add healthz endpoint

package.json

@@ -14,6 +14,7 @@
     "@digitalbazaar/ed25519-signature-2020": "^5.2.0",
     "@digitalbazaar/ed25519-verification-key-2020": "^4.1.0",
     "@digitalbazaar/vc": "^6.0.1",
+    "axios": "^1.7.2",
     "cookie-parser": "~1.4.4",
     "cors": "^2.8.5",
     "credentials-context": "^2.0.0",

src/TransactionException.js

@@ -0,0 +1,6 @@
+export default function TransactionException(code, message, stack) {
+    this.code = code
+    this.message = message
+    this.stack = stack
+  }
+

src/app.js

@@ -1,7 +1,11 @@
-import express from 'express';
+import express, { request } from 'express';
 import logger from 'morgan';
 import cors from 'cors';
+import axios from 'axios'
 import { initializeTransactionManager, setupExchange, retrieveStoredData, getVPR } from './transactionManager.js';
+import { getDataForExchangeSetupPost } from './test-fixtures/testData.js';
+import { getSignedDIDAuth } from './didAuth.js';
+import TransactionException from './TransactionException.js';
 
 export async function build(opts = {}) {
 
@@ -18,6 +22,37 @@ export async function build(opts = {}) {
         res.send({ message: 'transaction-service server status: ok.' })
     });
 
+    app.get('/healthz', async function (req, res) {
+
+        const baseURL = `${req.protocol}://${req.headers.host}`
+        const testData = getDataForExchangeSetupPost('test', baseURL)
+        const exchangeURL = `${baseURL}/exchange`
+        try {
+            const response = await axios.post(
+                exchangeURL,
+                testData
+            )
+            const { data: walletQuerys } = response
+            const walletQuery = walletQuerys.find(q => q.retrievalId === 'someId')
+            const parsedDeepLink = new URL(walletQuery.directDeepLink)
+            const requestURI = parsedDeepLink.searchParams.get('vc_request_url');
+            const challenge = parsedDeepLink.searchParams.get('challenge');
+            const didAuth = await getSignedDIDAuth('did:ex:223234', challenge)
+            const { data } = await axios.post(requestURI, didAuth)
+            const { tenantName, vc: unSignedVC } = data
+            if (!tenantName === 'test' || ! unSignedVC.name === "A Simply Wonderful Course") {
+                throw new TransactionException(503, 'transaction-service healthz failed')
+            }
+        } catch (e) {
+            console.log(`exception in healthz: ${JSON.stringify(e)}`)
+            return res.status(503).json({
+                error: `transaction-service healthz check failed with error: ${e}`,
+                healthy: false
+            })
+        }
+        res.send({ message: 'transaction-service server status: ok.', healthy: true })
+    })
+
     /*
     This is step 1 in an exchange.
     Creates a new exchange and stores the provided data
@@ -31,7 +66,7 @@ export async function build(opts = {}) {
         async (req, res) => {
             try {
                 const data = req.body;
-                if (!data || !Object.keys(data).length) return res.status(400).send({code: 400, message: 'No data was provided in the body.'})
+                if (!data || !Object.keys(data).length) return res.status(400).send({ code: 400, message: 'No data was provided in the body.' })
                 const walletQuerys = await setupExchange(data)
                 return res.json(walletQuerys)
             } catch (error) {
@@ -40,13 +75,13 @@ export async function build(opts = {}) {
             }
         })
 
-   /*
-    This is step 2 in an exchange, where the wallet
-    has asked to initiate the exchange, and we reply
-    here with a Verifiable Presentation Request, asking
-    for a DIDAuth. Note that in some scenarios the wallet
-    may skip this step and directly present the DIDAuth.
-   */
+    /*
+     This is step 2 in an exchange, where the wallet
+     has asked to initiate the exchange, and we reply
+     here with a Verifiable Presentation Request, asking
+     for a DIDAuth. Note that in some scenarios the wallet
+     may skip this step and directly present the DIDAuth.
+    */
     app.post("/exchange/:exchangeId",
         async (req, res) => {
             try {
@@ -58,12 +93,12 @@ export async function build(opts = {}) {
             }
         })
 
-     /*
-    This is step 3 in an exchange, where we verify the
-    supplied DIDAuth, and if verified we return the previously 
-    stored data for the exchange.
-    */
-    app.post("/exchange/:exchangeId/:transactionId", 
+    /*
+   This is step 3 in an exchange, where we verify the
+   supplied DIDAuth, and if verified we return the previously 
+   stored data for the exchange.
+   */
+    app.post("/exchange/:exchangeId/:transactionId",
         async (req, res) => {
             try {
                 const didAuth = req.body

src/app.test.js

@@ -50,12 +50,22 @@ describe('api', () => {
       expect(response.body.length).to.eql(testData.data.length)
     })
 
-
-
-
   })
 
+  describe('GET /healthz', () => {
+
+    it.only('returns 200 if running', async () => {
+
+      const response = await request(app)
+        .get("/healthz")
+
+      expect(response.header["content-type"]).to.have.string("json");
+      expect(response.status).to.eql(200);
+      expect(response.body).to.eql({ message: 'transaction-service server status: ok.', healthy: true })
+
+    })
 
+  })
 
 })
 

src/didAuth.js

@@ -1,12 +1,33 @@
-import {verify} from '@digitalbazaar/vc';
+import {signPresentation, createPresentation, verify} from '@digitalbazaar/vc';
+import {Ed25519VerificationKey2020} from '@digitalbazaar/ed25519-verification-key-2020';
 import {Ed25519Signature2020} from '@digitalbazaar/ed25519-signature-2020';
 import { securityLoader } from './securityLoader.js';
 
 const documentLoader = securityLoader().build()
-const suite = new Ed25519Signature2020();
+
+const signingKeyPairForTesting = await Ed25519VerificationKey2020.generate(
+    {
+        seed: new Uint8Array ([
+            217,  87, 166,  30,  75, 106, 132,  55,
+             32, 120, 171,  23, 116,  73, 254,  74,
+            230,  16, 127,  91,   2, 252, 224,  96,
+            184, 172, 245, 157,  58, 217,  91, 240
+          ]), 
+        controller: "did:key:z6MkvL5yVCgPhYvQwSoSRQou6k6ZGfD5mNM57HKxufEXwfnP"
+    }
+)
+const suiteForSigning = new Ed25519Signature2020({key: signingKeyPairForTesting});
+const suiteForVerification = new Ed25519Signature2020();
 
+export const getSignedDIDAuth = async (holder = 'did:ex:12345', challenge) => {
+    const presentation = createPresentation({holder});
+    return await signPresentation({
+        presentation, suite: suiteForSigning, challenge, documentLoader
+    });
+}
+
 export const verifyDIDAuth = async ({presentation, challenge}) => {
-    const result = await verify({presentation, challenge, suite, documentLoader});
+    const result = await verify({presentation, challenge, suite: suiteForVerification, documentLoader});
     return result.verified
 }
 

src/test-fixtures/testData.js

@@ -1,9 +1,9 @@
 import testVC from './testVC.js';
 
-const getDataForExchangeSetupPost = (tenantName) => {
+const getDataForExchangeSetupPost = (tenantName, exchangeHost = 'http://localhost:4005') => {
   const fakeData = {
     tenantName,
-    exchangeHost: 'http://localhost:4005',
+    exchangeHost,
     data: [
       { vc: testVC, retrievalId: 'someId',  },
       { vc: testVC, retrievalId: 'blah' }