Set up nginx integration test

This uses the system nginx (assumed to be available) to start a
server, then grabs a small html file and a larger 5MB download
with the system curl (using system openssl).

rustls-libssl/tests/runner.rs

@@ -1,6 +1,6 @@
 use std::io::Read;
 use std::process::{Child, Command, Output, Stdio};
-use std::{net, thread, time};
+use std::{fs, net, thread, time};
 
 /* Note:
  *
@@ -322,6 +322,95 @@ fn server() {
     assert_eq!(openssl_output, rustls_output);
 }
 
+const NGINX_LOG_LEVEL: &str = "info";
+
+#[test]
+#[ignore]
+fn nginx() {
+    fs::create_dir_all("target/nginx-tmp/basic/html").unwrap();
+    fs::write(
+        "target/nginx-tmp/basic/server.conf",
+        "
+daemon off;
+master_process off;
+pid nginx.pid;
+
+events {
+}
+
+http {
+    ssl_session_cache none;
+    access_log access.log;
+
+    server {
+        listen 8443 ssl;
+        server_name localhost;
+        ssl_certificate ../../../test-ca/rsa/server.cert;
+        ssl_certificate_key ../../../test-ca/rsa/server.key;
+    }
+}
+",
+    )
+    .unwrap();
+
+    fs::write(
+        "target/nginx-tmp/basic/html/welcome.html",
+        "<h1>hello world!</h1>",
+    )
+    .unwrap();
+    let big_file = vec![b'a'; 5 * 1024 * 1024];
+    fs::write("target/nginx-tmp/basic/html/large.html", &big_file).unwrap();
+
+    let nginx_server = KillOnDrop(Some(
+        Command::new("tests/maybe-valgrind.sh")
+            .args([
+                "nginx",
+                "-g",
+                &format!("error_log stderr {NGINX_LOG_LEVEL};"),
+                "-p",
+                "./target/nginx-tmp/basic",
+                "-c",
+                "server.conf",
+            ])
+            .spawn()
+            .unwrap(),
+    ));
+    wait_for_port(8443);
+
+    assert_eq!(
+        Command::new("curl")
+            .env("LD_LIBRARY_PATH", "")
+            .args([
+                "--cacert",
+                "test-ca/rsa/ca.cert",
+                "https://localhost:8443/welcome.html"
+            ])
+            .stdout(Stdio::piped())
+            .output()
+            .map(print_output)
+            .unwrap()
+            .stdout,
+        b"<h1>hello world!</h1>"
+    );
+
+    assert_eq!(
+        Command::new("curl")
+            .env("LD_LIBRARY_PATH", "")
+            .args([
+                "--cacert",
+                "test-ca/rsa/ca.cert",
+                "https://localhost:8443/large.html"
+            ])
+            .stdout(Stdio::piped())
+            .output()
+            .unwrap()
+            .stdout,
+        big_file
+    );
+
+    drop(nginx_server);
+}
+
 struct KillOnDrop(Option<Child>);
 
 impl KillOnDrop {