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// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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 collector
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"regexp"
"strconv"
"strings"
"time"
"github.com/google/cadvisor/container"
"github.com/google/cadvisor/info/v1"
)
type GenericCollector struct {
// name of the collector
name string
// holds information extracted from the config file for a collector
configFile Config
// holds information necessary to extract metrics
info *collectorInfo
// The Http client to use when connecting to metric endpoints
httpClient *http.Client
}
type collectorInfo struct {
// minimum polling frequency among all metrics
minPollingFrequency time.Duration
// regular expresssions for all metrics
regexps []*regexp.Regexp
// Limit for the number of srcaped metrics. If the count is higher,
// no metrics will be returned.
metricCountLimit int
}
// Returns a new collector using the information extracted from the configfile
func NewCollector(collectorName string, configFile []byte, metricCountLimit int, containerHandler container.ContainerHandler, httpClient *http.Client) (*GenericCollector, error) {
var configInJSON Config
err := json.Unmarshal(configFile, &configInJSON)
if err != nil {
return nil, err
}
configInJSON.Endpoint.configure(containerHandler)
// TODO : Add checks for validity of config file (eg : Accurate JSON fields)
if len(configInJSON.MetricsConfig) == 0 {
return nil, fmt.Errorf("No metrics provided in config")
}
minPollFrequency := time.Duration(0)
regexprs := make([]*regexp.Regexp, len(configInJSON.MetricsConfig))
for ind, metricConfig := range configInJSON.MetricsConfig {
// Find the minimum specified polling frequency in metric config.
if metricConfig.PollingFrequency != 0 {
if minPollFrequency == 0 || metricConfig.PollingFrequency < minPollFrequency {
minPollFrequency = metricConfig.PollingFrequency
}
}
regexprs[ind], err = regexp.Compile(metricConfig.Regex)
if err != nil {
return nil, fmt.Errorf("Invalid regexp %v for metric %v", metricConfig.Regex, metricConfig.Name)
}
}
// Minimum supported polling frequency is 1s.
minSupportedFrequency := 1 * time.Second
if minPollFrequency < minSupportedFrequency {
minPollFrequency = minSupportedFrequency
}
if len(configInJSON.MetricsConfig) > metricCountLimit {
return nil, fmt.Errorf("Too many metrics defined: %d limit: %d", len(configInJSON.MetricsConfig), metricCountLimit)
}
return &GenericCollector{
name: collectorName,
configFile: configInJSON,
info: &collectorInfo{
minPollingFrequency: minPollFrequency,
regexps: regexprs,
metricCountLimit: metricCountLimit,
},
httpClient: httpClient,
}, nil
}
// Returns name of the collector
func (collector *GenericCollector) Name() string {
return collector.name
}
func (collector *GenericCollector) configToSpec(config MetricConfig) v1.MetricSpec {
return v1.MetricSpec{
Name: config.Name,
Type: config.MetricType,
Format: config.DataType,
Units: config.Units,
}
}
func (collector *GenericCollector) GetSpec() []v1.MetricSpec {
specs := []v1.MetricSpec{}
for _, metricConfig := range collector.configFile.MetricsConfig {
spec := collector.configToSpec(metricConfig)
specs = append(specs, spec)
}
return specs
}
// Returns collected metrics and the next collection time of the collector
func (collector *GenericCollector) Collect(metrics map[string][]v1.MetricVal) (time.Time, map[string][]v1.MetricVal, error) {
currentTime := time.Now()
nextCollectionTime := currentTime.Add(time.Duration(collector.info.minPollingFrequency))
uri := collector.configFile.Endpoint.URL
response, err := collector.httpClient.Get(uri)
if err != nil {
return nextCollectionTime, nil, err
}
defer response.Body.Close()
pageContent, err := ioutil.ReadAll(response.Body)
if err != nil {
return nextCollectionTime, nil, err
}
var errorSlice []error
for ind, metricConfig := range collector.configFile.MetricsConfig {
matchString := collector.info.regexps[ind].FindStringSubmatch(string(pageContent))
if matchString != nil {
if metricConfig.DataType == v1.FloatType {
regVal, err := strconv.ParseFloat(strings.TrimSpace(matchString[1]), 64)
if err != nil {
errorSlice = append(errorSlice, err)
}
metrics[metricConfig.Name] = []v1.MetricVal{
{FloatValue: regVal, Timestamp: currentTime},
}
} else if metricConfig.DataType == v1.IntType {
regVal, err := strconv.ParseInt(strings.TrimSpace(matchString[1]), 10, 64)
if err != nil {
errorSlice = append(errorSlice, err)
}
metrics[metricConfig.Name] = []v1.MetricVal{
{IntValue: regVal, Timestamp: currentTime},
}
} else {
errorSlice = append(errorSlice, fmt.Errorf("Unexpected value of 'data_type' for metric '%v' in config ", metricConfig.Name))
}
} else {
errorSlice = append(errorSlice, fmt.Errorf("No match found for regexp: %v for metric '%v' in config", metricConfig.Regex, metricConfig.Name))
}
}
return nextCollectionTime, metrics, compileErrors(errorSlice)
}
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