opentelemetry: create a new module

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",
 

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"
+								}
+							]
+						}
+					]
+				}
+			}
+		}
+	}
+}

go.mod

@@ -24,6 +24,10 @@ require (
 	github.com/smallstep/truststore v0.10.1
 	github.com/yuin/goldmark v1.4.1
 	github.com/yuin/goldmark-highlighting v0.0.0-20210516132338-9216f9c5aa01
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.28.0
+	go.opentelemetry.io/otel v1.3.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.3.0
+	go.opentelemetry.io/otel/sdk v1.3.0
 	go.uber.org/zap v1.19.0
 	golang.org/x/crypto v0.0.0-20210915214749-c084706c2272
 	golang.org/x/net v0.0.0-20210913180222-943fd674d43e

go.sum

@@ -189,7 +189,10 @@ github.com/caddyserver/certmagic v0.15.2/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=
@@ -212,7 +215,11 @@ 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=
@@ -284,11 +291,14 @@ 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=
@@ -324,6 +334,11 @@ 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 v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.1 h1:DX7uPQ4WgAWfoh+NGGlbJQswnYIVvz0SRlLS3rPZQDA=
+github.com/go-logr/logr v1.2.1/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.0 h1:j4LrlVXgrbIWO83mmQUnK0Hi+YnbD+vzrE1z/EphbFE=
+github.com/go-logr/stdr v1.2.0/go.mod h1:YkVgnZu1ZjjL7xTxrfm/LLZBfkhTqSR1ydtm6jTKKwI=
 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=
@@ -479,6 +494,7 @@ 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=
@@ -982,17 +998,39 @@ 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 v0.28.0 h1:hpEoMBvKLC6CqFZogJypr9IHwwSNF3ayEkNzD502QAM=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.28.0/go.mod h1:Ihno+mNBfZlT0Qot3XyRTdZ/9U/Cg2Pfgj75DTdIfq4=
 go.opentelemetry.io/otel v0.20.0/go.mod h1:Y3ugLH2oa81t5QO+Lty+zXf8zC9L26ax4Nzoxm/dooo=
+go.opentelemetry.io/otel v1.3.0 h1:APxLf0eiBwLl+SOXiJJCVYzA1OOJNyAoV8C5RNRyy7Y=
+go.opentelemetry.io/otel v1.3.0/go.mod h1:PWIKzi6JCp7sM0k9yZ43VX+T345uNbAkDKwHVjb2PTs=
+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 v1.3.0 h1:R/OBkMoGgfy2fLhs2QhkCI1w4HLEQX92GCcJB6SSdNk=
+go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.3.0/go.mod h1:VpP4/RMn8bv8gNo9uK7/IMY4mtWLELsS+JIP0inH0h4=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.3.0 h1:giGm8w67Ja7amYNfYMdme7xSp2pIxThWopw8+QP51Yk=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.3.0/go.mod h1:hO1KLR7jcKaDDKDkvI9dP/FIhpmna5lkqPUQdEjFAM8=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.3.0 h1:VQbUHoJqytHHSJ1OZodPH9tvZZSVzUHjPHpkO85sT6k=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.3.0/go.mod h1:keUU7UfnwWTWpJ+FWnyqmogPa82nuU5VUANFq49hlMY=
+go.opentelemetry.io/otel/internal/metric v0.26.0 h1:dlrvawyd/A+X8Jp0EBT4wWEe4k5avYaXsXrBr4dbfnY=
+go.opentelemetry.io/otel/internal/metric v0.26.0/go.mod h1:CbBP6AxKynRs3QCbhklyLUtpfzbqCLiafV9oY2Zj1Jk=
 go.opentelemetry.io/otel/metric v0.20.0/go.mod h1:598I5tYlH1vzBjn+BTuhzTCSb/9debfNp6R3s7Pr1eU=
+go.opentelemetry.io/otel/metric v0.26.0 h1:VaPYBTvA13h/FsiWfxa3yZnZEm15BhStD8JZQSA773M=
+go.opentelemetry.io/otel/metric v0.26.0/go.mod h1:c6YL0fhRo4YVoNs6GoByzUgBp36hBL523rECoZA5UWg=
 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 v1.3.0 h1:3278edCoH89MEJ0Ky8WQXVmDQv3FX4ZJ3Pp+9fJreAI=
+go.opentelemetry.io/otel/sdk v1.3.0/go.mod h1:rIo4suHNhQwBIPg9axF8V9CA72Wz2mKF1teNrup8yzs=
 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 v1.3.0 h1:doy8Hzb1RJ+I3yFhtDmwNc7tIyw1tNMOIsyPzp1NOGY=
+go.opentelemetry.io/otel/trace v1.3.0/go.mod h1:c/VDhno8888bvQYmbYLqe41/Ldmr/KKunbvWM4/fEjk=
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
+go.opentelemetry.io/proto/otlp v0.11.0 h1:cLDgIBTf4lLOlztkhzAEdQsJ4Lj+i5Wc9k6Nn0K1VyU=
+go.opentelemetry.io/proto/otlp v0.11.0/go.mod h1:QpEjXPrNQzrFDZgoTo49dgHR9RYRSrg3NAKnUGl9YpQ=
 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=
@@ -1006,8 +1044,9 @@ go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 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 h1:z+mqJhf6ss6BSfSM671tgKyZBFPTTJM+HLxnhPC3wu0=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
+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=
@@ -1072,7 +1111,6 @@ golang.org/x/lint v0.0.0-20191125180803-fdd1cda4f05f/go.mod h1:5qLYkcX4OjUUV8bRu
 golang.org/x/lint v0.0.0-20200130185559-910be7a94367/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
 golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
-golang.org/x/lint v0.0.0-20210508222113-6edffad5e616 h1:VLliZ0d+/avPrXXH+OakdXhpJuEoBZuwh1m2j7U6Iug=
 golang.org/x/lint v0.0.0-20210508222113-6edffad5e616/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
 golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
 golang.org/x/mobile v0.0.0-20190719004257-d2bd2a29d028/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
@@ -1258,6 +1296,7 @@ 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=
@@ -1502,8 +1541,9 @@ google.golang.org/grpc v1.36.1/go.mod h1:qjiiYl8FncCW8feJPdyg3v6XW24KsRHe+dy9BAG
 google.golang.org/grpc v1.37.0/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQdJfM=
 google.golang.org/grpc v1.37.1/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQdJfM=
 google.golang.org/grpc v1.38.0/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQdJfM=
-google.golang.org/grpc v1.39.0 h1:Klz8I9kdtkIN6EpHHUOMLCYhTn/2WAe5a0s1hcBkdTI=
 google.golang.org/grpc v1.39.0/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnDzfrE=
+google.golang.org/grpc v1.42.0 h1:XT2/MFpuPFsEX2fWh3YQtHkZ+WYZFQRfaUgLZYj/p6A=
+google.golang.org/grpc v1.42.0/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=

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"
 )

modules/caddyhttp/tracing/module.go

@@ -0,0 +1,116 @@
+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.
+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)
+)