caddy/modules/caddyhttp/logging.go
Aziz Rmadi 4356635d12
logging: Add support for additional logger filters other than hostname (#6082)
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
2024-05-11 13:31:44 +00:00

239 lines
7.3 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddyhttp
import (
"encoding/json"
"errors"
"net"
"net/http"
"strings"
"go.uber.org/zap"
"go.uber.org/zap/zapcore"
"github.com/caddyserver/caddy/v2"
)
// ServerLogConfig describes a server's logging configuration. If
// enabled without customization, all requests to this server are
// logged to the default logger; logger destinations may be
// customized per-request-host.
type ServerLogConfig struct {
// The default logger name for all logs emitted by this server for
// hostnames that are not in the logger_names map.
DefaultLoggerName string `json:"default_logger_name,omitempty"`
// LoggerNames maps request hostnames to one or more custom logger
// names. For example, a mapping of `"example.com": ["example"]` would
// cause access logs from requests with a Host of example.com to be
// emitted by a logger named "http.log.access.example". If there are
// multiple logger names, then the log will be emitted to all of them.
// If the logger name is an empty, the default logger is used, i.e.
// the logger "http.log.access".
//
// Keys must be hostnames (without ports), and may contain wildcards
// to match subdomains. The value is an array of logger names.
//
// For backwards compatibility, if the value is a string, it is treated
// as a single-element array.
LoggerNames map[string]StringArray `json:"logger_names,omitempty"`
// By default, all requests to this server will be logged if
// access logging is enabled. This field lists the request
// hosts for which access logging should be disabled.
SkipHosts []string `json:"skip_hosts,omitempty"`
// If true, requests to any host not appearing in the
// logger_names map will not be logged.
SkipUnmappedHosts bool `json:"skip_unmapped_hosts,omitempty"`
// If true, credentials that are otherwise omitted, will be logged.
// The definition of credentials is defined by https://fetch.spec.whatwg.org/#credentials,
// and this includes some request and response headers, i.e `Cookie`,
// `Set-Cookie`, `Authorization`, and `Proxy-Authorization`.
ShouldLogCredentials bool `json:"should_log_credentials,omitempty"`
}
// wrapLogger wraps logger in one or more logger named
// according to user preferences for the given host.
func (slc ServerLogConfig) wrapLogger(logger *zap.Logger, req *http.Request) []*zap.Logger {
// using the `log_name` directive or the `access_logger_names` variable,
// the logger names can be overridden for the current request
if names := GetVar(req.Context(), AccessLoggerNameVarKey); names != nil {
if namesSlice, ok := names.([]any); ok {
loggers := make([]*zap.Logger, 0, len(namesSlice))
for _, loggerName := range namesSlice {
// no name, use the default logger
if loggerName == "" {
loggers = append(loggers, logger)
continue
}
// make a logger with the given name
loggers = append(loggers, logger.Named(loggerName.(string)))
}
return loggers
}
}
// get the hostname from the request, with the port number stripped
host, _, err := net.SplitHostPort(req.Host)
if err != nil {
host = req.Host
}
// get the logger names for this host from the config
hosts := slc.getLoggerHosts(host)
// make a list of named loggers, or the default logger
loggers := make([]*zap.Logger, 0, len(hosts))
for _, loggerName := range hosts {
// no name, use the default logger
if loggerName == "" {
loggers = append(loggers, logger)
continue
}
// make a logger with the given name
loggers = append(loggers, logger.Named(loggerName))
}
return loggers
}
func (slc ServerLogConfig) getLoggerHosts(host string) []string {
// try the exact hostname first
if hosts, ok := slc.LoggerNames[host]; ok {
return hosts
}
// try matching wildcard domains if other non-specific loggers exist
labels := strings.Split(host, ".")
for i := range labels {
if labels[i] == "" {
continue
}
labels[i] = "*"
wildcardHost := strings.Join(labels, ".")
if hosts, ok := slc.LoggerNames[wildcardHost]; ok {
return hosts
}
}
return []string{slc.DefaultLoggerName}
}
func (slc *ServerLogConfig) clone() *ServerLogConfig {
clone := &ServerLogConfig{
DefaultLoggerName: slc.DefaultLoggerName,
LoggerNames: make(map[string]StringArray),
SkipHosts: append([]string{}, slc.SkipHosts...),
SkipUnmappedHosts: slc.SkipUnmappedHosts,
ShouldLogCredentials: slc.ShouldLogCredentials,
}
for k, v := range slc.LoggerNames {
clone.LoggerNames[k] = append([]string{}, v...)
}
return clone
}
// StringArray is a slices of strings, but also accepts
// a single string as a value when JSON unmarshaling,
// converting it to a slice of one string.
type StringArray []string
// UnmarshalJSON satisfies json.Unmarshaler.
func (sa *StringArray) UnmarshalJSON(b []byte) error {
var jsonObj any
err := json.Unmarshal(b, &jsonObj)
if err != nil {
return err
}
switch obj := jsonObj.(type) {
case string:
*sa = StringArray([]string{obj})
return nil
case []any:
s := make([]string, 0, len(obj))
for _, v := range obj {
value, ok := v.(string)
if !ok {
return errors.New("unsupported type")
}
s = append(s, value)
}
*sa = StringArray(s)
return nil
}
return errors.New("unsupported type")
}
// errLogValues inspects err and returns the status code
// to use, the error log message, and any extra fields.
// If err is a HandlerError, the returned values will
// have richer information.
func errLogValues(err error) (status int, msg string, fields []zapcore.Field) {
var handlerErr HandlerError
if errors.As(err, &handlerErr) {
status = handlerErr.StatusCode
if handlerErr.Err == nil {
msg = err.Error()
} else {
msg = handlerErr.Err.Error()
}
fields = []zapcore.Field{
zap.Int("status", handlerErr.StatusCode),
zap.String("err_id", handlerErr.ID),
zap.String("err_trace", handlerErr.Trace),
}
return
}
status = http.StatusInternalServerError
msg = err.Error()
return
}
// ExtraLogFields is a list of extra fields to log with every request.
type ExtraLogFields struct {
fields []zapcore.Field
}
// Add adds a field to the list of extra fields to log.
func (e *ExtraLogFields) Add(field zap.Field) {
e.fields = append(e.fields, field)
}
// Set sets a field in the list of extra fields to log.
// If the field already exists, it is replaced.
func (e *ExtraLogFields) Set(field zap.Field) {
for i := range e.fields {
if e.fields[i].Key == field.Key {
e.fields[i] = field
return
}
}
e.fields = append(e.fields, field)
}
const (
// Variable name used to indicate that this request
// should be omitted from the access logs
LogSkipVar string = "log_skip"
// For adding additional fields to the access logs
ExtraLogFieldsCtxKey caddy.CtxKey = "extra_log_fields"
// Variable name used to indicate the logger to be used
AccessLoggerNameVarKey string = "access_logger_names"
)