kube-metrics-adapter/pkg/collector/hostname_collector.go
Lucas Thiesen cd986058e4 Delete unwanted comments
Signed-off-by: Lucas Thiesen <lucas.thiesen@zalando.de>
2023-05-23 15:46:38 +02:00

119 lines
2.9 KiB
Go

package collector
import (
"fmt"
"regexp"
"strconv"
"strings"
"time"
autoscalingv2 "k8s.io/api/autoscaling/v2"
)
const (
HostnameMetricType = "requests-per-second"
HostnameRPSQuery = `scalar(sum(rate(%s{host=~"%s"}[1m])) * %.4f)`
)
type HostnameCollectorPlugin struct {
metricName string
promPlugin CollectorPlugin
}
type HostnameCollector struct {
interval time.Duration
promCollector Collector
}
func NewHostnameCollectorPlugin(
promPlugin CollectorPlugin,
metricName string,
) (*HostnameCollectorPlugin, error) {
if metricName == "" {
return nil, fmt.Errorf("Failed to initialize hostname collector plugin, metric name was not defined")
}
return &HostnameCollectorPlugin{
metricName: metricName,
promPlugin: promPlugin,
}, nil
}
// NewCollector initializes a new skipper collector from the specified HPA.
func (p *HostnameCollectorPlugin) NewCollector(
hpa *autoscalingv2.HorizontalPodAutoscaler,
config *MetricConfig,
interval time.Duration,
) (Collector, error) {
if config == nil {
return nil, fmt.Errorf("Metric config not present, it is not possible to initialize the collector.")
}
// Need to copy config and add a promQL query in order to get
// RPS data from a specific hostname from prometheus. The idea
// of the copy is to not modify the original config struct.
confCopy := *config
if _, ok := config.Config["hostnames"]; !ok {
return nil, fmt.Errorf("Hostname is not specified, unable to create collector")
}
regex, err := regexp.Compile("^[a-zA-Z0-9.-]+$")
if err != nil {
return nil, fmt.Errorf("Failed to create regular expression to match hostname format")
}
hostnames := strings.Split(config.Config["hostnames"], ",")
for _, h := range hostnames {
if ok := regex.MatchString(h); !ok {
return nil, fmt.Errorf(
"Invalid hostname format, unable to create collector: %s",
h,
)
}
}
weight := 1.0
if w, ok := config.Config["weight"]; ok {
num, err := strconv.ParseFloat(w, 64)
if err != nil {
return nil, fmt.Errorf("Could not parse weight annotation, unable to create collector: %s", w)
}
weight = num / 100.0
}
confCopy.Config = map[string]string{
"query": fmt.Sprintf(
HostnameRPSQuery,
p.metricName,
strings.Replace(strings.Join(hostnames, "|"), ".", "_", -1),
weight,
),
}
c, err := p.promPlugin.NewCollector(hpa, &confCopy, interval)
if err != nil {
return nil, err
}
return &HostnameCollector{
interval: interval,
promCollector: c,
}, nil
}
// GetMetrics gets hostname metrics from Prometheus
func (c *HostnameCollector) GetMetrics() ([]CollectedMetric, error) {
v, err := c.promCollector.GetMetrics()
if err != nil {
return nil, err
}
if len(v) != 1 {
return nil, fmt.Errorf("Expected to only get one metric value, got %d", len(v))
}
return v, nil
}
// Interval returns the interval at which the collector should run.
func (c *HostnameCollector) Interval() time.Duration {
return c.interval
}