Support proxying console in server side (#2535)

#### What type of PR is this?

/kind feature
/area core
/milestone 2.0

#### What this PR does / why we need it:

Support proxying console in server side. We just need to configure the properties as following:

```yaml
halo:
  console:
    proxy:
      endpoint: http://localhost:3000/
      enabled: true
```

Before starting Halo server, please start the console first at port 3000 by checkouting halo-dev/console#638.

Now we can have a try to access console via <http://localhost:8090/console/>.

Please note that this feature should be only for development environment instead of production environment.

#### Todos

- [ ] Proxy WebSocket for hmr of Vite

#### Which issue(s) this PR fixes:

Fixes #2530

#### Does this PR introduce a user-facing change?

```release-note
None
```

src/main/java/run/halo/app/config/WebFluxConfig.java

@@ -8,6 +8,7 @@
 import java.net.URI;
 import java.time.Instant;
 import java.util.List;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -28,6 +29,7 @@
 import org.springframework.web.reactive.result.view.ViewResolutionResultHandler;
 import org.springframework.web.reactive.result.view.ViewResolver;
 import reactor.core.publisher.Mono;
+import run.halo.app.console.ConsoleProxyFilter;
 import run.halo.app.core.extension.endpoint.CustomEndpoint;
 import run.halo.app.core.extension.endpoint.CustomEndpointsBuilder;
 import run.halo.app.infra.properties.HaloProperties;
@@ -123,4 +125,10 @@ public void addResourceHandlers(ResourceHandlerRegistry registry) {
             .addResolver(new PathResourceResolver());
     }
 
+
+    @ConditionalOnProperty(name = "halo.console.proxy.enabled", havingValue = "true")
+    @Bean
+    ConsoleProxyFilter consoleProxyFilter() {
+        return new ConsoleProxyFilter(haloProp);
+    }
 }

src/main/java/run/halo/app/console/ConsoleProxyFilter.java

@@ -0,0 +1,72 @@
+package run.halo.app.console;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.security.web.server.util.matcher.AndServerWebExchangeMatcher;
+import org.springframework.security.web.server.util.matcher.MediaTypeServerWebExchangeMatcher;
+import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatcher;
+import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatchers;
+import org.springframework.web.reactive.function.BodyExtractors;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import org.springframework.web.util.UriComponentsBuilder;
+import reactor.core.publisher.Mono;
+import run.halo.app.infra.properties.ConsoleProperties.ProxyProperties;
+import run.halo.app.infra.properties.HaloProperties;
+
+@Slf4j
+public class ConsoleProxyFilter implements WebFilter {
+
+    private final ProxyProperties proxyProperties;
+
+    private final ServerWebExchangeMatcher consoleMatcher;
+
+    private final WebClient webClient;
+
+    public ConsoleProxyFilter(HaloProperties haloProperties) {
+        this.proxyProperties = haloProperties.getConsole().getProxy();
+        var consoleMatcher = ServerWebExchangeMatchers.pathMatchers(HttpMethod.GET, "/console/**");
+        consoleMatcher = new AndServerWebExchangeMatcher(consoleMatcher,
+            new MediaTypeServerWebExchangeMatcher(MediaType.TEXT_HTML));
+        this.consoleMatcher = consoleMatcher;
+        this.webClient = WebClient.create(proxyProperties.getEndpoint().toString());
+        log.info("Initialized ConsoleProxyFilter to proxy console");
+    }
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
+        return consoleMatcher.matches(exchange)
+            .filter(ServerWebExchangeMatcher.MatchResult::isMatch)
+            .switchIfEmpty(chain.filter(exchange).then(Mono.empty()))
+            .map(matchResult -> {
+                var request = exchange.getRequest();
+                return UriComponentsBuilder.fromUriString(
+                        request.getPath().pathWithinApplication().value())
+                    .queryParams(request.getQueryParams())
+                    .build()
+                    .toUriString();
+            })
+            .doOnNext(uri -> {
+                if (log.isDebugEnabled()) {
+                    log.debug("Proxy {} to {}", uri, proxyProperties.getEndpoint());
+                }
+            })
+            .flatMap(uri -> webClient.get()
+                .uri(uri)
+                .headers(httpHeaders -> httpHeaders.addAll(exchange.getRequest().getHeaders()))
+                .exchangeToMono(clientResponse -> {
+                    var response = exchange.getResponse();
+                    // set headers
+                    response.getHeaders().putAll(clientResponse.headers().asHttpHeaders());
+                    // set cookies
+                    response.getCookies().putAll(clientResponse.cookies());
+                    // set status code
+                    response.setStatusCode(clientResponse.statusCode());
+                    var body = clientResponse.body(BodyExtractors.toDataBuffers());
+                    return exchange.getResponse().writeAndFlushWith(Mono.just(body));
+                }));
+    }
+}

src/main/java/run/halo/app/infra/properties/ConsoleProperties.java

@@ -1,10 +1,28 @@
 package run.halo.app.infra.properties;
 
+import jakarta.validation.Valid;
+import java.net.URI;
 import lombok.Data;
 
 @Data
 public class ConsoleProperties {
 
     private String location = "classpath:/console/";
 
+    @Valid
+    private ProxyProperties proxy = new ProxyProperties();
+
+    @Data
+    public static class ProxyProperties {
+
+        /**
+         * Console endpoint in development environment to be proxied. e.g.: http://localhost:8090/
+         */
+        private URI endpoint;
+
+        /**
+         * Indicates if the proxy behaviour is enabled. Default is false
+         */
+        private boolean enabled = false;
+    }
 }