add a webpki-roots feature to optionally use WebPKI roots on rustls

Signed-off-by: Elias Wilken <[email protected]>

deny.toml

@@ -31,6 +31,8 @@ allow = [
     # Pulled in via aws_lc_rs when using rustls-tls and aws-lc-rs features
     # https://openssl-library.org/source/license/index.html
     "OpenSSL",
+    # Pulled in via hyper-rustls when using the webpki-roots feature
+    "MPL-2.0",
 ]
 
 exceptions = [

kube-client/Cargo.toml

@@ -14,6 +14,7 @@ categories = ["web-programming::http-client", "network-programming", "api-bindin
 [features]
 default = ["client"]
 rustls-tls = ["rustls", "rustls-pemfile", "hyper-rustls", "hyper-http-proxy?/rustls-tls-native-roots"]
+webpki-roots = ["hyper-rustls/webpki-roots"]
 aws-lc-rs = ["rustls?/aws-lc-rs"]
 openssl-tls = ["openssl", "hyper-openssl"]
 ws = ["client", "tokio-tungstenite", "rand", "kube-core/ws", "tokio/macros"]

kube-client/src/client/tls.rs

@@ -55,9 +55,18 @@ pub mod rustls_tls {
         let config_builder = if let Some(certs) = root_certs {
             ClientConfig::builder().with_root_certificates(root_store(certs)?)
         } else {
-            ClientConfig::builder()
-                .with_native_roots()
-                .map_err(Error::NoValidNativeRootCA)?
+            #[cfg(feature = "webpki-roots")]
+            {
+                // Use WebPKI roots.
+                ClientConfig::builder().with_webpki_roots()
+            }
+            #[cfg(not(feature = "webpki-roots"))]
+            {
+                // Use native roots. This will panic on Android and iOS.
+                ClientConfig::builder()
+                    .with_native_roots()
+                    .map_err(Error::NoValidNativeRootCA)?
+            }
         };
 
         let mut client_config = if let Some((chain, pkey)) = identity_pem.map(client_auth).transpose()? {

kube/Cargo.toml

@@ -37,6 +37,7 @@ unstable-runtime = ["kube-runtime/unstable-runtime", "runtime"]
 unstable-client = ["kube-client/unstable-client", "client"]
 socks5 = ["kube-client/socks5", "client"]
 http-proxy = ["kube-client/http-proxy", "client"]
+webpki-roots = ["kube-client/webpki-roots", "client"]
 
 [package.metadata.docs.rs]
 features = ["client", "rustls-tls", "openssl-tls", "derive", "ws", "oauth", "jsonpatch", "admission", "runtime", "k8s-openapi/latest", "unstable-runtime", "socks5", "http-proxy"]