ensean / lambda_sync_from_3rd_origin

lambda 镜像回源配置指引

用途

通过CloudFront origin group fallover功能，借助Lambda从第三方站点同步文件至S3桶，实现“镜像回源”功能。

架构图示意如下

配置流程及注意事项

1. 创建S3桶，并记录S3桶名称

2. 部署Lambda函数lambda_hanlder.py，参考这里添加Requests Layer

Lambda 环境变量

• endpoint: 外部站点URL
• s3_bucket: s3桶名称

Lambda 权限

• 额外添加S3桶访问权限

Lambda URL配置

CloudFront配置

• origin A: S3桶（带OAI访问）
• origin B: Lambda Function URL
• 缓存策略注意事项：Minimum TTL需要设置为0，否则Lambda Function 302被缓存导致循环重定向

参考资料

1. Lambda URL

2. Lambda URL event 格式

{
  "version": "2.0",
  "routeKey": "$default",
  "rawPath": "/photo/2018/08/14/13/23/ocean-3605547_960_720.jpg",
  "rawQueryString": "x-oss-process=image/resize,w_150/circle,r_100",
  "headers": {
    "x-amzn-trace-id": "Root=1-6252fa07-79d7a777368eae41c19",
    "x-forwarded-proto": "https",
    "host": "eczhzfsyouc4vnbx3f73mp6vce0wxxxx.lambda-url.ap-northeast-1.on.aws",
    "x-forwarded-port": "443",
    "x-forwarded-for": "13.248.48.12",
    "x-amz-cf-id": "2pygthUgDQ9PmrtyWOjer3GEDGQaDu0q4dmAZ0Npx2MOlQ==",
    "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
    "user-agent": "Amazon CloudFront",
    "via": "2.0 1b188969aee360ace67a42f.cloudfront.net (CloudFront)"
  },
  "queryStringParameters": {
    "x-oss-process": "image/resize,w_150/circle,r_100"
  },
  "requestContext": {
    "accountId": "anonymous",
    "apiId": "eczhzfsyouc4vnbx3f73mp6vce0wxxxx",
    "domainName": "eczhzfsyouc4vnbx3f73mp6vce0wxxxx.lambda-url.ap-northeast-1.on.aws",
    "domainPrefix": "eczhzfsyouc4vnbx3f73mp6vce0wxxxx",
    "http": {
      "method": "GET",
      "path": "/photo/2018/08/14/13/23/ocean-3605547_960_720.jpg",
      "protocol": "HTTP/1.1",
      "sourceIp": "64.252.103.125",
      "userAgent": "Amazon CloudFront"
    },
    "requestId": "a5322273-cedf-4a6b-b1fa-86bfa0b",
    "routeKey": "$default",
    "stage": "$default",
    "time": "10/Apr/2022:15:38:47 +0000",
    "timeEpoch": 1649605127949
  },
  "isBase64Encoded": False
}