OpenTelemetry integration: Allow exporting EXPLAIN plans as trace spans

This is an experimental feature that allows configuring the collector
to send an OTel tracing span for each processed EXPLAIN plan with an
associated "traceparent" query tag (e.g. set by sqlcommenter) to the
configured OpenTelemetry endpoint.

To configure the endpoint set the new config setting
otel_exporter_otlp_endpoint / OTEL_EXPORTER_OTLP_ENDPOINT, with a
endpoint string like "http://localhost:4318".

The tracing span contains the runtime of the EXPLAIN plan, as determined
from the logs, as well as a backlink to pganalyze as the "url.full" span
attribute, to allow accessing the full details within the pganalyze app.

Overall this aims to enable easy access of pganalyze for slow traces
collected in an APM tool, and helps identify when the database was
the bottleneck (and why). It requires the "traceparent" query tag to be
present on logged EXPLAIN plans, e.g. added by using sqlcommenter within
the application.

config/config.go

@@ -182,6 +182,9 @@ type ServerConfig struct {
 	FilterQuerySample string `ini:"filter_query_sample"` // none/normalize/all (defaults to "none")
 	FilterQueryText   string `ini:"filter_query_text"`   // none/unparsable (defaults to "unparsable")
 
+	// Configuration for OpenTelemetry trace exports
+	OtelExporterOtlpEndpoint string `ini:"otel_exporter_otlp_endpoint"` // See https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/protocol/exporter.md
+
 	// HTTP proxy overrides
 	HTTPProxy  string `ini:"http_proxy"`
 	HTTPSProxy string `ini:"https_proxy"`

config/read.go

@@ -254,6 +254,9 @@ func getDefaultConfig() *ServerConfig {
 	if filterQueryText := os.Getenv("FILTER_QUERY_TEXT"); filterQueryText != "" {
 		config.FilterQueryText = filterQueryText
 	}
+	if otelExporterOtlpEndpoint := os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT"); otelExporterOtlpEndpoint != "" {
+		config.FilterQueryText = otelExporterOtlpEndpoint
+	}
 	if httpProxy := os.Getenv("HTTP_PROXY"); httpProxy != "" {
 		config.HTTPProxy = httpProxy
 	}

go.mod

@@ -3,8 +3,8 @@
 module github.com/pganalyze/collector
 
 require (
-	cloud.google.com/go v0.68.0 // indirect
-	cloud.google.com/go/pubsub v1.8.1
+	cloud.google.com/go v0.110.4 // indirect
+	cloud.google.com/go/pubsub v1.32.0
 	github.com/AlecAivazis/survey/v2 v2.2.1
 	github.com/StackExchange/wmi v0.0.0-20150520194626-f3e2bae1e0cb // indirect
 	github.com/aws/aws-sdk-go v1.36.10
@@ -15,15 +15,14 @@ require (
 	github.com/go-ini/ini v1.62.0
 	github.com/go-ole/go-ole v0.0.0-20160708033836-be49f7c07711 // indirect
 	github.com/golang-jwt/jwt/v4 v4.5.0 // indirect
-	github.com/golang/protobuf v1.4.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e // indirect
 	github.com/gorhill/cronexpr v0.0.0-20160318121724-f0984319b442
 	github.com/guregu/null v0.0.0-20160228005316-41961cea0328
 	github.com/hashicorp/go-retryablehttp v0.7.0
 	github.com/jtolds/gls v4.2.0+incompatible // indirect
 	github.com/juju/syslog v0.0.0-20150205155936-6be94e8b7187
 	github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515
-	github.com/kr/pretty v0.2.1 // indirect
 	github.com/kylelemons/godebug v1.1.0
 	github.com/lib/pq v1.10.7
 	github.com/ogier/pflag v0.0.0-20160129220114-45c278ab3607
@@ -33,10 +32,10 @@ require (
 	github.com/shirou/gopsutil v3.21.10+incompatible
 	github.com/smartystreets/assertions v0.0.0-20160707190355-2063fd1cc7c9 // indirect
 	github.com/smartystreets/goconvey v0.0.0-20160704134950-4622128e06c7 // indirect
-	golang.org/x/crypto v0.9.0 // indirect
-	golang.org/x/net v0.10.0
-	google.golang.org/api v0.32.0
-	google.golang.org/protobuf v1.25.0
+	golang.org/x/crypto v0.11.0 // indirect
+	golang.org/x/net v0.12.0
+	google.golang.org/api v0.126.0
+	google.golang.org/protobuf v1.31.0
 	gopkg.in/ini.v1 v1.62.0 // indirect
 	gopkg.in/mcuadros/go-syslog.v2 v2.3.0
 )
@@ -47,38 +46,52 @@ require (
 	github.com/Azure/azure-sdk-for-go/sdk/messaging/azeventhubs v1.0.0
 	github.com/pganalyze/pg_query_go/v4 v4.2.1
 	github.com/prometheus/procfs v0.7.3
+	go.opentelemetry.io/otel v1.19.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.19.0
+	go.opentelemetry.io/otel/sdk v1.19.0
+	go.opentelemetry.io/otel/trace v1.19.0
 )
 
 require (
+	cloud.google.com/go/compute v1.21.0 // indirect
+	cloud.google.com/go/compute/metadata v0.2.3 // indirect
+	cloud.google.com/go/iam v1.1.1 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/internal v1.3.0 // indirect
 	github.com/Azure/go-amqp v1.0.0 // indirect
 	github.com/AzureAD/microsoft-authentication-library-for-go v1.0.0 // indirect
-	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
-	github.com/google/go-cmp v0.5.8 // indirect
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/go-logr/logr v1.2.4 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/google/s2a-go v0.1.4 // indirect
 	github.com/google/uuid v1.3.0 // indirect
-	github.com/googleapis/gax-go/v2 v2.0.5 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.2.3 // indirect
+	github.com/googleapis/gax-go/v2 v2.11.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.16.0 // indirect
 	github.com/hashicorp/go-cleanhttp v0.5.1 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
-	github.com/jstemmer/go-junit-report v0.9.1 // indirect
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect
 	github.com/mattn/go-colorable v0.1.2 // indirect
 	github.com/mattn/go-isatty v0.0.8 // indirect
 	github.com/mgutz/ansi v0.0.0-20170206155736-9520e82c474b // indirect
 	github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8 // indirect
 	github.com/tklauser/go-sysconf v0.3.9 // indirect
 	github.com/tklauser/numcpus v0.3.0 // indirect
-	go.opencensus.io v0.22.4 // indirect
-	golang.org/x/lint v0.0.0-20200302205851-738671d3881b // indirect
-	golang.org/x/mod v0.8.0 // indirect
-	golang.org/x/oauth2 v0.0.0-20200902213428-5d25da1a8d43 // indirect
-	golang.org/x/sync v0.1.0 // indirect
-	golang.org/x/sys v0.8.0 // indirect
-	golang.org/x/term v0.8.0 // indirect
-	golang.org/x/text v0.9.0 // indirect
-	golang.org/x/tools v0.6.0 // indirect
-	google.golang.org/appengine v1.6.6 // indirect
-	google.golang.org/genproto v0.0.0-20201002142447-3860012362da // indirect
-	google.golang.org/grpc v1.32.0 // indirect
+	go.opencensus.io v0.24.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.19.0 // indirect
+	go.opentelemetry.io/otel/metric v1.19.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.0.0 // indirect
+	golang.org/x/oauth2 v0.10.0 // indirect
+	golang.org/x/sync v0.3.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/term v0.10.0 // indirect
+	golang.org/x/text v0.11.0 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20230711160842-782d3b101e98 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20230711160842-782d3b101e98 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230711160842-782d3b101e98 // indirect
+	google.golang.org/grpc v1.58.2 // indirect
 )
 
 go 1.20