Update rdkafka to 0.39 and fix CI

.github/workflows/pull_requests_lints.yml

@@ -11,6 +11,8 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v7
+      - name: Install librdkafka build dependencies
+        run: sudo apt-get update && sudo apt-get install -y cmake libcurl4-openssl-dev
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: stable

.github/workflows/rust_tests.yml

@@ -28,11 +28,18 @@ jobs:
 
     # setup wasmedge
     - run: curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | sudo bash -s -- -p /usr/local
-    # Setup musl if needed
+    # Install native librdkafka build dependencies on Linux
     - run: sudo apt-get update
-      if: matrix.target == 'x86_64-unknown-linux-musl'
+      if: startsWith(matrix.target, 'x86_64-unknown-linux-')
+    - run: sudo apt-get install -y cmake libcurl4-openssl-dev
+      if: startsWith(matrix.target, 'x86_64-unknown-linux-')
+    # Setup musl if needed
     - run: sudo apt-get install -y musl musl-dev musl-tools cmake
       if: matrix.target == 'x86_64-unknown-linux-musl'
+    # librdkafka 2.12.1 includes curl headers even with WITH_CURL=0.
+    # Expose only those headers, not glibc's system headers, to musl-gcc.
+    - run: sudo ln -s /usr/include/x86_64-linux-gnu/curl /usr/include/x86_64-linux-musl/curl
+      if: matrix.target == 'x86_64-unknown-linux-musl'
     # # Caching stuff
     - uses: actions/cache@v5
       with:

Cargo.toml

@@ -47,8 +47,8 @@ uuid = { version = "1", features = ["v4"] }
 actix-web = { version = "4", optional = true }
 actix-http = { version = "3", optional = true }
 reqwest-lib = { version = "^0.12", default-features = false, features = ["rustls-tls"], optional = true, package = "reqwest" }
-rdkafka-lib = { version = "^0.38", features = ["cmake-build"], optional = true, package = "rdkafka" }
-rdkafka-sys = { version = "<4.10", optional = true }
+rdkafka-lib = { version = "0.39", features = ["cmake-build"], optional = true, package = "rdkafka" }
+rdkafka-sys = { version = "^4.10", optional = true }
 warp-lib = { version = "^0.3", optional = true, package = "warp" }
 async-trait = { version = "^0.1", optional = true }
 bytes = { version = "^1.0", optional = true }

example-projects/rdkafka-example/Cargo.toml

@@ -16,4 +16,4 @@ serde_json = "^1.0"
 futures = "^0.3"
 tokio = { version = "^1.0", features = ["full"] }
 clap = "2.33.1"
-rdkafka = { version = "^0.38", features = ["cmake-build"] }
+rdkafka = { version = "0.39", features = ["cmake-build"] }

src/binding/rdkafka/mod.rs

@@ -1,6 +1,12 @@
 //! This library provides Kafka protocol bindings for CloudEvents
 //! using the [rust-rdkafka](https://fede1024.github.io/rust-rdkafka) library.
 //!
+//! Building this binding requires a C compiler and CMake. With librdkafka 2.12.1,
+//! curl development headers are also required even when curl support is disabled.
+//! On Debian/Ubuntu, install `cmake` and `libcurl4-openssl-dev`. For musl builds,
+//! make the curl headers available in the musl compiler's include path without
+//! adding glibc's system headers. This does not enable or link curl support.
+//!
 //! To produce Cloudevents:
 //!
 //! ```