plugin: output loki (#8450)

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Labesse Kévin 2021-03-02 21:48:48 +01:00 committed by GitHub
parent cf9ae34d03
commit c17cc8cabb
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@ -27,6 +27,7 @@ import (
_ "github.com/influxdata/telegraf/plugins/outputs/kinesis"
_ "github.com/influxdata/telegraf/plugins/outputs/librato"
_ "github.com/influxdata/telegraf/plugins/outputs/logzio"
_ "github.com/influxdata/telegraf/plugins/outputs/loki"
_ "github.com/influxdata/telegraf/plugins/outputs/mqtt"
_ "github.com/influxdata/telegraf/plugins/outputs/nats"
_ "github.com/influxdata/telegraf/plugins/outputs/newrelic"

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@ -0,0 +1,34 @@
# Loki Output Plugin
This plugin sends logs to Loki, using tags as labels,
log line will content all fields in `key="value"` format which is easily parsable with `logfmt` parser in Loki.
### Configuration:
```toml
# A plugin that can transmit logs to Loki
[[outputs.loki]]
## The domain of Loki
domain = "https://loki.domain.tld"
## Endpoint to write api
# endpoint = "/loki/api/v1/push"
## Connection timeout, defaults to "5s" if not set.
# timeout = "5s"
## Basic auth credential
# username = "loki"
# password = "pass"
## Additional HTTP headers
# http_headers = {"X-Scope-OrgID" = "1"}
## If the request must be gzip encoded
# gzip_request = false
## Optional TLS Config
# tls_ca = "/etc/telegraf/ca.pem"
# tls_cert = "/etc/telegraf/cert.pem"
# tls_key = "/etc/telegraf/key.pem"
```

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@ -0,0 +1,209 @@
package loki
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net/http"
"strings"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/plugins/common/tls"
"github.com/influxdata/telegraf/plugins/outputs"
"golang.org/x/oauth2"
"golang.org/x/oauth2/clientcredentials"
)
const (
defaultEndpoint = "/loki/api/v1/push"
defaultClientTimeout = 5 * time.Second
)
var sampleConfig = `
## The domain of Loki
domain = "https://loki.domain.tld"
## Endpoint to write api
# endpoint = "/loki/api/v1/push"
## Connection timeout, defaults to "5s" if not set.
# timeout = "5s"
## Basic auth credential
# username = "loki"
# password = "pass"
## Additional HTTP headers
# http_headers = {"X-Scope-OrgID" = "1"}
## If the request must be gzip encoded
# gzip_request = false
## Optional TLS Config
# tls_ca = "/etc/telegraf/ca.pem"
# tls_cert = "/etc/telegraf/cert.pem"
# tls_key = "/etc/telegraf/key.pem"
`
type Loki struct {
Domain string `toml:"domain"`
Endpoint string `toml:"endpoint"`
Timeout internal.Duration `toml:"timeout"`
Username string `toml:"username"`
Password string `toml:"password"`
Headers map[string]string `toml:"headers"`
ClientID string `toml:"client_id"`
ClientSecret string `toml:"client_secret"`
TokenURL string `toml:"token_url"`
Scopes []string `toml:"scopes"`
GZipRequest bool `toml:"gzip_request"`
url string
client *http.Client
tls.ClientConfig
}
func (l *Loki) SampleConfig() string {
return sampleConfig
}
func (l *Loki) Description() string {
return "Send logs to Loki"
}
func (l *Loki) createClient(ctx context.Context) (*http.Client, error) {
tlsCfg, err := l.ClientConfig.TLSConfig()
if err != nil {
return nil, fmt.Errorf("tls config fail: %w", err)
}
client := &http.Client{
Transport: &http.Transport{
TLSClientConfig: tlsCfg,
Proxy: http.ProxyFromEnvironment,
},
Timeout: l.Timeout.Duration,
}
if l.ClientID != "" && l.ClientSecret != "" && l.TokenURL != "" {
oauthConfig := clientcredentials.Config{
ClientID: l.ClientID,
ClientSecret: l.ClientSecret,
TokenURL: l.TokenURL,
Scopes: l.Scopes,
}
ctx = context.WithValue(ctx, oauth2.HTTPClient, client)
client = oauthConfig.Client(ctx)
}
return client, nil
}
func (l *Loki) Connect() (err error) {
if l.Domain == "" {
return fmt.Errorf("domain is required")
}
if l.Endpoint == "" {
l.Endpoint = defaultEndpoint
}
l.url = fmt.Sprintf("%s%s", l.Domain, l.Endpoint)
if l.Timeout.Duration == 0 {
l.Timeout.Duration = defaultClientTimeout
}
ctx := context.Background()
l.client, err = l.createClient(ctx)
if err != nil {
return fmt.Errorf("http client fail: %w", err)
}
return
}
func (l *Loki) Close() error {
l.client.CloseIdleConnections()
return nil
}
func (l *Loki) Write(metrics []telegraf.Metric) error {
s := Streams{}
for _, m := range metrics {
tags := m.TagList()
var line string
for _, f := range m.FieldList() {
line += fmt.Sprintf("%s=\"%v\" ", f.Key, f.Value)
}
s.insertLog(tags, Log{fmt.Sprintf("%d", m.Time().UnixNano()), line})
}
return l.write(s)
}
func (l *Loki) write(s Streams) error {
bs, err := json.Marshal(s)
if err != nil {
return fmt.Errorf("json.Marshal: %w", err)
}
var reqBodyBuffer io.Reader = bytes.NewBuffer(bs)
if l.GZipRequest {
rc, err := internal.CompressWithGzip(reqBodyBuffer)
if err != nil {
return err
}
defer rc.Close()
reqBodyBuffer = rc
}
req, err := http.NewRequest(http.MethodPost, l.url, reqBodyBuffer)
if err != nil {
return err
}
if l.Username != "" {
req.SetBasicAuth(l.Username, l.Password)
}
for k, v := range l.Headers {
if strings.ToLower(k) == "host" {
req.Host = v
}
req.Header.Set(k, v)
}
req.Header.Set("User-Agent", internal.ProductToken())
req.Header.Set("Content-Type", "application/json")
if l.GZipRequest {
req.Header.Set("Content-Encoding", "gzip")
}
resp, err := l.client.Do(req)
if err != nil {
return err
}
_ = resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
return fmt.Errorf("when writing to [%s] received status code: %d", l.url, resp.StatusCode)
}
return nil
}
func init() {
outputs.Add("loki", func() telegraf.Output {
return &Loki{}
})
}

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@ -0,0 +1,356 @@
package loki
import (
"compress/gzip"
"encoding/json"
"fmt"
"github.com/influxdata/telegraf/testutil"
"io/ioutil"
"net/http"
"net/http/httptest"
"net/url"
"testing"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/stretchr/testify/require"
)
func getMetric() telegraf.Metric {
return testutil.MustMetric(
"log",
map[string]string{
"key1": "value1",
},
map[string]interface{}{
"line": "my log",
"field": 3.14,
},
time.Unix(123, 0),
)
}
func TestStatusCode(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
tests := []struct {
name string
plugin *Loki
statusCode int
errFunc func(t *testing.T, err error)
}{
{
name: "success",
plugin: &Loki{
Domain: u.String(),
},
statusCode: http.StatusNoContent,
errFunc: func(t *testing.T, err error) {
require.NoError(t, err)
},
},
{
name: "1xx status is an error",
plugin: &Loki{
Domain: u.String(),
},
statusCode: 103,
errFunc: func(t *testing.T, err error) {
require.Error(t, err)
},
},
{
name: "3xx status is an error",
plugin: &Loki{
Domain: u.String(),
},
statusCode: http.StatusMultipleChoices,
errFunc: func(t *testing.T, err error) {
require.Error(t, err)
},
},
{
name: "4xx status is an error",
plugin: &Loki{
Domain: u.String(),
},
statusCode: http.StatusMultipleChoices,
errFunc: func(t *testing.T, err error) {
require.Error(t, err)
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(tt.statusCode)
})
err = tt.plugin.Connect()
require.NoError(t, err)
err = tt.plugin.Write([]telegraf.Metric{getMetric()})
tt.errFunc(t, err)
})
}
}
func TestContentType(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
tests := []struct {
name string
plugin *Loki
expected string
}{
{
name: "default is application/json",
plugin: &Loki{
Domain: u.String(),
},
expected: "application/json",
},
{
name: "overwrite content_type",
plugin: &Loki{
Domain: u.String(),
Headers: map[string]string{"Content-Type": "plain/text"},
},
// plugin force content-type
expected: "application/json",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
require.Equal(t, tt.expected, r.Header.Get("Content-Type"))
w.WriteHeader(http.StatusOK)
})
err = tt.plugin.Connect()
require.NoError(t, err)
err = tt.plugin.Write([]telegraf.Metric{getMetric()})
require.NoError(t, err)
})
}
}
func TestContentEncodingGzip(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
tests := []struct {
name string
plugin *Loki
expected string
}{
{
name: "default is no content encoding",
plugin: &Loki{
Domain: u.String(),
},
expected: "",
},
{
name: "overwrite content_encoding",
plugin: &Loki{
Domain: u.String(),
GZipRequest: true,
},
expected: "gzip",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
require.Equal(t, tt.expected, r.Header.Get("Content-Encoding"))
body := r.Body
var err error
if r.Header.Get("Content-Encoding") == "gzip" {
body, err = gzip.NewReader(r.Body)
require.NoError(t, err)
}
payload, err := ioutil.ReadAll(body)
require.NoError(t, err)
var s Request
err = json.Unmarshal(payload, &s)
require.NoError(t, err)
require.Len(t, s.Streams, 1)
require.Len(t, s.Streams[0].Logs, 1)
require.Len(t, s.Streams[0].Logs[0], 2)
require.Equal(t, map[string]string{"key1": "value1"}, s.Streams[0].Labels)
require.Equal(t, "123000000000", s.Streams[0].Logs[0][0])
require.Contains(t, s.Streams[0].Logs[0][1], "line=\"my log\"")
require.Contains(t, s.Streams[0].Logs[0][1], "field=\"3.14\"")
w.WriteHeader(http.StatusNoContent)
})
err = tt.plugin.Connect()
require.NoError(t, err)
err = tt.plugin.Write([]telegraf.Metric{getMetric()})
require.NoError(t, err)
})
}
}
func TestBasicAuth(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
tests := []struct {
name string
plugin *Loki
}{
{
name: "default",
plugin: &Loki{
Domain: u.String(),
},
},
{
name: "username and password",
plugin: &Loki{
Domain: u.String(),
Username: "username",
Password: "pa$$word",
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
username, password, _ := r.BasicAuth()
require.Equal(t, tt.plugin.Username, username)
require.Equal(t, tt.plugin.Password, password)
w.WriteHeader(http.StatusOK)
})
err = tt.plugin.Connect()
require.NoError(t, err)
err = tt.plugin.Write([]telegraf.Metric{getMetric()})
require.NoError(t, err)
})
}
}
type TestHandlerFunc func(t *testing.T, w http.ResponseWriter, r *http.Request)
func TestOAuthClientCredentialsGrant(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
var token = "2YotnFZFEjr1zCsicMWpAA"
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
tests := []struct {
name string
plugin *Loki
tokenHandler TestHandlerFunc
handler TestHandlerFunc
}{
{
name: "no credentials",
plugin: &Loki{
Domain: u.String(),
},
handler: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
require.Len(t, r.Header["Authorization"], 0)
w.WriteHeader(http.StatusOK)
},
},
{
name: "success",
plugin: &Loki{
Domain: u.String(),
ClientID: "howdy",
ClientSecret: "secret",
TokenURL: u.String() + "/token",
Scopes: []string{"urn:opc:idm:__myscopes__"},
},
tokenHandler: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
values := url.Values{}
values.Add("access_token", token)
values.Add("token_type", "bearer")
values.Add("expires_in", "3600")
w.Write([]byte(values.Encode()))
},
handler: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
require.Equal(t, []string{"Bearer " + token}, r.Header["Authorization"])
w.WriteHeader(http.StatusOK)
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
switch r.URL.Path {
case defaultEndpoint:
tt.handler(t, w, r)
case "/token":
tt.tokenHandler(t, w, r)
}
})
err = tt.plugin.Connect()
require.NoError(t, err)
err = tt.plugin.Write([]telegraf.Metric{getMetric()})
require.NoError(t, err)
})
}
}
func TestDefaultUserAgent(t *testing.T) {
ts := httptest.NewServer(http.NotFoundHandler())
defer ts.Close()
u, err := url.Parse(fmt.Sprintf("http://%s", ts.Listener.Addr().String()))
require.NoError(t, err)
t.Run("default-user-agent", func(t *testing.T) {
ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
require.Equal(t, internal.ProductToken(), r.Header.Get("User-Agent"))
w.WriteHeader(http.StatusOK)
})
client := &Loki{
Domain: u.String(),
}
err = client.Connect()
require.NoError(t, err)
err = client.Write([]telegraf.Metric{getMetric()})
require.NoError(t, err)
})
}

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@ -0,0 +1,70 @@
package loki
import (
"encoding/json"
"fmt"
"strings"
"github.com/influxdata/telegraf"
)
type (
Log []string
Streams map[string]*Stream
Stream struct {
Labels map[string]string `json:"stream"`
Logs []Log `json:"values"`
}
Request struct {
Streams []Stream `json:"streams"`
}
)
func (s Streams) insertLog(ts []*telegraf.Tag, l Log) {
key := uniqKeyFromTagList(ts)
if _, ok := s[key]; !ok {
s[key] = newStream(ts)
}
s[key].Logs = append(s[key].Logs, l)
}
func (s Streams) MarshalJSON() ([]byte, error) {
r := Request{
Streams: make([]Stream, 0, len(s)),
}
for _, stream := range s {
r.Streams = append(r.Streams, *stream)
}
return json.Marshal(r)
}
func uniqKeyFromTagList(ts []*telegraf.Tag) (k string) {
for _, t := range ts {
k += fmt.Sprintf("%s-%s-",
strings.ReplaceAll(t.Key, "-", "--"),
strings.ReplaceAll(t.Value, "-", "--"),
)
}
return k
}
func newStream(ts []*telegraf.Tag) *Stream {
s := &Stream{
Logs: make([]Log, 0),
Labels: map[string]string{},
}
for _, t := range ts {
s.Labels[t.Key] = t.Value
}
return s
}

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@ -0,0 +1,157 @@
package loki
import (
"testing"
"github.com/influxdata/telegraf"
"github.com/stretchr/testify/require"
)
type tuple struct {
key, value string
}
func generateLabelsAndTag(tt ...tuple) (map[string]string, []*telegraf.Tag) {
labels := map[string]string{}
var tags []*telegraf.Tag
for _, t := range tt {
labels[t.key] = t.value
tags = append(tags, &telegraf.Tag{Key: t.key, Value: t.value})
}
return labels, tags
}
func TestGenerateLabelsAndTag(t *testing.T) {
labels, tags := generateLabelsAndTag(
tuple{key: "key1", value: "value1"},
tuple{key: "key2", value: "value2"},
tuple{key: "key3", value: "value3"},
)
expectedTags := []*telegraf.Tag{
{Key: "key1", Value: "value1"},
{Key: "key2", Value: "value2"},
{Key: "key3", Value: "value3"},
}
require.Len(t, labels, 3)
require.Len(t, tags, 3)
require.Equal(t, map[string]string{"key1": "value1", "key2": "value2", "key3": "value3"}, labels)
require.Equal(t, map[string]string{"key1": "value1", "key2": "value2", "key3": "value3"}, labels)
require.Equal(t, expectedTags, tags)
}
func TestStream_insertLog(t *testing.T) {
s := Streams{}
log1 := Log{"123", "this log isn't useful"}
log2 := Log{"124", "this log isn't useful neither"}
log3 := Log{"122", "again"}
key1 := "key1-value1-key2-value2-key3-value3-"
labels1, tags1 := generateLabelsAndTag(
tuple{key: "key1", value: "value1"},
tuple{key: "key2", value: "value2"},
tuple{key: "key3", value: "value3"},
)
key2 := "key2-value2-"
labels2, tags2 := generateLabelsAndTag(
tuple{key: "key2", value: "value2"},
)
s.insertLog(tags1, log1)
require.Len(t, s, 1)
require.Contains(t, s, key1)
require.Len(t, s[key1].Logs, 1)
require.Equal(t, labels1, s[key1].Labels)
require.Equal(t, "123", s[key1].Logs[0][0])
require.Equal(t, "this log isn't useful", s[key1].Logs[0][1])
s.insertLog(tags1, log2)
require.Len(t, s, 1)
require.Len(t, s[key1].Logs, 2)
require.Equal(t, "124", s[key1].Logs[1][0])
require.Equal(t, "this log isn't useful neither", s[key1].Logs[1][1])
s.insertLog(tags2, log3)
require.Len(t, s, 2)
require.Contains(t, s, key2)
require.Len(t, s[key2].Logs, 1)
require.Equal(t, labels2, s[key2].Labels)
require.Equal(t, "122", s[key2].Logs[0][0])
require.Equal(t, "again", s[key2].Logs[0][1])
}
func TestUniqKeyFromTagList(t *testing.T) {
tests := []struct {
in []*telegraf.Tag
out string
}{
{
in: []*telegraf.Tag{
{Key: "key1", Value: "value1"},
{Key: "key2", Value: "value2"},
{Key: "key3", Value: "value3"},
},
out: "key1-value1-key2-value2-key3-value3-",
},
{
in: []*telegraf.Tag{
{Key: "key1", Value: "value1"},
{Key: "key3", Value: "value3"},
{Key: "key4", Value: "value4"},
},
out: "key1-value1-key3-value3-key4-value4-",
},
{
in: []*telegraf.Tag{
{Key: "target", Value: "local"},
{Key: "host", Value: "host"},
{Key: "service", Value: "dns"},
},
out: "target-local-host-host-service-dns-",
},
{
in: []*telegraf.Tag{
{Key: "target", Value: "localhost"},
{Key: "hostservice", Value: "dns"},
},
out: "target-localhost-hostservice-dns-",
},
{
in: []*telegraf.Tag{
{Key: "target-local", Value: "host-"},
},
out: "target--local-host---",
},
}
for _, test := range tests {
require.Equal(t, test.out, uniqKeyFromTagList(test.in))
}
}
func Test_newStream(t *testing.T) {
labels, tags := generateLabelsAndTag(
tuple{key: "key1", value: "value1"},
tuple{key: "key2", value: "value2"},
tuple{key: "key3", value: "value3"},
)
s := newStream(tags)
require.Empty(t, s.Logs)
require.Equal(t, s.Labels, labels)
}
func Test_newStream_noTag(t *testing.T) {
s := newStream(nil)
require.Empty(t, s.Logs)
require.Empty(t, s.Labels)
}