Client respects DNS TTL.

Author: chickenchickenlove

core/src/main/java/com/linecorp/armeria/client/proxy/ConnectProxyConfig.java

@@ -18,6 +18,9 @@
 
 import java.net.InetSocketAddress;
 import java.util.Objects;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.function.BiConsumer;
 
 import com.google.common.base.MoreObjects;
 
@@ -29,7 +32,11 @@
  */
 public final class ConnectProxyConfig extends ProxyConfig {
 
-    private final InetSocketAddress proxyAddress;
+    private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
+
+    private long lastUpdateTime = System.currentTimeMillis();
+
+    private InetSocketAddress proxyAddress;
 
     @Nullable
     private final String username;
@@ -43,11 +50,30 @@ public final class ConnectProxyConfig extends ProxyConfig {
 
     ConnectProxyConfig(InetSocketAddress proxyAddress, @Nullable String username,
                        @Nullable String password, HttpHeaders headers, boolean useTls) {
+        this(proxyAddress, username, password, headers, useTls, -1);
+    }
+
+    ConnectProxyConfig(InetSocketAddress proxyAddress, @Nullable String username,
+                       @Nullable String password, HttpHeaders headers, boolean useTls,
+                       long refreshInterval) {
         this.proxyAddress = proxyAddress;
         this.username = username;
         this.password = password;
         this.headers = headers;
         this.useTls = useTls;
+
+        if (refreshInterval > 0) {
+            final BiConsumer<InetSocketAddress, Long> callback = (newProxyAddress, updateTime) -> {
+                this.proxyAddress = newProxyAddress;
+                this.lastUpdateTime = updateTime;
+            };
+
+            ProxyConfig.reserveDNSUpdate(callback,
+                                         proxyAddress.getHostName(),
+                                         proxyAddress.getPort(),
+                                         refreshInterval,
+                                         scheduler);
+        }
     }
 
     @Override

core/src/main/java/com/linecorp/armeria/client/proxy/HAProxyConfig.java

@@ -20,6 +20,9 @@
 
 import java.net.InetSocketAddress;
 import java.util.Objects;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.function.BiConsumer;
 
 import com.google.common.base.MoreObjects;
 
@@ -31,21 +34,72 @@
  */
 public final class HAProxyConfig extends ProxyConfig {
 
-    private final InetSocketAddress proxyAddress;
+    private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
+
+    private long lastUpdateTime = System.currentTimeMillis();
+
+    private InetSocketAddress proxyAddress;
 
     @Nullable
-    private final InetSocketAddress sourceAddress;
+    private InetSocketAddress sourceAddress;
 
     HAProxyConfig(InetSocketAddress proxyAddress) {
+        this(proxyAddress, -1);
+    }
+
+    HAProxyConfig(InetSocketAddress proxyAddress, long refreshInterval) {
         this.proxyAddress = proxyAddress;
         sourceAddress = null;
+
+        if (refreshInterval > 0) {
+            final BiConsumer<InetSocketAddress, Long> callback = (newProxyAddress, updateTime) -> {
+                this.proxyAddress = newProxyAddress;
+                this.lastUpdateTime = updateTime;
+            };
+
+            ProxyConfig.reserveDNSUpdate(callback,
+                                         proxyAddress.getHostName(),
+                                         proxyAddress.getPort(),
+                                         refreshInterval,
+                                         scheduler);
+        }
     }
 
     HAProxyConfig(InetSocketAddress proxyAddress, InetSocketAddress sourceAddress) {
+        this(proxyAddress, sourceAddress, -1);
+    }
+
+    HAProxyConfig(InetSocketAddress proxyAddress, InetSocketAddress sourceAddress, long refreshInterval) {
         checkArgument(sourceAddress.getAddress().getClass() == proxyAddress.getAddress().getClass(),
                       "sourceAddress and proxyAddress should be the same type");
         this.proxyAddress = proxyAddress;
         this.sourceAddress = sourceAddress;
+
+        if (refreshInterval > 0) {
+            final BiConsumer<InetSocketAddress, Long> callback = (newProxyAddress, updateTime) -> {
+                this.proxyAddress = newProxyAddress;
+                this.lastUpdateTime = updateTime;
+            };
+
+            ProxyConfig.reserveDNSUpdate(callback,
+                                         proxyAddress.getHostName(),
+                                         proxyAddress.getPort(),
+                                         refreshInterval,
+                                         scheduler);
+        }
+
+        if (refreshInterval > 0) {
+            final BiConsumer<InetSocketAddress, Long> callback = (newSourceAddress, updateTime) -> {
+                this.sourceAddress = newSourceAddress;
+                this.lastUpdateTime = updateTime;
+            };
+
+            ProxyConfig.reserveDNSUpdate(callback,
+                                         sourceAddress.getHostName(),
+                                         sourceAddress.getPort(),
+                                         refreshInterval,
+                                         scheduler);
+        }
     }
 
     @Override