Parse and Store Browser User Agent String

The first data we want to parse and store is the Web Browser User Agent so that we know what devices and browsers are visiting.

There is a lot of info about User Agents on MDN: developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent recommended reading for the curious.

For our purposes we only need to extract the user_agent data that interest us and thankfully, @mneudert has created a handy library we can use: ua_inspector

ua_inspector Usage Example

From the ua_inspector docs we get the following sample code/output:

iex> UAInspector.parse("Mozilla/5.0 (iPad; CPU OS 7_0_4 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11B554a Safari/9537.53")
%UAInspector.Result{
  client: %UAInspector.Result.Client{
    engine: "WebKit",
    engine_version: "537.51.1",
    name: "Mobile Safari",
    type: "browser",
    version: "7.0"
  },
  device: %UAInspector.Result.Device{
    brand: "Apple",
    model: "iPad",
    type: "tablet"
  },
  os: %UAInspector.Result.OS{
    name: "iOS",
    platform: :unknown,
    version: "7.0.4"
  },
  user_agent: "Mozilla/5.0 (iPad; CPU OS 7_0_4 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11B554a Safari/9537.53"
}

Additionally there is following sample output for a non-browser agent (Google Bot):

iex> UAInspector.parse("Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Safari/537.36")
%UAInspector.Result.Bot{
  category: "Search bot",
  name: "Googlebot",
  producer: %UAInspector.Result.BotProducer{
    name: "Google Inc.",
    url: "http://www.google.com"
  },
  url: "http://www.google.com/bot.html",
  user_agent: "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Safari/537.36"
}

From this sample output we can extract the following fields:

• engine: String e.g: "WebKit"
• engine_version: String e.g: "537.51.1" - sadly we can't store this as float unless we lose the last digit ...
• name: String e.g: "Mobile Safari"
• version: Float e.g: "7.0" - we will parse this float so that we can run queries on it.
• brand: String e.g: "Apple"
• model: String e.g: "iPad"
• device_type: String e.g: "tablet"
• os_name: String e.g: "iOS"
• platform: String e.g: "unknown" - Atom.to_string(:unknown)
• os_version: String e.g: "7.0.4"
• url: String e.g: "http://www.google.com/bot.html" - used by non-human agents; blank if null.
• user_agent: String, the full agent string. Even though ua_inspector does a good job of parsing the user_agent, we are storing the full user_agent string so that we can sense-check the parsed data when needed.

Fields we will ignore:

• type: String e.g: "browser" - we will skip this field as it's implied.