Merge pull request #207 from lmorchard/more-exception-handling

Add more try/catch blocks in processQueueItem for more granular errors

functions/processQueueItem.js

@@ -132,6 +132,20 @@ exports.handleOne = async function(event, context) {
 
   log.info("processing", { id });
 
+  const handleError = async (err, logType, extra = {}, isDone = true) => {
+    Raven.captureException(err);
+    metricsPing.is_error = true;
+    log.error(logType, Object.assign({ err }, extra));
+    return isDone ? done() : Promise.resolve();
+  };
+
+  const done = async () => {
+    const metricsResult = await Metrics.workerWorks(metricsPing);
+    log.verbose("metricsResult", { metricsResult });
+    return id;
+  };
+
+  // Step #1: Handle rate limiting and pause if necessary
   try {
     // Pause if we're at the rate limit for current expiration window
     let rateLimited = false;
@@ -168,7 +182,13 @@ exports.handleOne = async function(event, context) {
       .promise();
 
     log.verbose("hitRatePutResult", { hitRatePutResult });
+  } catch (err) {
+    return handleError(err, "hitRateError");
+  }
 
+  // Step #2: Make a request to the upstream service
+  let upstreamServiceResponse, IsMatch;
+  try {
     const imageUrl = S3.getSignedUrl("getObject", {
       Bucket,
       Key: image,
@@ -180,7 +200,7 @@ exports.handleOne = async function(event, context) {
     metricsPing.timing_sent = Date.now() - Date.parse(datestamp);
 
     const timingReceivedStart = Date.now();
-    const upstreamServiceResponse = await request.post({
+    upstreamServiceResponse = await request.post({
       url: `${upstreamServiceUrl}?enhance`,
       headers: {
         "Content-Type": "application/json",
@@ -195,20 +215,29 @@ exports.handleOne = async function(event, context) {
     metricsPing.timing_received = Date.now() - timingReceivedStart;
     metricsPing.photodna_tracking_id = upstreamServiceResponse.TrackingId;
 
-    log.verbose("upstreamServiceResponse", { upstreamServiceResponse });
-
-    const { IsMatch } = upstreamServiceResponse;
+    ({ IsMatch } = upstreamServiceResponse);
     metricsPing.is_match = IsMatch;
 
-    if (!IsMatch) {
-      // On negative match, clean up the image and request details.
+    log.verbose("upstreamServiceResponse", { upstreamServiceResponse });
+  } catch (err) {
+    return handleError(err, "upstreamServiceError");
+  }
+
+  // Step #3: Handle the response from the upstream service
+  if (!IsMatch) {
+    try {
+      // Step #3a: On negative match, clean up the image and request details.
       const deleteResult = await Promise.all([
         S3.deleteObject({ Bucket, Key: `${image}` }).promise(),
         S3.deleteObject({ Bucket, Key: `${image}-request.json` }).promise(),
       ]);
       log.verbose("deleteResult", { deleteResult });
-    } else {
-      // On positive match, store the details of the match response.
+    } catch (err) {
+      return handleError(err, "deleteError");
+    }
+  } else {
+    try {
+      // Step #3b: On positive match, store the details of the match response.
       const putResult = await S3.putObject({
         Bucket,
         Key: `${image}-response.json`,
@@ -226,8 +255,14 @@ exports.handleOne = async function(event, context) {
       }).promise();
 
       log.verbose("putResult", { putResult });
+    } catch (err) {
+      return handleError(err, "putError");
+    }
+  }
 
-      // Send an email alert on positive match, if addresses are available.
+  // Step #4: Send an email alert on positive match.
+  if (IsMatch) {
+    try {
       const ToAddresses = [];
       if (positive_email) {
         ToAddresses.push(positive_email);
@@ -291,15 +326,22 @@ exports.handleOne = async function(event, context) {
         log.verbose("emailResult", { emailResult });
         log.info("sentEmail", { messageId: emailResult.MessageId });
       }
+    } catch (err) {
+      // Do not bail out on an error from email, we can still send a callback
+      await handleError(err, "emailError", {}, false);
     }
+  }
 
+  // Step #5: Send a callback request to the client service
+  const callbackUrl = IsMatch ? positive_uri : negative_uri;
+  try {
     const timingSubmittedStart = Date.now();
     const upstreamIsError =
       !upstreamServiceResponse ||
       !upstreamServiceResponse.Status ||
       upstreamServiceResponse.Status.Code !== 3000;
     const callbackResult = await request.post({
-      url: IsMatch ? positive_uri : negative_uri,
+      url: callbackUrl,
       headers: {
         "Content-Type": "application/json",
       },
@@ -315,13 +357,8 @@ exports.handleOne = async function(event, context) {
     metricsPing.timing_submitted = Date.now() - timingSubmittedStart;
     log.verbose("callbackResult", { callbackResult });
   } catch (err) {
-    Raven.captureException(err);
-    metricsPing.is_error = true;
-    log.error("callbackError", { err });
-    throw err;
+    return handleError(err, "callbackError", { callbackUrl });
   }
 
-  const metricsResult = await Metrics.workerWorks(metricsPing);
-  log.verbose("metricsResult", { metricsResult });
-  return id;
+  return done();
 };