Allow direct proxy configuration

service-config/src/main/java/com/palantir/remoting2/config/service/ProxyConfiguration.java

@@ -36,45 +36,105 @@
 @Style(visibility = Style.ImplementationVisibility.PACKAGE, builder = "new")
 public abstract class ProxyConfiguration {
 
+    enum Type {
+
+        /**
+         * Use a direct connection. This option will bypass any JVM-level configured proxy settings.
+         */
+        direct,
+
+        /**
+         * Use an http-proxy specified by {@link ProxyConfiguration#hostAndPort()}  and (optionally)
+         * {@link ProxyConfiguration#credentials()}.
+         */
+        http;
+    }
+
     /**
      * The hostname and port of the HTTP/HTTPS Proxy. Recognized formats include those recognized by {@link
      * com.google.common.net.HostAndPort}, for instance {@code foo.com:80}, {@code 192.168.3.100:8080}, etc.
      */
-    public abstract String hostAndPort();
+    @JsonProperty("hostAndPort")
+    public abstract Optional<String> maybeHostAndPort();
+
+    /**
+     * @deprecated Use maybeHostAndPort().
+     */
+    @Deprecated
+    @SuppressWarnings("checkstyle:designforextension")
+    @JsonIgnore
+    @Lazy
+    public String hostAndPort() {
+        Preconditions.checkState(maybeHostAndPort().isPresent(), "hostAndPort was not configured");
+        return maybeHostAndPort().get();
+    }
 
     /**
      * Credentials if the proxy needs authentication.
      */
     public abstract Optional<BasicCredentials> credentials();
 
+    @Value.Default
+    @SuppressWarnings("checkstyle:designforextension")
+    public Type type() {
+        return Type.http;
+    }
+
     @Value.Check
     protected final void check() {
-        HostAndPort host = HostAndPort.fromString(hostAndPort());
-        Preconditions.checkArgument(host.hasPort(), "Given hostname does not contain a port number: " + host);
+        switch (type()) {
+            case http:
+                HostAndPort host = HostAndPort.fromString(maybeHostAndPort().get());
+                Preconditions.checkArgument(host.hasPort(),
+                        "Given hostname does not contain a port number: " + host);
+                break;
+            case direct:
+                Preconditions.checkArgument(!maybeHostAndPort().isPresent() && !credentials().isPresent(),
+                        "Neither credential nor host-and-port may be configured for direct proxies");
+                break;
+            default:
+                throw new IllegalStateException("Unrecognized case; this is a library bug");
+        }
+
+        if (credentials().isPresent()) {
+            Preconditions.checkArgument(type() == Type.http, "credentials only valid for http proxies");
+        }
     }
 
     @Lazy
     @SuppressWarnings("checkstyle:designforextension")
     @JsonIgnore
     public Proxy toProxy() {
-        HostAndPort hostAndPort = HostAndPort.fromString(hostAndPort());
-        return new Proxy(Proxy.Type.HTTP, new InetSocketAddress(hostAndPort.getHostText(), hostAndPort.getPort()));
+        switch (type()) {
+            case http:
+                HostAndPort hostAndPort = HostAndPort.fromString(maybeHostAndPort().get());
+                InetSocketAddress addr = new InetSocketAddress(hostAndPort.getHostText(), hostAndPort.getPort());
+                return new Proxy(Proxy.Type.HTTP, addr);
+            case direct:
+                return Proxy.NO_PROXY;
+            default:
+                throw new IllegalStateException("unrecognized proxy type; this is a library error");
+        }
     }
 
     public static ProxyConfiguration of(String hostAndPort) {
-        return new ProxyConfiguration.Builder().hostAndPort(hostAndPort).build();
+        return new ProxyConfiguration.Builder().maybeHostAndPort(hostAndPort).build();
     }
 
     public static ProxyConfiguration of(String hostAndPort, BasicCredentials credentials) {
-        return new ProxyConfiguration.Builder().hostAndPort(hostAndPort).credentials(credentials).build();
+        return new ProxyConfiguration.Builder().maybeHostAndPort(hostAndPort).credentials(credentials).build();
+    }
+
+    public static ProxyConfiguration direct() {
+        return new ProxyConfiguration.Builder().type(Type.direct).build();
     }
 
     // TODO(jnewman): #317 - remove kebab-case methods when Jackson 2.7 is picked up
     static final class Builder extends ImmutableProxyConfiguration.Builder {
 
         @JsonProperty("host-and-port")
         Builder hostAndPortKebabCase(String hostAndPort) {
-            return hostAndPort(hostAndPort);
+            return maybeHostAndPort(hostAndPort);
         }
     }
 }

service-config/src/test/java/com/palantir/remoting2/config/service/ProxyConfigurationTests.java

@@ -53,6 +53,21 @@ public void testDeserializationWithCredentials() throws IOException {
         assertEquals(expectedProxyConfiguration, actualProxyConfiguration);
     }
 
+    @Test
+    public void testDeserializationDirect() throws Exception {
+        URL resource = Resources.getResource("configs/proxy-config-direct.yml");
+        ProxyConfiguration config = mapper.readValue(resource, ProxyConfiguration.class);
+        assertEquals(config, ProxyConfiguration.direct());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testDirectProxyWithHostAndPort() {
+        new ProxyConfiguration.Builder()
+                .maybeHostAndPort("squid:3128")
+                .type(ProxyConfiguration.Type.direct)
+                .build();
+    }
+
     @Test
     public void testToProxy() {
         ProxyConfiguration proxyConfiguration = ProxyConfiguration.of("squid:3128");
@@ -61,13 +76,14 @@ public void testToProxy() {
         assertEquals(expected, proxyConfiguration.toProxy());
     }
 
+
     @Test
     public void serDe() throws Exception {
         ProxyConfiguration serialized = ProxyConfiguration.of("host:80", BasicCredentials.of("username", "password"));
-        String deserializedCamelCase =
-                "{\"hostAndPort\":\"host:80\",\"credentials\":{\"username\":\"username\",\"password\":\"password\"}}";
-        String deserializedKebabCase =
-                "{\"host-and-port\":\"host:80\",\"credentials\":{\"username\":\"username\",\"password\":\"password\"}}";
+        String deserializedCamelCase = "{\"hostAndPort\":\"host:80\",\"credentials\":{\"username\":\"username\","
+                + "\"password\":\"password\"},\"type\":\"http\"}";
+        String deserializedKebabCase = "{\"host-and-port\":\"host:80\",\"credentials\":{\"username\":\"username\","
+                + "\"password\":\"password\"},\"type\":\"http\"}";
 
         assertThat(ObjectMappers.newClientObjectMapper().writeValueAsString(serialized))
                 .isEqualTo(deserializedCamelCase);

service-config/src/test/java/com/palantir/remoting2/config/service/ServiceConfigurationTest.java

@@ -42,7 +42,8 @@ public void serDe() throws Exception {
                 + "\"keyStorePassword\":null,\"keyStoreType\":\"JKS\",\"keyStoreKeyAlias\":null},"
                 + "\"connectTimeout\":\"1 day\",\"readTimeout\":\"1 day\",\"writeTimeout\":\"1 day\","
                 + "\"enableGcmCipherSuites\":null,"
-                + "\"uris\":[\"uri1\"],\"proxyConfiguration\":{\"hostAndPort\":\"host:80\",\"credentials\":null}}";
+                + "\"uris\":[\"uri1\"],\"proxyConfiguration\":{\"hostAndPort\":\"host:80\",\"credentials\":null,"
+                + "\"type\":\"http\"}}";
         String deserializedKebabCase = "{\"api-token\":\"bearerToken\",\"security\":"
                 + "{\"trust-store-path\":\"truststore.jks\",\"trust-store-type\":\"JKS\",\"key-store-path\":null,"
                 + "\"key-store-password\":null,\"key-store-type\":\"JKS\",\"key-store-key-alias\":null},"

service-config/src/test/java/com/palantir/remoting2/config/service/ServiceDiscoveryConfigurationTests.java

@@ -186,7 +186,7 @@ public void serDe() throws Exception {
                 + "{\"service\":{\"apiToken\":null,\"security\":null,\"connectTimeout\":null,\"readTimeout\":null,"
                 + "\"writeTimeout\":null,\"enableGcmCipherSuites\":null,\"uris\":[\"uri\"],"
                 + "\"proxyConfiguration\":null}},\"proxyConfiguration\":"
-                + "{\"hostAndPort\":\"host:80\",\"credentials\":null},\"connectTimeout\":\"1 day\","
+                + "{\"hostAndPort\":\"host:80\",\"credentials\":null,\"type\":\"http\"},\"connectTimeout\":\"1 day\","
                 + "\"readTimeout\":\"1 day\",\"enableGcmCipherSuites\":null}";
         String deserializedKebabCase = "{\"api-token\":\"bearerToken\",\"security\":"
                 + "{\"trust-store-path\":\"truststore.jks\",\"trust-store-type\":\"JKS\",\"key-store-path\":null,"

service-config/src/test/resources/configs/proxy-config-direct.yml

@@ -0,0 +1 @@
+type: direct