Pull sampling probability from env var OTEL_TRACES_SAMPLER_ARG in t…

…he default sdk config Signed-off-by: jbtrystram <jbtrystram@redhat.com>
open-telemetry · Feb 16, 2022 · 7c73589 · 7c73589
1 parent ed71d80
commit 7c73589
Showing 1 changed file with 60 additions and 0 deletions.
diff --git a/opentelemetry/src/sdk/trace/config.rs b/opentelemetry/src/sdk/trace/config.rs
@@ -123,6 +123,66 @@ impl Default for Config {
             config.span_limits.max_links_per_span = max_links_per_span;
         }
 
+        let sampler_arg = env::var("OTEL_TRACES_SAMPLER_ARG").ok();
+        if let Ok(sampler) = env::var("OTEL_TRACES_SAMPLER") {
+            config.sampler = match sampler.as_str() {
+                "always_on" => Box::new(Sampler::AlwaysOn),
+                "always_off" => Box::new(Sampler::AlwaysOff),
+                "traceidratio" => {
+                    let ratio = sampler_arg.and_then(|r| r.parse::<f64>().ok());
+                    if let Some(r) = ratio {
+                        Box::new(Sampler::TraceIdRatioBased(r))
+                    } else {
+                        eprintln!(
+                            "WARNING: Missing or invalid OTEL_TRACES_SAMPLER_ARG value. Ignoring."
+                        );
+                        Box::new(Sampler::TraceIdRatioBased(1.0))
+                    }
+                }
+                "parentbased_always_on" => {
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOn)))
+                }
+                "parentbased_always_off" => {
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOff)))
+                }
+                "parentbased_traceidratio" => {
+                    let ratio = sampler_arg.and_then(|r| r.parse::<f64>().ok());
+                    if let Some(r) = ratio {
+                        Box::new(Sampler::ParentBased(Box::new(Sampler::TraceIdRatioBased(
+                            r,
+                        ))))
+                    } else {
+                        eprintln!(
+                            "WARNING: Missing or invalid OTEL_TRACES_SAMPLER_ARG value. Ignoring."
+                        );
+                        Box::new(Sampler::ParentBased(Box::new(Sampler::TraceIdRatioBased(
+                            1.0,
+                        ))))
+                    }
+                }
+                "parentbased_jaeger_remote" => {
+                    eprintln!("WARNING: Unimplemented parentbased_jaeger_remote sampler. Ignoring."
+                    );
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOn)))
+                }
+                "jaeger_remote" => {
+                    eprintln!(                        "WARNING: Unimplemented jaeger_remote sampler. Ignoring."
+                    );
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOn)))
+                }
+                "xray" => {
+                    eprintln!("WARNING: Unimplemented xray sampler. Ignoring.");
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOn)))
+                }
+                s => {
+                    eprintln!(                        "WARNING: Unrecognised OTEL_TRACES_SAMPLER value: {}. Ignoring.",
+                        s
+                    );
+                    Box::new(Sampler::ParentBased(Box::new(Sampler::AlwaysOn)))
+                }
+            }
+        }
+
         config
     }
 }