Add OTEL

go.mod

@@ -5,13 +5,42 @@ go 1.23.4
 require (
 	github.com/caarlos0/env/v9 v9.0.0
 	github.com/rs/zerolog v1.33.0
+	go.opentelemetry.io/otel v1.33.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.33.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.33.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.55.0
+	go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.33.0
+	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.33.0
+	go.opentelemetry.io/otel/sdk v1.33.0
+	go.opentelemetry.io/otel/sdk/metric v1.33.0
+	go.opentelemetry.io/otel/trace v1.33.0
 	golang.org/x/sys v0.28.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
-	github.com/kr/pretty v0.3.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/go-logr/logr v1.4.2 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.24.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
-	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/prometheus/client_golang v1.20.5 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.61.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.33.0 // indirect
+	go.opentelemetry.io/otel/metric v1.33.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.4.0 // indirect
+	golang.org/x/net v0.32.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 // indirect
+	google.golang.org/grpc v1.68.1 // indirect
+	google.golang.org/protobuf v1.35.2 // indirect
 )

go.sum

@@ -1,31 +1,108 @@
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/caarlos0/env/v9 v9.0.0 h1:SI6JNsOA+y5gj9njpgybykATIylrRMklbs5ch6wO6pc=
 github.com/caarlos0/env/v9 v9.0.0/go.mod h1:ye5mlCVMYh6tZ+vCgrs/B95sj88cg5Tlnc0XIzgZ020=
+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 v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
+github.com/go-logr/logr v1.4.2/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/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
+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/grpc-ecosystem/grpc-gateway/v2 v2.24.0 h1:TmHmbvxPmaegwhDubVz0lICL0J5Ka2vwTzhoePEXsGE=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.24.0/go.mod h1:qztMSjm835F2bXf+5HKAPIS5qsmQDqZna/PgVt4rWtI=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.20.5 h1:cxppBPuYhUnsO6yo/aoRol4L7q7UFfdm+bR9r+8l63Y=
+github.com/prometheus/client_golang v1.20.5/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/common v0.61.0 h1:3gv/GThfX0cV2lpO7gkTUwZru38mxevy90Bj8YFSRQQ=
+github.com/prometheus/common v0.61.0/go.mod h1:zr29OCN/2BsJRaFwG8QOBr41D6kkchKbpeNH7pAjb/s=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
+github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
+github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 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=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
+go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
+go.opentelemetry.io/otel v1.33.0 h1:/FerN9bax5LoK51X/sI0SVYrjSE0/yUL7DpxW4K3FWw=
+go.opentelemetry.io/otel v1.33.0/go.mod h1:SUUkR6csvUQl+yjReHu5uM3EtVV7MBm5FHKRlNx4I8I=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.33.0 h1:7F29RDmnlqk6B5d+sUqemt8TBfDqxryYW5gX6L74RFA=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.33.0/go.mod h1:ZiGDq7xwDMKmWDrN1XsXAj0iC7hns+2DhxBFSncNHSE=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.33.0 h1:Vh5HayB/0HHfOQA7Ctx69E/Y/DcQSMPpKANYVMQ7fBA=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.33.0/go.mod h1:cpgtDBaqD/6ok/UG0jT15/uKjAY8mRA53diogHBg3UI=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.33.0 h1:5pojmb1U1AogINhN3SurB+zm/nIcusopeBNp42f45QM=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.33.0/go.mod h1:57gTHJSE5S1tqg+EKsLPlTWhpHMsWlVmer+LA926XiA=
+go.opentelemetry.io/otel/exporters/prometheus v0.55.0 h1:sSPw658Lk2NWAv74lkD3B/RSDb+xRFx46GjkrL3VUZo=
+go.opentelemetry.io/otel/exporters/prometheus v0.55.0/go.mod h1:nC00vyCmQixoeaxF6KNyP42II/RHa9UdruK02qBmHvI=
+go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.33.0 h1:FiOTYABOX4tdzi8A0+mtzcsTmi6WBOxk66u0f1Mj9Gs=
+go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.33.0/go.mod h1:xyo5rS8DgzV0Jtsht+LCEMwyiDbjpsxBpWETwFRF0/4=
+go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.33.0 h1:W5AWUn/IVe8RFb5pZx1Uh9Laf/4+Qmm4kJL5zPuvR+0=
+go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.33.0/go.mod h1:mzKxJywMNBdEX8TSJais3NnsVZUaJ+bAy6UxPTng2vk=
+go.opentelemetry.io/otel/metric v1.33.0 h1:r+JOocAyeRVXD8lZpjdQjzMadVZp2M4WmQ+5WtEnklQ=
+go.opentelemetry.io/otel/metric v1.33.0/go.mod h1:L9+Fyctbp6HFTddIxClbQkjtubW6O9QS3Ann/M82u6M=
+go.opentelemetry.io/otel/sdk v1.33.0 h1:iax7M131HuAm9QkZotNHEfstof92xM+N8sr3uHXc2IM=
+go.opentelemetry.io/otel/sdk v1.33.0/go.mod h1:A1Q5oi7/9XaMlIWzPSxLRWOI8nG3FnzHJNbiENQuihM=
+go.opentelemetry.io/otel/sdk/metric v1.33.0 h1:Gs5VK9/WUJhNXZgn8MR6ITatvAmKeIuCtNbsP3JkNqU=
+go.opentelemetry.io/otel/sdk/metric v1.33.0/go.mod h1:dL5ykHZmm1B1nVRk9dDjChwDmt81MjVp3gLkQRwKf/Q=
+go.opentelemetry.io/otel/trace v1.33.0 h1:cCJuF7LRjUFso9LPnEAHJDB2pqzp+hbO8eu1qqW2d/s=
+go.opentelemetry.io/otel/trace v1.33.0/go.mod h1:uIcdVUZMpTAmz0tI1z04GoVSezK37CbGV4fr1f2nBck=
+go.opentelemetry.io/proto/otlp v1.4.0 h1:TA9WRvW6zMwP+Ssb6fLoUIuirti1gGbP28GcKG1jgeg=
+go.opentelemetry.io/proto/otlp v1.4.0/go.mod h1:PPBWZIP98o2ElSqI35IHfu7hIhSwvc5N38Jw8pXuGFY=
+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/net v0.32.0 h1:ZqPmj8Kzc+Y6e0+skZsuACbx+wzMgo5MQsJh9Qd6aYI=
+golang.org/x/net v0.32.0/go.mod h1:CwU0IoeOlnQQWJ6ioyFrfRuomB8GKF6KbYXZVyeXNfs=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576 h1:CkkIfIt50+lT6NHAVoRYEyAvQGFM7xEwXUUywFvEb3Q=
+google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576/go.mod h1:1R3kvZ1dtP3+4p4d3G8uJ8rFk/fWlScl38vanWACI08=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 h1:8ZmaLZE4XWrtU3MyClkYqqtl6Oegr3235h7jxsDyqCY=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576/go.mod h1:5uTbfoYQed2U9p3KIj2/Zzm02PYhndfdmML0qC3q3FU=
+google.golang.org/grpc v1.68.1 h1:oI5oTa11+ng8r8XMMN7jAOmWfPZWbYpCFaMUTACxkM0=
+google.golang.org/grpc v1.68.1/go.mod h1:+q1XYFJjShcqn0QZHvCyeR4CXPA+llXIeUIfIe00waw=
+google.golang.org/protobuf v1.35.2 h1:8Ar7bF+apOIoThw1EdZl0p1oWvMqTHmpA2fRTyZO8io=
+google.golang.org/protobuf v1.35.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -12,12 +12,16 @@ import (
 	"context"
 	"os"
 	"os/signal"
+	"time"
 
 	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
 	"golang.org/x/sys/unix"
 
 	"gitea.libretechconsulting.com/rmcguire/go-http-server-with-otel/pkg/config"
 	"gitea.libretechconsulting.com/rmcguire/go-http-server-with-otel/pkg/logging"
+	"gitea.libretechconsulting.com/rmcguire/go-http-server-with-otel/pkg/observability"
 )
 
 func main() {
@@ -32,8 +36,27 @@ func main() {
 
 	cfg := config.MustFromCtx(ctx)
 	ctx = logging.MustInitLogging(ctx)
-
 	l := zerolog.Ctx(ctx)
+
+	// Set up OTEL
+	opts := make([]observability.Option, 0)
+	if cfg.Logging.Level == "trace" {
+		opts = append(opts, observability.EnableStdoutExporter)
+	}
+	shutdown := observability.Init(ctx, opts...)
+	defer func() {
+		shutdownCtx, cncl := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cncl()
+		shutdown(shutdownCtx)
+	}()
+
+	// Begin Server init
+	tracer := otel.Tracer(cfg.Name)
+	_, initSpan := tracer.Start(ctx, "init")
+
+	// TODO: HTTP Server
+
+	// App Ready
 	l.Trace().Any("config", *cfg).Send()
 	l.Info().
 		Str("name", cfg.Name).
@@ -41,6 +64,9 @@ func main() {
 		Str("logLevel", cfg.Logging.Level).
 		Msg("app initialized")
 
+	initSpan.SetStatus(codes.Ok, "")
+	initSpan.End()
+
 	<-ctx.Done()
 }
 

pkg/observability/otel.go

@@ -0,0 +1,188 @@
+package observability
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	opentelemetry "go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/exporters/stdout/stdoutmetric"
+	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
+
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+	traceSDK "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	trace "go.opentelemetry.io/otel/trace"
+)
+
+const defaultMetricExportInterval = 15 * time.Second
+
+var (
+	EnableStdoutExporter Option = enableStdoutExporter{}
+	// Overide the default metric export interval
+	WithMetricExportInterval = func(interval time.Duration) Option {
+		return exportInterval{interval: interval}
+	}
+)
+
+func Init(ctx context.Context, options ...Option) (shutdown func(context.Context) error) {
+	var (
+		shutdownFuncs []func(context.Context) error
+		s             = &settings{
+			MetricExportInterval: defaultMetricExportInterval,
+		}
+	)
+	for _, opt := range options {
+		opt.apply(s)
+	}
+
+	// shutdown calls cleanup functions registered via shutdownFuncs.
+	// The errors from the calls are joined.
+	// Each registered cleanup will be invoked once.
+	shutdown = func(ctx context.Context) error {
+		var err error
+		for _, fn := range shutdownFuncs {
+			err = errors.Join(err, fn(ctx))
+		}
+		shutdownFuncs = nil
+		return err
+	}
+
+	// handleErr calls shutdown for cleanup and makes sure that all errors are returned.
+	handleErr := func(inErr error) {
+		if err := errors.Join(inErr, shutdown(ctx)); err != nil {
+			fmt.Fprintln(os.Stderr, "OTEL Error:", err)
+		}
+	}
+
+	// Set up meter provider.
+	meterProvider, err := s.newMeterProvider(ctx)
+	if err != nil {
+		handleErr(err)
+		return
+	}
+
+	shutdownFuncs = append(shutdownFuncs, meterProvider.Shutdown)
+	opentelemetry.SetMeterProvider(meterProvider)
+
+	// Set up tracing
+	opentelemetry.SetTextMapPropagator(newPropagator())
+	var tracerProvider *traceSDK.TracerProvider
+	tracerProvider, err = s.newTracerProvider(ctx)
+	if err != nil {
+		handleErr(err)
+		return
+	}
+	shutdownFuncs = append(shutdownFuncs, tracerProvider.Shutdown)
+	opentelemetry.SetTracerProvider(tracerProvider)
+
+	return
+}
+
+func newPropagator() propagation.TextMapPropagator {
+	return propagation.NewCompositeTextMapPropagator(
+		propagation.TraceContext{},
+		propagation.Baggage{},
+	)
+}
+
+func (s *settings) newTracerProvider(ctx context.Context) (traceProvider *traceSDK.TracerProvider, err error) {
+	traceOpts := []traceSDK.TracerProviderOption{
+		traceSDK.WithResource(newResource()),
+	}
+
+	host, set := os.LookupEnv("OTEL_EXPORTER_OTLP_ENDPOINT")
+	if set && host != "" {
+		exporter, err := otlptracegrpc.New(ctx)
+		if err != nil {
+			return nil, err
+		}
+		traceOpts = append(traceOpts, traceSDK.WithBatcher(exporter))
+	}
+
+	if s.EnableStdoutExporter {
+		stdoutExporter, err := stdouttrace.New(stdouttrace.WithPrettyPrint())
+		if err != nil {
+			return nil, err
+		}
+		traceOpts = append(traceOpts, traceSDK.WithBatcher(stdoutExporter))
+	}
+
+	traceProvider = traceSDK.NewTracerProvider(traceOpts...)
+
+	return
+}
+
+func newResource() *resource.Resource {
+	return resource.NewWithAttributes(semconv.SchemaURL)
+}
+
+// Configures meter provider
+// Always provides a prometheus metrics exporter
+// Conditionally provides an OTLP metrics exporter
+func (s *settings) newMeterProvider(ctx context.Context) (*metric.MeterProvider, error) {
+	// OTEL Prometheus Exporter
+	exporter, err := prometheus.New()
+	if err != nil {
+		return nil, err
+	}
+
+	metricOptions := make([]metric.Option, 0, 5)
+	if s.EnableStdoutExporter {
+		stdoutMetricExporter, err := stdoutmetric.New()
+		if err != nil {
+			return nil, err
+		}
+		metricOptions = append(metricOptions,
+			metric.WithReader(metric.NewPeriodicReader(stdoutMetricExporter)),
+		)
+	}
+
+	host, set := os.LookupEnv("OTEL_EXPORTER_OTLP_ENDPOINT")
+	var otlpExporter *otlpmetricgrpc.Exporter
+	if set && host != "" {
+		if exp, err := otlpmetricgrpc.New(ctx, otlpmetricgrpc.WithInsecure()); err != nil {
+			return nil, fmt.Errorf("otlpmetricgrpc.New: %w", err)
+		} else {
+			otlpExporter = exp
+		}
+	}
+
+	var meterProvider *metric.MeterProvider
+	if otlpExporter != nil {
+		metricOptions = append(metricOptions,
+			metric.WithReader(exporter),
+			metric.WithReader(
+				metric.NewPeriodicReader(
+					otlpExporter,
+					metric.WithInterval(defaultMetricExportInterval),
+				),
+			),
+			metric.WithResource(newResource()),
+		)
+	} else {
+		metricOptions = append(metricOptions,
+			metric.WithReader(exporter),
+			metric.WithResource(newResource()),
+		)
+	}
+
+	meterProvider = metric.NewMeterProvider(metricOptions...)
+
+	return meterProvider, nil
+}
+
+// Creates a new tracer from the global opentelemetry provider
+func NewTracer(options ...trace.TracerOption) trace.Tracer {
+	return opentelemetry.GetTracerProvider().Tracer(
+		os.Getenv("OTEL_SERVICE_NAME"),
+		options...,
+	)
+}

pkg/observability/settings.go

@@ -0,0 +1,29 @@
+package observability
+
+import "time"
+
+type settings struct {
+	EnableStdoutExporter bool
+	MetricExportInterval time.Duration
+}
+
+type Option interface {
+	apply(*settings)
+}
+
+type enableStdoutExporter struct {
+	Option
+}
+
+func (setting enableStdoutExporter) apply(o *settings) {
+	o.EnableStdoutExporter = true
+}
+
+type exportInterval struct {
+	Option
+	interval time.Duration
+}
+
+func (setting exportInterval) apply(o *settings) {
+	o.MetricExportInterval = setting.interval
+}