Fastly VCL User-Agent parser

A utility for parsing User-Agent strings in Fastly VCL, based on ua-parser/uap-core.

Usage

• Copy useragent-parser.vcl
• Include it in your main.vcl

  • include "useragent-parser.vcl";

• To get user-agent information, call get_parsed_useragent
  • The return value is a Dict type of Structure Field Values; use the subfield function to retrieve specific values

  • declare local var.useragent STRING;
    set var.useragent = get_parsed_useragent();
    set req.http.User-Agent-Family = subfield(var.useragent, "family");
    set req.http.User-Agent-Version =
      subfield(var.useragent, "major") "."
      subfield(var.useragent, "minor") "."
      subfield(var.useragent, "patch");

• To get OS information, call get_useragent_os
  • The return value is a Dict type of Structure Field Values; use the subfield function to retrieve specific values

  • declare local var.os STRING;
    set var.os = get_useragent_os();
    set req.http.User-Agent-OS = subfield(var.os, "family");

• To get device information, call get_useragent_device
  • The return value is a Dict type of Structure Field Values; use the subfield function to retrieve specific values

  • declare local var.device STRING;
    set var.device = get_useragent_device();
    set req.http.User-Agent-Device = subfield(var.device, "family");

API

get_parsed_useragent

Returns the parsed user-agent result. For details, see ua-parser/uap-core - docs/specification.md - user_agent_parsers.

Key
family	User-agent family name
major	Major version
minor	Minor version
patch	Patch version

get_useragent_os

Returns OS information inferred from the user-agent. For details, see ua-parser/uap-core - docs/specification.md - os_parsers.

Key
family	Common name of the OS
major	Major version
minor	Minor version
patch	Patch version
patchMinor	Patch minor version

get_useragent_device

Returns device information inferred from the user-agent. For details, see ua-parser/uap-core - docs/specification.md - device_parsers.

Key
family	Common name of the device
brand	Brand name
model	Model name

License

Apache License 2.0