Basic device detection

README.md

@@ -16,6 +16,7 @@ umami [<matcher>] {
 	client_ip_header <name>
 	cookie_consent [<name>]
 	cookie_resolution [<name>]
+	device_detection
 	trusted_ip_header <name>
 	report_all_resources
 	debug
@@ -34,6 +35,7 @@ umami [<matcher>] {
 - **client_ip_header** is the name of an HTTP header which will be sent to Umami **alongside** `X-Forwarded-For`, which contains the visitor's IP address.
 - **cookie_consent** is the name of a cookie, if that cookie's value is `false` then this plugin will not run. If a name is not set, the default name is `umami_consent`.
 - **cookie_resolution** is the name of a cookie whose value should be the user's screen resolution, for example `1920x1080`. It is your responsibility to set this cookie with client-side JavaScript (not provided). If this cookie is not set, device type will just be reported as unknown. If a name is not set, the default name is `umami_resolution`.
+- **device_detection** can be enabled to set the sent screen resolution based on `Sec-CH-UA-Mobile`/`Sec-CH-UA-Platform`, for some rudimentary device detection without cookies. If this and `cookie_resolution` are both enabled, a screen resolution set by the cookie will take precedence.
 - **trusted_ip_header** is the name of an incoming HTTP request header which contains the visitor's true IP, which will then be sent to Umami via the `X-Forwarded-For`. This may be useful if your Caddy server is behind a reverse proxy.
 - **report_all_resources** can be included to report **all** requests to Umami, overriding allowed_extensions. By default, only requests with certain extensions are reported. This may be especially useful when using this module with a matcher.
 
@@ -53,8 +55,7 @@ example.com {
 		website_uuid "4fa2c16a-6c0f-488f-986f-bc26d90c76d1"
 		allowed_extensions "" .html .htm .php
 		client_ip_header X-Real-IP
-		cookie_consent
-		cookie_resolution screenres
+		device_detection
 	}
 
 	// ...

umami.go

@@ -32,6 +32,7 @@ type Umami struct {
 	TrustedIPHeader    string
 	CookieConsent      string
 	CookieResolution   string
+	DeviceDetection    bool
 }
 
 // CaddyModule returns the Caddy module information.
@@ -110,15 +111,27 @@ func (p Umami) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.
 					fmt.Printf("Error getting resolution cookie: %v\n", err)
 				}
 			}
+			if cookie != nil {
+				payload["screen"] = cookie.Value
+			}
+		}
 
-			// handle if cookie does not exist
-			if cookie == nil {
-				cookie = &http.Cookie{
-					Name:  p.CookieResolution,
-					Value: "",
-				}
+		if payload["screen"] == nil && p.DeviceDetection {
+			mobile := r.Header.Get("Sec-CH-UA-Mobile")
+			platform := r.Header.Get("Sec-CH-UA-Platform")
+
+			if p.DebugLogging {
+				fmt.Printf("Mobile: %s\n", mobile)
+				fmt.Printf("Platform: %s\n", platform)
+			}
+
+			if mobile == "?1" {
+				payload["screen"] = "400x800" // mobile
+			} else if platform == `"Android"` {
+				payload["screen"] = "900x600" // tablet
+			} else if platform == `"Chrome OS"` || platform == `"macOS"` {
+				payload["screen"] = "1200x800" // laptop
 			}
-			payload["screen"] = cookie.Value
 		}
 
 		visitorInfo := map[string]interface{}{
@@ -189,7 +202,7 @@ func (p *Umami) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				}
 				p.WebsiteUUID = d.Val()
 			case "report_all_resources":
-				p.ReportAllResources = d.Val() == "true"
+				p.ReportAllResources = true
 			case "allowed_extensions":
 				if !d.NextArg() {
 					return d.ArgErr()
@@ -222,6 +235,8 @@ func (p *Umami) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				} else {
 					p.CookieResolution = d.Val()
 				}
+			case "device_detection":
+				p.DeviceDetection = true
 
 			default:
 				return d.Errf("unknown option '%s'", d.Val())
@@ -252,7 +267,9 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
 	if umami.DebugLogging {
 		fmt.Printf("Event Endpoint: %s\n", umami.EventEndpoint)
 		fmt.Printf("Website UUID: %s\n", umami.WebsiteUUID)
+		fmt.Printf("Reporting All Resources: %v\n", umami.ReportAllResources)
 		fmt.Printf("Allowed Extensions: %v\n", umami.AllowedExtensions)
+		fmt.Printf("Device Detection: %v\n", umami.DeviceDetection)
 	}
 	return umami, nil
 }