test(iroh-dns): APK-based smoke test for the Android JNI path

.github/workflows/ci.yml

@@ -142,6 +142,18 @@ jobs:
       - name: Install cargo-ndk
         run: cargo install --version 4.1.2 cargo-ndk
 
+      # cargo-apk is used by the NativeActivity smoke test under
+      # iroh-dns/tests/android_apk/. Only x86_64-linux-android runs the
+      # emulator, but installing it on every Android matrix entry is
+      # cheap with cargo-binstall.
+      - name: Install cargo-binstall
+        if: matrix.target == 'x86_64-linux-android'
+        uses: cargo-bins/cargo-binstall@main
+
+      - name: Install cargo-apk
+        if: matrix.target == 'x86_64-linux-android'
+        run: cargo binstall --no-confirm cargo-apk
+
       # Replace cargo-ndk-runner with a wrapper that forwards RUST_LOG
       # and RUST_BACKTRACE into the emulator shell. The upstream binary
       # does `adb shell <bin>` without inheriting any host env.
@@ -220,6 +232,16 @@ jobs:
             cargo ndk test -p iroh-dns --features tls-ring
             cargo ndk test -p iroh-relay --features tls-ring,metrics
             cargo ndk test -p iroh --features tls-ring,metrics,portmapper,test-utils
+            # APK smoke test: a real NativeActivity exercises the JNI path
+            # against the emulator's ConnectivityService. cargo-apk does not
+            # propagate the in-app exit code, so poll logcat for `RESULT=ok`.
+            # `android-emulator-runner` runs each line in its own `sh -c`,
+            # so multi-line constructs have to stay on one line.
+            adb logcat -c
+            (cd iroh-dns/tests/android_apk && cargo apk run --no-logcat --target $CARGO_NDK_TARGET)
+            for _ in $(seq 1 60); do adb logcat -d -v raw | grep -qF 'RESULT=ok' && break || sleep 1; done
+            adb logcat -d -v raw | grep -qF 'RESULT=ok' || { echo "iroh-dns-android-test: timed out waiting for RESULT=ok" >&2; adb logcat -d | grep -E 'iroh_dns_smoke|net.iroh.dns.test|FATAL|AndroidRuntime' | tail -100; exit 1; }
+            echo "iroh-dns-android-test: ok"
 
   cross_test:
     name: Cross Test

iroh-dns/src/android.rs

@@ -18,28 +18,40 @@
 //! [`ndk_context`]: https://docs.rs/ndk-context
 
 use std::ffi::c_void;
+#[cfg(debug_assertions)]
+use std::panic::{AssertUnwindSafe, catch_unwind};
 
 use hickory_resolver::{
     config::{ResolverConfig, ResolverOpts},
     net::NetError,
 };
+use tracing::debug;
 
 /// Reads the active network's DNS configuration via JNI.
 pub(crate) fn read_system_conf() -> Result<(ResolverConfig, ResolverOpts), NetError> {
-    #[cfg(debug_assertions)]
-    {
-        use std::panic::{AssertUnwindSafe, catch_unwind};
-        match catch_unwind(AssertUnwindSafe(
-            hickory_resolver::system_conf::read_system_conf,
-        )) {
-            Ok(Ok(conf)) => Ok(conf),
-            Ok(Err(err)) => Err(NetError::from(err)),
-            Err(_) => Err(NetError::Msg(
-                "ndk_context not initialized; call install_android_jni_context".to_string(),
-            )),
-        }
+    let (config, options) = read_inner()?;
+    debug!(
+        nameserver_count = config.name_servers().len(),
+        "read system DNS via Android JNI",
+    );
+    Ok((config, options))
+}
+
+#[cfg(debug_assertions)]
+fn read_inner() -> Result<(ResolverConfig, ResolverOpts), NetError> {
+    match catch_unwind(AssertUnwindSafe(
+        hickory_resolver::system_conf::read_system_conf,
+    )) {
+        Ok(Ok(conf)) => Ok(conf),
+        Ok(Err(err)) => Err(NetError::from(err)),
+        Err(_) => Err(NetError::Msg(
+            "ndk_context not initialized; call install_android_jni_context".to_string(),
+        )),
     }
-    #[cfg(not(debug_assertions))]
+}
+
+#[cfg(not(debug_assertions))]
+fn read_inner() -> Result<(ResolverConfig, ResolverOpts), NetError> {
     Ok(hickory_resolver::system_conf::read_system_conf()?)
 }
 

iroh-dns/tests/android_apk/.gitignore

@@ -0,0 +1 @@
+target/