EdgeScript scenarios

• Request URL format: /path/digest/?.ts? key=&t=
• For .ts requests, the requirements for customizing hotlinking protection are:
  • Rule 1: If the request does not contain the t or key parameter, the CDN node returns the 403 status code and adds the X-AUTH-MSG response header to indicate the failure cause.
  • Rule 2: The t parameter specifies the expiration time. If the specified t parameter is earlier than the current time, the CDN node returns the 403 status code and adds the X-AUTH-MSG response header to indicate the failure cause.
  • Rule 3: The CDN node compares the md5 parameter with the digest parameter. If md5 does not match digest, the CDN node returns the 403 status code.

    Value format of the md5 parameter: Private key + Path + File name.extension.

if eq(substr($uri, -3, -1), '.ts') {

   if or(not($arg_t), not($arg_key)) {
       add_rsp_header('X-AUTH-MSG', 'auth failed - missing necessary arg')
       exit(403)
   }

   t = tonumber($arg_t)
   if not(t) {
       add_rsp_header('X-AUTH-MSG', 'auth failed - invalid time')
       exit(403)
   }

   if gt(now(), t) {
       add_rsp_header('X-AUTH-MSG', 'auth failed - expired url')
       exit(403)
   }

    pcs = capture_re($request_uri,'^/([^/]+)/([^/]+)/([^?] +)\?(.*)')
    sec1 = get(pcs, 1)
    sec2 = get(pcs, 2)
    sec3 = get(pcs, 3)

    if or(not(sec1), not(sec2), not(sec3)) {
        add_rsp_header('X-AUTH-MSG', 'auth failed - malformed url')
        exit(403)
    }

    key = 'b98d643a-9170-4937-8524-6c33514bbc23'
    signstr = concat(key, sec1, sec3)
    digest = md5(signstr)
    if ne(digest, sec2) {
        add_rsp_header('X-AUTH-DEBUG', concat('signstr: ', signstr))
        add_rsp_header('X-AUTH-MSG', 'auth failed - invalid digest')
        exit(403)
    }

}

If the filename parameter is set, the file is automatically renamed the value specified by the filename parameter. If no file name is specified, the default file name is used.

// The value for the filename parameter is enclosed in a pair of double quotation marks (""). The string "34" is the ASCII string for double quotation marks. It can be converted back to the quotation mark string ("") through the tochar function.
// Example: add_rsp_header('Content-Disposition', concat('attachment;filename=', tochar(34), filename, tochar(34)))
// Output: Content-Disposition: attachment;filename="monitor.apk"

if $arg_filename {
    hn = 'Content-Disposition'
    hv = concat('attachment;filename=', $arg_filename)
    add_rsp_header(hn, hv)
}

• Requirements

  Configure Alibaba Cloud Content Delivery Network (CDN) to rewrite /hello as /index.html. As a result, the URI of the back-to-origin request is changed to /index.html and the parameters remain unchanged.

• Corresponding EdgeScript script:

  if match_re($uri, '^/hello$') {
      rewrite('/index.html', 'break')
  }

• Requirements

  Configure Alibaba Cloud CDN to rewrite /1.txt as /1<url parameter type>. For example, /1.txt? type=mp4 will be rewritten as /1.mp4? type=mp4 in back-to-origin requests and cached on CDN nodes.

• Corresponding EdgeScript script:

  if and(match_re($uri, '^/1.txt$'), $arg_type) {
       rewrite(concat('/1.', $arg_type), 'break')
  }

• Requirements

  Convert the URI string to lowercase letters.

• Corresponding EdgeScript script:

  pcs = capture_re($uri, '^(. +%.)([ ^.]+)')
  section = get(pcs, 1)
  postfix = get(pcs, 2)
  
  if and(section, postfix) {
      rewrite(concat(section, lower(postfix)), 'break')
  }

• Requirements

  Configure Alibaba Cloud CDN to rewrite ^/nn_live/(. *) as /3rd/nn_live/$1.

• Corresponding EdgeScript script:

  pcs = capture_re($uri, '^/nn_live/(.*)')
  sec = get(pcs, 1)
  
  if sec {
       dst = concat('/3rd/nn_live/', sec)
       rewrite(dst, 'break')
  }

• Requirements

  Perform a 302 redirect to /app/movie/pages/index/index.html for the / root directory.

• Corresponding EdgeScript script:

  if eq($uri, '/') {
      rewrite('/app/movie/pages/index/index.html', 'redirect')
  }

• Requirements
  Redirect the following URIs that match the ^/$ root directory to https://rtmp.cdnpe.com/index.html. You can specify the destination URI as needed.

  • http://rtmp.cdnpe.com
  • https://rtmp.cdnpe.com
• Corresponding EdgeScript script:

  if eq($uri, '/') {
      rewrite('https://rtmp.cdnpe.com/index.html', 'redirect')
  }

Customize the resource cache duration based on various conditions.

// Note: Set the cache duration for status codes responded to requests whose URIs start with "/image". Set 10 seconds for the 301 status code and 5 seconds for the 302 status code.
if match_re($uri, '^/image') {
    set_cache_ttl('code', '301=10,302=5')
}

if eq(substr($uri, -4, -1), '.mp4') {
    set_cache_ttl('path', 5)
}
if match_re($uri, '^/201801/mp4/') {
    set_cache_ttl('path', 50)
}
if match_re($uri, '^/201802/flv/') {
    set_cache_ttl('path', 10)
}

If the sp and unit parameters are set, throttling is implemented. The sp parameter specifies the throttling threshold. The unit parameter specifies the unit. The unit can be KB or MB.

if and($arg_sp, $arg_unit) {
    sp = tonumber($arg_sp)
    if not(sp) {
        add_rsp_header('X-LIMIT-DEBUG', 'invalid sp')
        return false
    }

    if and(ne($arg_unit, 'k'), ne($arg_unit, 'm')) {
        add_rsp_header('X-LIMIT-DEBUG', 'invalid unit')
        return false
    }

    add_rsp_header('X-LIMIT-DEBUG', concat('set on: ', sp, $arg_unit))
    limit_rate(sp, $arg_unit)
    return true
}