Add prometheus remote write serializer (#8360)

docs/LICENSE_OF_DEPENDENCIES.md

@@ -71,6 +71,7 @@ following works:
 - github.com/googleapis/gax-go [BSD 3-Clause "New" or "Revised" License](https://github.com/googleapis/gax-go/blob/master/LICENSE)
 - github.com/gopcua/opcua [MIT License](https://github.com/gopcua/opcua/blob/master/LICENSE)
 - github.com/gorilla/mux [BSD 3-Clause "New" or "Revised" License](https://github.com/gorilla/mux/blob/master/LICENSE)
+- github.com/grpc-ecosystem/grpc-gateway [BSD 3-Clause "New" or "Revised" License](https://github.com/grpc-ecosystem/grpc-gateway/blob/master/LICENSE.txt)
 - github.com/hailocab/go-hostpool [MIT License](https://github.com/hailocab/go-hostpool/blob/master/LICENSE)
 - github.com/harlow/kinesis-consumer [MIT License](https://github.com/harlow/kinesis-consumer/blob/master/MIT-LICENSE)
 - github.com/hashicorp/consul [Mozilla Public License 2.0](https://github.com/hashicorp/consul/blob/master/LICENSE)
@@ -122,6 +123,7 @@ following works:
 - github.com/prometheus/client_model [Apache License 2.0](https://github.com/prometheus/client_model/blob/master/LICENSE)
 - github.com/prometheus/common [Apache License 2.0](https://github.com/prometheus/common/blob/master/LICENSE)
 - github.com/prometheus/procfs [Apache License 2.0](https://github.com/prometheus/procfs/blob/master/LICENSE)
+- github.com/prometheus/prometheus [Apache License 2.0](https://github.com/prometheus/prometheus/blob/master/LICENSE)
 - github.com/rcrowley/go-metrics [MIT License](https://github.com/rcrowley/go-metrics/blob/master/LICENSE)
 - github.com/riemann/riemann-go-client [MIT License](https://github.com/riemann/riemann-go-client/blob/master/LICENSE)
 - github.com/safchain/ethtool [Apache License 2.0](https://github.com/safchain/ethtool/blob/master/LICENSE)

go.mod

@@ -61,10 +61,12 @@ require (
 	github.com/gogo/protobuf v1.2.2-0.20190723190241-65acae22fc9d
 	github.com/golang/geo v0.0.0-20190916061304-5b978397cfec
 	github.com/golang/protobuf v1.3.5
+	github.com/golang/snappy v0.0.1
 	github.com/google/go-cmp v0.5.2
 	github.com/google/go-github/v32 v32.1.0
 	github.com/gopcua/opcua v0.1.12
 	github.com/gorilla/mux v1.6.2
+	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
 	github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed // indirect
 	github.com/harlow/kinesis-consumer v0.3.1-0.20181230152818-2f58b136fee0
 	github.com/hashicorp/consul v1.2.1
@@ -108,6 +110,7 @@ require (
 	github.com/prometheus/client_model v0.2.0
 	github.com/prometheus/common v0.9.1
 	github.com/prometheus/procfs v0.0.8
+	github.com/prometheus/prometheus v2.5.0+incompatible
 	github.com/riemann/riemann-go-client v0.5.0
 	github.com/safchain/ethtool v0.0.0-20200218184317-f459e2d13664
 	github.com/samuel/go-zookeeper v0.0.0-20180130194729-c4fab1ac1bec // indirect
@@ -142,8 +145,8 @@ require (
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20200205215550-e35592f146e4
 	gonum.org/v1/gonum v0.6.2 // indirect
 	google.golang.org/api v0.20.0
-	google.golang.org/genproto v0.0.0-20200317114155-1f3552e48f24
+	google.golang.org/genproto v0.0.0-20200513103714-09dca8ec2884
-	google.golang.org/grpc v1.28.0
+	google.golang.org/grpc v1.33.1
 	gopkg.in/fatih/pool.v2 v2.0.0 // indirect
 	gopkg.in/gorethink/gorethink.v3 v3.0.5
 	gopkg.in/ldap.v3 v3.1.0

go.sum

@@ -103,6 +103,7 @@ github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4 h1:Hs82Z41s6SdL1C
 github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/amir/raidman v0.0.0-20170415203553-1ccc43bfb9c9 h1:FXrPTd8Rdlc94dKccl7KPmdmIbVh/OjelJ8/vgMRzcQ=
 github.com/amir/raidman v0.0.0-20170415203553-1ccc43bfb9c9/go.mod h1:eliMa/PW+RDr2QLWRmLH1R1ZA4RInpmvOzDDXtaIZkc=
+github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
 github.com/apache/thrift v0.12.0 h1:pODnxUFNcjP9UTLZGTdeh+j16A8lJbRvD3rOtrk/7bs=
 github.com/apache/thrift v0.12.0/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/aristanetworks/glog v0.0.0-20191112221043-67e8567f59f3 h1:Bmjk+DjIi3tTAU0wxGaFbfjGUqlxxSXARq9A96Kgoos=
@@ -204,6 +205,7 @@ github.com/frankban/quicktest v1.10.2/go.mod h1:K+q6oSqb0W0Ininfk863uOk1lMy69l/P
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v0.0.0-20150909031657-73d445a93680/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/ghodss/yaml v1.0.1-0.20190212211648-25d852aebe32 h1:Mn26/9ZMNWSw9C9ERFA1PUxfmGpolnw2v0bKOREu5ew=
 github.com/ghodss/yaml v1.0.1-0.20190212211648-25d852aebe32/go.mod h1:GIjDIg/heH5DOkXY3YJ/wNhfHsQHoXGjl8G8amsYQ1I=
 github.com/glinton/ping v0.1.4-0.20200311211934-5ac87da8cd96 h1:YpooqMW354GG47PXNBiaCv6yCQizyP3MXD9NUPrCEQ8=
@@ -300,6 +302,8 @@ github.com/google/pprof v0.0.0-20200212024743-f11f1df84d12/go.mod h1:ZgVRPoUq/hf
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/google/uuid v1.1.2 h1:EVhdT+1Kseyi1/pUmXKaFxYsDNy9RQYkMWRH68J/W7Y=
+github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4 h1:hU4mGcQI4DaAYW+IbTun+2qEZVFxK0ySjQLTbS0VQKc=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5 h1:sjZBwGj9Jlw33ImPtvFviGYvseOtDM7hkSKB7+Tv3SM=
@@ -311,6 +315,8 @@ github.com/gorilla/context v1.1.1 h1:AWwleXJkX/nhcU9bZSnZoi3h/qGYqQAGhq6zZe/aQW8
 github.com/gorilla/context v1.1.1/go.mod h1:kBGZzfjB9CEq2AlWe17Uuf7NDRt0dE0s8S51q0aT7Yg=
 github.com/gorilla/mux v1.6.2 h1:Pgr17XVTNXAk3q/r4CpKzC5xBM/qW1uVLV+IhRZpIIk=
 github.com/gorilla/mux v1.6.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
+github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
+github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
 github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed h1:5upAirOpQc1Q53c0bnx2ufif5kANL7bfZWcc6VJWJd8=
 github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed/go.mod h1:tMWxXQ9wFIaZeTI9F+hmhFiGpFmhOHzyShyFUhRm0H4=
 github.com/harlow/kinesis-consumer v0.3.1-0.20181230152818-2f58b136fee0 h1:U0KvGD9CJIl1nbgu9yLsfWxMT6WqL8fG0IBB7RvOZZQ=
@@ -534,6 +540,8 @@ github.com/prometheus/procfs v0.0.0-20190117184657-bf6a532e95b1/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.8 h1:+fpWZdT24pJBiqJdAwYBjPSk+5YmQzYNPYzQsdzLkt8=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
+github.com/prometheus/prometheus v2.5.0+incompatible h1:7QPitgO2kOFG8ecuRn9O/4L9+10He72rVRJvMXrE9Hg=
+github.com/prometheus/prometheus v2.5.0+incompatible/go.mod h1:oAIUtOny2rjMX0OWN5vPR5/q/twIROJvdqnQKDdil/s=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a h1:9ZKAASQSHhDYGoxY8uLVpewe1GDZ2vu2Tr/vTdVAkFQ=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/rcrowley/go-metrics v0.0.0-20200313005456-10cdbea86bc0 h1:MkV+77GLUNo5oJ0jf870itWm3D0Sjh7+Za9gazKc5LQ=
@@ -542,6 +550,7 @@ github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0 h1:OdAsTTz6O
 github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 github.com/riemann/riemann-go-client v0.5.0 h1:yPP7tz1vSYJkSZvZFCsMiDsHHXX57x8/fEX3qyEXuAA=
 github.com/riemann/riemann-go-client v0.5.0/go.mod h1:FMiaOL8dgBnRfgwENzV0xlYJ2eCbV1o7yqVwOBLbShQ=
+github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/safchain/ethtool v0.0.0-20200218184317-f459e2d13664 h1:gvolwzuDhul9qK6/oHqxCHD5TEYfsWNBGidOeG6kvpk=
 github.com/safchain/ethtool v0.0.0-20200218184317-f459e2d13664/go.mod h1:Z0q5wiBQGYcxhMZ6gUqHn6pYNLypFAvaL3UvgZLR0U4=
@@ -698,6 +707,7 @@ golang.org/x/net v0.0.0-20200114155413-6afb5195e5aa/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2 h1:CCH4IOTTfewWjGOlSp+zGcjutRKlBEZQ6wTn8ozI/nI=
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200904194848-62affa334b73 h1:MXfv8rhZWmFeqX3GNZRsd6vOLoaCHjYEX3qkRo3YBUA=
 golang.org/x/net v0.0.0-20200904194848-62affa334b73/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
@@ -856,8 +866,8 @@ google.golang.org/genproto v0.0.0-20200115191322-ca5a22157cba/go.mod h1:n3cpQtvx
 google.golang.org/genproto v0.0.0-20200122232147-0452cf42e150/go.mod h1:n3cpQtvxv34hfy77yVDNjmbRyujviMdxYliBSkLhpCc=
 google.golang.org/genproto v0.0.0-20200204135345-fa8e72b47b90/go.mod h1:GmwEX6Z4W5gMy59cAlVYjN9JhxgbQH6Gn+gFDQe2lzA=
 google.golang.org/genproto v0.0.0-20200212174721-66ed5ce911ce/go.mod h1:55QSHmfGQM9UVYDPBsyGGes0y52j32PQ3BqQfXhyH3c=
-google.golang.org/genproto v0.0.0-20200317114155-1f3552e48f24 h1:IGPykv426z7LZSVPlaPufOyphngM4at5uZ7x5alaFvE=
+google.golang.org/genproto v0.0.0-20200513103714-09dca8ec2884 h1:fiNLklpBwWK1mth30Hlwk+fcdBmIALlgF5iy77O37Ig=
-google.golang.org/genproto v0.0.0-20200317114155-1f3552e48f24/go.mod h1:55QSHmfGQM9UVYDPBsyGGes0y52j32PQ3BqQfXhyH3c=
+google.golang.org/genproto v0.0.0-20200513103714-09dca8ec2884/go.mod h1:55QSHmfGQM9UVYDPBsyGGes0y52j32PQ3BqQfXhyH3c=
 google.golang.org/grpc v1.17.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
 google.golang.org/grpc v1.19.0 h1:cfg4PD8YEdSFnm7qLV4++93WcmhH2nIUhMjhdCvl3j8=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
@@ -868,8 +878,8 @@ google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQ
 google.golang.org/grpc v1.26.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.27.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.27.1/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
-google.golang.org/grpc v1.28.0 h1:bO/TA4OxCOummhSf10siHuG7vJOiwh7SpRpFZDkOgl4=
+google.golang.org/grpc v1.33.1 h1:DGeFlSan2f+WEtCERJ4J9GJWk15TxUi8QGagfI87Xyc=
-google.golang.org/grpc v1.28.0/go.mod h1:rpkK4SK4GF4Ach/+MFLZUBavHOvF2JJB5uozKKal+60=
+google.golang.org/grpc v1.33.1/go.mod h1:fr5YgcSWrqhRRxogOsw7RzIpsmvOZ6IcH4kBYTpR3n0=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/asn1-ber.v1 v1.0.0-20181015200546-f715ec2f112d h1:TxyelI5cVkbREznMhfzycHdkp5cLA7DpE+GKjSslYhM=
 gopkg.in/asn1-ber.v1 v1.0.0-20181015200546-f715ec2f112d/go.mod h1:cuepJuh7vyXfUyUwEgHQXw849cJrilpS5NeIjOWESAw=
@@ -914,6 +924,7 @@ gopkg.in/tomb.v2 v2.0.0-20161208151619-d5d1b5820637 h1:yiW+nvdHb9LVqSHQBXfZCieqV
 gopkg.in/tomb.v2 v2.0.0-20161208151619-d5d1b5820637/go.mod h1:BHsqpu/nsuzkT5BpiH1EMZPLyqSMM8JbIavyFACoFNk=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.3/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.5 h1:ymVxjfMaHvXD8RqPRmzHHsB3VvucivSkIAvJFDI5O3c=

plugins/serializers/prometheusremotewrite/README.md

@@ -0,0 +1,38 @@
+# Prometheus
+
+The `prometheusremotewrite` data format converts metrics into the Prometheus protobuf
+exposition format.
+
+**Warning**: When generating histogram and summary types, output may
+not be correct if the metric spans multiple batches.  This issue can be
+somewhat, but not fully, mitigated by using outputs that support writing in
+"batch format".  When using histogram and summary types, it is recommended to
+use only the `prometheus_client` output.
+
+### Configuration
+
+```toml
+[[outputs.http]]
+  url = "https://cortex/api/prom/push"
+  data_format = "prometheusremotewrite"
+  tls_ca = "/etc/telegraf/ca.pem"
+  tls_cert = "/etc/telegraf/cert.pem"
+  tls_key = "/etc/telegraf/key.pem"
+  [outputs.http.headers]
+     Content-Type = "application/x-protobuf"
+     Content-Encoding = "snappy"
+     X-Prometheus-Remote-Write-Version = "0.1.0"
+```
+
+### Metrics
+
+A Prometheus metric is created for each integer, float, boolean or unsigned
+field.  Boolean values are converted to *1.0* for true and *0.0* for false.
+
+The Prometheus metric names are produced by joining the measurement name with
+the field key.  In the special case where the measurement name is `prometheus`
+it is not included in the final metric name.
+
+Prometheus labels are produced for each tag.
+
+**Note:** String fields are ignored and do not produce Prometheus metrics.

plugins/serializers/prometheusremotewrite/prometheusremotewrite.go

@@ -0,0 +1,341 @@
+package prometheusremotewrite
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/influxdata/telegraf/plugins/serializers/prometheus"
+	"hash/fnv"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/prometheus/prometheus/prompb"
+)
+
+type MetricKey uint64
+
+// MetricSortOrder controls if the output is sorted.
+type MetricSortOrder int
+
+const (
+	NoSortMetrics MetricSortOrder = iota
+	SortMetrics
+)
+
+// StringHandling defines how to process string fields.
+type StringHandling int
+
+const (
+	DiscardStrings StringHandling = iota
+	StringAsLabel
+)
+
+type FormatConfig struct {
+	MetricSortOrder MetricSortOrder
+	StringHandling  StringHandling
+}
+
+type Serializer struct {
+	config FormatConfig
+}
+
+func NewSerializer(config FormatConfig) (*Serializer, error) {
+	s := &Serializer{config: config}
+	return s, nil
+}
+
+func (s *Serializer) Serialize(metric telegraf.Metric) ([]byte, error) {
+	return s.SerializeBatch([]telegraf.Metric{metric})
+}
+
+func (s *Serializer) SerializeBatch(metrics []telegraf.Metric) ([]byte, error) {
+	var buf bytes.Buffer
+	var entries = make(map[MetricKey]*prompb.TimeSeries)
+	for _, metric := range metrics {
+		commonLabels := s.createLabels(metric)
+		var metrickey MetricKey
+		var promts *prompb.TimeSeries
+		for _, field := range metric.FieldList() {
+			metricName := prometheus.MetricName(metric.Name(), field.Key, metric.Type())
+			metricName, ok := prometheus.SanitizeMetricName(metricName)
+			if !ok {
+				continue
+			}
+			switch metric.Type() {
+			case telegraf.Counter:
+				fallthrough
+			case telegraf.Gauge:
+				fallthrough
+			case telegraf.Untyped:
+				value, ok := prometheus.SampleValue(field.Value)
+				if !ok {
+					continue
+				}
+				metrickey, promts = getPromTS(metricName, commonLabels, value, metric.Time())
+			case telegraf.Histogram:
+				switch {
+				case strings.HasSuffix(field.Key, "_bucket"):
+					// if bucket only, init sum, count, inf
+					metrickeysum, promtssum := getPromTS(fmt.Sprintf("%s_sum", metricName), commonLabels, float64(0), metric.Time())
+					if _, ok = entries[metrickeysum]; !ok {
+						entries[metrickeysum] = promtssum
+					}
+					metrickeycount, promtscount := getPromTS(fmt.Sprintf("%s_count", metricName), commonLabels, float64(0), metric.Time())
+					if _, ok = entries[metrickeycount]; !ok {
+						entries[metrickeycount] = promtscount
+					}
+					labels := make([]*prompb.Label, len(commonLabels), len(commonLabels)+1)
+					copy(labels, commonLabels)
+					labels = append(labels, &prompb.Label{
+						Name:  "le",
+						Value: "+Inf",
+					})
+					metrickeyinf, promtsinf := getPromTS(fmt.Sprintf("%s_bucket", metricName), labels, float64(0), metric.Time())
+					if _, ok = entries[metrickeyinf]; !ok {
+						entries[metrickeyinf] = promtsinf
+					}
+
+					le, ok := metric.GetTag("le")
+					if !ok {
+						continue
+					}
+					bound, err := strconv.ParseFloat(le, 64)
+					if err != nil {
+						continue
+					}
+					count, ok := prometheus.SampleCount(field.Value)
+					if !ok {
+						continue
+					}
+
+					labels = make([]*prompb.Label, len(commonLabels), len(commonLabels)+1)
+					copy(labels, commonLabels)
+					labels = append(labels, &prompb.Label{
+						Name:  "le",
+						Value: fmt.Sprint(bound),
+					})
+					metrickey, promts = getPromTS(fmt.Sprintf("%s_bucket", metricName), labels, float64(count), metric.Time())
+				case strings.HasSuffix(field.Key, "_sum"):
+					sum, ok := prometheus.SampleSum(field.Value)
+					if !ok {
+						continue
+					}
+
+					metrickey, promts = getPromTS(fmt.Sprintf("%s_sum", metricName), commonLabels, sum, metric.Time())
+				case strings.HasSuffix(field.Key, "_count"):
+					count, ok := prometheus.SampleCount(field.Value)
+					if !ok {
+						continue
+					}
+
+					// if no bucket generate +Inf entry
+					labels := make([]*prompb.Label, len(commonLabels), len(commonLabels)+1)
+					copy(labels, commonLabels)
+					labels = append(labels, &prompb.Label{
+						Name:  "le",
+						Value: "+Inf",
+					})
+					metrickeyinf, promtsinf := getPromTS(fmt.Sprintf("%s_bucket", metricName), labels, float64(count), metric.Time())
+					if minf, ok := entries[metrickeyinf]; !ok || minf.Samples[0].Value == 0 {
+						entries[metrickeyinf] = promtsinf
+					}
+
+					metrickey, promts = getPromTS(fmt.Sprintf("%s_count", metricName), commonLabels, float64(count), metric.Time())
+				default:
+					continue
+				}
+			case telegraf.Summary:
+				switch {
+				case strings.HasSuffix(field.Key, "_sum"):
+					sum, ok := prometheus.SampleSum(field.Value)
+					if !ok {
+						continue
+					}
+
+					metrickey, promts = getPromTS(fmt.Sprintf("%s_sum", metricName), commonLabels, sum, metric.Time())
+				case strings.HasSuffix(field.Key, "_count"):
+					count, ok := prometheus.SampleCount(field.Value)
+					if !ok {
+						continue
+					}
+
+					metrickey, promts = getPromTS(fmt.Sprintf("%s_count", metricName), commonLabels, float64(count), metric.Time())
+				default:
+					quantileTag, ok := metric.GetTag("quantile")
+					if !ok {
+						continue
+					}
+					quantile, err := strconv.ParseFloat(quantileTag, 64)
+					if err != nil {
+						continue
+					}
+					value, ok := prometheus.SampleValue(field.Value)
+					if !ok {
+						continue
+					}
+
+					labels := make([]*prompb.Label, len(commonLabels), len(commonLabels)+1)
+					copy(labels, commonLabels)
+					labels = append(labels, &prompb.Label{
+						Name:  "quantile",
+						Value: fmt.Sprint(quantile),
+					})
+					metrickey, promts = getPromTS(metricName, labels, value, metric.Time())
+				}
+			default:
+				return nil, fmt.Errorf("Unknown type %v", metric.Type())
+			}
+
+			// A batch of metrics can contain multiple values for a single
+			// Prometheus sample.  If this metric is older than the existing
+			// sample then we can skip over it.
+			m, ok := entries[metrickey]
+			if ok {
+				if metric.Time().Before(time.Unix(m.Samples[0].Timestamp, 0)) {
+					continue
+				}
+			}
+			entries[metrickey] = promts
+		}
+
+	}
+
+	var promTS = make([]*prompb.TimeSeries, len(entries))
+	var i int64 = 0
+	for _, promts := range entries {
+		promTS[i] = promts
+		i++
+	}
+
+	switch s.config.MetricSortOrder {
+	case SortMetrics:
+		sort.Slice(promTS, func(i, j int) bool {
+			lhs := promTS[i].Labels
+			rhs := promTS[j].Labels
+			if len(lhs) != len(rhs) {
+				return len(lhs) < len(rhs)
+			}
+
+			for index := range lhs {
+				l := lhs[index]
+				r := rhs[index]
+
+				if l.Name != r.Name {
+					return l.Name < r.Name
+				}
+
+				if l.Value != r.Value {
+					return l.Value < r.Value
+				}
+			}
+
+			return false
+		})
+
+	}
+	data, err := proto.Marshal(&prompb.WriteRequest{Timeseries: promTS})
+	if err != nil {
+		return nil, fmt.Errorf("unable to marshal protobuf: %v", err)
+	}
+	encoded := snappy.Encode(nil, data)
+	buf.Write(encoded)
+	return buf.Bytes(), nil
+}
+
+func hasLabel(name string, labels []*prompb.Label) bool {
+	for _, label := range labels {
+		if name == label.Name {
+			return true
+		}
+	}
+	return false
+}
+
+func (s *Serializer) createLabels(metric telegraf.Metric) []*prompb.Label {
+	labels := make([]*prompb.Label, 0, len(metric.TagList()))
+	for _, tag := range metric.TagList() {
+		// Ignore special tags for histogram and summary types.
+		switch metric.Type() {
+		case telegraf.Histogram:
+			if tag.Key == "le" {
+				continue
+			}
+		case telegraf.Summary:
+			if tag.Key == "quantile" {
+				continue
+			}
+		}
+
+		name, ok := prometheus.SanitizeLabelName(tag.Key)
+		if !ok {
+			continue
+		}
+
+		labels = append(labels, &prompb.Label{Name: name, Value: tag.Value})
+	}
+
+	if s.config.StringHandling != StringAsLabel {
+		return labels
+	}
+
+	addedFieldLabel := false
+	for _, field := range metric.FieldList() {
+		value, ok := field.Value.(string)
+		if !ok {
+			continue
+		}
+
+		name, ok := prometheus.SanitizeLabelName(field.Key)
+		if !ok {
+			continue
+		}
+
+		// If there is a tag with the same name as the string field, discard
+		// the field and use the tag instead.
+		if hasLabel(name, labels) {
+			continue
+		}
+
+		labels = append(labels, &prompb.Label{Name: name, Value: value})
+		addedFieldLabel = true
+
+	}
+
+	if addedFieldLabel {
+		sort.Slice(labels, func(i, j int) bool {
+			return labels[i].Name < labels[j].Name
+		})
+	}
+
+	return labels
+}
+
+func MakeMetricKey(labels []*prompb.Label) MetricKey {
+	h := fnv.New64a()
+	for _, label := range labels {
+		h.Write([]byte(label.Name))
+		h.Write([]byte("\x00"))
+		h.Write([]byte(label.Value))
+		h.Write([]byte("\x00"))
+	}
+	return MetricKey(h.Sum64())
+}
+
+func getPromTS(name string, labels []*prompb.Label, value float64, ts time.Time) (MetricKey, *prompb.TimeSeries) {
+	sample := []prompb.Sample{{
+		// Timestamp is int milliseconds for remote write.
+		Timestamp: ts.UnixNano() / int64(time.Millisecond),
+		Value:     value,
+	}}
+	labelscopy := make([]*prompb.Label, len(labels), len(labels)+1)
+	copy(labelscopy, labels)
+	labels = append(labelscopy, &prompb.Label{
+		Name:  "__name__",
+		Value: name,
+	})
+	return MakeMetricKey(labels), &prompb.TimeSeries{Labels: labels, Samples: sample}
+}

plugins/serializers/prometheusremotewrite/prometheusremotewrite_test.go

@@ -0,0 +1,674 @@
+package prometheusremotewrite
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/prometheus/common/model"
+	"github.com/prometheus/prometheus/prompb"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRemoteWriteSerialize(t *testing.T) {
+	tests := []struct {
+		name     string
+		config   FormatConfig
+		metric   telegraf.Metric
+		expected []byte
+	}{
+		{
+			name: "simple",
+			metric: testutil.MustMetric(
+				"cpu",
+				map[string]string{
+					"host": "example.org",
+				},
+				map[string]interface{}{
+					"time_idle": 42.0,
+				},
+				time.Unix(0, 0),
+			),
+			expected: []byte(`
+cpu_time_idle{host="example.org"} 42
+`),
+		},
+		{
+			name: "prometheus input untyped",
+			metric: testutil.MustMetric(
+				"prometheus",
+				map[string]string{
+					"code":   "400",
+					"method": "post",
+				},
+				map[string]interface{}{
+					"http_requests_total": 3.0,
+				},
+				time.Unix(0, 0),
+				telegraf.Untyped,
+			),
+			expected: []byte(`
+http_requests_total{code="400", method="post"} 3
+`),
+		},
+		{
+			name: "prometheus input counter",
+			metric: testutil.MustMetric(
+				"prometheus",
+				map[string]string{
+					"code":   "400",
+					"method": "post",
+				},
+				map[string]interface{}{
+					"http_requests_total": 3.0,
+				},
+				time.Unix(0, 0),
+				telegraf.Counter,
+			),
+			expected: []byte(`
+http_requests_total{code="400", method="post"} 3
+`),
+		},
+		{
+			name: "prometheus input gauge",
+			metric: testutil.MustMetric(
+				"prometheus",
+				map[string]string{
+					"code":   "400",
+					"method": "post",
+				},
+				map[string]interface{}{
+					"http_requests_total": 3.0,
+				},
+				time.Unix(0, 0),
+				telegraf.Gauge,
+			),
+			expected: []byte(`
+http_requests_total{code="400", method="post"} 3
+`),
+		},
+		{
+			name: "prometheus input histogram no buckets",
+			metric: testutil.MustMetric(
+				"prometheus",
+				map[string]string{},
+				map[string]interface{}{
+					"http_request_duration_seconds_sum":   53423,
+					"http_request_duration_seconds_count": 144320,
+				},
+				time.Unix(0, 0),
+				telegraf.Histogram,
+			),
+			expected: []byte(`
+http_request_duration_seconds_count 144320
+http_request_duration_seconds_sum 53423
+http_request_duration_seconds_bucket{le="+Inf"} 144320
+`),
+		},
+		{
+			name: "prometheus input histogram only bucket",
+			metric: testutil.MustMetric(
+				"prometheus",
+				map[string]string{
+					"le": "0.5",
+				},
+				map[string]interface{}{
+					"http_request_duration_seconds_bucket": 129389.0,
+				},
+				time.Unix(0, 0),
+				telegraf.Histogram,
+			),
+			expected: []byte(`
+http_request_duration_seconds_count 0
+http_request_duration_seconds_sum 0
+http_request_duration_seconds_bucket{le="+Inf"} 0
+http_request_duration_seconds_bucket{le="0.5"} 129389
+`),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s, err := NewSerializer(FormatConfig{
+				MetricSortOrder: SortMetrics,
+				StringHandling:  tt.config.StringHandling,
+			})
+			require.NoError(t, err)
+			data, err := s.Serialize(tt.metric)
+			actual, err := prompbToText(data)
+			require.NoError(t, err)
+
+			require.Equal(t, strings.TrimSpace(string(tt.expected)),
+				strings.TrimSpace(string(actual)))
+		})
+	}
+}
+
+func TestRemoteWriteSerializeBatch(t *testing.T) {
+	tests := []struct {
+		name     string
+		config   FormatConfig
+		metrics  []telegraf.Metric
+		expected []byte
+	}{
+		{
+			name: "simple",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"host": "one.example.org",
+					},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"host": "two.example.org",
+					},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{host="one.example.org"} 42
+cpu_time_idle{host="two.example.org"} 42
+`),
+		},
+		{
+			name: "multiple metric families",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"host": "one.example.org",
+					},
+					map[string]interface{}{
+						"time_idle":  42.0,
+						"time_guest": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_guest{host="one.example.org"} 42
+cpu_time_idle{host="one.example.org"} 42
+`),
+		},
+		{
+			name: "histogram",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{},
+					map[string]interface{}{
+						"http_request_duration_seconds_sum":   53423,
+						"http_request_duration_seconds_count": 144320,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "0.05"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 24054.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "0.1"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 33444.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "0.2"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 100392.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "0.5"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 129389.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "1.0"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 133988.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"le": "+Inf"},
+					map[string]interface{}{
+						"http_request_duration_seconds_bucket": 144320.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Histogram,
+				),
+			},
+			expected: []byte(`
+http_request_duration_seconds_count 144320
+http_request_duration_seconds_sum 53423
+http_request_duration_seconds_bucket{le="+Inf"} 144320
+http_request_duration_seconds_bucket{le="0.05"} 24054
+http_request_duration_seconds_bucket{le="0.1"} 33444
+http_request_duration_seconds_bucket{le="0.2"} 100392
+http_request_duration_seconds_bucket{le="0.5"} 129389
+http_request_duration_seconds_bucket{le="1"} 133988
+`),
+		},
+		{
+			name: "summary with quantile",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{},
+					map[string]interface{}{
+						"rpc_duration_seconds_sum":   1.7560473e+07,
+						"rpc_duration_seconds_count": 2693,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"quantile": "0.01"},
+					map[string]interface{}{
+						"rpc_duration_seconds": 3102.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"quantile": "0.05"},
+					map[string]interface{}{
+						"rpc_duration_seconds": 3272.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"quantile": "0.5"},
+					map[string]interface{}{
+						"rpc_duration_seconds": 4773.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"quantile": "0.9"},
+					map[string]interface{}{
+						"rpc_duration_seconds": 9001.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{"quantile": "0.99"},
+					map[string]interface{}{
+						"rpc_duration_seconds": 76656.0,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+			},
+			expected: []byte(`
+rpc_duration_seconds_count 2693
+rpc_duration_seconds_sum 17560473
+rpc_duration_seconds{quantile="0.01"} 3102
+rpc_duration_seconds{quantile="0.05"} 3272
+rpc_duration_seconds{quantile="0.5"} 4773
+rpc_duration_seconds{quantile="0.9"} 9001
+rpc_duration_seconds{quantile="0.99"} 76656
+`),
+		},
+		{
+			name: "newer sample",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"time_idle": 43.0,
+					},
+					time.Unix(1, 0),
+				),
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle 43
+`),
+		},
+		{
+			name: "colons are not replaced in metric name from measurement",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu::xyzzy",
+					map[string]string{},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu::xyzzy_time_idle 42
+`),
+		},
+		{
+			name: "colons are not replaced in metric name from field",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"time:idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time:idle 42
+`),
+		},
+		{
+			name: "invalid label",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"host-name": "example.org",
+					},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{host_name="example.org"} 42
+`),
+		},
+		{
+			name: "colons are replaced in label name",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"host:name": "example.org",
+					},
+					map[string]interface{}{
+						"time_idle": 42.0,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{host_name="example.org"} 42
+`),
+		},
+		{
+			name: "discard strings",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"time_idle": 42.0,
+						"cpu":       "cpu0",
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle 42
+`),
+		},
+		{
+			name: "string as label",
+			config: FormatConfig{
+				MetricSortOrder: SortMetrics,
+				StringHandling:  StringAsLabel,
+			},
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"time_idle": 42.0,
+						"cpu":       "cpu0",
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{cpu="cpu0"} 42
+`),
+		},
+		{
+			name: "string as label duplicate tag",
+			config: FormatConfig{
+				MetricSortOrder: SortMetrics,
+				StringHandling:  StringAsLabel,
+			},
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"cpu": "cpu0",
+					},
+					map[string]interface{}{
+						"time_idle": 42.0,
+						"cpu":       "cpu1",
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{cpu="cpu0"} 42
+`),
+		},
+		{
+			name: "replace characters when using string as label",
+			config: FormatConfig{
+				MetricSortOrder: SortMetrics,
+				StringHandling:  StringAsLabel,
+			},
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"host:name": "example.org",
+						"time_idle": 42.0,
+					},
+					time.Unix(1574279268, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_idle{host_name="example.org"} 42
+`),
+		},
+		{
+			name: "multiple fields grouping",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"cpu": "cpu0",
+					},
+					map[string]interface{}{
+						"time_guest":  8106.04,
+						"time_system": 26271.4,
+						"time_user":   92904.33,
+					},
+					time.Unix(0, 0),
+				),
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"cpu": "cpu1",
+					},
+					map[string]interface{}{
+						"time_guest":  8181.63,
+						"time_system": 25351.49,
+						"time_user":   96912.57,
+					},
+					time.Unix(0, 0),
+				),
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"cpu": "cpu2",
+					},
+					map[string]interface{}{
+						"time_guest":  7470.04,
+						"time_system": 24998.43,
+						"time_user":   96034.08,
+					},
+					time.Unix(0, 0),
+				),
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{
+						"cpu": "cpu3",
+					},
+					map[string]interface{}{
+						"time_guest":  7517.95,
+						"time_system": 24970.82,
+						"time_user":   94148,
+					},
+					time.Unix(0, 0),
+				),
+			},
+			expected: []byte(`
+cpu_time_guest{cpu="cpu0"} 8106.04
+cpu_time_system{cpu="cpu0"} 26271.4
+cpu_time_user{cpu="cpu0"} 92904.33
+cpu_time_guest{cpu="cpu1"} 8181.63
+cpu_time_system{cpu="cpu1"} 25351.49
+cpu_time_user{cpu="cpu1"} 96912.57
+cpu_time_guest{cpu="cpu2"} 7470.04
+cpu_time_system{cpu="cpu2"} 24998.43
+cpu_time_user{cpu="cpu2"} 96034.08
+cpu_time_guest{cpu="cpu3"} 7517.95
+cpu_time_system{cpu="cpu3"} 24970.82
+cpu_time_user{cpu="cpu3"} 94148
+`),
+		},
+		{
+			name: "summary with no quantile",
+			metrics: []telegraf.Metric{
+				testutil.MustMetric(
+					"prometheus",
+					map[string]string{},
+					map[string]interface{}{
+						"rpc_duration_seconds_sum":   1.7560473e+07,
+						"rpc_duration_seconds_count": 2693,
+					},
+					time.Unix(0, 0),
+					telegraf.Summary,
+				),
+			},
+			expected: []byte(`
+rpc_duration_seconds_count 2693
+rpc_duration_seconds_sum 17560473
+`),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s, err := NewSerializer(FormatConfig{
+				MetricSortOrder: SortMetrics,
+				StringHandling:  tt.config.StringHandling,
+			})
+			require.NoError(t, err)
+			data, err := s.SerializeBatch(tt.metrics)
+			require.NoError(t, err)
+			actual, err := prompbToText(data)
+			require.NoError(t, err)
+
+			require.Equal(t,
+				strings.TrimSpace(string(tt.expected)),
+				strings.TrimSpace(string(actual)))
+		})
+	}
+}
+
+func prompbToText(data []byte) ([]byte, error) {
+	var buf = bytes.Buffer{}
+	protobuff, err := snappy.Decode(nil, data)
+	if err != nil {
+		return nil, err
+	}
+	var req prompb.WriteRequest
+	err = proto.Unmarshal(protobuff, &req)
+	if err != nil {
+		return nil, err
+	}
+	samples := protoToSamples(&req)
+	for _, sample := range samples {
+		buf.Write([]byte(fmt.Sprintf("%s %s\n", sample.Metric.String(), sample.Value.String())))
+	}
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func protoToSamples(req *prompb.WriteRequest) model.Samples {
+	var samples model.Samples
+	for _, ts := range req.Timeseries {
+		metric := make(model.Metric, len(ts.Labels))
+		for _, l := range ts.Labels {
+			metric[model.LabelName(l.Name)] = model.LabelValue(l.Value)
+		}
+
+		for _, s := range ts.Samples {
+			samples = append(samples, &model.Sample{
+				Metric:    metric,
+				Value:     model.SampleValue(s.Value),
+				Timestamp: model.Time(s.Timestamp),
+			})
+		}
+	}
+	return samples
+}

plugins/serializers/registry.go

@@ -2,6 +2,7 @@ package serializers
 
 import (
 	"fmt"
+	"github.com/influxdata/telegraf/plugins/serializers/prometheusremotewrite"
 	"time"
 
 	"github.com/influxdata/telegraf"
@@ -126,12 +127,31 @@ func NewSerializer(config *Config) (Serializer, error) {
 		serializer, err = NewWavefrontSerializer(config.Prefix, config.WavefrontUseStrict, config.WavefrontSourceOverride)
 	case "prometheus":
 		serializer, err = NewPrometheusSerializer(config)
+	case "prometheusremotewrite":
+		serializer, err = NewPrometheusRemoteWriteSerializer(config)
 	default:
 		err = fmt.Errorf("Invalid data format: %s", config.DataFormat)
 	}
 	return serializer, err
 }
 
+func NewPrometheusRemoteWriteSerializer(config *Config) (Serializer, error) {
+	sortMetrics := prometheusremotewrite.NoSortMetrics
+	if config.PrometheusExportTimestamp {
+		sortMetrics = prometheusremotewrite.SortMetrics
+	}
+
+	stringAsLabels := prometheusremotewrite.DiscardStrings
+	if config.PrometheusStringAsLabel {
+		stringAsLabels = prometheusremotewrite.StringAsLabel
+	}
+
+	return prometheusremotewrite.NewSerializer(prometheusremotewrite.FormatConfig{
+		MetricSortOrder: sortMetrics,
+		StringHandling:  stringAsLabels,
+	})
+}
+
 func NewPrometheusSerializer(config *Config) (Serializer, error) {
 	exportTimestamp := prometheus.NoExportTimestamp
 	if config.PrometheusExportTimestamp {