tracing: New OpenTelemetry module (#4361)

* opentelemetry: create a new module

* fix imports

* fix test

* Update modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update modules/caddyhttp/opentelemetry/tracer.go

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* rename error ErrUnsupportedTracesProtocol

* replace spaces with tabs in the test data

* Update modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Francis Lavoie <lavofr@gmail.com>

* Update modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Francis Lavoie <lavofr@gmail.com>

* replace spaces with tabs in the README.md

* use default values for a propagation and exporter protocol

* set http attributes with helper

* simplify code

* Cleanup modules/caddyhttp/opentelemetry/README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update link in README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update documentation in README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update link to naming spec in README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Rename module from opentelemetry to tracing

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Rename span_name to span

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Rename span_name to span

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Simplify otel resource creation

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* handle extra attributes

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* update go.opentelemetry.io/otel/semconv to 1.7.0

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* update go.opentelemetry.io/otel version

* remove environment variable handling

* always use tracecontext,baggage as propagators

* extract tracer name into variable

* rename OpenTelemetry to Tracing

* simplify resource creation

* update go.mod

* rename package from opentelemetry to tracing

* cleanup tests

* update Caddyfile example in README.md

* update README.md

* fix test

* fix module name in README.md

* fix module name in README.md

* change names in README.md and tests

* order imports

* remove redundant tests

* Update documentation README.md

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Fix grammar

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update comments

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* Update comments

Co-authored-by: Dave Henderson <dhenderson@gmail.com>

* update go.sum

* update go.sum

* Add otelhttp instrumentation, update OpenTelemetry libraries.

* Use otelhttp instrumentation for instrumenting HTTP requests.

This change uses context.WithValue to inject the next handler into the
request context via a "nextCall" carrier struct, and pass it on to a
standard Go HTTP handler returned by otelhttp.NewHandler. The
underlying handler will extract the next handler from the context,
call it and pass the returned error to the carrier struct.

* use zap.Error() for the error log

* remove README.md

* update dependencies

* clean up the code

* change comment

* move serveHTTP method from separate file

* add syntax to the UnmarshalCaddyfile comment

* go import the file

* admin: Write proper status on invalid requests (#4569) (fix #4561)

* update dependencies

Co-authored-by: Dave Henderson <dhenderson@gmail.com>
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
Co-authored-by: Vibhav Pant <vibhavp@gmail.com>
Co-authored-by: Alok Naushad <alokme123@gmail.com>
Co-authored-by: Cedric Ziel <cedric@cedric-ziel.com>

11 files changed, 632 insertions, 2 deletions

diff --git a/caddyconfig/httpcaddyfile/directives.go b/caddyconfig/httpcaddyfile/directives.go
index feb8e91..03e6753 100644
--- a/caddyconfig/httpcaddyfile/directives.go
+++ b/caddyconfig/httpcaddyfile/directives.go
@@ -37,6 +37,8 @@ import (
 // The header directive goes second so that headers
 // can be manipulated before doing redirects.
 var directiveOrder = []string{
+	"tracing",
+
 	"map",
 	"root",
 
diff --git a/caddytest/integration/caddyfile_adapt/tracing.txt b/caddytest/integration/caddyfile_adapt/tracing.txt
new file mode 100644
index 0000000..3228660
--- /dev/null
+++ b/caddytest/integration/caddyfile_adapt/tracing.txt
@@ -0,0 +1,36 @@
+:80 {
+	tracing /myhandler {
+		span my-span
+	}
+}
+----------
+{
+	"apps": {
+		"http": {
+			"servers": {
+				"srv0": {
+					"listen": [
+						":80"
+					],
+					"routes": [
+						{
+							"match": [
+								{
+									"path": [
+										"/myhandler"
+									]
+								}
+							],
+							"handle": [
+								{
+									"handler": "tracing",
+									"span": "my-span"
+								}
+							]
+						}
+					]
+				}
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/go.mod b/go.mod
index 511d2a8..61e2360 100644
--- a/go.mod
+++ b/go.mod
@@ -28,6 +28,10 @@ require (
 	github.com/tailscale/tscert v0.0.0-20220125204807-4509a5fbaf74
 	github.com/yuin/goldmark v1.4.4
 	github.com/yuin/goldmark-highlighting v0.0.0-20210516132338-9216f9c5aa01
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0
+	go.opentelemetry.io/otel v1.4.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.4.0
+	go.opentelemetry.io/otel/sdk v1.4.0
 	go.uber.org/zap v1.20.0
 	golang.org/x/crypto v0.0.0-20210915214749-c084706c2272
 	golang.org/x/net v0.0.0-20210913180222-943fd674d43e
diff --git a/go.sum b/go.sum
index 2107d53..ff454d4 100644
--- a/go.sum
+++ b/go.sum
@@ -194,7 +194,10 @@ github.com/caddyserver/certmagic v0.15.4/go.mod h1:qhkAOthf72ufAcp3Y5jF2RaGE96oi
 github.com/campoy/unique v0.0.0-20180121183637-88950e537e7e/go.mod h1:9IOqJGCPMSc6E5ydlp5NIonxObaeu/Iub/X03EKPVYo=
 github.com/casbin/casbin/v2 v2.1.2/go.mod h1:YcPU1XXisHhLzuxH9coDNf2FbKpjGlbCg3n9yuLkIJQ=
 github.com/cavaliercoder/go-cpio v0.0.0-20180626203310-925f9528c45e/go.mod h1:oDpT4efm8tSYHXV5tHSdRvBet/b/QzxZ+XyyPehvm3A=
+github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
+github.com/cenkalti/backoff/v4 v4.1.2 h1:6Yo7N8UP2K6LWZnW94DLVSSrbobcWdVzAYOisuDPIFo=
+github.com/cenkalti/backoff/v4 v4.1.2/go.mod h1:scbssz8iZGpm3xbr14ovlUdkxfGXNInqkPWOWmG2CLw=
 github.com/census-instrumentation/opencensus-proto v0.2.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.3.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
@@ -218,7 +221,11 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
+github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4/go.mod h1:6pvJx4me5XPnfI9Z40ddWsdw2W/uZgQLFXToKeRcDiI=
 github.com/cncf/xds/go v0.0.0-20210312221358-fbca930ec8ed/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20210805033703-aa0b78936158/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20210922020428-25de7278fc84/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
+github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
 github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
 github.com/cockroachdb/datadriven v0.0.0-20200714090401-bf6692d28da5/go.mod h1:h6jFvWxBdQXxjopDMZyH2UVceIRfR84bdzbkoKrsWNo=
 github.com/cockroachdb/errors v1.2.4/go.mod h1:rQD95gz6FARkaKkQXUksEje/d9a6wBJoCr5oaCLELYA=
@@ -289,11 +296,14 @@ github.com/envoyproxy/go-control-plane v0.9.7/go.mod h1:cwu0lG7PUMfa9snN8LXBig5y
 github.com/envoyproxy/go-control-plane v0.9.9-0.20201210154907-fd9021fe5dad/go.mod h1:cXg6YxExXjJnVBQHBLXeUAgxn2UodCpnH306RInaBQk=
 github.com/envoyproxy/go-control-plane v0.9.9-0.20210217033140-668b12f5399d/go.mod h1:cXg6YxExXjJnVBQHBLXeUAgxn2UodCpnH306RInaBQk=
 github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0/go.mod h1:hliV/p42l8fGbc6Y9bQ70uLwIvmJyVE5k4iMKlh8wCQ=
+github.com/envoyproxy/go-control-plane v0.9.10-0.20210907150352-cf90f659a021/go.mod h1:AFq3mo9L8Lqqiid3OhADV3RfLJnjiw63cSpi+fDTRC0=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/envoyproxy/protoc-gen-validate v0.3.0-java/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/etcd-io/gofail v0.0.0-20190801230047-ad7f989257ca/go.mod h1:49H/RkXP8pKaZy4h0d+NW16rSLhyVBt4o6VLJbmOqDE=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
+github.com/felixge/httpsnoop v1.0.2 h1:+nS9g82KMXccJ/wp0zyRW9ZBHFETmMGtkk+2CTTrW4o=
+github.com/felixge/httpsnoop v1.0.2/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
 github.com/form3tech-oss/jwt-go v3.2.2+incompatible/go.mod h1:pbq4aXjuKjdthFRnoDwaVPLA+WlJuPGy+QneDUgJi2k=
 github.com/form3tech-oss/jwt-go v3.2.3+incompatible/go.mod h1:pbq4aXjuKjdthFRnoDwaVPLA+WlJuPGy+QneDUgJi2k=
@@ -330,6 +340,10 @@ github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-logfmt/logfmt v0.5.0 h1:TrB8swr/68K7m9CcGut2g3UOihhbcbiMAYiuTXdEih4=
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
+github.com/go-logr/logr v1.2.2 h1:ahHml/yUpnlb96Rp8HCvtYVPY8ZYpxq3g7UYchIYwbs=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-piv/piv-go v1.7.0/go.mod h1:ON2WvQncm7dIkCQ7kYJs+nc3V4jHGfrrJnSF8HKy7Gk=
 github.com/go-redis/redis v6.15.9+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
 github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
@@ -412,8 +426,9 @@ github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.3/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
 github.com/google/go-github v17.0.0+incompatible/go.mod h1:zLgOLi98H3fifZn+44m+umXrS52loVEgC2AApnigrVQ=
 github.com/google/go-github/v28 v28.1.1/go.mod h1:bsqJWQX05omyWVmc00nEUql9mhQyv38lDZ8kPZcQVoM=
 github.com/google/go-licenses v0.0.0-20210329231322-ce1d9163b77d/go.mod h1:+TYOmkVoJOpwnS0wfdsJCV9CoD5nJYsHoFk/0CrTK4M=
@@ -489,6 +504,7 @@ github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t
 github.com/grpc-ecosystem/grpc-gateway v1.9.2/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/grpc-ecosystem/grpc-gateway v1.14.6/go.mod h1:zdiPV4Yse/1gnckTHtghG4GkDEdKCRJduHpTxT3/jcw=
+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/hashicorp/consul/api v1.1.0/go.mod h1:VmuI/Lkw1nC05EYQWNKwWGbkg+FbDBtguAZLlVdkD9Q=
 github.com/hashicorp/consul/api v1.3.0/go.mod h1:MmDNSzIMUjNpY/mQ398R4bk2FnqQLoPndWW5VkKPlCE=
@@ -1001,17 +1017,39 @@ go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
 go.opencensus.io v0.22.6/go.mod h1:XItmlyltB5F7CS4xOC1DcqMoFqwtC6OG2xF7mCv7P7E=
 go.opencensus.io v0.23.0 h1:gqCw0LfLxScz8irSi8exQc7fyQ0fKQU/qnC/X8+V/1M=
 go.opencensus.io v0.23.0/go.mod h1:XItmlyltB5F7CS4xOC1DcqMoFqwtC6OG2xF7mCv7P7E=
+go.opentelemetry.io/contrib v0.20.0 h1:ubFQUn0VCZ0gPwIoJfBJVpeBlyRMxu8Mm/huKWYd9p0=
 go.opentelemetry.io/contrib v0.20.0/go.mod h1:G/EtFaa6qaN7+LxqfIAT3GiZa7Wv5DTBUzl5H4LY0Kc=
 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.20.0/go.mod h1:oVGt1LRbBOBq1A5BQLlUg9UaU/54aiHw8cgjV3aWZ/E=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0 h1:SLme4Porm+UwX0DdHMxlwRt7FzPSE0sys81bet2o0pU=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0/go.mod h1:tLYsuf2v8fZreBVwp9gVMhefZlLFZaUiNVSq8QxXRII=
 go.opentelemetry.io/otel v0.20.0/go.mod h1:Y3ugLH2oa81t5QO+Lty+zXf8zC9L26ax4Nzoxm/dooo=
+go.opentelemetry.io/otel v1.4.0 h1:7ESuKPq6zpjRaY5nvVDGiuwK7VAJ8MwkKnmNJ9whNZ4=
+go.opentelemetry.io/otel v1.4.0/go.mod h1:jeAqMFKy2uLIxCtKxoFj0FAL5zAPKQagc3+GtBWakzk=
+go.opentelemetry.io/otel/exporters/otlp v0.20.0 h1:PTNgq9MRmQqqJY0REVbZFvwkYOA85vbdQU/nVfxDyqg=
 go.opentelemetry.io/otel/exporters/otlp v0.20.0/go.mod h1:YIieizyaN77rtLJra0buKiNBOm9XQfkPEKBeuhoMwAM=
+go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.4.0 h1:j7AwzDdAQBJjcqayAaYbvpYeZzII7cEe5qJTu+De6UY=
+go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.4.0/go.mod h1:VpP4/RMn8bv8gNo9uK7/IMY4mtWLELsS+JIP0inH0h4=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.4.0 h1:lRpP10E8oTGVmY1nVXcwelCT1Z8ca41/l5ce7AqLAss=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.4.0/go.mod h1:3oS+j2WUoJVyj6/BzQN/52G17lNJDulngsOxDm1w2PY=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.4.0 h1:buSx4AMC/0Z232slPhicN/fU5KIlj0bMngct5pcZhkI=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.4.0/go.mod h1:ew1NcwkHo0QFT3uTm3m2IVZMkZdVIpbOYNPasgWwpdk=
+go.opentelemetry.io/otel/internal/metric v0.27.0 h1:9dAVGAfFiiEq5NVB9FUJ5et+btbDQAUIJehJ+ikyryk=
+go.opentelemetry.io/otel/internal/metric v0.27.0/go.mod h1:n1CVxRqKqYZtqyTh9U/onvKapPGv7y/rpyOTI+LFNzw=
 go.opentelemetry.io/otel/metric v0.20.0/go.mod h1:598I5tYlH1vzBjn+BTuhzTCSb/9debfNp6R3s7Pr1eU=
+go.opentelemetry.io/otel/metric v0.27.0 h1:HhJPsGhJoKRSegPQILFbODU56NS/L1UE4fS1sC5kIwQ=
+go.opentelemetry.io/otel/metric v0.27.0/go.mod h1:raXDJ7uP2/Jc0nVZWQjJtzoyssOYWu/+pjZqRzfvZ7g=
 go.opentelemetry.io/otel/oteltest v0.20.0/go.mod h1:L7bgKf9ZB7qCwT9Up7i9/pn0PWIa9FqQ2IQ8LoxiGnw=
 go.opentelemetry.io/otel/sdk v0.20.0/go.mod h1:g/IcepuwNsoiX5Byy2nNV0ySUF1em498m7hBWC279Yc=
+go.opentelemetry.io/otel/sdk v1.4.0 h1:LJE4SW3jd4lQTESnlpQZcBhQ3oci0U2MLR5uhicfTHQ=
+go.opentelemetry.io/otel/sdk v1.4.0/go.mod h1:71GJPNJh4Qju6zJuYl1CrYtXbrgfau/M9UAggqiy1UE=
 go.opentelemetry.io/otel/sdk/export/metric v0.20.0/go.mod h1:h7RBNMsDJ5pmI1zExLi+bJK+Dr8NQCh0qGhm1KDnNlE=
 go.opentelemetry.io/otel/sdk/metric v0.20.0/go.mod h1:knxiS8Xd4E/N+ZqKmUPf3gTTZ4/0TjTXukfxjzSTpHE=
 go.opentelemetry.io/otel/trace v0.20.0/go.mod h1:6GjCW8zgDjwGHGa6GkyeB8+/5vjT16gUEi0Nf1iBdgw=
+go.opentelemetry.io/otel/trace v1.4.0 h1:4OOUrPZdVFQkbzl/JSdvGCWIdw5ONXXxzHlaLlWppmo=
+go.opentelemetry.io/otel/trace v1.4.0/go.mod h1:uc3eRsqDfWs9R7b92xbQbU42/eTNz4N+gLP8qJCi4aE=
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
+go.opentelemetry.io/proto/otlp v0.12.0 h1:CMJ/3Wp7iOWES+CYLfnBv+DVmPbB+kmy9PJ92XvlR6c=
+go.opentelemetry.io/proto/otlp v0.12.0/go.mod h1:TsIjwGWIx5VFYv9KGVlOpxoBl5Dy+63SUguV7GGvlSQ=
 go.step.sm/cli-utils v0.7.0 h1:2GvY5Muid1yzp7YQbfCCS+gK3q7zlHjjLL5Z0DXz8ds=
 go.step.sm/cli-utils v0.7.0/go.mod h1:Ur6bqA/yl636kCUJbp30J7Unv5JJ226eW2KqXPDwF/E=
 go.step.sm/crypto v0.9.0/go.mod h1:+CYG05Mek1YDqi5WK0ERc6cOpKly2i/a5aZmU1sfGj0=
@@ -1026,8 +1064,9 @@ go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
-go.uber.org/goleak v1.1.11 h1:wy28qYRKZgnJTxGxvye5/wgWr1EKjmUDGYox5mGlRlI=
 go.uber.org/goleak v1.1.11/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
+go.uber.org/goleak v1.1.12 h1:gZAh5/EyT/HQwlpkCy6wTpqfH9H8Lz8zbm3dZh+OyzA=
+go.uber.org/goleak v1.1.12/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.3.0/go.mod h1:VgVr7evmIr6uPjLBxg28wmKNXyqE9akIJ5XnfpiKl+4=
 go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
@@ -1279,6 +1318,7 @@ golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210412220455-f1c623a9e750/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210503080704-8803ae5d1324/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210514084401-e8d321eab015/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -1557,6 +1597,9 @@ google.golang.org/grpc v1.39.0/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnD
 google.golang.org/grpc v1.39.1/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnDzfrE=
 google.golang.org/grpc v1.40.0 h1:AGJ0Ih4mHjSeibYkFGh1dD9KJ/eOtZ93I6hoHhukQ5Q=
 google.golang.org/grpc v1.40.0/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
+google.golang.org/grpc v1.43.0/go.mod h1:k+4IHHFw41K8+bbowsex27ge2rCb65oeWqe4jJ590SU=
+google.golang.org/grpc v1.44.0 h1:weqSxi/TMs1SqFRMHCtBgXRs8k3X39QIDEZ0pRcttUg=
+google.golang.org/grpc v1.44.0/go.mod h1:k+4IHHFw41K8+bbowsex27ge2rCb65oeWqe4jJ590SU=
 google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.1.0/go.mod h1:6Kw0yEErY5E/yWrBtf03jp27GLLJujG4z/JK95pnjjw=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
diff --git a/modules/caddyhttp/standard/imports.go b/modules/caddyhttp/standard/imports.go
index 0e2203c..8ce2395 100644
--- a/modules/caddyhttp/standard/imports.go
+++ b/modules/caddyhttp/standard/imports.go
@@ -17,4 +17,5 @@ import (
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/fastcgi"
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/rewrite"
 	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/templates"
+	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/tracing"
 )
diff --git a/modules/caddyhttp/tracing/module.go b/modules/caddyhttp/tracing/module.go
new file mode 100644
index 0000000..7cce669
--- /dev/null
+++ b/modules/caddyhttp/tracing/module.go
@@ -0,0 +1,121 @@
+package tracing
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"go.uber.org/zap"
+)
+
+func init() {
+	caddy.RegisterModule(Tracing{})
+	httpcaddyfile.RegisterHandlerDirective("tracing", parseCaddyfile)
+}
+
+// Tracing implements an HTTP handler that adds support for distributed tracing,
+// using OpenTelemetry. This module is responsible for the injection and
+// propagation of the trace context. Configure this module via environment
+// variables (see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/sdk-environment-variables.md).
+// Some values can be overwritten in the configuration file.
+type Tracing struct {
+	// SpanName is a span name. It should follow the naming guidelines here:
+	// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#span
+	SpanName string `json:"span"`
+
+	// otel implements opentelemetry related logic.
+	otel openTelemetryWrapper
+
+	logger *zap.Logger
+}
+
+// CaddyModule returns the Caddy module information.
+func (Tracing) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		ID:  "http.handlers.tracing",
+		New: func() caddy.Module { return new(Tracing) },
+	}
+}
+
+// Provision implements caddy.Provisioner.
+func (ot *Tracing) Provision(ctx caddy.Context) error {
+	ot.logger = ctx.Logger(ot)
+
+	var err error
+	ot.otel, err = newOpenTelemetryWrapper(ctx, ot.SpanName)
+
+	return err
+}
+
+// Cleanup implements caddy.CleanerUpper and closes any idle connections. It
+// calls Shutdown method for a trace provider https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk.md#shutdown.
+func (ot *Tracing) Cleanup() error {
+	if err := ot.otel.cleanup(ot.logger); err != nil {
+		return fmt.Errorf("tracerProvider shutdown: %w", err)
+	}
+	return nil
+}
+
+// ServeHTTP implements caddyhttp.MiddlewareHandler.
+func (ot *Tracing) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
+	return ot.otel.ServeHTTP(w, r, next)
+}
+
+// UnmarshalCaddyfile sets up the module from Caddyfile tokens. Syntax:
+//
+//     tracing {
+//         [span <span_name>]
+//     }
+//
+func (ot *Tracing) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
+	setParameter := func(d *caddyfile.Dispenser, val *string) error {
+		if d.NextArg() {
+			*val = d.Val()
+		} else {
+			return d.ArgErr()
+		}
+		if d.NextArg() {
+			return d.ArgErr()
+		}
+		return nil
+	}
+
+	// paramsMap is a mapping between "string" parameter from the Caddyfile and its destination within the module
+	paramsMap := map[string]*string{
+		"span": &ot.SpanName,
+	}
+
+	for d.Next() {
+		args := d.RemainingArgs()
+		if len(args) > 0 {
+			return d.ArgErr()
+		}
+
+		for d.NextBlock(0) {
+			if dst, ok := paramsMap[d.Val()]; ok {
+				if err := setParameter(d, dst); err != nil {
+					return err
+				}
+			} else {
+				return d.ArgErr()
+			}
+		}
+	}
+	return nil
+}
+
+func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
+	var m Tracing
+	err := m.UnmarshalCaddyfile(h.Dispenser)
+	return &m, err
+}
+
+// Interface guards
+var (
+	_ caddy.Provisioner           = (*Tracing)(nil)
+	_ caddyhttp.MiddlewareHandler = (*Tracing)(nil)
+	_ caddyfile.Unmarshaler       = (*Tracing)(nil)
+)
diff --git a/modules/caddyhttp/tracing/module_test.go b/modules/caddyhttp/tracing/module_test.go
new file mode 100644
index 0000000..0fbc05b
--- /dev/null
+++ b/modules/caddyhttp/tracing/module_test.go
@@ -0,0 +1,182 @@
+package tracing
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+)
+
+func TestTracing_UnmarshalCaddyfile(t *testing.T) {
+	tests := []struct {
+		name     string
+		spanName string
+		d        *caddyfile.Dispenser
+		wantErr  bool
+	}{
+		{
+			name:     "Full config",
+			spanName: "my-span",
+			d: caddyfile.NewTestDispenser(`
+tracing {
+	span my-span
+}`),
+			wantErr: false,
+		},
+		{
+			name:     "Only span name in the config",
+			spanName: "my-span",
+			d: caddyfile.NewTestDispenser(`
+tracing {
+	span my-span
+}`),
+			wantErr: false,
+		},
+		{
+			name: "Empty config",
+			d: caddyfile.NewTestDispenser(`
+tracing {
+}`),
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ot := &Tracing{}
+			if err := ot.UnmarshalCaddyfile(tt.d); (err != nil) != tt.wantErr {
+				t.Errorf("UnmarshalCaddyfile() error = %v, wantErrType %v", err, tt.wantErr)
+			}
+
+			if ot.SpanName != tt.spanName {
+				t.Errorf("UnmarshalCaddyfile() SpanName = %v, want SpanName %v", ot.SpanName, tt.spanName)
+			}
+		})
+	}
+}
+
+func TestTracing_UnmarshalCaddyfile_Error(t *testing.T) {
+	tests := []struct {
+		name    string
+		d       *caddyfile.Dispenser
+		wantErr bool
+	}{
+		{
+			name: "Unknown parameter",
+			d: caddyfile.NewTestDispenser(`
+		tracing {
+			foo bar
+		}`),
+			wantErr: true,
+		},
+		{
+			name: "Missed argument",
+			d: caddyfile.NewTestDispenser(`
+tracing {
+	span
+}`),
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ot := &Tracing{}
+			if err := ot.UnmarshalCaddyfile(tt.d); (err != nil) != tt.wantErr {
+				t.Errorf("UnmarshalCaddyfile() error = %v, wantErrType %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestTracing_ServeHTTP_Propagation_Without_Initial_Headers(t *testing.T) {
+	ot := &Tracing{
+		SpanName: "mySpan",
+	}
+
+	req := httptest.NewRequest("GET", "https://example.com/foo", nil)
+	w := httptest.NewRecorder()
+
+	var handler caddyhttp.HandlerFunc = func(writer http.ResponseWriter, request *http.Request) error {
+		traceparent := request.Header.Get("Traceparent")
+		if traceparent == "" || strings.HasPrefix(traceparent, "00-00000000000000000000000000000000-0000000000000000") {
+			t.Errorf("Invalid traceparent: %v", traceparent)
+		}
+
+		return nil
+	}
+
+	ctx, cancel := caddy.NewContext(caddy.Context{Context: context.Background()})
+	defer cancel()
+
+	if err := ot.Provision(ctx); err != nil {
+		t.Errorf("Provision error: %v", err)
+		t.FailNow()
+	}
+
+	if err := ot.ServeHTTP(w, req, handler); err != nil {
+		t.Errorf("ServeHTTP error: %v", err)
+	}
+}
+
+func TestTracing_ServeHTTP_Propagation_With_Initial_Headers(t *testing.T) {
+	ot := &Tracing{
+		SpanName: "mySpan",
+	}
+
+	req := httptest.NewRequest("GET", "https://example.com/foo", nil)
+	req.Header.Set("traceparent", "00-11111111111111111111111111111111-1111111111111111-01")
+	w := httptest.NewRecorder()
+
+	var handler caddyhttp.HandlerFunc = func(writer http.ResponseWriter, request *http.Request) error {
+		traceparent := request.Header.Get("Traceparent")
+		if !strings.HasPrefix(traceparent, "00-11111111111111111111111111111111") {
+			t.Errorf("Invalid traceparent: %v", traceparent)
+		}
+
+		return nil
+	}
+
+	ctx, cancel := caddy.NewContext(caddy.Context{Context: context.Background()})
+	defer cancel()
+
+	if err := ot.Provision(ctx); err != nil {
+		t.Errorf("Provision error: %v", err)
+		t.FailNow()
+	}
+
+	if err := ot.ServeHTTP(w, req, handler); err != nil {
+		t.Errorf("ServeHTTP error: %v", err)
+	}
+}
+
+func TestTracing_ServeHTTP_Next_Error(t *testing.T) {
+	ot := &Tracing{
+		SpanName: "mySpan",
+	}
+
+	req := httptest.NewRequest("GET", "https://example.com/foo", nil)
+	w := httptest.NewRecorder()
+
+	expectErr := errors.New("test error")
+
+	var handler caddyhttp.HandlerFunc = func(writer http.ResponseWriter, request *http.Request) error {
+		return expectErr
+	}
+
+	ctx, cancel := caddy.NewContext(caddy.Context{Context: context.Background()})
+	defer cancel()
+
+	if err := ot.Provision(ctx); err != nil {
+		t.Errorf("Provision error: %v", err)
+		t.FailNow()
+	}
+
+	if err := ot.ServeHTTP(w, req, handler); err == nil || !errors.Is(err, expectErr) {
+		t.Errorf("expected error, got: %v", err)
+	}
+}
diff --git a/modules/caddyhttp/tracing/tracer.go b/modules/caddyhttp/tracing/tracer.go
new file mode 100644
index 0000000..ce23944
--- /dev/null
+++ b/modules/caddyhttp/tracing/tracer.go
@@ -0,0 +1,108 @@
+package tracing
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/caddyserver/caddy/v2"
+
+	caddycmd "github.com/caddyserver/caddy/v2/cmd"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	"go.uber.org/zap"
+)
+
+const (
+	webEngineName                = "Caddy"
+	defaultSpanName              = "handler"
+	nextCallCtxKey  caddy.CtxKey = "nextCall"
+)
+
+// nextCall store the next handler, and the error value return on calling it (if any)
+type nextCall struct {
+	next caddyhttp.Handler
+	err  error
+}
+
+// openTelemetryWrapper is responsible for the tracing injection, extraction and propagation.
+type openTelemetryWrapper struct {
+	propagators propagation.TextMapPropagator
+
+	handler http.Handler
+
+	spanName string
+}
+
+// newOpenTelemetryWrapper is responsible for the openTelemetryWrapper initialization using provided configuration.
+func newOpenTelemetryWrapper(
+	ctx context.Context,
+	spanName string,
+) (openTelemetryWrapper, error) {
+	if spanName == "" {
+		spanName = defaultSpanName
+	}
+
+	ot := openTelemetryWrapper{
+		spanName: spanName,
+	}
+
+	res, err := ot.newResource(webEngineName, caddycmd.CaddyVersion())
+	if err != nil {
+		return ot, fmt.Errorf("creating resource error: %w", err)
+	}
+
+	traceExporter, err := otlptracegrpc.New(ctx)
+	if err != nil {
+		return ot, fmt.Errorf("creating trace exporter error: %w", err)
+	}
+
+	ot.propagators = propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{})
+
+	tracerProvider := globalTracerProvider.getTracerProvider(
+		sdktrace.WithBatcher(traceExporter),
+		sdktrace.WithResource(res),
+	)
+
+	ot.handler = otelhttp.NewHandler(http.HandlerFunc(ot.serveHTTP), ot.spanName, otelhttp.WithTracerProvider(tracerProvider), otelhttp.WithPropagators(ot.propagators))
+	return ot, nil
+}
+
+// serveHTTP injects a tracing context and call the next handler.
+func (ot *openTelemetryWrapper) serveHTTP(w http.ResponseWriter, r *http.Request) {
+	ot.propagators.Inject(r.Context(), propagation.HeaderCarrier(r.Header))
+	next := r.Context().Value(nextCallCtxKey).(*nextCall)
+	next.err = next.next.ServeHTTP(w, r)
+}
+
+// ServeHTTP propagates call to the by wrapped by `otelhttp` next handler.
+func (ot *openTelemetryWrapper) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
+	n := &nextCall{
+		next: next,
+		err:  nil,
+	}
+	ot.handler.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), nextCallCtxKey, n)))
+
+	return n.err
+}
+
+// cleanup flush all remaining data and shutdown a tracerProvider
+func (ot *openTelemetryWrapper) cleanup(logger *zap.Logger) error {
+	return globalTracerProvider.cleanupTracerProvider(logger)
+}
+
+// newResource creates a resource that describe current handler instance and merge it with a default attributes value.
+func (ot *openTelemetryWrapper) newResource(
+	webEngineName,
+	webEngineVersion string,
+) (*resource.Resource, error) {
+	return resource.Merge(resource.Default(), resource.NewSchemaless(
+		semconv.WebEngineNameKey.String(webEngineName),
+		semconv.WebEngineVersionKey.String(webEngineVersion),
+	))
+}
diff --git a/modules/caddyhttp/tracing/tracer_test.go b/modules/caddyhttp/tracing/tracer_test.go
new file mode 100644
index 0000000..36a32ff
--- /dev/null
+++ b/modules/caddyhttp/tracing/tracer_test.go
@@ -0,0 +1,27 @@
+package tracing
+
+import (
+	"context"
+	"testing"
+
+	"github.com/caddyserver/caddy/v2"
+)
+
+func TestOpenTelemetryWrapper_newOpenTelemetryWrapper(t *testing.T) {
+	ctx, cancel := caddy.NewContext(caddy.Context{Context: context.Background()})
+	defer cancel()
+
+	var otw openTelemetryWrapper
+	var err error
+
+	if otw, err = newOpenTelemetryWrapper(ctx,
+		"",
+	); err != nil {
+		t.Errorf("newOpenTelemetryWrapper() error = %v", err)
+		t.FailNow()
+	}
+
+	if otw.propagators == nil {
+		t.Errorf("Propagators should not be empty")
+	}
+}
diff --git a/modules/caddyhttp/tracing/tracerprovider.go b/modules/caddyhttp/tracing/tracerprovider.go
new file mode 100644
index 0000000..035425e
--- /dev/null
+++ b/modules/caddyhttp/tracing/tracerprovider.go
@@ -0,0 +1,63 @@
+package tracing
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	"go.uber.org/zap"
+)
+
+// globalTracerProvider stores global tracer provider and is responsible for graceful shutdown when nobody is using it.
+var globalTracerProvider = &tracerProvider{}
+
+type tracerProvider struct {
+	mu                     sync.Mutex
+	tracerProvider         *sdktrace.TracerProvider
+	tracerProvidersCounter int
+}
+
+// getTracerProvider create or return an existing global TracerProvider
+func (t *tracerProvider) getTracerProvider(opts ...sdktrace.TracerProviderOption) *sdktrace.TracerProvider {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	t.tracerProvidersCounter++
+
+	if t.tracerProvider == nil {
+		t.tracerProvider = sdktrace.NewTracerProvider(
+			opts...,
+		)
+	}
+
+	return t.tracerProvider
+}
+
+// cleanupTracerProvider gracefully shutdown a TracerProvider
+func (t *tracerProvider) cleanupTracerProvider(logger *zap.Logger) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.tracerProvidersCounter > 0 {
+		t.tracerProvidersCounter--
+	}
+
+	if t.tracerProvidersCounter == 0 {
+		if t.tracerProvider != nil {
+			// tracerProvider.ForceFlush SHOULD be invoked according to https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk.md#forceflush
+			if err := t.tracerProvider.ForceFlush(context.Background()); err != nil {
+				logger.Error("forcing flush", zap.Error(err))
+			}
+
+			// tracerProvider.Shutdown MUST be invoked according to https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk.md#shutdown
+			if err := t.tracerProvider.Shutdown(context.Background()); err != nil {
+				return fmt.Errorf("tracerProvider shutdown error: %w", err)
+			}
+		}
+
+		t.tracerProvider = nil
+	}
+
+	return nil
+}
diff --git a/modules/caddyhttp/tracing/tracerprovider_test.go b/modules/caddyhttp/tracing/tracerprovider_test.go
new file mode 100644
index 0000000..cb2e593
--- /dev/null
+++ b/modules/caddyhttp/tracing/tracerprovider_test.go
@@ -0,0 +1,43 @@
+package tracing
+
+import (
+	"testing"
+
+	"go.uber.org/zap"
+)
+
+func Test_tracersProvider_getTracerProvider(t *testing.T) {
+	tp := tracerProvider{}
+
+	tp.getTracerProvider()
+	tp.getTracerProvider()
+
+	if tp.tracerProvider == nil {
+		t.Errorf("There should be tracer provider")
+	}
+
+	if tp.tracerProvidersCounter != 2 {
+		t.Errorf("Tracer providers counter should equal to 2")
+	}
+}
+
+func Test_tracersProvider_cleanupTracerProvider(t *testing.T) {
+	tp := tracerProvider{}
+
+	tp.getTracerProvider()
+	tp.getTracerProvider()
+
+	err := tp.cleanupTracerProvider(zap.NewNop())
+
+	if err != nil {
+		t.Errorf("There should be no error: %v", err)
+	}
+
+	if tp.tracerProvider == nil {
+		t.Errorf("There should be tracer provider")
+	}
+
+	if tp.tracerProvidersCounter != 1 {
+		t.Errorf("Tracer providers counter should equal to 1")
+	}
+}