Loki: Create component for sending logs to Loki (#51500)

go.mod

@@ -54,7 +54,6 @@ require (
 	github.com/grafana/grafana-aws-sdk v0.10.7
 	github.com/grafana/grafana-azure-sdk-go v1.2.0
 	github.com/grafana/grafana-plugin-sdk-go v0.138.0
-	github.com/grafana/loki v1.6.2-0.20211015002020-7832783b1caa
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
 	github.com/hashicorp/go-hclog v1.0.0
 	github.com/hashicorp/go-plugin v1.4.3
@@ -140,7 +139,6 @@ require (
 	github.com/apache/arrow/go/arrow v0.0.0-20211112161151-bc219186db40 // indirect
 	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/c2h5oh/datasize v0.0.0-20200112174442-28bbd4740fee // indirect
 	github.com/cenkalti/backoff/v4 v4.1.2 // indirect
 	github.com/centrifugal/protocol v0.7.6 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
@@ -171,7 +169,7 @@ require (
 	github.com/golang-sql/civil v0.0.0-20190719163853-cb61b32ac6fe // indirect
 	github.com/golang/glog v1.0.0 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
-	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/golang/protobuf v1.5.2
 	github.com/gomodule/redigo v2.0.0+incompatible // indirect
 	github.com/google/btree v1.0.1 // indirect
 	github.com/google/flatbuffers v2.0.0+incompatible // indirect
@@ -259,6 +257,7 @@ require (
 	cloud.google.com/go v0.100.2 // indirect
 	github.com/armon/go-metrics v0.3.10 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
+	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/gosimple/unidecode v1.0.1 // indirect
 	github.com/hashicorp/go-immutable-radix v1.3.1 // indirect
 	github.com/hashicorp/memberlist v0.3.0 // indirect

pkg/components/loki/README

@@ -0,0 +1,5 @@
+The Loki package is derived from the Grafana Loki project's logproto and
+promtail packages with removals to support Grafana's needs.
+
+- https://github.com/grafana/loki/tree/2fc20af9a4e55483afe0f09f8a8119ab380daea9/clients/pkg/promtail/client
+- https://github.com/grafana/loki/tree/2fc20af9a4e55483afe0f09f8a8119ab380daea9/pkg/logproto

pkg/components/loki/logproto/LICENSE_APACHE2

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
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+      and distribution as defined by Sections 1 through 9 of this document.
+
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+
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+
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+      whether in tort (including negligence), contract, or otherwise,
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+   Unless required by applicable law or agreed to in writing, software
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+   limitations under the License.

pkg/components/loki/logproto/extensions.go

@@ -0,0 +1,7 @@
+package logproto
+
+type Streams []Stream
+
+func (xs Streams) Len() int           { return len(xs) }
+func (xs Streams) Swap(i, j int)      { xs[i], xs[j] = xs[j], xs[i] }
+func (xs Streams) Less(i, j int) bool { return xs[i].Labels <= xs[j].Labels }

pkg/components/loki/logproto/logproto.proto

@@ -0,0 +1,47 @@
+syntax = "proto3";
+
+// COPIED FROM LOKI
+// If you modify this file, you need to manually generate the
+// logproto.pb.go file as well.
+//
+// Install gogoslick from https://github.com/gogo/protobuf
+// protoc --proto_path=$GOPATH/src/ --proto_path=. --gogoslick_out=plugins=grpc:. logproto.proto
+
+package logproto;
+
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+import "google/protobuf/timestamp.proto";
+
+option go_package = "logproto";
+
+service Pusher {
+  rpc Push(PushRequest) returns (PushResponse) {}
+}
+
+message PushRequest {
+  repeated StreamAdapter streams = 1 [
+    (gogoproto.jsontag) = "streams",
+    (gogoproto.customtype) = "Stream"
+  ];
+}
+
+message PushResponse {}
+
+message StreamAdapter {
+  string labels = 1 [(gogoproto.jsontag) = "labels"];
+  repeated EntryAdapter entries = 2 [
+    (gogoproto.nullable) = false,
+    (gogoproto.jsontag) = "entries"
+  ];
+  // hash contains the original hash of the stream.
+  uint64 hash = 3 [(gogoproto.jsontag) = "-"];
+}
+
+message EntryAdapter {
+  google.protobuf.Timestamp timestamp = 1 [
+    (gogoproto.stdtime) = true,
+    (gogoproto.nullable) = false,
+    (gogoproto.jsontag) = "ts"
+  ];
+  string line = 2 [(gogoproto.jsontag) = "line"];
+}

pkg/components/loki/logproto/timestamp.go

@@ -0,0 +1,106 @@
+package logproto
+
+import (
+	"errors"
+	"strconv"
+	"time"
+
+	"github.com/gogo/protobuf/types"
+)
+
+const (
+	// Seconds field of the earliest valid Timestamp.
+	// This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	minValidSeconds = -62135596800
+	// Seconds field just after the latest valid Timestamp.
+	// This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	maxValidSeconds = 253402300800
+)
+
+// validateTimestamp determines whether a Timestamp is valid.
+// A valid timestamp represents a time in the range
+// [0001-01-01, 10000-01-01) and has a Nanos field
+// in the range [0, 1e9).
+//
+// If the Timestamp is valid, validateTimestamp returns nil.
+// Otherwise, it returns an error that describes
+// the problem.
+//
+// Every valid Timestamp can be represented by a time.Time, but the converse is not true.
+func validateTimestamp(ts *types.Timestamp) error {
+	if ts == nil {
+		return errors.New("timestamp: nil Timestamp")
+	}
+	if ts.Seconds < minValidSeconds {
+		return errors.New("timestamp: " + formatTimestamp(ts) + " before 0001-01-01")
+	}
+	if ts.Seconds >= maxValidSeconds {
+		return errors.New("timestamp: " + formatTimestamp(ts) + " after 10000-01-01")
+	}
+	if ts.Nanos < 0 || ts.Nanos >= 1e9 {
+		return errors.New("timestamp: " + formatTimestamp(ts) + ": nanos not in range [0, 1e9)")
+	}
+	return nil
+}
+
+// formatTimestamp is equivalent to fmt.Sprintf("%#v", ts)
+// but avoids the escape incurred by using fmt.Sprintf, eliminating
+// unnecessary heap allocations.
+func formatTimestamp(ts *types.Timestamp) string {
+	if ts == nil {
+		return "nil"
+	}
+
+	seconds := strconv.FormatInt(ts.Seconds, 10)
+	nanos := strconv.FormatInt(int64(ts.Nanos), 10)
+	return "&types.Timestamp{Seconds: " + seconds + ",\nNanos: " + nanos + ",\n}"
+}
+
+func SizeOfStdTime(t time.Time) int {
+	ts, err := timestampProto(t)
+	if err != nil {
+		return 0
+	}
+	return ts.Size()
+}
+
+func StdTimeMarshalTo(t time.Time, data []byte) (int, error) {
+	ts, err := timestampProto(t)
+	if err != nil {
+		return 0, err
+	}
+	return ts.MarshalTo(data)
+}
+
+func StdTimeUnmarshal(t *time.Time, data []byte) error {
+	ts := &types.Timestamp{}
+	if err := ts.Unmarshal(data); err != nil {
+		return err
+	}
+	tt, err := timestampFromProto(ts)
+	if err != nil {
+		return err
+	}
+	*t = tt
+	return nil
+}
+
+func timestampFromProto(ts *types.Timestamp) (time.Time, error) {
+	// Don't return the zero value on error, because corresponds to a valid
+	// timestamp. Instead return whatever time.Unix gives us.
+	var t time.Time
+	if ts == nil {
+		t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp
+	} else {
+		t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC()
+	}
+	return t, validateTimestamp(ts)
+}
+
+func timestampProto(t time.Time) (types.Timestamp, error) {
+	ts := types.Timestamp{
+		Seconds: t.Unix(),
+		Nanos:   int32(t.Nanosecond()),
+	}
+	return ts, validateTimestamp(&ts)
+}

pkg/components/loki/logproto/types.go

@@ -0,0 +1,467 @@
+package logproto
+
+import (
+	"fmt"
+	"io"
+	"time"
+)
+
+// Stream contains a unique labels set as a string and a set of entries for it.
+// We are not using the proto generated version but this custom one so that we
+// can improve serialization see benchmark.
+type Stream struct {
+	Labels  string  `protobuf:"bytes,1,opt,name=labels,proto3" json:"labels"`
+	Entries []Entry `protobuf:"bytes,2,rep,name=entries,proto3,customtype=EntryAdapter" json:"entries"`
+	Hash    uint64  `protobuf:"varint,3,opt,name=hash,proto3" json:"-"`
+}
+
+// Entry is a log entry with a timestamp.
+type Entry struct {
+	Timestamp time.Time `protobuf:"bytes,1,opt,name=timestamp,proto3,stdtime" json:"ts"`
+	Line      string    `protobuf:"bytes,2,opt,name=line,proto3" json:"line"`
+}
+
+func (m *Stream) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Stream) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Stream) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.Hash != 0 {
+		i = encodeVarintLogproto(dAtA, i, m.Hash)
+		i--
+		dAtA[i] = 0x18
+	}
+	if len(m.Entries) > 0 {
+		for iNdEx := len(m.Entries) - 1; iNdEx >= 0; iNdEx-- {
+			{
+				size, err := m.Entries[iNdEx].MarshalToSizedBuffer(dAtA[:i])
+				if err != nil {
+					return 0, err
+				}
+				i -= size
+				i = encodeVarintLogproto(dAtA, i, uint64(size))
+			}
+			i--
+			dAtA[i] = 0x12
+		}
+	}
+	if len(m.Labels) > 0 {
+		i -= len(m.Labels)
+		copy(dAtA[i:], m.Labels)
+		i = encodeVarintLogproto(dAtA, i, uint64(len(m.Labels)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func (m *Entry) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Entry) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Entry) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if len(m.Line) > 0 {
+		i -= len(m.Line)
+		copy(dAtA[i:], m.Line)
+		i = encodeVarintLogproto(dAtA, i, uint64(len(m.Line)))
+		i--
+		dAtA[i] = 0x12
+	}
+	n7, err7 := StdTimeMarshalTo(m.Timestamp, dAtA[i-SizeOfStdTime(m.Timestamp):])
+	if err7 != nil {
+		return 0, err7
+	}
+	i -= n7
+	i = encodeVarintLogproto(dAtA, i, uint64(n7))
+	i--
+	dAtA[i] = 0xa
+	return len(dAtA) - i, nil
+}
+
+//nolint: gocyclo
+func (m *Stream) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowLogproto
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: StreamAdapter: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: StreamAdapter: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Labels", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLogproto
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Labels = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Entries", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLogproto
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			postIndex := iNdEx + msglen
+			if postIndex < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Entries = append(m.Entries, Entry{})
+			if err := m.Entries[len(m.Entries)-1].Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Hash", wireType)
+			}
+			m.Hash = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLogproto
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Hash |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipLogproto(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+
+//nolint: gocyclo
+func (m *Entry) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowLogproto
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: EntryAdapter: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: EntryAdapter: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Timestamp", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLogproto
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			postIndex := iNdEx + msglen
+			if postIndex < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if err := StdTimeUnmarshal(&m.Timestamp, dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Line", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLogproto
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Line = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipLogproto(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthLogproto
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+
+func (m *Stream) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Labels)
+	if l > 0 {
+		n += 1 + l + sovLogproto(uint64(l))
+	}
+	if len(m.Entries) > 0 {
+		for _, e := range m.Entries {
+			l = e.Size()
+			n += 1 + l + sovLogproto(uint64(l))
+		}
+	}
+	if m.Hash != 0 {
+		n += 1 + sovLogproto(m.Hash)
+	}
+	return n
+}
+
+func (m *Entry) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = SizeOfStdTime(m.Timestamp)
+	n += 1 + l + sovLogproto(uint64(l))
+	l = len(m.Line)
+	if l > 0 {
+		n += 1 + l + sovLogproto(uint64(l))
+	}
+	return n
+}
+
+func (m *Stream) Equal(that interface{}) bool {
+	if that == nil {
+		return m == nil
+	}
+
+	that1, ok := that.(*Stream)
+	if !ok {
+		that2, ok := that.(Stream)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		return m == nil
+	} else if m == nil {
+		return false
+	}
+	if m.Labels != that1.Labels {
+		return false
+	}
+	if len(m.Entries) != len(that1.Entries) {
+		return false
+	}
+	for i := range m.Entries {
+		if !m.Entries[i].Equal(that1.Entries[i]) {
+			return false
+		}
+	}
+	return m.Hash == that1.Hash
+}
+
+func (m *Entry) Equal(that interface{}) bool {
+	if that == nil {
+		return m == nil
+	}
+
+	that1, ok := that.(*Entry)
+	if !ok {
+		that2, ok := that.(Entry)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		return m == nil
+	} else if m == nil {
+		return false
+	}
+	if !m.Timestamp.Equal(that1.Timestamp) {
+		return false
+	}
+	if m.Line != that1.Line {
+		return false
+	}
+	return true
+}

pkg/components/loki/logproto/types_test.go

@@ -0,0 +1,111 @@
+package logproto
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	now    = time.Now().UTC()
+	line   = `level=info ts=2019-12-12T15:00:08.325Z caller=compact.go:441 component=tsdb msg="compact blocks" count=3 mint=1576130400000 maxt=1576152000000 ulid=01DVX9ZHNM71GRCJS7M34Q0EV7 sources="[01DVWNC6NWY1A60AZV3Z6DGS65 01DVWW7XXX75GHA6ZDTD170CSZ 01DVX33N5W86CWJJVRPAVXJRWJ]" duration=2.897213221s`
+	stream = Stream{
+		Labels: `{job="foobar", cluster="foo-central1", namespace="bar", container_name="buzz"}`,
+		Hash:   1234*10 ^ 9,
+		Entries: []Entry{
+			{Timestamp: now, Line: line},
+			{Timestamp: now.Add(1 * time.Second), Line: line},
+			{Timestamp: now.Add(2 * time.Second), Line: line},
+			{Timestamp: now.Add(3 * time.Second), Line: line},
+		},
+	}
+	streamAdapter = StreamAdapter{
+		Labels: `{job="foobar", cluster="foo-central1", namespace="bar", container_name="buzz"}`,
+		Hash:   1234*10 ^ 9,
+		Entries: []EntryAdapter{
+			{Timestamp: now, Line: line},
+			{Timestamp: now.Add(1 * time.Second), Line: line},
+			{Timestamp: now.Add(2 * time.Second), Line: line},
+			{Timestamp: now.Add(3 * time.Second), Line: line},
+		},
+	}
+)
+
+func TestStream(t *testing.T) {
+	avg := testing.AllocsPerRun(200, func() {
+		b, err := stream.Marshal()
+		require.NoError(t, err)
+
+		var new Stream
+		err = new.Unmarshal(b)
+		require.NoError(t, err)
+
+		require.Equal(t, stream, new)
+	})
+	t.Log("avg allocs per run:", avg)
+}
+
+func TestStreamAdapter(t *testing.T) {
+	avg := testing.AllocsPerRun(200, func() {
+		b, err := streamAdapter.Marshal()
+		require.NoError(t, err)
+
+		var new StreamAdapter
+		err = new.Unmarshal(b)
+		require.NoError(t, err)
+
+		require.Equal(t, streamAdapter, new)
+	})
+	t.Log("avg allocs per run:", avg)
+}
+
+func TestCompatibility(t *testing.T) {
+	b, err := stream.Marshal()
+	require.NoError(t, err)
+
+	var adapter StreamAdapter
+	err = adapter.Unmarshal(b)
+	require.NoError(t, err)
+	require.Equal(t, streamAdapter, adapter)
+
+	ba, err := adapter.Marshal()
+	require.NoError(t, err)
+	require.Equal(t, b, ba)
+
+	var new Stream
+	err = new.Unmarshal(ba)
+	require.NoError(t, err)
+
+	require.Equal(t, stream, new)
+}
+
+func BenchmarkStream(b *testing.B) {
+	b.ReportAllocs()
+	for n := 0; n < b.N; n++ {
+		by, err := stream.Marshal()
+		if err != nil {
+			b.Fatal(err)
+		}
+		var new Stream
+		err = new.Unmarshal(by)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkStreamAdapter(b *testing.B) {
+	b.ReportAllocs()
+	for n := 0; n < b.N; n++ {
+		by, err := streamAdapter.Marshal()
+		if err != nil {
+			b.Fatal(err)
+		}
+		var new StreamAdapter
+		err = new.Unmarshal(by)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}

pkg/components/loki/lokihttp/batch.go

@@ -0,0 +1,110 @@
+package lokihttp
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/prometheus/common/model"
+
+	"github.com/grafana/grafana/pkg/components/loki/logproto"
+)
+
+// batch holds pending log streams waiting to be sent to Loki, and it's used
+// to reduce the number of push requests to Loki aggregating multiple log streams
+// and entries in a single batch request. In case of multi-tenant Promtail, log
+// streams for each tenant are stored in a dedicated batch.
+type batch struct {
+	streams   map[string]*logproto.Stream
+	bytes     int
+	createdAt time.Time
+}
+
+func newBatch(entries ...Entry) *batch {
+	b := &batch{
+		streams:   map[string]*logproto.Stream{},
+		bytes:     0,
+		createdAt: time.Now(),
+	}
+
+	// Add entries to the batch
+	for _, entry := range entries {
+		b.add(entry)
+	}
+
+	return b
+}
+
+// add an entry to the batch
+func (b *batch) add(entry Entry) {
+	b.bytes += len(entry.Line)
+
+	// Append the entry to an already existing stream (if any)
+	labels := labelsMapToString(entry.Labels, ReservedLabelTenantID)
+	if stream, ok := b.streams[labels]; ok {
+		stream.Entries = append(stream.Entries, entry.Entry)
+		return
+	}
+
+	// Add the entry as a new stream
+	b.streams[labels] = &logproto.Stream{
+		Labels:  labels,
+		Entries: []logproto.Entry{entry.Entry},
+	}
+}
+
+func labelsMapToString(ls model.LabelSet, without ...model.LabelName) string {
+	lstrs := make([]string, 0, len(ls))
+Outer:
+	for l, v := range ls {
+		for _, w := range without {
+			if l == w {
+				continue Outer
+			}
+		}
+		lstrs = append(lstrs, fmt.Sprintf("%s=%q", l, v))
+	}
+
+	sort.Strings(lstrs)
+	return fmt.Sprintf("{%s}", strings.Join(lstrs, ", "))
+}
+
+// sizeBytesAfter returns the size of the batch after the input entry
+// will be added to the batch itself
+func (b *batch) sizeBytesAfter(entry Entry) int {
+	return b.bytes + len(entry.Line)
+}
+
+// age of the batch since its creation
+func (b *batch) age() time.Duration {
+	return time.Since(b.createdAt)
+}
+
+// encode the batch as snappy-compressed push request, and returns
+// the encoded bytes and the number of encoded entries
+func (b *batch) encode() ([]byte, int, error) {
+	req, entriesCount := b.createPushRequest()
+	buf, err := proto.Marshal(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	buf = snappy.Encode(nil, buf)
+	return buf, entriesCount, nil
+}
+
+// creates push request and returns it, together with number of entries
+func (b *batch) createPushRequest() (*logproto.PushRequest, int) {
+	req := logproto.PushRequest{
+		Streams: make([]logproto.Stream, 0, len(b.streams)),
+	}
+
+	entriesCount := 0
+	for _, stream := range b.streams {
+		req.Streams = append(req.Streams, *stream)
+		entriesCount += len(stream.Entries)
+	}
+	return &req, entriesCount
+}

pkg/components/loki/lokihttp/client.go

@@ -0,0 +1,363 @@
+package lokihttp
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/grafana/dskit/backoff"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/config"
+
+	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+const (
+	contentType  = "application/x-protobuf"
+	maxErrMsgLen = 1024
+
+	// Label reserved to override the tenant ID while processing
+	// pipeline stages
+	ReservedLabelTenantID = "__tenant_id__"
+
+	LatencyLabel = "filename"
+	HostLabel    = "host"
+)
+
+var UserAgent = fmt.Sprintf("grafana/%s", setting.BuildVersion)
+
+type metrics struct {
+	encodedBytes     *prometheus.CounterVec
+	sentBytes        *prometheus.CounterVec
+	droppedBytes     *prometheus.CounterVec
+	sentEntries      *prometheus.CounterVec
+	droppedEntries   *prometheus.CounterVec
+	requestDuration  *prometheus.HistogramVec
+	batchRetries     *prometheus.CounterVec
+	countersWithHost []*prometheus.CounterVec
+}
+
+func newMetrics(reg prometheus.Registerer) *metrics {
+	var m metrics
+
+	m.encodedBytes = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "encoded_bytes_total",
+		Help:      "Number of bytes encoded and ready to send.",
+	}, []string{HostLabel})
+	m.sentBytes = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "sent_bytes_total",
+		Help:      "Number of bytes sent.",
+	}, []string{HostLabel})
+	m.droppedBytes = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "dropped_bytes_total",
+		Help:      "Number of bytes dropped because failed to be sent to the ingester after all retries.",
+	}, []string{HostLabel})
+	m.sentEntries = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "sent_entries_total",
+		Help:      "Number of log entries sent to the ingester.",
+	}, []string{HostLabel})
+	m.droppedEntries = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "dropped_entries_total",
+		Help:      "Number of log entries dropped because failed to be sent to the ingester after all retries.",
+	}, []string{HostLabel})
+	m.requestDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "promtail",
+		Name:      "request_duration_seconds",
+		Help:      "Duration of send requests.",
+	}, []string{"status_code", HostLabel})
+	m.batchRetries = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "promtail",
+		Name:      "batch_retries_total",
+		Help:      "Number of times batches has had to be retried.",
+	}, []string{HostLabel})
+
+	m.countersWithHost = []*prometheus.CounterVec{
+		m.encodedBytes, m.sentBytes, m.droppedBytes, m.sentEntries, m.droppedEntries,
+	}
+
+	if reg != nil {
+		m.encodedBytes = mustRegisterOrGet(reg, m.encodedBytes).(*prometheus.CounterVec)
+		m.sentBytes = mustRegisterOrGet(reg, m.sentBytes).(*prometheus.CounterVec)
+		m.droppedBytes = mustRegisterOrGet(reg, m.droppedBytes).(*prometheus.CounterVec)
+		m.sentEntries = mustRegisterOrGet(reg, m.sentEntries).(*prometheus.CounterVec)
+		m.droppedEntries = mustRegisterOrGet(reg, m.droppedEntries).(*prometheus.CounterVec)
+		m.requestDuration = mustRegisterOrGet(reg, m.requestDuration).(*prometheus.HistogramVec)
+		m.batchRetries = mustRegisterOrGet(reg, m.batchRetries).(*prometheus.CounterVec)
+	}
+
+	return &m
+}
+
+func mustRegisterOrGet(reg prometheus.Registerer, c prometheus.Collector) prometheus.Collector {
+	if err := reg.Register(c); err != nil {
+		promError := prometheus.AlreadyRegisteredError{}
+		if errors.As(err, &promError) {
+			return promError.ExistingCollector
+		}
+		panic(err)
+	}
+	return c
+}
+
+// Client pushes entries to Loki and can be stopped
+type Client interface {
+	Chan() chan<- Entry
+
+	Stop()
+	StopNow()
+}
+
+// Client for pushing logs in snappy-compressed protos over HTTP.
+type client struct {
+	metrics *metrics
+	logger  log.Logger
+	cfg     Config
+	client  *http.Client
+	entries chan Entry
+
+	once sync.Once
+	wg   sync.WaitGroup
+
+	// ctx is used in any upstream calls from the `client`.
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+// Tripperware can wrap a roundtripper.
+type Tripperware func(http.RoundTripper) http.RoundTripper
+
+// New makes a new Client.
+func New(reg prometheus.Registerer, cfg Config, logger log.Logger) (Client, error) {
+	return newClient(reg, cfg, logger)
+}
+
+func newClient(reg prometheus.Registerer, cfg Config, logger log.Logger) (*client, error) {
+	if cfg.URL.URL == nil {
+		return nil, errors.New("client needs target URL")
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	c := &client{
+		logger:  logger.New("host", cfg.URL.Host),
+		cfg:     cfg,
+		entries: make(chan Entry),
+		metrics: newMetrics(reg),
+
+		ctx:    ctx,
+		cancel: cancel,
+	}
+
+	err := cfg.Client.Validate()
+	if err != nil {
+		return nil, err
+	}
+
+	c.client, err = config.NewClientFromConfig(cfg.Client, "promtail", config.WithHTTP2Disabled())
+	if err != nil {
+		return nil, err
+	}
+
+	c.client.Timeout = cfg.Timeout
+
+	// Initialize counters to 0 so the metrics are exported before the first
+	// occurrence of incrementing to avoid missing metrics.
+	for _, counter := range c.metrics.countersWithHost {
+		counter.WithLabelValues(c.cfg.URL.Host).Add(0)
+	}
+
+	c.wg.Add(1)
+	go c.run()
+	return c, nil
+}
+
+// NewWithTripperware creates a new Loki client with a custom tripperware.
+func NewWithTripperware(reg prometheus.Registerer, cfg Config, logger log.Logger, tp Tripperware) (Client, error) {
+	c, err := newClient(reg, cfg, logger)
+	if err != nil {
+		return nil, err
+	}
+
+	if tp != nil {
+		c.client.Transport = tp(c.client.Transport)
+	}
+
+	return c, nil
+}
+
+func (c *client) run() {
+	batches := map[string]*batch{}
+
+	// Given the client handles multiple batches (1 per tenant) and each batch
+	// can be created at a different point in time, we look for batches whose
+	// max wait time has been reached every 10 times per BatchWait, so that the
+	// maximum delay we have sending batches is 10% of the max waiting time.
+	// We apply a cap of 10ms to the ticker, to avoid too frequent checks in
+	// case the BatchWait is very low.
+	minWaitCheckFrequency := 10 * time.Millisecond
+	maxWaitCheckFrequency := c.cfg.BatchWait / 10
+	if maxWaitCheckFrequency < minWaitCheckFrequency {
+		maxWaitCheckFrequency = minWaitCheckFrequency
+	}
+
+	maxWaitCheck := time.NewTicker(maxWaitCheckFrequency)
+
+	defer func() {
+		maxWaitCheck.Stop()
+		// Send all pending batches
+		for tenantID, batch := range batches {
+			c.sendBatch(tenantID, batch)
+		}
+
+		c.wg.Done()
+	}()
+
+	for {
+		select {
+		case e, ok := <-c.entries:
+			if !ok {
+				return
+			}
+			tenantID := ""
+			batch, ok := batches[tenantID]
+
+			// If the batch doesn't exist yet, we create a new one with the entry
+			if !ok {
+				batches[tenantID] = newBatch(e)
+				break
+			}
+
+			// If adding the entry to the batch will increase the size over the max
+			// size allowed, we do send the current batch and then create a new one
+			if batch.sizeBytesAfter(e) > c.cfg.BatchSize {
+				c.sendBatch(tenantID, batch)
+
+				batches[tenantID] = newBatch(e)
+				break
+			}
+
+			// The max size of the batch isn't reached, so we can add the entry
+			batch.add(e)
+
+		case <-maxWaitCheck.C:
+			// Send all batches whose max wait time has been reached
+			for tenantID, batch := range batches {
+				if batch.age() < c.cfg.BatchWait {
+					continue
+				}
+
+				c.sendBatch(tenantID, batch)
+				delete(batches, tenantID)
+			}
+		}
+	}
+}
+
+func (c *client) Chan() chan<- Entry {
+	return c.entries
+}
+
+func (c *client) sendBatch(tenantID string, batch *batch) {
+	buf, entriesCount, err := batch.encode()
+	if err != nil {
+		c.logger.Error("error encoding batch", "error", err)
+		return
+	}
+	bufBytes := float64(len(buf))
+	c.metrics.encodedBytes.WithLabelValues(c.cfg.URL.Host).Add(bufBytes)
+
+	backoff := backoff.New(c.ctx, c.cfg.BackoffConfig)
+	var status int
+	for {
+		start := time.Now()
+		// send uses `timeout` internally, so `context.Background` is good enough.
+		status, err = c.send(context.Background(), tenantID, buf)
+
+		c.metrics.requestDuration.WithLabelValues(strconv.Itoa(status), c.cfg.URL.Host).Observe(time.Since(start).Seconds())
+
+		// Only retry 429s, 500s and connection-level errors.
+		if status > 0 && status != 429 && status/100 != 5 {
+			break
+		}
+
+		c.logger.Warn("error sending batch, will retry", "status", status, "error", err)
+		c.metrics.batchRetries.WithLabelValues(c.cfg.URL.Host).Inc()
+		backoff.Wait()
+
+		// Make sure it sends at least once before checking for retry.
+		if !backoff.Ongoing() {
+			break
+		}
+	}
+
+	if err != nil {
+		c.logger.Error("final error sendnig batch", "status", status, "error")
+		c.metrics.droppedBytes.WithLabelValues(c.cfg.URL.Host).Add(bufBytes)
+		c.metrics.droppedEntries.WithLabelValues(c.cfg.URL.Host).Add(float64(entriesCount))
+	}
+}
+
+func (c *client) send(ctx context.Context, tenantID string, buf []byte) (int, error) {
+	ctx, cancel := context.WithTimeout(ctx, c.cfg.Timeout)
+	defer cancel()
+	req, err := http.NewRequest("POST", c.cfg.URL.String(), bytes.NewReader(buf))
+	if err != nil {
+		return -1, err
+	}
+	req = req.WithContext(ctx)
+	req.Header.Set("Content-Type", contentType)
+	req.Header.Set("User-Agent", UserAgent)
+
+	// If the tenant ID is not empty promtail is running in multi-tenant mode, so
+	// we should send it to Loki
+	if tenantID != "" {
+		req.Header.Set("X-Scope-OrgID", tenantID)
+	}
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return -1, err
+	}
+	defer func() {
+		err := resp.Body.Close()
+		if err != nil {
+			c.logger.Error("closing response body", "error", err)
+		}
+	}()
+
+	if resp.StatusCode/100 != 2 {
+		scanner := bufio.NewScanner(io.LimitReader(resp.Body, maxErrMsgLen))
+		line := ""
+		if scanner.Scan() {
+			line = scanner.Text()
+		}
+		err = fmt.Errorf("server returned HTTP status %s (%d): %s", resp.Status, resp.StatusCode, line)
+	}
+	return resp.StatusCode, err
+}
+
+// Stop the client.
+func (c *client) Stop() {
+	c.once.Do(func() { close(c.entries) })
+	c.wg.Wait()
+}
+
+// StopNow stops the client without retries
+func (c *client) StopNow() {
+	// cancel will stop retrying http requests.
+	c.cancel()
+	c.Stop()
+}

pkg/components/loki/lokihttp/config.go

@@ -0,0 +1,21 @@
+package lokihttp
+
+import (
+	"time"
+
+	"github.com/grafana/dskit/backoff"
+	"github.com/grafana/dskit/flagext"
+	"github.com/prometheus/common/config"
+)
+
+// Config describes configuration for a HTTP pusher client.
+type Config struct {
+	URL       flagext.URLValue
+	BatchWait time.Duration
+	BatchSize int
+
+	Client config.HTTPClientConfig
+
+	BackoffConfig backoff.Config
+	Timeout       time.Duration
+}

pkg/components/loki/lokihttp/fake.go

@@ -0,0 +1,39 @@
+package lokihttp
+
+import (
+	"sync"
+
+	"github.com/prometheus/common/model"
+)
+
+type Fake struct {
+	Labels model.LabelSet
+	Entry  string
+
+	entries chan Entry
+	wg      *sync.WaitGroup
+}
+
+func NewFake() *Fake {
+	c := &Fake{
+		entries: make(chan Entry, 1),
+		wg:      &sync.WaitGroup{},
+	}
+
+	c.wg.Add(1)
+
+	go func() {
+		entry := <-c.entries
+		c.Labels = entry.Labels
+		c.Entry = entry.Line
+		c.wg.Done()
+	}()
+
+	return c
+}
+
+func (c *Fake) Stop() { c.wg.Wait() }
+
+func (c *Fake) Chan() chan<- Entry { return c.entries }
+
+func (c *Fake) StopNow() {}

pkg/components/loki/lokihttp/types.go

@@ -0,0 +1,13 @@
+package lokihttp
+
+import (
+	"github.com/prometheus/common/model"
+
+	"github.com/grafana/grafana/pkg/components/loki/logproto"
+)
+
+// Entry is a log entry with labels.
+type Entry struct {
+	Labels model.LabelSet
+	logproto.Entry
+}

pkg/extensions/main.go

@@ -14,8 +14,6 @@ import (
 	_ "github.com/googleapis/gax-go/v2"
 	_ "github.com/grafana/dskit/backoff"
 	_ "github.com/grafana/dskit/flagext"
-	_ "github.com/grafana/loki/clients/pkg/promtail/client"
-	_ "github.com/grafana/loki/pkg/logproto"
 	_ "github.com/grpc-ecosystem/go-grpc-middleware"
 	_ "github.com/jung-kurt/gofpdf"
 	_ "github.com/linkedin/goavro/v2"