Add telemetry settings to config

Instead of relying on obfuscated default env variables, make telemetry
configurable via config.toml or `PJ_` env variables.

Author: spacebear21

payjoin-service/Cargo.toml

@@ -34,7 +34,9 @@ clap = { version = "4.5", features = ["derive", "env"] }
 config = "0.15"
 ohttp-relay = { path = "../ohttp-relay", features = ["bootstrap"] }
 opentelemetry = "0.31"
-opentelemetry-otlp = { version = "0.31", optional = true }
+opentelemetry-otlp = { version = "0.31", optional = true, features = [
+  "reqwest-rustls",
+] }
 opentelemetry_sdk = "0.31"
 payjoin-directory = { path = "../payjoin-directory" }
 rand = "0.8"

payjoin-service/src/config.rs

@@ -12,10 +12,20 @@ pub struct Config {
     pub storage_dir: PathBuf,
     #[serde(deserialize_with = "deserialize_duration_secs")]
     pub timeout: Duration,
+    #[cfg(feature = "telemetry")]
+    pub telemetry: Option<TelemetryConfig>,
     #[cfg(feature = "acme")]
     pub acme: Option<AcmeConfig>,
 }
 
+#[cfg(feature = "telemetry")]
+#[derive(Debug, Clone, Deserialize)]
+pub struct TelemetryConfig {
+    pub endpoint: String,
+    pub auth_token: String,
+    pub operator_domain: String,
+}
+
 #[cfg(feature = "acme")]
 #[derive(Debug, Clone, Deserialize)]
 pub struct AcmeConfig {
@@ -48,6 +58,8 @@ impl Default for Config {
             listener: "[::]:8080".parse().expect("valid default listener address"),
             storage_dir: PathBuf::from("./data"),
             timeout: Duration::from_secs(30),
+            #[cfg(feature = "telemetry")]
+            telemetry: None,
             #[cfg(feature = "acme")]
             acme: None,
         }
@@ -68,6 +80,8 @@ impl Config {
             listener,
             storage_dir,
             timeout,
+            #[cfg(feature = "telemetry")]
+            telemetry: None,
             #[cfg(feature = "acme")]
             acme: None,
         }

payjoin-service/src/main.rs

@@ -6,12 +6,18 @@ use tracing_subscriber::EnvFilter;
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    let meter_provider = init_tracing();
-
     let args = cli::Args::parse();
     let config_path = args.config.unwrap_or_else(|| "config.toml".into());
     let config = config::Config::from_file(&config_path)?;
 
+    #[cfg(feature = "telemetry")]
+    let meter_provider = match &config.telemetry {
+        Some(telemetry) => Some(init_tracing_with_telemetry(telemetry)),
+        None => init_tracing(),
+    };
+    #[cfg(not(feature = "telemetry"))]
+    let meter_provider = init_tracing();
+
     #[cfg(feature = "acme")]
     if config.acme.is_some() {
         return payjoin_service::serve_acme(config, meter_provider).await;
@@ -20,7 +26,6 @@ async fn main() -> anyhow::Result<()> {
     payjoin_service::serve(config, meter_provider).await
 }
 
-#[cfg(not(feature = "telemetry"))]
 fn init_tracing() -> Option<SdkMeterProvider> {
     let env_filter =
         EnvFilter::builder().with_default_directive(LevelFilter::INFO.into()).from_env_lossy();
@@ -30,29 +35,23 @@ fn init_tracing() -> Option<SdkMeterProvider> {
 }
 
 #[cfg(feature = "telemetry")]
-fn init_tracing() -> Option<SdkMeterProvider> {
-    use opentelemetry::trace::TracerProvider;
+fn init_tracing_with_telemetry(telemetry: &config::TelemetryConfig) -> SdkMeterProvider {
     use opentelemetry::KeyValue;
-    use opentelemetry_appender_tracing::layer::OpenTelemetryTracingBridge;
-    use opentelemetry_otlp::WithHttpConfig;
+    use opentelemetry_otlp::{WithExportConfig, WithHttpConfig};
     use opentelemetry_sdk::Resource;
 
-    let mut resource_builder = Resource::builder().with_service_name("payjoin-service");
-    if let Ok(domain) = std::env::var("OPERATOR_DOMAIN") {
-        resource_builder =
-            resource_builder.with_attribute(KeyValue::new("operator.domain", domain));
-    }
-    let resource = resource_builder.build();
+    let resource = Resource::builder()
+        .with_service_name("payjoin-service")
+        .with_attribute(KeyValue::new("operator.domain", telemetry.operator_domain.clone()))
+        .build();
 
     let headers: std::collections::HashMap<String, String> =
-        std::env::var("OTEL_EXPORTER_OTLP_TOKEN")
-            .ok()
-            .map(|token| [("Authorization".to_string(), format!("Basic {}", token))].into())
-            .unwrap_or_default();
+        [("Authorization".to_string(), format!("Basic {}", telemetry.auth_token))].into();
 
     // Initialize metric exporter and provider
     let metric_exporter = opentelemetry_otlp::MetricExporter::builder()
         .with_http()
+        .with_endpoint(format!("{}/v1/metrics", &telemetry.endpoint))
         .with_headers(headers)
         .build()
         .expect("Failed to build OTLP metric exporter");
@@ -68,5 +67,5 @@ fn init_tracing() -> Option<SdkMeterProvider> {
 
     opentelemetry::global::set_meter_provider(meter_provider.clone());
 
-    Some(meter_provider)
+    meter_provider
 }