options.go

Documentation: k8s.io/component-base/metrics

     1  /*
     2  Copyright 2019 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package metrics
    18  
    19  import (
    20  	"fmt"
    21  	"regexp"
    22  
    23  	"github.com/blang/semver/v4"
    24  	"github.com/spf13/pflag"
    25  
    26  	"k8s.io/component-base/version"
    27  )
    28  
    29  // Options has all parameters needed for exposing metrics from components
    30  type Options struct {
    31  	ShowHiddenMetricsForVersion string
    32  	DisabledMetrics             []string
    33  	AllowListMapping            map[string]string
    34  	AllowListMappingManifest    string
    35  }
    36  
    37  // NewOptions returns default metrics options
    38  func NewOptions() *Options {
    39  	return &Options{}
    40  }
    41  
    42  // Validate validates metrics flags options.
    43  func (o *Options) Validate() []error {
    44  	if o == nil {
    45  		return nil
    46  	}
    47  
    48  	var errs []error
    49  	err := validateShowHiddenMetricsVersion(parseVersion(version.Get()), o.ShowHiddenMetricsForVersion)
    50  	if err != nil {
    51  		errs = append(errs, err)
    52  	}
    53  
    54  	if err := validateAllowMetricLabel(o.AllowListMapping); err != nil {
    55  		errs = append(errs, err)
    56  	}
    57  
    58  	if len(errs) == 0 {
    59  		return nil
    60  	}
    61  	return errs
    62  }
    63  
    64  // AddFlags adds flags for exposing component metrics.
    65  func (o *Options) AddFlags(fs *pflag.FlagSet) {
    66  	if o == nil {
    67  		return
    68  	}
    69  	fs.StringVar(&o.ShowHiddenMetricsForVersion, "show-hidden-metrics-for-version", o.ShowHiddenMetricsForVersion,
    70  		"The previous version for which you want to show hidden metrics. "+
    71  			"Only the previous minor version is meaningful, other values will not be allowed. "+
    72  			"The format is <major>.<minor>, e.g.: '1.16'. "+
    73  			"The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, "+
    74  			"rather than being surprised when they are permanently removed in the release after that.")
    75  	fs.StringSliceVar(&o.DisabledMetrics,
    76  		"disabled-metrics",
    77  		o.DisabledMetrics,
    78  		"This flag provides an escape hatch for misbehaving metrics. "+
    79  			"You must provide the fully qualified metric name in order to disable it. "+
    80  			"Disclaimer: disabling metrics is higher in precedence than showing hidden metrics.")
    81  	fs.StringToStringVar(&o.AllowListMapping, "allow-metric-labels", o.AllowListMapping,
    82  		"The map from metric-label to value allow-list of this label. The key's format is <MetricName>,<LabelName>. "+
    83  			"The value's format is <allowed_value>,<allowed_value>..."+
    84  			"e.g. metric1,label1='v1,v2,v3', metric1,label2='v1,v2,v3' metric2,label1='v1,v2,v3'.")
    85  	fs.StringVar(&o.AllowListMappingManifest, "allow-metric-labels-manifest", o.AllowListMappingManifest,
    86  		"The path to the manifest file that contains the allow-list mapping. "+
    87  			"The format of the file is the same as the flag --allow-metric-labels. "+
    88  			"Note that the flag --allow-metric-labels will override the manifest file.")
    89  }
    90  
    91  // Apply applies parameters into global configuration of metrics.
    92  func (o *Options) Apply() {
    93  	if o == nil {
    94  		return
    95  	}
    96  	if len(o.ShowHiddenMetricsForVersion) > 0 {
    97  		SetShowHidden()
    98  	}
    99  	// set disabled metrics
   100  	for _, metricName := range o.DisabledMetrics {
   101  		SetDisabledMetric(metricName)
   102  	}
   103  	if o.AllowListMapping != nil {
   104  		SetLabelAllowListFromCLI(o.AllowListMapping)
   105  	} else if len(o.AllowListMappingManifest) > 0 {
   106  		SetLabelAllowListFromManifest(o.AllowListMappingManifest)
   107  	}
   108  }
   109  
   110  func validateShowHiddenMetricsVersion(currentVersion semver.Version, targetVersionStr string) error {
   111  	if targetVersionStr == "" {
   112  		return nil
   113  	}
   114  
   115  	validVersionStr := fmt.Sprintf("%d.%d", currentVersion.Major, currentVersion.Minor-1)
   116  	if targetVersionStr != validVersionStr {
   117  		return fmt.Errorf("--show-hidden-metrics-for-version must be omitted or have the value '%v'. Only the previous minor version is allowed", validVersionStr)
   118  	}
   119  
   120  	return nil
   121  }
   122  
   123  func validateAllowMetricLabel(allowListMapping map[string]string) error {
   124  	if allowListMapping == nil {
   125  		return nil
   126  	}
   127  	metricNameRegex := `[a-zA-Z_:][a-zA-Z0-9_:]*`
   128  	labelRegex := `[a-zA-Z_][a-zA-Z0-9_]*`
   129  	for k := range allowListMapping {
   130  		reg := regexp.MustCompile(metricNameRegex + `,` + labelRegex)
   131  		if reg.FindString(k) != k {
   132  			return fmt.Errorf("--allow-metric-labels must have a list of kv pair with format `metricName:labelName=labelValue, labelValue,...`")
   133  		}
   134  	}
   135  	return nil
   136  }
   137
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