aws/logs?resource=${encodeURIComponent(`/aws/lambda/${trigger.functionName}`)}`} aria-label={`Open logs for ${trigger.functionName}`}><ScrollText size={13}/> Logs</a>
+                </td>
+            </tr>
+        ))}</tbody></table></div>}
+    </>
+}
+
+function triggersOf(pool?: CloudResource): LambdaTrigger[] {
+    const triggers = pool?.metadata.lambdaTriggers
+    if (!Array.isArray(triggers)) return []
+    return triggers.filter((trigger): trigger is LambdaTrigger => typeof trigger?.functionName === 'string' && typeof trigger?.label === 'string')
+}

packages/frontend/src/components/CognitoUsersPanel.test.tsx

@@ -64,6 +64,24 @@ test('shows the app client id and the pool users', async () => {
     expect(api.getCloudResource).toHaveBeenCalledWith('aws', 'userpools', summary.id, expect.anything())
 })
 
+test('lists the pool\'s Lambda triggers with links to the function and its logs', async () => {
+    api.getCloudResource.mockResolvedValue({...pool('email'), metadata: {...pool('email').metadata, lambdaTriggers: [
+        {trigger: 'PreTokenGeneration', label: 'Pre token generation', functionArn: 'arn:aws:lambda:us-east-1:000000000000:function:notes-demo-pre-token', functionName: 'notes-demo-pre-token', version: null},
+    ]}})
+    renderPanel()
+
+    expect(await screen.findByText('Pre token generation')).toBeInTheDocument()
+    expect(screen.getByRole('link', {name: 'Open function notes-demo-pre-token'})).toHaveAttribute('href', '/cloud-explorer/aws/serverless?resource=notes-demo-pre-token')
+    expect(screen.getByRole('link', {name: 'Open logs for notes-demo-pre-token'})).toHaveAttribute('href', '/cloud-explorer/aws/logs?resource=%2Faws%2Flambda%2Fnotes-demo-pre-token')
+})
+
+test('says when a pool has no Lambda triggers', async () => {
+    api.getCloudResource.mockResolvedValue(pool('email'))
+    renderPanel()
+
+    expect(await screen.findByText('This pool runs no Lambda triggers.')).toBeInTheDocument()
+})
+
 test('creates an email user who can sign in immediately', async () => {
     const user = userEvent.setup()
     api.getCloudResource.mockResolvedValue(pool('email'))

packages/frontend/src/components/CognitoUsersPanel.tsx

@@ -4,6 +4,7 @@ import {useEffect, useState} from 'react'
 import {deleteFlatItem, getCloudResource, listFlatItems, listUserPoolGroups, putFlatItem} from '@/api/cloudProxyClient'
 import {CognitoGroupsSection} from '@/components/CognitoGroupsSection'
 import {CognitoSignInTest} from '@/components/CognitoSignInTest'
+import {CognitoTriggersSection} from '@/components/CognitoTriggersSection'
 import {CognitoUserDetail} from '@/components/CognitoUserDetail'
 import {CopyValueButton} from '@/components/CopyValueButton'
 import {useAccountId} from '@/lib/accountStore'
@@ -97,6 +98,8 @@ export function CognitoUsersPanel({resource, runtimeReachable}: Props) {
             <tr key={client.clientId}><td>{client.clientName || '—'}</td><td><span className="copy-value mono">{client.clientId}<CopyValueButton value={client.clientId} label="Client ID"/></span></td></tr>
         ))}</tbody></table></div>}
 
+        <CognitoTriggersSection pool={poolQuery.data ?? undefined}/>
+
         <CognitoSignInTest poolId={resource.id} appClients={appClients} loginLabel={loginLabel} runtimeReachable={runtimeReachable}/>
 
         <CognitoGroupsSection poolId={resource.id} groupsQuery={groupsQuery} groupsKey={groupsKey} runtimeReachable={runtimeReachable}/>