tsweb: use a ResponseWriter wrapper to log more accurately.

Also adds tests, because the logging handler is acquiring a fair
number of branches.

Signed-off-by: David Anderson <dave@natulte.net>

tsweb/log.go

@@ -10,30 +10,46 @@ import (
 	"time"
 )
 
-// Msg is a structured event log entry.
-type Msg struct {
-	Where    string        `json:"where"`
-	When     time.Time     `json:"when"`
-	Duration time.Duration `json:"duration,omitempty"`
-	Domain   string        `json:"domain,omitempty"`
-	Msg      string        `json:"msg,omitempty"`
-	Err      error         `json:"err,omitempty"`
-	HTTP     *MsgHTTP      `json:"http,omitempty"`
-	Data     interface{}   `json:"data,omitempty"`
-}
+// AccessLogRecord is a record of one HTTP request served.
+type AccessLogRecord struct {
+	// Timestamp at which request processing started.
+	When time.Time `json:"when"`
+	// Time it took to finish processing the request. It does not
+	// include the entire lifetime of the underlying connection in
+	// cases like connection hijacking, only the lifetime of the HTTP
+	// request handler.
+	Seconds float64 `json:"duration"`
 
-// MsgHTTP contains information about the processing of one HTTP
-// request.
-type MsgHTTP struct {
-	Code       int    `json:"code"`
-	Path       string `json:"path"`
+	// The client's ip:port.
 	RemoteAddr string `json:"remote_addr"`
-	UserAgent  string `json:"user_agent"`
-	Referer    string `json:"referer"`
+	// The HTTP protocol version, usually "HTTP/1.1 or HTTP/2".
+	Proto string `json:"proto"`
+	// Whether the request was received over TLS.
+	TLS bool `json:"tls"`
+	// The target hostname in the request.
+	Host string `json:"host"`
+	// The HTTP method invoked.
+	Method string `json:"method"`
+	// The unescaped request URI, including query parameters.
+	RequestURI string `json:"request_uri"`
+
+	// The client's user-agent
+	UserAgent string `json:"user_agent"`
+	// Where the client was before making this request.
+	Referer string `json:"referer"`
+
+	// The HTTP response code sent to the client.
+	Code int `json:"code"`
+	// Number of bytes sent in response body to client. If the request
+	// was hijacked, only includes bytes sent up to the point of
+	// hijacking.
+	Bytes int `json:"bytes"`
+	// Error encountered during request processing.
+	Err string `json:"err"`
 }
 
 // String returns m as a JSON string.
-func (m Msg) String() string {
+func (m AccessLogRecord) String() string {
 	if m.When.IsZero() {
 		m.When = time.Now()
 	}