prometheus/scrape/target_test.go
xjewer 0d1a69353e scrape: Add global jitter for HA server (#5181)
* scrape: Add global jitter for HA server

Covers issue in https://github.com/prometheus/prometheus/pull/4926#issuecomment-449039848
where the HA setup become a problem for targets unable to be scraped simultaneously.
The new jitter per server relies on the hostname and external labels which necessarily to be uniq.

As before, scrape offset will be calculated with regard the absolute time, so even
restart/reload doesn't change scrape time per scrape target + prometheus instance.

Use fqdn if possible, otherwise fall back to the hostname. It adds extra random seed
to calculate server hash to be distinguish on machines with the same hostname, but
different DC.

Signed-off-by: Aleksei Semiglazov <xjewer@gmail.com>
2019-03-12 10:46:15 +00:00

374 lines
9.3 KiB
Go

// Copyright 2013 The Prometheus 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 scrape
import (
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
"net/http"
"net/http/httptest"
"net/url"
"reflect"
"strings"
"testing"
"time"
"github.com/prometheus/common/model"
config_util "github.com/prometheus/common/config"
"github.com/prometheus/prometheus/pkg/labels"
)
const (
caCertPath = "testdata/ca.cer"
)
func TestTargetLabels(t *testing.T) {
target := newTestTarget("example.com:80", 0, labels.FromStrings("job", "some_job", "foo", "bar"))
want := labels.FromStrings(model.JobLabel, "some_job", "foo", "bar")
got := target.Labels()
if !reflect.DeepEqual(want, got) {
t.Errorf("want base labels %v, got %v", want, got)
}
}
func TestTargetOffset(t *testing.T) {
interval := 10 * time.Second
jitter := uint64(0)
offsets := make([]time.Duration, 10000)
// Calculate offsets for 10000 different targets.
for i := range offsets {
target := newTestTarget("example.com:80", 0, labels.FromStrings(
"label", fmt.Sprintf("%d", i),
))
offsets[i] = target.offset(interval, jitter)
}
// Put the offsets into buckets and validate that they are all
// within bounds.
bucketSize := 1 * time.Second
buckets := make([]int, interval/bucketSize)
for _, offset := range offsets {
if offset < 0 || offset >= interval {
t.Fatalf("Offset %v out of bounds", offset)
}
bucket := offset / bucketSize
buckets[bucket]++
}
t.Log(buckets)
// Calculate whether the number of targets per bucket
// does not differ more than a given tolerance.
avg := len(offsets) / len(buckets)
tolerance := 0.15
for _, bucket := range buckets {
diff := bucket - avg
if diff < 0 {
diff = -diff
}
if float64(diff)/float64(avg) > tolerance {
t.Fatalf("Bucket out of tolerance bounds")
}
}
}
func TestTargetURL(t *testing.T) {
params := url.Values{
"abc": []string{"foo", "bar", "baz"},
"xyz": []string{"hoo"},
}
labels := labels.FromMap(map[string]string{
model.AddressLabel: "example.com:1234",
model.SchemeLabel: "https",
model.MetricsPathLabel: "/metricz",
"__param_abc": "overwrite",
"__param_cde": "huu",
})
target := NewTarget(labels, labels, params)
// The reserved labels are concatenated into a full URL. The first value for each
// URL query parameter can be set/modified via labels as well.
expectedParams := url.Values{
"abc": []string{"overwrite", "bar", "baz"},
"cde": []string{"huu"},
"xyz": []string{"hoo"},
}
expectedURL := url.URL{
Scheme: "https",
Host: "example.com:1234",
Path: "/metricz",
RawQuery: expectedParams.Encode(),
}
if u := target.URL(); !reflect.DeepEqual(u.String(), expectedURL.String()) {
t.Fatalf("Expected URL %q, but got %q", expectedURL.String(), u.String())
}
}
func newTestTarget(targetURL string, deadline time.Duration, lbls labels.Labels) *Target {
lb := labels.NewBuilder(lbls)
lb.Set(model.SchemeLabel, "http")
lb.Set(model.AddressLabel, strings.TrimPrefix(targetURL, "http://"))
lb.Set(model.MetricsPathLabel, "/metrics")
return &Target{labels: lb.Labels()}
}
func TestNewHTTPBearerToken(t *testing.T) {
server := httptest.NewServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
expected := "Bearer 1234"
received := r.Header.Get("Authorization")
if expected != received {
t.Fatalf("Authorization header was not set correctly: expected '%v', got '%v'", expected, received)
}
},
),
)
defer server.Close()
cfg := config_util.HTTPClientConfig{
BearerToken: "1234",
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPBearerTokenFile(t *testing.T) {
server := httptest.NewServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
expected := "Bearer 12345"
received := r.Header.Get("Authorization")
if expected != received {
t.Fatalf("Authorization header was not set correctly: expected '%v', got '%v'", expected, received)
}
},
),
)
defer server.Close()
cfg := config_util.HTTPClientConfig{
BearerTokenFile: "testdata/bearertoken.txt",
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPBasicAuth(t *testing.T) {
server := httptest.NewServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
username, password, ok := r.BasicAuth()
if !(ok && username == "user" && password == "password123") {
t.Fatalf("Basic authorization header was not set correctly: expected '%v:%v', got '%v:%v'", "user", "password123", username, password)
}
},
),
)
defer server.Close()
cfg := config_util.HTTPClientConfig{
BasicAuth: &config_util.BasicAuth{
Username: "user",
Password: "password123",
},
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPCACert(t *testing.T) {
server := httptest.NewUnstartedServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", `text/plain; version=0.0.4`)
w.Write([]byte{})
},
),
)
server.TLS = newTLSConfig("server", t)
server.StartTLS()
defer server.Close()
cfg := config_util.HTTPClientConfig{
TLSConfig: config_util.TLSConfig{
CAFile: caCertPath,
},
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPClientCert(t *testing.T) {
server := httptest.NewUnstartedServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", `text/plain; version=0.0.4`)
w.Write([]byte{})
},
),
)
tlsConfig := newTLSConfig("server", t)
tlsConfig.ClientAuth = tls.RequireAndVerifyClientCert
tlsConfig.ClientCAs = tlsConfig.RootCAs
tlsConfig.BuildNameToCertificate()
server.TLS = tlsConfig
server.StartTLS()
defer server.Close()
cfg := config_util.HTTPClientConfig{
TLSConfig: config_util.TLSConfig{
CAFile: caCertPath,
CertFile: "testdata/client.cer",
KeyFile: "testdata/client.key",
},
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPWithServerName(t *testing.T) {
server := httptest.NewUnstartedServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", `text/plain; version=0.0.4`)
w.Write([]byte{})
},
),
)
server.TLS = newTLSConfig("servername", t)
server.StartTLS()
defer server.Close()
cfg := config_util.HTTPClientConfig{
TLSConfig: config_util.TLSConfig{
CAFile: caCertPath,
ServerName: "prometheus.rocks",
},
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err != nil {
t.Fatal(err)
}
}
func TestNewHTTPWithBadServerName(t *testing.T) {
server := httptest.NewUnstartedServer(
http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", `text/plain; version=0.0.4`)
w.Write([]byte{})
},
),
)
server.TLS = newTLSConfig("servername", t)
server.StartTLS()
defer server.Close()
cfg := config_util.HTTPClientConfig{
TLSConfig: config_util.TLSConfig{
CAFile: caCertPath,
ServerName: "badname",
},
}
c, err := config_util.NewClientFromConfig(cfg, "test")
if err != nil {
t.Fatal(err)
}
_, err = c.Get(server.URL)
if err == nil {
t.Fatal("Expected error, got nil.")
}
}
func newTLSConfig(certName string, t *testing.T) *tls.Config {
tlsConfig := &tls.Config{}
caCertPool := x509.NewCertPool()
caCert, err := ioutil.ReadFile(caCertPath)
if err != nil {
t.Fatalf("Couldn't set up TLS server: %v", err)
}
caCertPool.AppendCertsFromPEM(caCert)
tlsConfig.RootCAs = caCertPool
tlsConfig.ServerName = "127.0.0.1"
certPath := fmt.Sprintf("testdata/%s.cer", certName)
keyPath := fmt.Sprintf("testdata/%s.key", certName)
cert, err := tls.LoadX509KeyPair(certPath, keyPath)
if err != nil {
t.Errorf("Unable to use specified server cert (%s) & key (%v): %s", certPath, keyPath, err)
}
tlsConfig.Certificates = []tls.Certificate{cert}
tlsConfig.BuildNameToCertificate()
return tlsConfig
}
func TestNewClientWithBadTLSConfig(t *testing.T) {
cfg := config_util.HTTPClientConfig{
TLSConfig: config_util.TLSConfig{
CAFile: "testdata/nonexistent_ca.cer",
CertFile: "testdata/nonexistent_client.cer",
KeyFile: "testdata/nonexistent_client.key",
},
}
_, err := config_util.NewClientFromConfig(cfg, "test")
if err == nil {
t.Fatalf("Expected error, got nil.")
}
}