fix: fallback on intake urls

bottlecap/src/config/mod.rs

@@ -38,10 +38,24 @@ pub struct FallbackConfig {
     trace_otel_enabled: bool,
     otlp_config_receiver_protocols_http_endpoint: Option<String>,
     otlp_config_receiver_protocols_grpc_endpoint: Option<String>,
-    // YAML otel, we don't care about the content
-    otlp_config: Option<Value>,
+    // intake urls
+    url: Option<String>,
+    dd_url: Option<String>,
+    logs_config_logs_dd_url: Option<String>,
+    // APM, as opposed to logs, does not use the `apm_config` prefix for env vars
+    apm_dd_url: Option<String>,
 }
 
+/// `FallbackYamlConfig` is a struct that represents fields in `datadog.yaml` not yet supported in the extension yet.
+///
+#[derive(Debug, PartialEq, Deserialize, Clone, Default)]
+#[serde(default)]
+#[allow(clippy::module_name_repetitions)]
+pub struct FallbackYamlConfig {
+    logs_config: Option<Value>,
+    apm_config: Option<Value>,
+    otlp_config: Option<Value>,
+}
 #[derive(Debug, PartialEq, Deserialize, Clone, Default)]
 #[serde(default)]
 #[allow(clippy::module_name_repetitions)]
@@ -143,17 +157,18 @@ fn log_fallback_reason(reason: &str) {
     println!("{{\"DD_EXTENSION_FALLBACK_REASON\":\"{reason}\"}}");
 }
 
-fn fallback(figment: &Figment) -> Result<(), ConfigError> {
-    let fallback_config: FallbackConfig = match figment.extract() {
-        Ok(fallback_config) => fallback_config,
-        Err(err) => {
-            println!("Failed to parse Datadog config: {err}");
-            return Err(ConfigError::ParseError(err.to_string()));
-        }
-    };
+fn fallback(figment: &Figment, yaml_figment: &Figment) -> Result<(), ConfigError> {
+    let (config, yaml_config): (FallbackConfig, FallbackYamlConfig) =
+        match (figment.extract(), yaml_figment.extract()) {
+            (Ok(env_config), Ok(yaml_config)) => (env_config, yaml_config),
+            (_, Err(err)) | (Err(err), _) => {
+                println!("Failed to parse Datadog config: {err}");
+                return Err(ConfigError::ParseError(err.to_string()));
+            }
+        };
 
     // Customer explicitly opted out of the Next Gen extension
-    let opted_out = match fallback_config.extension_version.as_deref() {
+    let opted_out = match config.extension_version.as_deref() {
         Some("compatibility") => true,
         // We want customers using the `next` to not be affected
         _ => false,
@@ -166,35 +181,46 @@ fn fallback(figment: &Figment) -> Result<(), ConfigError> {
         ));
     }
 
-    if fallback_config.serverless_appsec_enabled || fallback_config.appsec_enabled {
+    if config.serverless_appsec_enabled || config.appsec_enabled {
         log_fallback_reason("appsec_enabled");
         return Err(ConfigError::UnsupportedField("appsec_enabled".to_string()));
     }
 
-    if fallback_config.profiling_enabled {
+    if config.profiling_enabled {
         log_fallback_reason("profiling_enabled");
         return Err(ConfigError::UnsupportedField(
             "profiling_enabled".to_string(),
         ));
     }
 
     // OTEL env
-    if fallback_config.trace_otel_enabled
-        || fallback_config
+    if config.trace_otel_enabled
+        || config
             .otlp_config_receiver_protocols_http_endpoint
             .is_some()
-        || fallback_config
+        || config
             .otlp_config_receiver_protocols_grpc_endpoint
             .is_some()
+        || yaml_config.otlp_config.is_some()
     {
         log_fallback_reason("otel");
         return Err(ConfigError::UnsupportedField("otel".to_string()));
     }
 
-    // OTEL YAML
-    if fallback_config.otlp_config.is_some() {
-        log_fallback_reason("otel");
-        return Err(ConfigError::UnsupportedField("otel".to_string()));
+    // Intake URLs
+    if config.url.is_some()
+        || config.dd_url.is_some()
+        || config.logs_config_logs_dd_url.is_some()
+        || config.apm_dd_url.is_some()
+        || yaml_config
+            .logs_config
+            .is_some_and(|c| c.get("logs_dd_url").is_some())
+        || yaml_config
+            .apm_config
+            .is_some_and(|c| c.get("apm_dd_url").is_some())
+    {
+        log_fallback_reason("intake_urls");
+        return Err(ConfigError::UnsupportedField("intake_urls".to_string()));
     }
 
     Ok(())
@@ -214,7 +240,7 @@ pub fn get_config(config_directory: &Path) -> Result<Config, ConfigError> {
     // Get YAML nested fields
     let yaml_figment = Figment::from(Yaml::file(&path));
 
-    fallback(&figment)?;
+    fallback(&figment, &yaml_figment)?;
 
     let (mut config, yaml_config): (Config, YamlConfig) =
         match (figment.extract(), yaml_figment.extract()) {
@@ -362,6 +388,42 @@ pub mod tests {
         });
     }
 
+    #[test]
+    fn test_fallback_on_intake_urls() {
+        figment::Jail::expect_with(|jail| {
+            jail.clear_env();
+            jail.set_env("DD_APM_DD_URL", "some_url");
+
+            let config = get_config(Path::new("")).expect_err("should reject unknown fields");
+            assert_eq!(
+                config,
+                ConfigError::UnsupportedField("intake_urls".to_string())
+            );
+            Ok(())
+        });
+    }
+
+    #[test]
+    fn test_fallback_on_intake_urls_yaml() {
+        figment::Jail::expect_with(|jail| {
+            jail.clear_env();
+            jail.create_file(
+                "datadog.yaml",
+                r"
+                apm_config:
+                  apm_dd_url: some_url
+            ",
+            )?;
+
+            let config = get_config(Path::new("")).expect_err("should reject unknown fields");
+            assert_eq!(
+                config,
+                ConfigError::UnsupportedField("intake_urls".to_string())
+            );
+            Ok(())
+        });
+    }
+
     #[test]
     fn test_allowed_but_disabled() {
         figment::Jail::expect_with(|jail| {