Add draft of tracing package.

README.md

@@ -28,6 +28,7 @@ This project is in active use by [telegram-bot.app](https://telegram-bot.app), a
     - [Cache operations](#cache-operations)
   - [General](#general)
     - [Metrics which matter](#metrics-which-matter)
+    - [Tracing](#tracing)
     - [Healthcheck](#healthcheck)
     - [Monitoring endpoint](#monitoring-endpoint)
 
@@ -144,6 +145,8 @@ You can still use the non-prefixed environment variables in the spirit of the ba
 | `HASURA_EVENT_CLEANER`   | Enable the hasura event cleaner          | `false`                    |
 | `HASURA_EVENT_CLEANER_OLDER_THAN` | The interval for the hasura event cleaner (in days) | `1`                  |
 | `HASURA_EVENT_METADATA_DB` | URL to the hasura metadata database    | `postgresql://localhost:5432/hasura` |
+| `ENABLE_TRACE` | Enables tracing | `false` |
+| `TRACER_ENDPOINT` | Tracing endpoint | `localhost:4317` |
 
 ### Speed
 
@@ -293,6 +296,12 @@ With the `PURGE_METRICS_ON_CRAWL` enabled, the `graphql_proxy_requests_failed`,
 
 If you prefer more control over the metrics purging - you can enable `PURGE_METRICS_ON_TIMER` environment variable and set the interval in seconds. This will allow you to purge the metrics on a regular basis, for example every 90 seconds. It could be better solution if you have multiple crawlers checking the metrics endpoints and you want to avoid the situation when metrics are purged by for example healthcheck.
 
+#### Tracing
+
+Tracing can be enabled by setting `ENABLE_TRACE` to `true` and providing compatible with OTEL `TRACER_ENDPOINT` value ( default is `localhost:4317` ). From that moment you can include `X-Trace-Span` in your requests to the proxy.
+
+The value of X-Trace-Span should be in following format !!#TODO!!
+
 #### Healthcheck
 
 If you'd like the `/healthz` endpoint to perform actual check for the connectivity to the graphql endpoint - set the `HEALTHCHECK_GRAPHQL_URL` environment variable to the exact URL of the graphql endpoint. The query executed will be `query { __typename }` and if the response is not `200 OK` - the healthcheck will fail. Remember that the endpoint is a full URL which you'd like to check, so it should include the protocol, host and path - for example `http://localhost:8080/v1/graphql` and it's NOT the same as value of `HOST_GRAPHQL` environment variable which should provide only the host, without path, ending with slash.

go.mod

@@ -19,25 +19,32 @@ require (
 	github.com/redis/go-redis/v9 v9.5.3
 	github.com/stretchr/testify v1.9.0
 	github.com/valyala/fasthttp v1.55.0
+	go.opentelemetry.io/otel v1.27.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.27.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.27.0
+	go.opentelemetry.io/otel/sdk v1.27.0
+	go.opentelemetry.io/otel/trace v1.27.0
 )
 
 require (
 	github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a // indirect
 	github.com/andybalholm/brotli v1.1.0 // indirect
+	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/gookit/color v1.5.4 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/klauspost/compress v1.17.9 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
-	github.com/rogpeppe/go-internal v1.11.0 // indirect
 	github.com/rs/zerolog v1.33.0 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fastrand v1.1.0 // indirect
@@ -45,6 +52,8 @@ require (
 	github.com/valyala/tcplisten v1.0.0 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	github.com/yuin/gopher-lua v1.1.1 // indirect
+	go.opentelemetry.io/otel/metric v1.27.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.2.0 // indirect
 	golang.org/x/crypto v0.24.0 // indirect
 	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 // indirect
 	golang.org/x/net v0.26.0 // indirect
@@ -52,5 +61,9 @@ require (
 	golang.org/x/sys v0.21.0 // indirect
 	golang.org/x/term v0.21.0 // indirect
 	golang.org/x/text v0.16.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240520151616-dc85e6b867a5 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240515191416-fc5f0ca64291 // indirect
+	google.golang.org/grpc v1.64.0 // indirect
+	google.golang.org/protobuf v1.34.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -12,15 +12,21 @@ github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
 github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
 github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
 github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
+github.com/cenkalti/backoff/v4 v4.3.0 h1:MyRJ/UdXutAwSAT+s3wNd7MfTIcy71VQueUuFK343L8=
+github.com/cenkalti/backoff/v4 v4.3.0/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
+github.com/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+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/goccy/go-json v0.10.3 h1:KZ5WoDbxAIgm2HNbYckL0se1fHD6rz5j4ywS6ebzDqA=
 github.com/goccy/go-json v0.10.3/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
@@ -28,6 +34,8 @@ github.com/gofiber/fiber/v2 v2.52.4 h1:P+T+4iK7VaqUsq2PALYEfBBo6bJZ4q3FP8cZ84Egg
 github.com/gofiber/fiber/v2 v2.52.4/go.mod h1:KEOE+cXMhXG0zHc9d8+E38hoX+ZN7bhOtgeF2oT6jrQ=
 github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gookit/color v1.5.4 h1:FZmqs7XOyGgCAxmWyPslpiok1k05wmY3SJTytgvYFs0=
@@ -36,6 +44,8 @@ github.com/gookit/goutil v0.6.15 h1:mMQ0ElojNZoyPD0eVROk5QXJPh2uKR4g06slgPDF5Jo=
 github.com/gookit/goutil v0.6.15/go.mod h1:qdKdYEHQdEtyH+4fNdQNZfJHhI0jUZzHxQVAV3DaMDY=
 github.com/graphql-go/graphql v0.8.1 h1:p7/Ou/WpmulocJeEx7wjQy611rtXGQaAcXGqanuMMgc=
 github.com/graphql-go/graphql v0.8.1/go.mod h1:nKiHzRM0qopJEwCITUuIsxk9PlVlwIiiI8pnJEhordQ=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 h1:bkypFPDjIYGfCYD5mRBvpqxfYX1YCS1PXdKYWi8FsN0=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0/go.mod h1:P+Lt/0by1T8bfcF3z737NnSbmxQAppXMRziHUxPOC8k=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
 github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
@@ -64,7 +74,6 @@ github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWE
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
-github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -73,9 +82,8 @@ github.com/redis/go-redis/v9 v9.5.3/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
-github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDNXVBh4M=
+github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
-github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
@@ -98,6 +106,22 @@ github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavM
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
 github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
+go.opentelemetry.io/otel v1.27.0 h1:9BZoF3yMK/O1AafMiQTVu0YDj5Ea4hPhxCs7sGva+cg=
+go.opentelemetry.io/otel v1.27.0/go.mod h1:DMpAK8fzYRzs+bi3rS5REupisuqTheUlSZJ1WnZaPAQ=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.27.0 h1:R9DE4kQ4k+YtfLI2ULwX82VtNQ2J8yZmA7ZIF/D+7Mc=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.27.0/go.mod h1:OQFyQVrDlbe+R7xrEyDr/2Wr67Ol0hRUgsfA+V5A95s=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.27.0 h1:qFffATk0X+HD+f1Z8lswGiOQYKHRlzfmdJm0wEaVrFA=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.27.0/go.mod h1:MOiCmryaYtc+V0Ei+Tx9o5S1ZjA7kzLucuVuyzBZloQ=
+go.opentelemetry.io/otel/metric v1.27.0 h1:hvj3vdEKyeCi4YaYfNjv2NUje8FqKqUY8IlF0FxV/ik=
+go.opentelemetry.io/otel/metric v1.27.0/go.mod h1:mVFgmRlhljgBiuk/MP/oKylr4hs85GZAylncepAX/ak=
+go.opentelemetry.io/otel/sdk v1.27.0 h1:mlk+/Y1gLPLn84U4tI8d3GNJmGT/eXe3ZuOXN9kTWmI=
+go.opentelemetry.io/otel/sdk v1.27.0/go.mod h1:Ha9vbLwJE6W86YstIywK2xFfPjbWlCuwPtMkKdz/Y4A=
+go.opentelemetry.io/otel/trace v1.27.0 h1:IqYb813p7cmbHk0a5y6pD5JPakbVfftRXABGt5/Rscw=
+go.opentelemetry.io/otel/trace v1.27.0/go.mod h1:6RiD1hkAprV4/q+yd2ln1HG9GoPx39SuvvstaLBl+l4=
+go.opentelemetry.io/proto/otlp v1.2.0 h1:pVeZGk7nXDC9O2hncA6nHldxEjm6LByfA2aN8IOkz94=
+go.opentelemetry.io/proto/otlp v1.2.0/go.mod h1:gGpR8txAl5M03pDhMC79G6SdqNV26naRm/KDsgaHD8A=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 golang.org/x/crypto v0.24.0 h1:mnl8DM0o513X8fdIkmyFE/5hTYxbwYOjDS/+rK6qpRI=
 golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5DM=
 golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
@@ -115,6 +139,14 @@ golang.org/x/term v0.21.0 h1:WVXCp+/EBEHOj53Rvu+7KiT/iElMrO8ACK16SMZ3jaA=
 golang.org/x/term v0.21.0/go.mod h1:ooXLefLobQVslOqselCNF4SxFAaoS6KujMbsGzSDmX0=
 golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
 golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+google.golang.org/genproto/googleapis/api v0.0.0-20240520151616-dc85e6b867a5 h1:P8OJ/WCl/Xo4E4zoe4/bifHpSmmKwARqyqE4nW6J2GQ=
+google.golang.org/genproto/googleapis/api v0.0.0-20240520151616-dc85e6b867a5/go.mod h1:RGnPtTG7r4i8sPlNyDeikXF99hMM+hN6QMm4ooG9g2g=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240515191416-fc5f0ca64291 h1:AgADTJarZTBqgjiUzRgfaBchgYB3/WFTC80GPwsMcRI=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240515191416-fc5f0ca64291/go.mod h1:EfXuqaE1J41VCDicxHzUDm+8rk+7ZdXzHV0IhO/I6s0=
+google.golang.org/grpc v1.64.0 h1:KH3VH9y/MgNQg1dE7b3XfVK0GsPSIzJwdF617gUSbvY=
+google.golang.org/grpc v1.64.0/go.mod h1:oxjF8E3FBnjp+/gVFYdWacaLDx9na1aqy9oovLpxQYg=
+google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
+google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

main.go

@@ -12,6 +12,7 @@ import (
 	libpack_cache "github.com/lukaszraczylo/graphql-monitoring-proxy/cache"
 	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
 	libpack_logging "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
+	libpack_trace "github.com/lukaszraczylo/graphql-monitoring-proxy/trace"
 )
 
 var cfg *config
@@ -88,6 +89,8 @@ func parseConfig() {
 	c.HasuraEventCleaner.Enable = getDetailsFromEnv("HASURA_EVENT_CLEANER", false)
 	c.HasuraEventCleaner.ClearOlderThan = getDetailsFromEnv("HASURA_EVENT_CLEANER_OLDER_THAN", 1)
 	c.HasuraEventCleaner.EventMetadataDb = getDetailsFromEnv("HASURA_EVENT_METADATA_DB", "")
+	c.Trace.Enable = getDetailsFromEnv("ENABLE_TRACE", false)
+	c.Trace.TraceEndpoint = getDetailsFromEnv("TRACER_ENDPOINT", "localhost:4317")
 	cfg = &c
 
 	if cfg.Cache.CacheEnable || cfg.Cache.CacheRedisEnable {
@@ -103,8 +106,21 @@ func parseConfig() {
 		}
 		libpack_cache.EnableCache(cacheConfig)
 	}
+
 	loadRatelimitConfig()
 	once.Do(func() {
+		if cfg.Trace.Enable {
+			var err error
+			cfg.Trace.Client, err = libpack_trace.NewClient(c.Trace.TraceEndpoint)
+			if err != nil {
+				cfg.Logger.Error(&libpack_logging.LogMessage{
+					Message: "Failed to start tracer",
+					Pairs: map[string]interface{}{
+						"error": err,
+					},
+				})
+			}
+		}
 		go enableApi()
 		go enableHasuraEventCleaner()
 	})

server.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"strconv"
 	"time"
@@ -14,6 +15,7 @@ import (
 	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
 	libpack_logger "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
 	libpack_monitoring "github.com/lukaszraczylo/graphql-monitoring-proxy/monitoring"
+	libpack_trace "github.com/lukaszraczylo/graphql-monitoring-proxy/trace"
 )
 
 // StartHTTPProxy starts the HTTP and points it to the GraphQL server.
@@ -109,6 +111,23 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 	extractedRoleName := "-"
 	var queryCacheHash string
 
+	if cfg.Trace.Enable {
+		trace_header := c.Request().Header.Peek("X-Trace-Span")
+		if trace_header != nil {
+			traceHeaders := make(map[string]string)
+			err := json.Unmarshal([]byte(trace_header), &traceHeaders)
+			if err != nil {
+				cfg.Logger.Error(&libpack_logger.LogMessage{
+					Message: "Error unmarshalling tracer header",
+					Pairs:   map[string]interface{}{"error": err},
+				})
+			}
+			ctx := libpack_trace.TraceContextExtract(context.Background(), traceHeaders)
+			_, span := libpack_trace.ContinueSpanFromContext(ctx, "processingGraphQLRequest")
+			defer span.End()
+		}
+	}
+
 	authorization := c.Request().Header.Peek("Authorization")
 	if authorization != nil && (len(cfg.Client.JWTUserClaimPath) > 0 || len(cfg.Client.JWTRoleClaimPath) > 0) {
 		extractedUserID, extractedRoleName = extractClaimsFromJWTHeader(string(authorization))

struct_config.go

@@ -9,6 +9,11 @@ import (
 
 // config is a struct that holds the configuration of the application.
 type config struct {
+	Trace struct {
+		Client        func()
+		Enable        bool
+		TraceEndpoint string
+	}
 	Logger     *libpack_logging.Logger
 	LogLevel   string
 	Monitoring *libpack_monitoring.MetricsSetup

trace/tracing.go

@@ -0,0 +1,89 @@
+package libpack_trace
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/sdk/trace"
+	oteltrace "go.opentelemetry.io/otel/trace"
+
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+)
+
+func NewClient(otelGRPCCollector string, attr ...attribute.KeyValue) (func(), error) {
+	attr = append(attr, semconv.ServiceNameKey.String(libpack_config.PKG_NAME))
+	fmt.Printf("Starting OpenTelemetry tracer: otlp, configured with endpoint: %s\n", otelGRPCCollector)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	client := otlptracegrpc.NewClient(
+		otlptracegrpc.WithInsecure(),
+		otlptracegrpc.WithEndpoint(otelGRPCCollector),
+	)
+
+	exporter, err := otlptrace.New(ctx, client)
+	if err != nil {
+		fmt.Printf("ERROR: failed to create exporter: %v\n", err)
+		return nil, err
+	}
+
+	tp := trace.NewTracerProvider(
+		trace.WithSampler(trace.AlwaysSample()),
+		trace.WithBatcher(exporter, trace.WithMaxExportBatchSize(1), trace.WithBatchTimeout(30*time.Second)),
+		trace.WithResource(resource.NewWithAttributes(semconv.SchemaURL, attr...)),
+	)
+
+	otel.SetTracerProvider(tp)
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+
+	shutdownFunc := func() {
+		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer shutdownCancel()
+		fmt.Println("Shutting down otlp tracer")
+		if err := tp.Shutdown(shutdownCtx); err != nil {
+			fmt.Printf("ERROR: failed to shutdown tracer provider: %v\n", err)
+		}
+	}
+
+	return shutdownFunc, nil
+}
+
+func TraceContextInject(ctx context.Context) map[string]string {
+	carrier := propagation.MapCarrier{}
+	propagator := otel.GetTextMapPropagator()
+	propagator.Inject(ctx, carrier)
+	return map[string]string(carrier)
+}
+
+func TraceContextExtract(ctx context.Context, traceContext map[string]string) context.Context {
+	carrier := propagation.MapCarrier(traceContext)
+	propagator := otel.GetTextMapPropagator()
+	return propagator.Extract(ctx, carrier)
+}
+
+func StartSpanFromContext(ctx context.Context, operationName string) (context.Context, oteltrace.Span) {
+	tr := otel.GetTracerProvider().Tracer("")
+	return tr.Start(ctx, operationName, oteltrace.WithSpanKind(oteltrace.SpanKindInternal))
+}
+
+func ContinueSpanFromContext(ctx context.Context, operationName string) (context.Context, oteltrace.Span) {
+	tr := otel.GetTracerProvider().Tracer("")
+	options := []oteltrace.SpanStartOption{
+		oteltrace.WithSpanKind(oteltrace.SpanKindInternal),
+		oteltrace.WithAttributes(attribute.String("cont", "true")),
+	}
+	return tr.Start(ctx, operationName, options...)
+}
+
+func AddAttributesToSpan(span oteltrace.Span, attributes ...attribute.KeyValue) {
+	span.SetAttributes(attributes...)
+}