Ignore hosts from ALB health checks when they are not present

calavera · calavera · commit edd82d30b523 · 2022-06-23T18:55:33.000-07:00
ALB health checks don't include a host value.

Signed-off-by: David Calavera &lt;david.calavera@gmail.com&gt;
diff --git a/lambda-http/src/request.rs b/lambda-http/src/request.rs
@@ -76,21 +76,20 @@ fn into_api_gateway_v2_request(ag: ApiGatewayV2httpRequest) -> http::Request<Bod
 
     let builder = http::Request::builder()
         .uri({
-            let scheme = ag
-                .headers
-                .get(x_forwarded_proto())
-                .and_then(|s| s.to_str().ok())
-                .unwrap_or("https");
-            let host = ag
-                .headers
-                .get(http::header::HOST)
-                .and_then(|s| s.to_str().ok())
-                .or(ag.request_context.domain_name.as_deref())
-                .unwrap_or_default();
-
+            let host = ag.headers.get(http::header::HOST).and_then(|s| s.to_str().ok());
             let path = apigw_path_with_stage(&ag.request_context.stage, &raw_path);
-            let mut url = format!("{}://{}{}", scheme, host, path);
 
+            let mut url = match host {
+                None => path,
+                Some(host) => {
+                    let scheme = ag
+                        .headers
+                        .get(x_forwarded_proto())
+                        .and_then(|s| s.to_str().ok())
+                        .unwrap_or("https");
+                    format!("{}://{}{}", scheme, host, path)
+                }
+            };
             if let Some(query) = ag.raw_query_string {
                 url.push('?');
                 url.push_str(&query);
@@ -199,18 +198,20 @@ fn into_alb_request(alb: AlbTargetGroupRequest) -> http::Request<Body> {
 
     let builder = http::Request::builder()
         .uri({
-            let scheme = alb
-                .headers
-                .get(x_forwarded_proto())
-                .and_then(|s| s.to_str().ok())
-                .unwrap_or("https");
-            let host = alb
-                .headers
-                .get(http::header::HOST)
-                .and_then(|s| s.to_str().ok())
-                .unwrap_or_default();
-
-            let mut url = format!("{}://{}{}", scheme, host, &raw_path);
+            let host = alb.headers.get(http::header::HOST).and_then(|s| s.to_str().ok());
+
+            let mut url = match host {
+                None => raw_path.clone(),
+                Some(host) => {
+                    let scheme = alb
+                        .headers
+                        .get(x_forwarded_proto())
+                        .and_then(|s| s.to_str().ok())
+                        .unwrap_or("https");
+                    format!("{}://{}{}", scheme, host, &raw_path)
+                }
+            };
+
             if !alb.multi_value_query_string_parameters.is_empty() {
                 url.push('?');
                 url.push_str(&alb.multi_value_query_string_parameters.to_query_string());
@@ -625,4 +626,20 @@ mod tests {
         assert_eq!(req.method(), "GET");
         assert_eq!(req.uri(), "/test/test/hello?name=me");
     }
+
+    #[test]
+    fn deserialize_alb_no_host() {
+        // generated from ALB health checks
+        let input = include_str!("../tests/data/alb_no_host.json");
+        let result = from_str(input);
+        assert!(
+            result.is_ok(),
+            "event was not parsed as expected {:?} given {}",
+            result,
+            input
+        );
+        let req = result.expect("failed to parse request");
+        assert_eq!(req.method(), "GET");
+        assert_eq!(req.uri(), "/v1/health/");
+    }
 }
diff --git a/lambda-http/tests/data/alb_no_host.json b/lambda-http/tests/data/alb_no_host.json
@@ -0,0 +1,17 @@
+{
+  "body": "",
+  "headers": {
+    "user-agent": "ELB-HealthChecker/2.0"
+  },
+  "httpMethod": "GET",
+
+  "isBase64Encoded": false,
+
+  "path": "/v1/health/",
+  "queryStringParameters": {},
+  "requestContext": {
+    "elb": {
+      "targetGroupArn": "arn:aws:elasticloadbalancing:us-east-1:111111111:targetgroup/cdn-ingestor-tg-usea1-dev/3fe2aca58c0da101"
+    }
+  }
+}
