use expires header rather than last-modified and a small code tidy

serverless-nextjs · Apr 29, 2021 · fc8bd38 · jvarho · Apr 29, 2021 · kirkness
1 parent 6f1ce93
commit fc8bd38
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Showing 8 changed files with 212 additions and 82 deletions.
diff --git a/packages/libs/lambda-at-edge/src/default-handler.ts b/packages/libs/lambda-at-edge/src/default-handler.ts
@@ -44,6 +44,9 @@ import {
   getLocalePrefixFromUri
 } from "./routing/locale-utils";
 import { removeBlacklistedHeaders } from "./headers/removeBlacklistedHeaders";
+import { getStaticRegenerationResponse } from "./lib/getStaticRegenerationResponse";
+import { s3BucketNameFromEventRequest } from "./s3/s3BucketNameFromEventRequest";
+import { triggerStaticRegeneration } from "./lib/triggerStaticRegeneration";
 
 const basePath = RoutesManifestJson.basePath;
 
@@ -590,7 +593,6 @@ const handleOriginRequest = async ({
 const handleOriginResponse = async ({
   event,
   manifest,
-  prerenderManifest,
   routesManifest
 }: {
   event: OriginResponseEvent;
@@ -602,8 +604,7 @@ const handleOriginResponse = async ({
   const request = event.Records[0].cf.request;
   const { uri } = request;
   const { status } = response;
-  const { region, domainName } = request.origin?.s3 || {};
-  const bucketName = domainName?.replace(`.s3.${region}.amazonaws.com`, "");
+  const bucketName = s3BucketNameFromEventRequest(request);
 
   if (status !== "403") {
     // Set 404 status code for 404.html page. We do not need normalised URI as it will always be "/404.html"
@@ -613,83 +614,32 @@ const handleOriginResponse = async ({
       return response;
     }
 
-    const initialRevalidateSeconds =
-      manifest.pages.ssg.nonDynamic?.[uri.replace(".html", "")]
-        ?.initialRevalidateSeconds;
-    const lastModifiedHeaderString =
-      response.headers?.["last-modified"]?.[0]?.value;
-    const lastModifiedAt = lastModifiedHeaderString
-      ? new Date(lastModifiedHeaderString)
-      : null;
-    if (typeof initialRevalidateSeconds === "number" && lastModifiedAt) {
-      /**
-       * TODO: Refactor to use the returned `Expired` header.
-       */
-      const createdAgo =
-        (Date.now() - (lastModifiedAt.getTime() || Date.now())) / 1000;
-
-      const timeToRevalidate = Math.floor(
-        initialRevalidateSeconds - createdAgo
-      );
+    const staticRegenerationResponse = getStaticRegenerationResponse({
+      requestedOriginUri: uri,
+      expiresHeader: response.headers.expires?.[0]?.value || "",
+      manifest
+    });
 
+    if (staticRegenerationResponse) {
       response.headers["cache-control"] = [
         {
           key: "Cache-Control",
-          value:
-            timeToRevalidate < 0
-              ? "public, max-age=0, s-maxage=0, must-revalidate"
-              : `public, max-age=0, s-maxage=${timeToRevalidate}, must-revalidate`
+          value: staticRegenerationResponse.cacheControl
         }
       ];
 
-      if (timeToRevalidate < 0) {
-        const { SQSClient, SendMessageCommand } = await import(
-          "@aws-sdk/client-sqs"
-        );
-        const sqs = new SQSClient({
-          region,
-          maxAttempts: 3,
-          retryStrategy: await buildS3RetryStrategy()
+      // We don't want the `expires` header to be sent to the client we manage
+      // the cache at the edge using the s-maxage directive in the cache-control
+      // header
+      delete response.headers.expires;
+
+      if (staticRegenerationResponse.secondsRemainingUntilRevalidation === 0) {
+        await triggerStaticRegeneration({
+          basePath,
+          manifest,
+          request,
+          response
         });
-        await sqs.send(
-          new SendMessageCommand({
-            QueueUrl: `https://sqs.${region}.amazonaws.com/${bucketName}.fifo`,
-            MessageBody: uri,
-            MessageAttributes: {
-              BucketRegion: {
-                DataType: "String",
-                StringValue: region
-              },
-              BucketName: {
-                DataType: "String",
-                StringValue: bucketName
-              },
-              CloudFrontEventRequest: {
-                DataType: "String",
-                StringValue: JSON.stringify(request)
-              },
-              Manifest: {
-                DataType: "String",
-                StringValue: JSON.stringify(manifest)
-              },
-              ...(basePath
-                ? {
-                    BasePath: {
-                      DataType: "String",
-                      StringValue: basePath
-                    }
-                  }
-                : {})
-            },
-            // We only want to trigger the regeneration once for every previous
-            // update. This will prevent the case where this page is being
-            // requested again whilst its already started to regenerate.
-            MessageDeduplicationId: lastModifiedAt.getTime().toString(),
-            // Only deduplicate based on the object, i.e. we can generate
-            // different pages in parallel, just not the same one
-            MessageGroupId: uri
-          })
-        );
       }
     }
 

diff --git a/packages/libs/lambda-at-edge/src/image-handler.ts b/packages/libs/lambda-at-edge/src/image-handler.ts
@@ -20,6 +20,7 @@ import {
 } from "./routing/redirector";
 import { getUnauthenticatedResponse } from "./auth/authenticator";
 import { removeBlacklistedHeaders } from "./headers/removeBlacklistedHeaders";
+import { s3BucketNameFromEventRequest } from "./s3/s3BucketNameFromEventRequest";
 
 const basePath = RoutesManifestJson.basePath;
 
@@ -88,11 +89,11 @@ export const handler = async (
       true
     );
 
-    const { domainName, region } = request.origin!.s3!;
-    const bucketName = domainName.replace(`.s3.${region}.amazonaws.com`, "");
+    const { region } = request.origin!.s3!;
+    const bucketName = s3BucketNameFromEventRequest(request);
 
     await imageOptimizer(
-      { basePath: basePath, bucketName: bucketName, region: region },
+      { basePath: basePath, bucketName: bucketName || "", region: region },
       imagesManifest,
       req,
       res,

diff --git a/packages/libs/lambda-at-edge/src/lib/getStaticRegenerationResponse.ts b/packages/libs/lambda-at-edge/src/lib/getStaticRegenerationResponse.ts
@@ -0,0 +1,52 @@
+import { OriginRequestDefaultHandlerManifest } from "../types";
+
+interface StaticRegenerationResponseOptions {
+  // URI of the origin object
+  requestedOriginUri: string;
+  // Header as set on the origin object
+  expiresHeader: string;
+  manifest: OriginRequestDefaultHandlerManifest;
+}
+
+interface StaticRegenerationResponseValue {
+  // Cache-Control header
+  cacheControl: string;
+  secondsRemainingUntilRevalidation: number;
+}
+
+/**
+ * Function called within an origin response as part of the Incremental Static
+ * Regeneration logic. Returns required headers for the response, or false if
+ * this response is not compatible with ISR.
+ */
+const getStaticRegenerationResponse = (
+  options: StaticRegenerationResponseOptions
+): StaticRegenerationResponseValue | false => {
+  const initialRevalidateSeconds =
+    options.manifest.pages.ssg.nonDynamic?.[
+      options.requestedOriginUri.replace(".html", "")
+    ]?.initialRevalidateSeconds;
+
+  // If this page did not write a revalidate value at build time it is not an
+  // ISR page
+  if (typeof initialRevalidateSeconds !== "number") {
+    return false;
+  }
+
+  const expiresAt = new Date(options.expiresHeader);
+
+  // isNaN will resolve true on initial load of this page (as the expiresHeader
+  // won't be set), in which case we trigger a regeneration now
+  const secondsRemainingUntilRevalidation = isNaN(expiresAt.getTime())
+    ? 0
+    : // Never return a negative amount of seconds if revalidation could have
+      // happened sooner
+      Math.floor(Math.max(0, (expiresAt.getTime() - Date.now()) / 1000));
+
+  return {
+    secondsRemainingUntilRevalidation,
+    cacheControl: `public, max-age=0, s-maxage=${secondsRemainingUntilRevalidation}, must-revalidate`
+  };
+};
+
+export { getStaticRegenerationResponse };
diff --git a/packages/libs/lambda-at-edge/src/lib/triggerStaticRegeneration.ts b/packages/libs/lambda-at-edge/src/lib/triggerStaticRegeneration.ts
@@ -0,0 +1,70 @@
+import { s3BucketNameFromEventRequest } from "../s3/s3BucketNameFromEventRequest";
+import { buildS3RetryStrategy } from "../s3/s3RetryStrategy";
+import { OriginRequestDefaultHandlerManifest } from "../types";
+
+interface TriggerStaticRegenerationOptions {
+  request: AWSLambda.CloudFrontRequest;
+  response: AWSLambda.CloudFrontResponse;
+  manifest: OriginRequestDefaultHandlerManifest;
+  basePath: string | undefined;
+}
+
+export const triggerStaticRegeneration = async (
+  options: TriggerStaticRegenerationOptions
+): Promise<void> => {
+  const { region } = options.request.origin?.s3 || {};
+  const bucketName = s3BucketNameFromEventRequest(options.request);
+
+  const { SQSClient, SendMessageCommand } = await import("@aws-sdk/client-sqs");
+  const sqs = new SQSClient({
+    region,
+    maxAttempts: 3,
+    retryStrategy: await buildS3RetryStrategy()
+  });
+
+  const lastModifiedAt = new Date(
+    options.response.headers["last-modified"]?.[0].value
+  )
+    .getTime()
+    .toString();
+
+  await sqs.send(
+    new SendMessageCommand({
+      QueueUrl: `https://sqs.${region}.amazonaws.com/${bucketName}.fifo`,
+      MessageBody: options.request.uri, // This is not used, however it is a required property
+      MessageAttributes: {
+        BucketRegion: {
+          DataType: "String",
+          StringValue: region
+        },
+        BucketName: {
+          DataType: "String",
+          StringValue: bucketName
+        },
+        CloudFrontEventRequest: {
+          DataType: "String",
+          StringValue: JSON.stringify(options.request)
+        },
+        Manifest: {
+          DataType: "String",
+          StringValue: JSON.stringify(options.manifest)
+        },
+        ...(options.basePath
+          ? {
+              BasePath: {
+                DataType: "String",
+                StringValue: options.basePath
+              }
+            }
+          : {})
+      },
+      // We only want to trigger the regeneration once for every previous
+      // update. This will prevent the case where this page is being
+      // requested again whilst its already started to regenerate.
+      MessageDeduplicationId: lastModifiedAt,
+      // Only deduplicate based on the object, i.e. we can generate
+      // different pages in parallel, just not the same one
+      MessageGroupId: options.request.uri
+    })
+  );
+};
diff --git a/packages/libs/lambda-at-edge/src/regeneration-handler.ts b/packages/libs/lambda-at-edge/src/regeneration-handler.ts
@@ -59,7 +59,9 @@ export const handler: AWSLambda.SQSHandler = async (event) => {
         "passthrough"
       );
 
-      const expires = new Date(Date.now() + renderOpts.revalidate * 1000);
+      const revalidate =
+        renderOpts.revalidate ?? ssgRoute.initialRevalidateSeconds;
+      const expires = new Date(Date.now() + revalidate * 1000);
       const s3BasePath = basePath ? `${basePath.replace(/^\//, "")}/` : "";
       const s3JsonParams = {
         Bucket: bucketName,

diff --git a/packages/libs/lambda-at-edge/src/s3/s3BucketNameFromEventRequest.ts b/packages/libs/lambda-at-edge/src/s3/s3BucketNameFromEventRequest.ts
@@ -0,0 +1,6 @@
+export const s3BucketNameFromEventRequest = (
+  request: AWSLambda.CloudFrontRequest
+): string | undefined => {
+  const { region, domainName } = request.origin?.s3 || {};
+  return domainName?.replace(`.s3.${region}.amazonaws.com`, "");
+};
diff --git a/packages/libs/lambda-at-edge/yarn.lock b/packages/libs/lambda-at-edge/yarn.lock
@@ -1501,9 +1501,9 @@ fast-base64-decode@^1.0.0:
   integrity sha512-qwaScUgUGBYeDNRnbc/KyllVU88Jk1pRHPStuF/lO7B0/RTRLj7U0lkdTAutlBblY08rwZDff6tNU9cjv6j//Q==
 
 fast-xml-parser@^3.16.0:
-  version "3.17.4"
-  resolved "https://registry.yarnpkg.com/fast-xml-parser/-/fast-xml-parser-3.17.4.tgz#d668495fb3e4bbcf7970f3c24ac0019d82e76477"
-  integrity sha512-qudnQuyYBgnvzf5Lj/yxMcf4L9NcVWihXJg7CiU1L+oUCq8MUnFEfH2/nXR/W5uq+yvUN1h7z6s7vs2v1WkL1A==
+  version "3.19.0"
+  resolved "https://registry.yarnpkg.com/fast-xml-parser/-/fast-xml-parser-3.19.0.tgz#cb637ec3f3999f51406dd8ff0e6fc4d83e520d01"
+  integrity sha512-4pXwmBplsCPv8FOY1WRakF970TjNGnGnfbOnLqjlYvMiF1SR3yOHyxMR/YCXpPTOspNF5gwudqktIP4VsWkvBg==
 
 fetch-mock-jest@^1.5.1:
   version "1.5.1"
@@ -2399,9 +2399,9 @@ rc@^1.2.7:
     strip-json-comments "~2.0.1"
 
 react-native-get-random-values@^1.4.0:
-  version "1.5.0"
-  resolved "https://registry.yarnpkg.com/react-native-get-random-values/-/react-native-get-random-values-1.5.0.tgz#91cda18f0e66e3d9d7660ba80c61c914030c1e05"
-  integrity sha512-LK+Wb8dEimJkd/dub7qziDmr9Tw4chhpzVeQ6JDo4czgfG4VXbptRyOMdu8503RiMF6y9pTH6ZUTkrrpprqT7w==
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/react-native-get-random-values/-/react-native-get-random-values-1.7.0.tgz#86d9d1960828b606392dba4540bf760605448530"
+  integrity sha512-zDhmpWUekGRFb9I+MQkxllHcqXN9HBSsgPwBQfrZ1KZYpzDspWLZ6/yLMMZrtq4pVqNR7C7N96L3SuLpXv1nhQ==
   dependencies:
     fast-base64-decode "^1.0.0"
 

diff --git a/yarn.lock b/yarn.lock
@@ -178,6 +178,46 @@
     fast-xml-parser "^3.16.0"
     tslib "^2.0.0"
 
+"@aws-sdk/[email protected]":
+  version "1.0.0-rc.3"
+  resolved "https://registry.yarnpkg.com/@aws-sdk/client-sqs/-/client-sqs-1.0.0-rc.3.tgz#aca468b52f77db00ffdf27d825022124d802da4d"
+  integrity sha512-qEXJ++GJ46sPboyhRUJIv03buEvmXT5lLgjUdWjZKwzHaU34GPH0B7xxlLOUWmA+JvyPaK91ESjGqLc/82GLaA==
+  dependencies:
+    "@aws-crypto/sha256-browser" "^1.0.0"
+    "@aws-crypto/sha256-js" "^1.0.0"
+    "@aws-sdk/config-resolver" "1.0.0-rc.3"
+    "@aws-sdk/credential-provider-node" "1.0.0-rc.3"
+    "@aws-sdk/fetch-http-handler" "1.0.0-rc.3"
+    "@aws-sdk/hash-node" "1.0.0-rc.3"
+    "@aws-sdk/invalid-dependency" "1.0.0-rc.3"
+    "@aws-sdk/md5-js" "1.0.0-rc.3"
+    "@aws-sdk/middleware-content-length" "1.0.0-rc.3"
+    "@aws-sdk/middleware-host-header" "1.0.0-rc.3"
+    "@aws-sdk/middleware-logger" "1.0.0-rc.3"
+    "@aws-sdk/middleware-retry" "1.0.0-rc.3"
+    "@aws-sdk/middleware-sdk-sqs" "1.0.0-rc.3"
+    "@aws-sdk/middleware-serde" "1.0.0-rc.3"
+    "@aws-sdk/middleware-signing" "1.0.0-rc.3"
+    "@aws-sdk/middleware-stack" "1.0.0-rc.3"
+    "@aws-sdk/middleware-user-agent" "1.0.0-rc.3"
+    "@aws-sdk/node-config-provider" "1.0.0-rc.3"
+    "@aws-sdk/node-http-handler" "1.0.0-rc.3"
+    "@aws-sdk/protocol-http" "1.0.0-rc.3"
+    "@aws-sdk/smithy-client" "1.0.0-rc.3"
+    "@aws-sdk/types" "1.0.0-rc.3"
+    "@aws-sdk/url-parser-browser" "1.0.0-rc.3"
+    "@aws-sdk/url-parser-node" "1.0.0-rc.3"
+    "@aws-sdk/util-base64-browser" "1.0.0-rc.3"
+    "@aws-sdk/util-base64-node" "1.0.0-rc.3"
+    "@aws-sdk/util-body-length-browser" "1.0.0-rc.3"
+    "@aws-sdk/util-body-length-node" "1.0.0-rc.3"
+    "@aws-sdk/util-user-agent-browser" "1.0.0-rc.3"
+    "@aws-sdk/util-user-agent-node" "1.0.0-rc.3"
+    "@aws-sdk/util-utf8-browser" "1.0.0-rc.3"
+    "@aws-sdk/util-utf8-node" "1.0.0-rc.3"
+    fast-xml-parser "^3.16.0"
+    tslib "^2.0.0"
+
 "@aws-sdk/[email protected]":
   version "1.0.0-rc.3"
   resolved "https://registry.yarnpkg.com/@aws-sdk/config-resolver/-/config-resolver-1.0.0-rc.3.tgz#0eb877cdabffb75ba3ed89f14e86301faeec12d2"
@@ -441,6 +481,15 @@
     "@aws-sdk/util-arn-parser" "1.0.0-rc.3"
     tslib "^1.8.0"
 
+"@aws-sdk/[email protected]":
+  version "1.0.0-rc.3"
+  resolved "https://registry.yarnpkg.com/@aws-sdk/middleware-sdk-sqs/-/middleware-sdk-sqs-1.0.0-rc.3.tgz#5f02a97b0f34a4848ef8769e1e21d09d178d3cd8"
+  integrity sha512-d3kL0IDQtXf/kP3RXMH6+AsjYS69tPC+9r9O28ri/qPDQFUdeHVFxybneAA/5JWikDM6tZ4htgkm+Tm4PUm5hA==
+  dependencies:
+    "@aws-sdk/types" "1.0.0-rc.3"
+    "@aws-sdk/util-hex-encoding" "1.0.0-rc.3"
+    tslib "^1.8.0"
+
 "@aws-sdk/[email protected]":
   version "1.0.0-rc.3"
   resolved "https://registry.yarnpkg.com/@aws-sdk/middleware-serde/-/middleware-serde-1.0.0-rc.3.tgz#81307310c51d50ec8425bee9fb08d35a7458dcfc"