fix: android CI

Author: Frando

.github/workflows/ci.yml

@@ -201,18 +201,32 @@ jobs:
         uses: reactivecircus/android-emulator-runner@v2
         env:
           ANDROID_NDK_HOME: ${{ steps.setup-ndk.outputs.ndk-path }}
+          RUST_LOG: trace
         with:
           api-level: ${{ matrix.api-level }}
           arch: x86_64
           target: google_apis
           force-avd-creation: false
-          emulator-options: -no-window -no-audio -no-boot-anim -gpu swiftshader_indirect
+          # `-dns-server` + `-netfast` + `-no-metrics` are the combination
+          # reported to give working public-internet connectivity on the
+          # GH-hosted runner; without them `wlan0` stays NO-CARRIER and
+          # every connect() to a public IP fails with ENETUNREACH. See
+          # https://github.com/ReactiveCircus/android-emulator-runner/issues/348#issuecomment-2578082030
+          emulator-options: -no-window -no-audio -no-boot-anim -gpu swiftshader_indirect -dns-server 8.8.8.8 -netfast -no-metrics
           disable-animations: true
           # cargo-ndk pushes each test binary to /data/local/tmp on the
           # emulator and runs it via adb.
           script: |
             adb wait-for-device
             adb shell 'i=0; while [ -z "$(getprop sys.boot_completed | tr -d "\r")" ]; do i=$((i+1)); if [ $i -gt 300 ]; then echo "boot did not complete within 600s"; exit 1; fi; sleep 2; done'
+            # `sys.boot_completed=1` only signals that Android finished
+            # booting, not that the radio/Wi-Fi stack is up. Poll until
+            # the kernel actually has a route to a public IP, otherwise
+            # any test that hits the network fails with ENETUNREACH.
+            adb shell 'i=0; while ! ip route get 8.8.8.8 >/dev/null 2>&1; do i=$((i+1)); if [ $i -gt 60 ]; then echo "no route to 8.8.8.8 after 60s"; ip addr; ip route; exit 1; fi; sleep 1; done'
+            echo "=== ip addr ===" && adb shell ip addr
+            echo "=== ip route ===" && adb shell ip route
+            echo "=== net.dns1 ===" && adb shell getprop net.dns1
             cargo ndk test -p iroh-base --all-features
             cargo ndk test -p iroh-dns --features tls-ring
             cargo ndk test -p iroh-relay --features tls-ring,metrics

iroh-dns/tests/integration.rs

@@ -6,25 +6,13 @@
 
 use std::time::Duration;
 
+#[cfg(target_os = "android")]
+use iroh_dns::dns::DnsProtocol;
 use iroh_dns::dns::DnsResolver;
 
 const TIMEOUT: Duration = Duration::from_secs(8);
 const HOST: &str = "dns.iroh.link";
 
-#[tokio::test]
-async fn resolver_constructs_without_panic() {
-    let _resolver = DnsResolver::new();
-}
-
-// Ignored on Android: in the GitHub-hosted emulator the public DNS
-// fallback's hickory connection pool repeatedly returns
-// "no connections available" within ~30 ms, well before the 8s
-// per-lookup timeout, so a resolution that works locally fails in
-// CI. Tracking the actual fix separately; see Frando/android-dns-fix.
-#[cfg_attr(
-    target_os = "android",
-    ignore = "flaky on emulator (no connections available)"
-)]
 #[tokio::test]
 async fn resolver_resolves_dns_iroh_link() {
     let resolver = DnsResolver::new();
@@ -54,3 +42,33 @@ async fn resolver_resolves_dns_iroh_link() {
     );
     eprintln!("{HOST} resolved to: {hits:?}");
 }
+
+/// Resolves through the Android emulator's QEMU NAT DNS proxy.
+///
+/// 10.0.2.3 is the well-known emulator DNS gateway, documented at
+/// <https://developer.android.com/studio/run/emulator-networking>.
+/// Pointing the resolver at it explicitly sidesteps the missing
+/// system-DNS reader (no JNI context here) so this test exercises
+/// hickory's pool, sockets, and our `DnsResolver` plumbing against a
+/// nameserver that is always reachable inside the emulator,
+/// independent of whether public DNS is reachable on the runner.
+#[cfg(target_os = "android")]
+#[tokio::test]
+async fn resolves_via_emulator_dns_proxy() {
+    let nameserver = "10.0.2.3:53".parse().unwrap();
+    let resolver = DnsResolver::builder()
+        .with_nameserver(nameserver, DnsProtocol::Udp)
+        .build();
+
+    let addrs: Vec<_> = resolver
+        .lookup_ipv4(HOST, TIMEOUT)
+        .await
+        .expect("IPv4 lookup via 10.0.2.3 should succeed in the emulator")
+        .collect();
+
+    assert!(
+        !addrs.is_empty(),
+        "expected at least one A record for {HOST} via 10.0.2.3",
+    );
+    eprintln!("{HOST} resolved via 10.0.2.3 to: {addrs:?}");
+}

iroh/tests/integration.rs

@@ -32,8 +32,6 @@ use wasm_bindgen_test::wasm_bindgen_test as test;
 
 const ECHO_ALPN: &[u8] = b"echo";
 
-// Skipped on Android: Test is flaky in the emulator.
-#[cfg_attr(target_os = "android", ignore = "flaky against staging from emulator")]
 #[test]
 async fn simple_endpoint_id_based_connection_transfer() -> Result {
     std::panic::set_hook(Box::new(console_error_panic_hook::hook));