feat(push-to-gateway): add ability to retry pushing metrics (#9)

* feat(push-to-gateway): add ability to retry pushing metrics

* feat(push-to-gateway): fix review - use a constants file

config/jest.config.json

@@ -0,0 +1,7 @@
+{
+    "verbose": true,
+    "bail": true,
+    "rootDir": "../",
+    "roots": ["<rootDir>/src"],
+    "silent": true
+}

package.json

@@ -4,7 +4,7 @@
   "description": "Github action for compute and monitor of test coverage via jest",
   "main": "index.js",
   "scripts": {
-    "test": "jest src/"
+    "test": "jest src/ --config ./config/jest.config.json"
   },
   "repository": {
     "type": "git",

src/monitor/constants.js

@@ -0,0 +1,4 @@
+module.exports = {
+    MAX_ATTEMPTS: 5,
+    RETRY_DELAY: 1000, // ms
+}

src/monitor/push-metrics-for-folder.js

@@ -11,6 +11,7 @@
 
 const path = require("path")
 
+const { MAX_ATTEMPTS, RETRY_DELAY } = require('./constants')
 const { getMetricsList } = require('./metrics-list.js')
 const { formatMetricPayload } = require('./format-metric-payload.js')
 const { pushToGateway } = require('./push-to-pushgateway.js')
@@ -36,14 +37,27 @@ const pushMetricsForFolder = ({ coverageArtifactsPath, folderName, jobName, push
     const metricsPayload = getMetricsList(testStats, coverageStats)
         .reduce((metricsAsText, metric) => metricsAsText + formatMetricPayload(metric), "")
 
-    // Sent metrics to Prometheus
-    pushToGateway(`${pushGatewayUri}/metrics/job/${jobName}/folder_name/${folderName}`, metricsPayload, (err, data) => {
-        if (err) {
-            throw new Error(err.message)
-        }
+    // Sent metrics to Prometheus - try MAX_ATTEMPTS times
+    const pushAttempt = (attemptsCount) => {
+        console.log(`Push metrics attempt #${attemptsCount}...`)
+        pushToGateway(`${pushGatewayUri}/metrics/job/${jobName}/folder_name/${folderName}`, metricsPayload, (err, data) => {
+            if (err) {
+                if (attemptsCount < MAX_ATTEMPTS) {
+                    console.error("Failed to push metrics:", err.message, ` - will retry in ${RETRY_DELAY}ms...`)
+                    // Wait and retry
+                    setTimeout(() => pushAttempt(attemptsCount + 1), RETRY_DELAY)
+                }
+                else {
+                    throw err
+                }
+            }
+            else {
+                console.log("Done -", data.body)
+            }
+        })
+    }
 
-        console.log("Done -", data.body)
-    })
+    pushAttempt(0)
 }
 
 // If script is used from command-line as standalone

src/monitor/push-metrics-for-folder.spec.js

@@ -1,5 +1,6 @@
 const path = require("path")
 const fs = require("fs")
+const { MAX_ATTEMPTS } = require('./constants')
 const { pushToGateway } = require('./push-to-pushgateway.js')
 const { pushMetricsForFolder } = require("./push-metrics-for-folder")
 
@@ -52,4 +53,26 @@ describe("pushMetricsForFolder", () => {
         expect(lastMockCallArgs[0]).toEqual(`http://pushgateway/metrics/job/test-jobname/folder_name/${FOLDERNAME}`)
         expect(lastMockCallArgs[1]).toEqual("{\"foo\":\"bar\"}")
     })
+
+    it(`should attempt ${MAX_ATTEMPTS} times to push metrics before failing`, () => {
+        jest.useFakeTimers()
+
+        let attemptsCount = 0
+        const pushToGatewayMock = jest.fn((url, payload, callback) => {
+            callback(new Error("Test error."))
+            attemptsCount++
+            jest.runAllTimers()
+        })
+        pushToGateway.mockImplementation(pushToGatewayMock)
+
+        expect(() => {
+            pushMetricsForFolder({
+                coverageArtifactsPath: ".",
+                folderName: FOLDERNAME,
+                jobName: "test-jobname",
+                pushGatewayUri: "http://pushgateway",
+            })
+        }).toThrow(/Test error/)
+        expect(attemptsCount).toEqual(MAX_ATTEMPTS)
+    })
 })