env_config.go raw

   1  /*
   2   *
   3   * Copyright 2018 gRPC authors.
   4   *
   5   * Licensed under the Apache License, Version 2.0 (the "License");
   6   * you may not use this file except in compliance with the License.
   7   * You may obtain a copy of the License at
   8   *
   9   *     http://www.apache.org/licenses/LICENSE-2.0
  10   *
  11   * Unless required by applicable law or agreed to in writing, software
  12   * distributed under the License is distributed on an "AS IS" BASIS,
  13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14   * See the License for the specific language governing permissions and
  15   * limitations under the License.
  16   *
  17   */
  18  
  19  package binarylog
  20  
  21  import (
  22  	"errors"
  23  	"fmt"
  24  	"regexp"
  25  	"strconv"
  26  	"strings"
  27  )
  28  
  29  // NewLoggerFromConfigString reads the string and build a logger. It can be used
  30  // to build a new logger and assign it to binarylog.Logger.
  31  //
  32  // Example filter config strings:
  33  //   - "" Nothing will be logged
  34  //   - "*" All headers and messages will be fully logged.
  35  //   - "*{h}" Only headers will be logged.
  36  //   - "*{m:256}" Only the first 256 bytes of each message will be logged.
  37  //   - "Foo/*" Logs every method in service Foo
  38  //   - "Foo/*,-Foo/Bar" Logs every method in service Foo except method /Foo/Bar
  39  //   - "Foo/*,Foo/Bar{m:256}" Logs the first 256 bytes of each message in method
  40  //     /Foo/Bar, logs all headers and messages in every other method in service
  41  //     Foo.
  42  //
  43  // If two configs exist for one certain method or service, the one specified
  44  // later overrides the previous config.
  45  func NewLoggerFromConfigString(s string) Logger {
  46  	if s == "" {
  47  		return nil
  48  	}
  49  	l := newEmptyLogger()
  50  	methods := strings.Split(s, ",")
  51  	for _, method := range methods {
  52  		if err := l.fillMethodLoggerWithConfigString(method); err != nil {
  53  			grpclogLogger.Warningf("failed to parse binary log config: %v", err)
  54  			return nil
  55  		}
  56  	}
  57  	return l
  58  }
  59  
  60  // fillMethodLoggerWithConfigString parses config, creates TruncatingMethodLogger and adds
  61  // it to the right map in the logger.
  62  func (l *logger) fillMethodLoggerWithConfigString(config string) error {
  63  	// "" is invalid.
  64  	if config == "" {
  65  		return errors.New("empty string is not a valid method binary logging config")
  66  	}
  67  
  68  	// "-service/method", blacklist, no * or {} allowed.
  69  	if config[0] == '-' {
  70  		s, m, suffix, err := parseMethodConfigAndSuffix(config[1:])
  71  		if err != nil {
  72  			return fmt.Errorf("invalid config: %q, %v", config, err)
  73  		}
  74  		if m == "*" {
  75  			return fmt.Errorf("invalid config: %q, %v", config, "* not allowed in blacklist config")
  76  		}
  77  		if suffix != "" {
  78  			return fmt.Errorf("invalid config: %q, %v", config, "header/message limit not allowed in blacklist config")
  79  		}
  80  		if err := l.setBlacklist(s + "/" + m); err != nil {
  81  			return fmt.Errorf("invalid config: %v", err)
  82  		}
  83  		return nil
  84  	}
  85  
  86  	// "*{h:256;m:256}"
  87  	if config[0] == '*' {
  88  		hdr, msg, err := parseHeaderMessageLengthConfig(config[1:])
  89  		if err != nil {
  90  			return fmt.Errorf("invalid config: %q, %v", config, err)
  91  		}
  92  		if err := l.setDefaultMethodLogger(&MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
  93  			return fmt.Errorf("invalid config: %v", err)
  94  		}
  95  		return nil
  96  	}
  97  
  98  	s, m, suffix, err := parseMethodConfigAndSuffix(config)
  99  	if err != nil {
 100  		return fmt.Errorf("invalid config: %q, %v", config, err)
 101  	}
 102  	hdr, msg, err := parseHeaderMessageLengthConfig(suffix)
 103  	if err != nil {
 104  		return fmt.Errorf("invalid header/message length config: %q, %v", suffix, err)
 105  	}
 106  	if m == "*" {
 107  		if err := l.setServiceMethodLogger(s, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 108  			return fmt.Errorf("invalid config: %v", err)
 109  		}
 110  	} else {
 111  		if err := l.setMethodMethodLogger(s+"/"+m, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 112  			return fmt.Errorf("invalid config: %v", err)
 113  		}
 114  	}
 115  	return nil
 116  }
 117  
 118  const (
 119  	// TODO: this const is only used by env_config now. But could be useful for
 120  	// other config. Move to binarylog.go if necessary.
 121  	maxUInt = ^uint64(0)
 122  
 123  	// For "p.s/m" plus any suffix. Suffix will be parsed again. See test for
 124  	// expected output.
 125  	longMethodConfigRegexpStr = `^([\w./]+)/((?:\w+)|[*])(.+)?$`
 126  
 127  	// For suffix from above, "{h:123,m:123}". See test for expected output.
 128  	optionalLengthRegexpStr      = `(?::(\d+))?` // Optional ":123".
 129  	headerConfigRegexpStr        = `^{h` + optionalLengthRegexpStr + `}$`
 130  	messageConfigRegexpStr       = `^{m` + optionalLengthRegexpStr + `}$`
 131  	headerMessageConfigRegexpStr = `^{h` + optionalLengthRegexpStr + `;m` + optionalLengthRegexpStr + `}$`
 132  )
 133  
 134  var (
 135  	longMethodConfigRegexp    = regexp.MustCompile(longMethodConfigRegexpStr)
 136  	headerConfigRegexp        = regexp.MustCompile(headerConfigRegexpStr)
 137  	messageConfigRegexp       = regexp.MustCompile(messageConfigRegexpStr)
 138  	headerMessageConfigRegexp = regexp.MustCompile(headerMessageConfigRegexpStr)
 139  )
 140  
 141  // Turn "service/method{h;m}" into "service", "method", "{h;m}".
 142  func parseMethodConfigAndSuffix(c string) (service, method, suffix string, _ error) {
 143  	// Regexp result:
 144  	//
 145  	// in:  "p.s/m{h:123,m:123}",
 146  	// out: []string{"p.s/m{h:123,m:123}", "p.s", "m", "{h:123,m:123}"},
 147  	match := longMethodConfigRegexp.FindStringSubmatch(c)
 148  	if match == nil {
 149  		return "", "", "", fmt.Errorf("%q contains invalid substring", c)
 150  	}
 151  	service = match[1]
 152  	method = match[2]
 153  	suffix = match[3]
 154  	return
 155  }
 156  
 157  // Turn "{h:123;m:345}" into 123, 345.
 158  //
 159  // Return maxUInt if length is unspecified.
 160  func parseHeaderMessageLengthConfig(c string) (hdrLenStr, msgLenStr uint64, err error) {
 161  	if c == "" {
 162  		return maxUInt, maxUInt, nil
 163  	}
 164  	// Header config only.
 165  	if match := headerConfigRegexp.FindStringSubmatch(c); match != nil {
 166  		if s := match[1]; s != "" {
 167  			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
 168  			if err != nil {
 169  				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
 170  			}
 171  			return hdrLenStr, 0, nil
 172  		}
 173  		return maxUInt, 0, nil
 174  	}
 175  
 176  	// Message config only.
 177  	if match := messageConfigRegexp.FindStringSubmatch(c); match != nil {
 178  		if s := match[1]; s != "" {
 179  			msgLenStr, err = strconv.ParseUint(s, 10, 64)
 180  			if err != nil {
 181  				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
 182  			}
 183  			return 0, msgLenStr, nil
 184  		}
 185  		return 0, maxUInt, nil
 186  	}
 187  
 188  	// Header and message config both.
 189  	if match := headerMessageConfigRegexp.FindStringSubmatch(c); match != nil {
 190  		// Both hdr and msg are specified, but one or two of them might be empty.
 191  		hdrLenStr = maxUInt
 192  		msgLenStr = maxUInt
 193  		if s := match[1]; s != "" {
 194  			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
 195  			if err != nil {
 196  				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
 197  			}
 198  		}
 199  		if s := match[2]; s != "" {
 200  			msgLenStr, err = strconv.ParseUint(s, 10, 64)
 201  			if err != nil {
 202  				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
 203  			}
 204  		}
 205  		return hdrLenStr, msgLenStr, nil
 206  	}
 207  	return 0, 0, fmt.Errorf("%q contains invalid substring", c)
 208  }
 209