simpler /api/conference cache by cloudfront invalidation

Author: sorah

Gemfile

@@ -15,6 +15,7 @@ gem 'aws-sdk-chimesdkidentity'
 gem 'aws-sdk-chimesdkmessaging'
 gem 'aws-sdk-ivs'
 gem 'aws-sdk-medialive'
+gem 'aws-sdk-cloudfront'
 
 gem 'shoryuken'
 gem 'aws-sdk-sqs'

Gemfile.lock

@@ -74,6 +74,9 @@ GEM
     aws-sdk-chimesdkmessaging (1.18.0)
       aws-sdk-core (~> 3, >= 3.165.0)
       aws-sigv4 (~> 1.1)
+    aws-sdk-cloudfront (1.76.0)
+      aws-sdk-core (~> 3, >= 3.165.0)
+      aws-sigv4 (~> 1.1)
     aws-sdk-core (3.171.0)
       aws-eventstream (~> 1, >= 1.0.2)
       aws-partitions (~> 1, >= 1.651.0)
@@ -239,6 +242,7 @@ PLATFORMS
 DEPENDENCIES
   aws-sdk-chimesdkidentity
   aws-sdk-chimesdkmessaging
+  aws-sdk-cloudfront
   aws-sdk-core
   aws-sdk-ivs
   aws-sdk-medialive

app/controllers/api/conferences_controller.rb

@@ -3,12 +3,9 @@ class Api::ConferencesController < Api::ApplicationController
 
   def show
     now = Time.zone.now
-    lifetime = 15.seconds
-    grace = 2.minutes
-    response.date = now
-    response.headers['expires'] = (now+lifetime).httpdate
+
+    expires_in 5.seconds, public: true, 's-maxage' => 300
     (response.cache_control[:extras] ||= []) << 'no-cache="Set-Cookie"'
-    response.cache_control.merge!( public: true, stale_while_revalidate: grace, stale_if_error: grace )
 
     render(json: {
       requested_at: now.to_i,

app/javascript/ScreenAnnounceView.tsx

@@ -23,14 +23,7 @@ import { GitHubIcon } from "./GitHubIcon";
 import { TwitterIcon } from "./TwitterIcon";
 
 export const ScreenAnnounceView: React.FC = () => {
-  const { data, mutate } = Api.useConference();
-
-  // XXX: i know i can use useSWR refreshInterval
-  //React.useEffect(() => {
-  //  const interval = setInterval(() => mutate(), 1000);
-  //  return () => clearInterval(interval);
-  //}, []);
-
+  const { data } = Api.useConference();
   const card = data?.conference?.tracks?._screen?.card;
 
   const fillerElem = (

app/javascript/SubScreen.tsx

@@ -37,7 +37,7 @@ export const SubScreen: React.FC = () => {
 type InfoMode = "announcement" | "lightning_timer" | "caption";
 
 export const SubScreenInner: React.FC<{ trackSlug: TrackSlug }> = ({ trackSlug }) => {
-  const { data: conferenceData, error: conferenceError, mutate: mutateConferenceData } = Api.useConference();
+  const { data: conferenceData } = Api.useConference();
   const chat = useChat();
   const systemsChannel = chat.systems_channel_arn;
 

app/javascript/TrackPage.tsx

@@ -29,33 +29,7 @@ export const TrackPageInner: React.FC = () => {
   const { slug: trackSlug } = useParams();
   if (!trackSlug) throw new Error("?"); // XXX:
 
-  const { data: conferenceData, error: conferenceError, mutate: mutateConferenceData } = Api.useConference();
-
-  React.useEffect(() => {
-    if (!conferenceData) return;
-    if (conferenceData.requested_at === 0) return; // Partially mutated by consumeIvsMetadata
-
-    const now = dayjs();
-    const isStale = conferenceData.stale_after && conferenceData.stale_after - 2 <= now.unix();
-    console.log("conferenceData freshness", {
-      isStale,
-      now: now.toISOString(),
-      at: dayjs.unix(conferenceData.requested_at).toISOString(),
-      stale_after: dayjs.unix(conferenceData.stale_after).toISOString(),
-    });
-
-    if (isStale) {
-      console.log("conferenceData is stale; request revalidation");
-      mutateConferenceData();
-      const interval = setInterval(() => {
-        console.log("Revalidating stale conferenceData...");
-        mutateConferenceData();
-      }, 1000);
-      return () => clearInterval(interval);
-    } else {
-      console.log("conferenceData is fresh!");
-    }
-  }, [conferenceData?.requested_at, conferenceData?.stale_after]);
+  const { data: conferenceData, error: conferenceError } = Api.useConference();
 
   if (!conferenceData) {
     return (

app/jobs/emit_conference_data_job.rb

@@ -20,6 +20,8 @@ def perform(t: Time.zone.now, route:)
       body: JSON.generate(body),
     )
 
+    PurgeCloudfrontCacheJob.perform_later(['/api/conference'])
+
     case route
     when :both
       send_ivs(outpost_key)

app/jobs/purge_cloudfront_cache_job.rb

@@ -0,0 +1,18 @@
+class PurgeCloudfrontCacheJob < ApplicationJob
+  def perform(paths)
+    distribution_id = Rails.configuration.x.cdn.cloudfront_distribution_id
+    return unless distribution_id
+
+    @cloudfront = Aws::CloudFront::Client.new(region: 'us-east-1', logger: Rails.logger)
+    @cloudfront.create_invalidation(
+      distribution_id: distribution_id,
+      invalidation_batch: {
+        paths: {
+          quantity: paths.size,
+          items: paths
+        },
+        caller_reference: "#{self.class.name}-#{Rails.env}-#{job_id}"
+      },
+    )
+  end
+end

config/environments/development.rb

@@ -14,16 +14,19 @@
   config.x.s3.public_prefix = ENV['TAKEOUT_S3_PREFIX'] || 'dev/'
   config.x.s3.public_region = ENV['TAKEOUT_S3_REGION'] || 'ap-northeast-1'
   config.x.sentry.dsn = ENV['SENTRY_DSN']
-  config.x.release_meta.commit = ''
-  config.x.release_meta.version = ''
-  config.x.release_meta.cache_buster = ENV['TAKEOUT_CACHE_BUSTER']
+
+  config.x.cdn.cloudfront_distribution_id = ENV['TAKEOUT_CLOUDFRONT_DISTRIBUTION_ID']
 
   config.x.control.password = ENV['TAKEOUT_CONTROL_PASSWORD']
   config.x.kiosk.password = ENV['TAKEOUT_KIOSK_PASSWORD']
 
   config.x.oidc.signing_key = ENV['OIDC_SIGNING_KEY']&.yield_self { |der| OpenSSL::PKey::RSA.new(der.unpack1('m*'), '') } \
     || (Rails.root.join('tmp', 'oidc.key').read rescue nil)&.yield_self { |pem| OpenSSL::PKey::RSA.new(pem, '') }
 
+  config.x.release_meta.commit = ''
+  config.x.release_meta.version = ''
+  config.x.release_meta.cache_buster = ENV['TAKEOUT_CACHE_BUSTER']
+
   config.active_job.queue_adapter = ENV.fetch('ENABLE_SHORYUKEN', '1') == '1' ? :inline : :shoryuken
 
   # In the development environment your application's code is reloaded any time

config/environments/production.rb

@@ -18,6 +18,8 @@
     config.x.s3.public_prefix = ENV.fetch('TAKEOUT_S3_PREFIX')
     config.x.s3.public_region = ENV.fetch('TAKEOUT_S3_REGION')
 
+    config.x.cdn.cloudfront_distribution_id = ENV['TAKEOUT_CLOUDFRONT_DISTRIBUTION_ID']
+
     config.x.control.password = ENV.fetch('TAKEOUT_CONTROL_PASSWORD')
     config.x.kiosk.password = ENV.fetch('TAKEOUT_KIOSK_PASSWORD')
 

deploy/hako/base.libsonnet

@@ -38,6 +38,8 @@ local secret = utils.makeSecretParameterStore('takeout-app');
 
       TAKEOUT_STAFF_ONLY: '1',
       TAKEOUT_STAFF_ONLY_STREAM: '0',
+
+      TAKEOUT_CLOUDFRONT_DISTRIBUTION_ID: 'E3G1QIEKS0IAW',
     },
     secrets: [
       secret('DATABASE_URL'),

tf/cloudfront.tf

@@ -126,7 +126,7 @@ resource "aws_cloudfront_distribution" "takeout-rk-o" {
 
     min_ttl     = 0
     default_ttl = 0
-    max_ttl     = 60
+    max_ttl     = 3600
 
     compress               = true
     viewer_protocol_policy = "redirect-to-https"

tf/iam_heroku-takeout-prd.tf

@@ -105,6 +105,14 @@ data "aws_iam_policy_document" "takeout-prd" {
     ]
   }
 
+  statement {
+    effect = "Allow"
+    actions = [
+      "cloudfront:GetInvalidation",
+      "cloudfront:CreateInvalidation",
+    ]
+    resources = [aws_cloudfront_distribution.takeout-rk-o.arn]
+  }
 }
 
 resource "aws_iam_policy" "heroku-takeout-prd" {