Adds Prometheus Remote Write

BACKENDS.md

@@ -285,3 +285,46 @@ Additional options are available to rename attributes if required.
 	timer-sum = "samples_sum"
 	timer-sumsquare = "samples_sum_squares"
 ```
+
+Prometheus Remote Writer Backend
+--------------------------------
+The `promremotewriter` backend supports sending metrics to a Prometheus Remote Writer compatible backend.  It currently
+drops events.  At present there is no authentication supported.
+
+### Settings
+The following settings apply to all versions:
+- `api-endpoint`: the API endpoint to use, should include the full path.  Required with No default.
+- `max-request-elapsed-time`: the maximum amount of time to retry before giving up and dropping data, defaults to `15s`
+- `max-requests`: the maximum number of parallel requests.  This is primarily network I/O, with very little CPU, it
+  should be capped if it is overwhelming the remote server.  Defaults to 10 times the number of logical cores.
+- `metrics-per-batch`: the number of metrics to send per request.  Defaults to `1000`.
+- `transport`: the HTTP transport to use, see [TRANSPORT.md](TRANSPORT.md) for further information.
+- `user-agent`: configures the user-agent, defaults to `gostatsd`
+
+##### Example configuration
+```toml
+[promremotewriter]
+api-endpoint='https://prometheus.local/'
+max-request-elapsed-time='15s'
+max-requests=20
+metrics-per-batch=7500
+transport='default'
+```
+
+### Tag normalization
+As the dogstatsd protocol doesn't have exact parity with Prometheus Remote Write protocol, there is some cleanup
+applied to the tags before sending them.  Specifically:
+- tags with only a value (`value`) are normalized as `unnamed:value`
+- tags with an empty key (`:value`) are normalized as `unnamed:value`
+- tags with an empty value (`key:`) are normalized as `key:__unset__`
+- multiple values for duplicate keys are sorted
+- keys with multiple values have their values concatenated with `__`
+- metric and label names have invalid characters replaced with `_`
+
+For example, given the tags `foo, key:bar, unnamed:baz, key:thing, other:something`, the result will be normalized
+as `key=bar__thing,other=something,unnamed=baz__foo`.
+
+
+### Events
+Events are dropped, as Prometheus Remote Write doesn't support them.  A Grafana specific events backend may be added
+to fill this gap at some point.

CHANGELOG.md

@@ -1,5 +1,10 @@
+29.1.0
+------
+- Initial Prometheus Remote Write support added
+
 29.0.2
 ------
+- New Relic backend handles infinities and NaN better
 - Update to Alpine 3.14.1
 
 29.0.1

Makefile

@@ -34,18 +34,23 @@ setup-ci: tools/bin/protoc
 build-cluster: fmt
 	go build -i -v -o build/bin/$(ARCH)/cluster $(GOBUILD_VERSION_ARGS) $(CLUSTER_PKG)
 
+pb/remote_write.pb.go: pb/remote_write.proto
+	go build -o protoc-gen-go github.com/golang/protobuf/protoc-gen-go/ && \
+	    tools/bin/protoc --go_out=. $< && \
+	    rm protoc-gen-go
+
 pb/gostatsd.pb.go: pb/gostatsd.proto
 	go build -o protoc-gen-go github.com/golang/protobuf/protoc-gen-go/ && \
 	    tools/bin/protoc --go_out=. $< && \
 	    rm protoc-gen-go
 
-build: pb/gostatsd.pb.go fmt
+build: pb/gostatsd.pb.go pb/remote_write.pb.go fmt
 	go build -i -v -o build/bin/$(ARCH)/$(BINARY_NAME) $(GOBUILD_VERSION_ARGS) $(MAIN_PKG)
 
 build-race: fmt
 	go build -i -v -race -o build/bin/$(ARCH)/$(BINARY_NAME) $(GOBUILD_VERSION_ARGS) $(MAIN_PKG)
 
-build-all: pb/gostatsd.pb.go
+build-all: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go install -v ./...
 
 test-all: fmt cover test-race bench bench-race check
@@ -56,49 +61,49 @@ fmt:
 	gofmt -w=true -s $$(find . -type f -name '*.go' -not -path "./vendor/*" -not -path "./pb/*")
 	goimports -w=true -d -local github.com/atlassian/gostatsd $$(find . -type f -name '*.go' -not -path "./vendor/*" -not -path "./pb/*")
 
-test-full: pb/gostatsd.pb.go
+test-full: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test ./...
 
-test-race-full: pb/gostatsd.pb.go
+test-race-full: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -race ./...
 
-bench-full: pb/gostatsd.pb.go
+bench-full: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -bench=. -run=XXX ./...
 
-bench-race-full: pb/gostatsd.pb.go
+bench-race-full: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -race -bench=. -run=XXX ./...
 
-test: pb/gostatsd.pb.go
+test: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -short ./...
 
-test-race: pb/gostatsd.pb.go
+test-race: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -short -race ./...
 
-bench: pb/gostatsd.pb.go
+bench: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -short -bench=. -run=XXX ./...
 
-bench-race: pb/gostatsd.pb.go
+bench-race: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go test -short -race -bench=. -run=XXX ./...
 
-cover: pb/gostatsd.pb.go
+cover: pb/gostatsd.pb.go pb/remote_write.pb.go
 	./cover.sh
 	go tool cover -func=coverage.out
 	go tool cover -html=coverage.out
 
-coveralls: pb/gostatsd.pb.go
+coveralls: pb/gostatsd.pb.go pb/remote_write.pb.go
 	./cover.sh
 	goveralls -coverprofile=coverage.out -service=travis-ci
 
 junit-test: build
 	go test -short -v ./... | go-junit-report > test-report.xml
 
-check: pb/gostatsd.pb.go
+check: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go install ./cmd/gostatsd
 	go install ./cmd/tester
 	golangci-lint run --deadline=600s --enable=gocyclo --enable=dupl \
 		--disable=interfacer --disable=golint
 
-check-all: pb/gostatsd.pb.go
+check-all: pb/gostatsd.pb.go pb/remote_write.pb.go
 	go install ./cmd/gostatsd
 	go install ./cmd/tester
 	golangci-lint run --deadline=600s --enable=gocyclo --enable=dupl
@@ -117,7 +122,7 @@ git-hook:
 	cp dev/push-hook.sh .git/hooks/pre-push
 
 # Compile a static binary. Cannot be used with -race
-docker: pb/gostatsd.pb.go
+docker: pb/gostatsd.pb.go pb/remote_write.pb.go
 	docker pull golang:$(GOVERSION)
 	docker run \
 		--rm \
@@ -130,7 +135,7 @@ docker: pb/gostatsd.pb.go
 	docker build --pull -t $(IMAGE_NAME):$(GIT_HASH) build
 
 # Compile a binary with -race. Needs to be run on a glibc-based system.
-docker-race: pb/gostatsd.pb.go
+docker-race: pb/gostatsd.pb.go pb/remote_write.pb.go
 	docker pull golang:$(GOVERSION)
 	docker run \
 		--rm \
@@ -142,7 +147,7 @@ docker-race: pb/gostatsd.pb.go
 	docker build --pull -t $(IMAGE_NAME):$(GIT_HASH)-race -f build/Dockerfile-glibc build
 
 # Compile a static binary with symbols. Cannot be used with -race
-docker-symbols: pb/gostatsd.pb.go
+docker-symbols: pb/gostatsd.pb.go pb/remote_write.pb.go
 	docker pull golang:$(GOVERSION)
 	docker run \
 		--rm \

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/githubnemo/CompileDaemon v1.0.0
 	github.com/go-redis/redis v6.15.7+incompatible
 	github.com/golang/protobuf v1.3.3
+	github.com/golang/snappy v0.0.4
 	github.com/golangci/golangci-lint v1.23.3
 	github.com/gorilla/mux v1.7.3
 	github.com/howeyc/fsnotify v0.9.0 // indirect

go.sum

@@ -122,6 +122,8 @@ github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I=
 github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
+github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
+github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golangci/check v0.0.0-20180506172741-cfe4005ccda2 h1:23T5iq8rbUYlhpt5DB4XJkc6BU31uODLD1o1gKvZmD0=
 github.com/golangci/check v0.0.0-20180506172741-cfe4005ccda2/go.mod h1:k9Qvh+8juN+UKMCS/3jFtGICgW8O96FVaZsaxdzDkR4=
 github.com/golangci/dupl v0.0.0-20180902072040-3e9179ac440a h1:w8hkcTqaFpzKqonE9uMCefW1WDie15eSP/4MssdenaM=

internal/lexer/lexer_test.go

@@ -39,6 +39,7 @@ func TestMetricsLexer(t *testing.T) {
 		"a:1|g|#":                       {Name: "a", Value: 1, Type: gostatsd.GAUGE, Rate: 1.0},
 		"a:1|g|#,":                      {Name: "a", Value: 1, Type: gostatsd.GAUGE, Rate: 1.0},
 		"a:1|g|#,,":                     {Name: "a", Value: 1, Type: gostatsd.GAUGE, Rate: 1.0},
+		"foo:10|g|#a:b,c:,:d":           {Name: "foo", Value: 10, Type: gostatsd.GAUGE, Rate: 1.0, Tags: gostatsd.Tags{"a:b", "c:", ":d"}},
 	}
 
 	compareMetric(t, tests, "")
@@ -55,15 +56,6 @@ func TestInvalidMetricsLexer(t *testing.T) {
 			assert.Error(t, err, result)
 		})
 	}
-
-	tests := map[string]gostatsd.Metric{
-		"foo.bar.baz:2|c": {Name: "stats.foo.bar.baz", Value: 2, Type: gostatsd.COUNTER, Rate: 1.0},
-		"abc.def.g:3|g":   {Name: "stats.abc.def.g", Value: 3, Type: gostatsd.GAUGE, Rate: 1.0},
-		"def.g:10|ms":     {Name: "stats.def.g", Value: 10, Type: gostatsd.TIMER, Rate: 1.0},
-		"uniq.usr:joe|s":  {Name: "stats.uniq.usr", StringValue: "joe", Type: gostatsd.SET, Rate: 1.0},
-	}
-
-	compareMetric(t, tests, "stats")
 }
 
 func TestEventsLexer(t *testing.T) {