1.7: Add back support for OTLP config from toml

cpuguy83 · cpuguy83 · commit 1ce1c8f3e6d3 · 2024-06-19T15:03:17.000Z
This was broken due to 9360e37 (backport from main). The backport should not have broken the toml config so this more or less restores that. This treats the env vars as preferred. It is not perfect since, as an example, `Endpoint` could be set on the config and the env to set the protocol could be set and these could conflict, however I think this is an unlikely scenario and people should use one or the other, not both. This change converts the config into the relevant environment variables before initializing tracers. Signed-off-by: Brian Goff <cpuguy83@gmail.com>
diff --git a/tracing/plugin/otlp.go b/tracing/plugin/otlp.go
@@ -50,9 +50,15 @@ const (
 	otlpTracesEndpointEnv = "OTEL_EXPORTER_OTLP_TRACES_ENDPOINT"
 	otlpProtocolEnv       = "OTEL_EXPORTER_OTLP_PROTOCOL"
 	otlpTracesProtocolEnv = "OTEL_EXPORTER_OTLP_TRACES_PROTOCOL"
+	otlpInsecureEnv       = "OTEL_EXPORTER_OTLP_INSECURE"
+	otlpTracesInsecureEnv = "OTEL_EXPORTER_OTLP_TRACES_INSECURE"
 
-	otelTracesExporterEnv = "OTEL_TRACES_EXPORTER"
-	otelServiceNameEnv    = "OTEL_SERVICE_NAME"
+	otelTracesExporterEnv   = "OTEL_TRACES_EXPORTER"
+	otelServiceNameEnv      = "OTEL_SERVICE_NAME"
+	otelTracesSamplerEnv    = "OTEL_TRACES_SAMPLER"
+	otelTracesSamplerArgEnv = "OTEL_TRACES_SAMPLER_ARG"
+
+	traceIDRatioSampler = "traceidratio"
 )
 
 func init() {
@@ -64,6 +70,7 @@ func init() {
 			if err := warnOTLPConfig(ic); err != nil {
 				return nil, err
 			}
+			convertOTLPToEnv(ic)
 			if err := checkDisabled(); err != nil {
 				return nil, err
 			}
@@ -91,6 +98,7 @@ func init() {
 			if err := warnTraceConfig(ic); err != nil {
 				return nil, err
 			}
+			convertToTracesEnv(ic)
 			if err := checkDisabled(); err != nil {
 				return nil, err
 			}
@@ -135,6 +143,35 @@ type TraceConfig struct {
 	TraceSamplingRatio float64 `toml:"sampling_ratio,omitempty"`
 }
 
+func convertOTLPToEnv(ic *plugin.InitContext) {
+	cfg := ic.Config.(*OTLPConfig)
+
+	if cfg.Endpoint != "" && os.Getenv(otlpEndpointEnv) == "" && os.Getenv(otlpTracesEndpointEnv) == "" {
+		os.Setenv(otlpEndpointEnv, cfg.Endpoint)
+	}
+
+	if cfg.Protocol != "" && os.Getenv(otlpProtocolEnv) == "" && os.Getenv(otlpTracesProtocolEnv) == "" {
+		os.Setenv(otlpProtocolEnv, cfg.Protocol)
+	}
+
+	if cfg.Insecure && os.Getenv(otlpInsecureEnv) == "" && os.Getenv(otlpTracesInsecureEnv) == "" {
+		os.Setenv(otlpInsecureEnv, "true")
+	}
+}
+
+func convertToTracesEnv(ic *plugin.InitContext) {
+	cfg := ic.Config.(*TraceConfig)
+
+	if cfg.ServiceName != "" && os.Getenv(otelServiceNameEnv) == "" {
+		os.Setenv(otelServiceNameEnv, cfg.ServiceName)
+	}
+
+	if cfg.TraceSamplingRatio > 0 && os.Getenv(otelTracesSamplerArgEnv) == "" && os.Getenv(otelTracesSamplerEnv) == "" {
+		os.Setenv(otelTracesSamplerEnv, traceIDRatioSampler)
+		os.Setenv(otelTracesSamplerArgEnv, strconv.FormatFloat(cfg.TraceSamplingRatio, 'f', -1, 64))
+	}
+}
+
 func checkDisabled() error {
 	v := os.Getenv(sdkDisabledEnv)
 	if v != "" {
