Automatically transmit some headers specified by a environment varaible that directly defines header keys. (#606)

Co-authored-by: Haotian Zhang <928016560@qq.com>

CHANGELOG.md

@@ -5,4 +5,5 @@
 - [Optimize: remove discovery module useless code](https://github.com/Tencent/spring-cloud-tencent/pull/595)
 - [Optimize: remove useless code for rest template router](https://github.com/Tencent/spring-cloud-tencent/pull/601)
 - [Optimize: optimize configuration conditional & optimize config data tips](https://github.com/Tencent/spring-cloud-tencent/pull/603)
+- [Automatically transmit some headers specified by a environment varaible that directly defines header keys.](https://github.com/Tencent/spring-cloud-tencent/pull/606)
 - [Optimize: Maybe remove Chinese characters](https://github.com/Tencent/spring-cloud-tencent/pull/607)

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/DecodeTransferMetadataReactiveFilter.java

@@ -20,8 +20,13 @@ package com.tencent.cloud.metadata.core;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 
 import com.tencent.cloud.common.constant.MetadataConstant;
 import com.tencent.cloud.common.metadata.MetadataContextHolder;
@@ -33,6 +38,7 @@ import reactor.core.publisher.Mono;
 import org.springframework.core.Ordered;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
@@ -41,6 +47,8 @@ import org.springframework.web.server.WebFilterChain;
 import static com.tencent.cloud.common.constant.ContextConstant.UTF_8;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_DISPOSABLE_METADATA;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_METADATA;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS_KV;
 
 /**
  * Filter used for storing the metadata from upstream temporarily when web application is
@@ -79,12 +87,41 @@ public class DecodeTransferMetadataReactiveFilter implements WebFilter, Ordered
 				MetadataConstant.HeaderName.METADATA_CONTEXT,
 				MetadataContextHolder.get());
 
+		setCompleteTransHeaderIntoMC(serverHttpRequest);
 		return webFilterChain.filter(serverWebExchange)
 				.doOnError(throwable -> LOG.error("handle metadata[{}] error.",
 						MetadataContextHolder.get(), throwable))
 				.doFinally((type) -> MetadataContextHolder.remove());
 	}
 
+	/**
+	 * According to ServerHttpRequest and trans-headers(key list in string type) in metadata, build
+	 * the complete headers(key-value list in map type) into metadata.
+	 */
+	private void setCompleteTransHeaderIntoMC(ServerHttpRequest serverHttpRequest) {
+		// transHeaderMetadata: for example, {"trans-headers" : {"header1;header2;header3":""}}
+		Map<String, String> transHeaderMetadata =  MetadataContextHolder.get()
+				.getFragmentContext(FRAGMENT_RAW_TRANSHEADERS);
+		if (!CollectionUtils.isEmpty(transHeaderMetadata)) {
+			Optional<String> transHeaders = transHeaderMetadata.keySet().stream().findFirst();
+			String[] transHeaderArray = transHeaders.get().split(";");
+			HttpHeaders headers = serverHttpRequest.getHeaders();
+			Set<String> headerKeys = headers.keySet();
+			Iterator<String> iterator = headerKeys.iterator();
+			while (iterator.hasNext()) {
+				String httpHeader = iterator.next();
+				Arrays.stream(transHeaderArray).forEach(transHeader -> {
+					if (transHeader.equals(httpHeader)) {
+						List<String> list = headers.get(httpHeader);
+						String httpHeaderValue = JacksonUtils.serialize2Json(list);
+						MetadataContextHolder.get().putContext(FRAGMENT_RAW_TRANSHEADERS_KV,	httpHeader, httpHeaderValue);
+						return;
+					}
+				});
+			}
+		}
+	}
+
 	private Map<String, String> getIntervalMetadata(ServerHttpRequest serverHttpRequest, String headerName) {
 		HttpHeaders httpHeaders = serverHttpRequest.getHeaders();
 		String customMetadataStr = httpHeaders.getFirst(headerName);

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/DecodeTransferMetadataServletFilter.java

@@ -21,8 +21,11 @@ package com.tencent.cloud.metadata.core;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
+import java.util.Arrays;
+import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
@@ -37,12 +40,15 @@ import org.slf4j.LoggerFactory;
 
 import org.springframework.core.annotation.Order;
 import org.springframework.lang.NonNull;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.filter.OncePerRequestFilter;
 
 import static com.tencent.cloud.common.constant.ContextConstant.UTF_8;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_DISPOSABLE_METADATA;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_METADATA;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS_KV;
 
 /**
  * Filter used for storing the metadata from upstream temporarily when web application is
@@ -71,9 +77,35 @@ public class DecodeTransferMetadataServletFilter extends OncePerRequestFilter {
 
 		MetadataContextHolder.init(mergedTransitiveMetadata, mergedDisposableMetadata);
 
+		setCompleteTransHeaderIntoMC(httpServletRequest);
 		filterChain.doFilter(httpServletRequest, httpServletResponse);
 	}
 
+	/**
+	 * According to HttpServletRequest and trans-headers(key list in string type) in metadata, build
+	 * the complete headers(key-value list in map type) into metadata.
+	 */
+	private void setCompleteTransHeaderIntoMC(HttpServletRequest httpServletRequest) {
+		// transHeaderMetadata: for example, {"trans-headers" : {"header1;header2;header3":""}}
+		Map<String, String> transHeaderMetadata =  MetadataContextHolder.get()
+				.getFragmentContext(FRAGMENT_RAW_TRANSHEADERS);
+		if (!CollectionUtils.isEmpty(transHeaderMetadata)) {
+			Optional<String> transHeaders = transHeaderMetadata.keySet().stream().findFirst();
+			String[] transHeaderArray = transHeaders.get().split(";");
+			Enumeration<String> httpHeaders = httpServletRequest.getHeaderNames();
+			while (httpHeaders.hasMoreElements()) {
+				String httpHeader = httpHeaders.nextElement();
+				Arrays.stream(transHeaderArray).forEach(transHeader -> {
+					if (transHeader.equals(httpHeader)) {
+						String httpHeaderValue = httpServletRequest.getHeader(httpHeader);
+						MetadataContextHolder.get().putContext(FRAGMENT_RAW_TRANSHEADERS_KV,	httpHeader, httpHeaderValue);
+						return;
+					}
+				});
+			}
+		}
+	}
+
 	private Map<String, String> getInternalMetadata(HttpServletRequest httpServletRequest, String headerName) {
 		// Get custom metadata string from http header.
 		String customMetadataStr = httpServletRequest.getHeader(headerName);

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/EncodeTransferMedataFeignInterceptor.java

@@ -61,6 +61,7 @@ public class EncodeTransferMedataFeignInterceptor implements RequestInterceptor,
 		MetadataContext metadataContext = MetadataContextHolder.get();
 		Map<String, String> customMetadata = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_TRANSITIVE);
 		Map<String, String> disposableMetadata = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_DISPOSABLE);
+		Map<String, String> transHeaders = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_RAW_TRANSHEADERS_KV);
 
 		// Clean up one-time metadata coming from upstream .
 		Map<String, String> newestCustomMetadata = new HashMap<>();
@@ -71,8 +72,20 @@ public class EncodeTransferMedataFeignInterceptor implements RequestInterceptor,
 		});
 		this.buildMetadataHeader(requestTemplate, disposableMetadata, CUSTOM_DISPOSABLE_METADATA);
 
-		// process custom metadata finally
+		// process custom metadata
 		this.buildMetadataHeader(requestTemplate, newestCustomMetadata, CUSTOM_METADATA);
+
+		// set headers that need to be transmitted from the upstream
+		this.buildTransmittedHeader(requestTemplate, transHeaders);
+	}
+
+	private void buildTransmittedHeader(RequestTemplate requestTemplate, Map<String, String> transHeaders) {
+		if (!CollectionUtils.isEmpty(transHeaders)) {
+			transHeaders.entrySet().stream().forEach(entry -> {
+				requestTemplate.removeHeader(entry.getKey());
+				requestTemplate.header(entry.getKey(), entry.getValue());
+			});
+		}
 	}
 
 	/**

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/EncodeTransferMedataRestTemplateInterceptor.java

@@ -61,6 +61,7 @@ public class EncodeTransferMedataRestTemplateInterceptor implements ClientHttpRe
 		MetadataContext metadataContext = MetadataContextHolder.get();
 		Map<String, String> customMetadata = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_TRANSITIVE);
 		Map<String, String> disposableMetadata = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_DISPOSABLE);
+		Map<String, String> transHeaders = metadataContext.getFragmentContext(MetadataContext.FRAGMENT_RAW_TRANSHEADERS_KV);
 
 		Map<String, String> newestCustomMetadata = new HashMap<>();
 		customMetadata.forEach((key, value) -> {
@@ -74,9 +75,20 @@ public class EncodeTransferMedataRestTemplateInterceptor implements ClientHttpRe
 		// build custom metadata request header
 		this.buildMetadataHeader(httpRequest, newestCustomMetadata, CUSTOM_METADATA);
 
+		// set headers that need to be transmitted from the upstream
+		this.buildTransmittedHeader(httpRequest, transHeaders);
+
 		return clientHttpRequestExecution.execute(httpRequest, bytes);
 	}
 
+	private void buildTransmittedHeader(HttpRequest request, Map<String, String> transHeaders) {
+		if (!CollectionUtils.isEmpty(transHeaders)) {
+			transHeaders.entrySet().stream().forEach(entry -> {
+				request.getHeaders().set(entry.getKey(), entry.getValue());
+			});
+		}
+	}
+
 	/**
 	 * Set metadata into the request header for {@link HttpRequest} .
 	 *

spring-cloud-starter-tencent-metadata-transfer/src/main/java/com/tencent/cloud/metadata/core/EncodeTransferMedataScgFilter.java

@@ -20,8 +20,13 @@ package com.tencent.cloud.metadata.core;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 
 import com.tencent.cloud.common.constant.MetadataConstant;
 import com.tencent.cloud.common.metadata.MetadataContext;
@@ -32,6 +37,7 @@ import reactor.core.publisher.Mono;
 import org.springframework.cloud.gateway.filter.GatewayFilterChain;
 import org.springframework.cloud.gateway.filter.GlobalFilter;
 import org.springframework.core.Ordered;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.util.CollectionUtils;
 import org.springframework.web.server.ServerWebExchange;
@@ -39,6 +45,8 @@ import org.springframework.web.server.ServerWebExchange;
 import static com.tencent.cloud.common.constant.ContextConstant.UTF_8;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_DISPOSABLE_METADATA;
 import static com.tencent.cloud.common.constant.MetadataConstant.HeaderName.CUSTOM_METADATA;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS_KV;
 import static org.springframework.cloud.gateway.filter.ReactiveLoadBalancerClientFilter.LOAD_BALANCER_CLIENT_FILTER_ORDER;
 
 /**
@@ -80,9 +88,39 @@ public class EncodeTransferMedataScgFilter implements GlobalFilter, Ordered {
 		this.buildMetadataHeader(builder, newestCustomMetadata, CUSTOM_METADATA);
 		this.buildMetadataHeader(builder, disposableMetadata, CUSTOM_DISPOSABLE_METADATA);
 
+		setCompleteTransHeaderIntoMC(exchange.getRequest());
 		return chain.filter(exchange.mutate().request(builder.build()).build());
 	}
 
+	/**
+	 * According to ServerHttpRequest and trans-headers(key list in string type) in metadata, build
+	 * the complete headers(key-value list in map type) into metadata.
+	 */
+	private void setCompleteTransHeaderIntoMC(ServerHttpRequest serverHttpRequest) {
+		// transHeaderMetadata: for example, {"trans-headers" : {"header1;header2;header3":""}}
+		Map<String, String> transHeaderMetadata =  MetadataContextHolder.get()
+				.getFragmentContext(FRAGMENT_RAW_TRANSHEADERS);
+		if (!CollectionUtils.isEmpty(transHeaderMetadata)) {
+			Optional<String> transHeaders = transHeaderMetadata.keySet().stream().findFirst();
+			String[] transHeaderArray = transHeaders.get().split(";");
+			HttpHeaders headers = serverHttpRequest.getHeaders();
+			Set<String> headerKeys = headers.keySet();
+			Iterator<String> iterator = headerKeys.iterator();
+			while (iterator.hasNext()) {
+				String httpHeader = iterator.next();
+				Arrays.stream(transHeaderArray).forEach(transHeader -> {
+					if (transHeader.equals(httpHeader)) {
+						List<String> list = headers.get(httpHeader);
+						String httpHeaderValue = JacksonUtils.serialize2Json(list);
+						// for example, {"trans-headers-kv" : {"header1":"v1","header2":"v2"...}}
+						MetadataContextHolder.get().putContext(FRAGMENT_RAW_TRANSHEADERS_KV,	httpHeader, httpHeaderValue);
+						return;
+					}
+				});
+			}
+		}
+	}
+
 	/**
 	 * Set metadata into the request header for {@link ServerHttpRequest.Builder} .
 	 * @param builder instance of {@link ServerHttpRequest.Builder}

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/metadata/MetadataContext.java

@@ -56,6 +56,16 @@ public class MetadataContext {
 	 */
 	public static final String FRAGMENT_UPSTREAM_DISPOSABLE = "upstream-disposable";
 
+	/**
+	 * the key of the header(key) list needed to be transmitted from upstream to downstream.
+	 */
+	public static final String FRAGMENT_RAW_TRANSHEADERS = "trans-headers";
+
+	/**
+	 * the key of the header(key-value) list needed to be transmitted from upstream to downstream.
+	 */
+	public static final String FRAGMENT_RAW_TRANSHEADERS_KV = "trans-headers-kv";
+
 	private static final Logger LOG = LoggerFactory.getLogger(MetadataContext.class);
 	/**
 	 * Namespace of local instance.

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/metadata/MetadataContextHolder.java

@@ -28,6 +28,7 @@ import com.tencent.cloud.common.util.ApplicationContextAwareUtils;
 import org.springframework.util.CollectionUtils;
 
 import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_DISPOSABLE;
+import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_RAW_TRANSHEADERS;
 import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_TRANSITIVE;
 import static com.tencent.cloud.common.metadata.MetadataContext.FRAGMENT_UPSTREAM_DISPOSABLE;
 
@@ -67,6 +68,7 @@ public final class MetadataContextHolder {
 		MetadataContext metadataContext = new MetadataContext();
 		metadataContext.putFragmentContext(FRAGMENT_TRANSITIVE, staticMetadataManager.getMergedStaticTransitiveMetadata());
 		metadataContext.putFragmentContext(FRAGMENT_DISPOSABLE, staticMetadataManager.getMergedStaticDisposableMetadata());
+		metadataContext.putContext(FRAGMENT_RAW_TRANSHEADERS, staticMetadataManager.getEnvTransHeaderMetadata(), "");
 
 		METADATA_CONTEXT.set(metadataContext);
 

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/metadata/StaticMetadataManager.java

@@ -55,6 +55,12 @@ public class StaticMetadataManager {
 	private static final int ENV_METADATA_PREFIX_LENGTH = ENV_METADATA_PREFIX.length();
 	private static final String ENV_METADATA_CONTENT_TRANSITIVE = "SCT_METADATA_CONTENT_TRANSITIVE";
 	private static final String ENV_METADATA_CONTENT_DISPOSABLE = "SCT_METADATA_CONTENT_DISPOSABLE";
+	/**
+	 * This is the key of the header's key list needed to be transmitted. The list is a string split with ;.
+	 * The value mapped by this key was specified by user.
+	 * This is configured in environment variables.
+	 */
+	private static final String ENV_METADATA_CONTENT_RAW_TRANSHEADERS = "SCT_METADATA_CONTENT_RAW_TRANSHEADERS";
 	private static final String ENV_METADATA_ZONE = "SCT_METADATA_ZONE";
 	private static final String ENV_METADATA_REGION = "SCT_METADATA_REGION";
 	private static final String ENV_METADATA_CAMPUS = "SCT_METADATA_CAMPUS";
@@ -100,7 +106,13 @@ public class StaticMetadataManager {
 			String value = entry.getValue();
 			if (StringUtils.isNotBlank(key) && key.startsWith(ENV_METADATA_PREFIX)
 					&& !key.equals(ENV_METADATA_CONTENT_TRANSITIVE)) {
-				String sourceKey = StringUtils.substring(key, ENV_METADATA_PREFIX_LENGTH);
+				String sourceKey = "";
+				if (key.equals(ENV_METADATA_CONTENT_RAW_TRANSHEADERS)) {
+					sourceKey = key;
+				}
+				else {
+					sourceKey = StringUtils.substring(key, ENV_METADATA_PREFIX_LENGTH);
+				}
 				envMetadata.put(sourceKey, value);
 
 				LOGGER.info("[SCT] resolve metadata from env. key = {}, value = {}", sourceKey, value);
@@ -270,6 +282,10 @@ public class StaticMetadataManager {
 		return envMetadata;
 	}
 
+	public String getEnvTransHeaderMetadata() {
+		return envMetadata.get(ENV_METADATA_CONTENT_RAW_TRANSHEADERS);
+	}
+
 	public Map<String, String> getEnvTransitiveMetadata() {
 		return envTransitiveMetadata;
 	}