From 08e31228d011e5d8f274a4276215528339668542 Mon Sep 17 00:00:00 2001
From: John Sonnenschein <johnny@crowdalert.com>
Date: Wed, 8 Nov 2023 10:37:36 -0800
Subject: [PATCH] feat(http_server source): allow wildcard matching in headers

---
 src/sources/http_server.rs | 91 ++++++++++++++++++++++++++++----------
 1 file changed, 67 insertions(+), 24 deletions(-)

diff --git a/src/sources/http_server.rs b/src/sources/http_server.rs
index d1553ae6944d09..b2c667e31a5fea 100644
--- a/src/sources/http_server.rs
+++ b/src/sources/http_server.rs
@@ -6,14 +6,14 @@ use http::{StatusCode, Uri};
 use http_serde;
 use tokio_util::codec::Decoder as _;
 use vrl::value::{kind::Collection, Kind};
-use warp::http::HeaderMap;
+use warp::http::{ HeaderMap, HeaderValue};
 
 use codecs::{
     decoding::{DeserializerConfig, FramingConfig},
     BytesDecoderConfig, BytesDeserializerConfig, JsonDeserializerConfig,
     NewlineDelimitedDecoderConfig,
 };
-use lookup::{lookup_v2::OptionalValuePath, OwnedValuePath, owned_value_path, path};
+use lookup::{lookup_v2::OptionalValuePath, owned_value_path, path};
 use vector_config::configurable_component;
 use vector_core::{
     config::{DataType, LegacyKey, LogNamespace},
@@ -322,6 +322,26 @@ fn remove_duplicates(mut list: Vec<String>, list_name: &str) -> Vec<String> {
     }
     list
 }
+/// Removes glob matches from the list, and logs a `warn!()` for each.
+fn remove_glob_matches(list: &Vec<String>, patterns: &Vec<glob::Pattern>, list_name: &str) -> Vec<String> {
+
+    let mut ret = Vec::new();
+
+    for pattern in patterns.iter() {
+        for name in list.iter() {
+            if pattern.matches(name) {
+                warn!(
+                    "`{}` configuration contains specific entry `{}` that matches wildcard entry `{}`. Removing.",
+                    list_name, name, pattern.as_str()
+                );
+            } else {
+                ret.push(name.clone());
+            }
+        }
+    }
+
+    ret
+}
 
 #[async_trait::async_trait]
 #[typetag::serde(name = "http_server")]
@@ -330,8 +350,23 @@ impl SourceConfig for SimpleHttpConfig {
         let decoder = self.get_decoding_config()?.build()?;
         let log_namespace = cx.log_namespace(self.log_namespace);
 
+        let (glob_headers, mut headers): (Vec<String>, Vec<String>) = self.headers
+            .clone()
+            .into_iter()
+            .partition(|s| s.contains('*'));
+
+        let glob_headers: Vec<glob::Pattern> = remove_duplicates(glob_headers, "headers")
+            .into_iter()
+            .map(|s| glob::Pattern::new(&s).unwrap())
+            .collect();
+
+        if !glob_headers.is_empty() {
+            headers = remove_glob_matches(&headers, &glob_headers, "headers");
+        }
+
         let source = SimpleHttpSource {
-            headers: remove_duplicates(self.headers.clone(), "headers"),
+            headers: remove_duplicates(headers, "headers"),
+            glob_headers: glob_headers.clone(),
             query_parameters: remove_duplicates(self.query_parameters.clone(), "query_parameters"),
             path_key: self.path_key.clone(),
             decoder,
@@ -378,6 +413,7 @@ impl SourceConfig for SimpleHttpConfig {
 #[derive(Clone)]
 struct SimpleHttpSource {
     headers: Vec<String>,
+    glob_headers: Vec<glob::Pattern>,
     query_parameters: Vec<String>,
     path_key: OptionalValuePath,
     decoder: Decoder,
@@ -407,29 +443,36 @@ impl HttpSource for SimpleHttpSource {
                         request_path.to_owned(),
                     );
 
-                    // add each header to each event
-                    let mut received_headers = headers_config.clone();
-                    for header_name in &self.headers {
-                        if let Some(header_value) = received_headers.remove(header_name) {
-                            self.log_namespace.insert_source_metadata(
-                                SimpleHttpConfig::NAME,
-                                log,
-                                Some(LegacyKey::InsertIfEmpty(path!(header_name))),
-                                path!("headers", header_name),
-                                Value::from(header_value.as_bytes()),
-                            );
+                    // add any matching wildcard headers to each event
+                    for header_pattern in &self.glob_headers {
+                        for header_name in headers_config.keys() {
+                            if header_pattern.matches(header_name.as_str()) {
+
+                                let value = headers_config.get(header_name).map(HeaderValue::as_bytes);
+
+                                self.log_namespace.insert_source_metadata(
+                                    SimpleHttpConfig::NAME,
+                                    log,
+                                    Some(LegacyKey::InsertIfEmpty(path!(header_name.as_str()))),
+                                    path!("headers", header_name.as_str()),
+                                    Value::from(value.map(Bytes::copy_from_slice)),
+                                );
+                            }
                         }
                     }
-                    if self.log_namespace == LogNamespace::Vector {
-                        for (header_name, value) in received_headers.iter() {
-                            self.log_namespace.insert_source_metadata(
-                                SimpleHttpConfig::NAME,
-                                log,
-                                None::<LegacyKey<&OwnedValuePath>>,
-                                path!("headers", header_name.as_str()),
-                                Value::from(value.as_bytes()),
-                            );
-                        }
+
+                    // add each specific header to each event
+                    for header_name in &self.headers {
+                        let value = headers_config.get(header_name).map(HeaderValue::as_bytes);
+
+                        self.log_namespace.insert_source_metadata(
+                            SimpleHttpConfig::NAME,
+                            log,
+                            Some(LegacyKey::InsertIfEmpty(path!(header_name))),
+                            path!("headers", header_name),
+                            Value::from(value.map(Bytes::copy_from_slice)),
+                        );
+
                     }
 
                     self.log_namespace.insert_standard_vector_source_metadata(