Add Custom Http Headers to HTTP Clients

- Change app2mzs schema: Add Custom Headers to ClientType Element.
- Set custom headers in ClientFactory.
- Parse custom headers from spring environment.
- Merge custom headers from two different profiles.
- Add example to application.yaml.
- Test conversion of custom headers from spring profile
- Test merging and overriding custom headers.

2 files changed, 64 insertions, 1 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/preprocess/ConfigProfileGenerator.java b/src/main/java/at/gv/egiz/moazs/preprocess/ConfigProfileGenerator.java
index 0637f98..ed67154 100644
--- a/src/main/java/at/gv/egiz/moazs/preprocess/ConfigProfileGenerator.java
+++ b/src/main/java/at/gv/egiz/moazs/preprocess/ConfigProfileGenerator.java
@@ -43,7 +43,8 @@ public class ConfigProfileGenerator {
     private ConfigProfileGenerator(
             SpringPropertiesFacade properties,
             ConfigUtil util,
-            MzsDeliveryRequestValidator validator, boolean verifyCompletenessOfDefaultConfiguration,
+            MzsDeliveryRequestValidator validator,
+            boolean verifyCompletenessOfDefaultConfiguration,
             String profilePrefix,
             String defaultConfigKey) {
         this.util = util;
diff --git a/src/main/java/at/gv/egiz/moazs/preprocess/ConfigUtil.java b/src/main/java/at/gv/egiz/moazs/preprocess/ConfigUtil.java
index f49132f..ec7b7c8 100644
--- a/src/main/java/at/gv/egiz/moazs/preprocess/ConfigUtil.java
+++ b/src/main/java/at/gv/egiz/moazs/preprocess/ConfigUtil.java
@@ -5,15 +5,19 @@ import at.gv.zustellung.app2mzs.xsd.*;
 import org.springframework.stereotype.Component;
 
 import java.math.BigInteger;
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Stream;
 
 import static at.gv.zustellung.app2mzs.xsd.ClientType.clientTypeBuilder;
 import static at.gv.zustellung.app2mzs.xsd.ConfigType.configTypeBuilder;
+import static at.gv.zustellung.app2mzs.xsd.CustomHTTPHeaderType.*;
 import static at.gv.zustellung.app2mzs.xsd.ForwardResponseToServiceType.forwardResponseToServiceTypeBuilder;
 import static at.gv.zustellung.app2mzs.xsd.KeyStoreType.keyStoreTypeBuilder;
 import static at.gv.zustellung.app2mzs.xsd.MsgResponseSinksType.msgResponseSinksTypeBuilder;
 import static at.gv.zustellung.app2mzs.xsd.SSLType.SSLTypeBuilder;
 import static at.gv.zustellung.app2mzs.xsd.SaveResponseToFileType.saveResponseToFileTypeBuilder;
+import static java.util.stream.Collectors.toList;
 import static java.util.stream.Collectors.toMap;
 
 @Component
@@ -41,6 +45,7 @@ public class ConfigUtil {
     public static final String FORWARD_RESPONSE_TO_SERVICE_KEY = "forward-response-to-service";
     public static final String MZS_CLIENT_KEY = "mzs-client";
     public static final String SERVICE_TIMEOUT_KEY = "service-timeout";
+    public static final String CUSTOM_HTTP_HEADERS_KEY = "custom-http-headers";
 
 
     /**
@@ -95,11 +100,16 @@ public class ConfigUtil {
         SSLType ssl = sslParams.isEmpty()
                 ? null : buildSSL(sslParams);
 
+        var customHeaderParams = filterMapByPrefix(clientParams, CUSTOM_HTTP_HEADERS_KEY);
+        var customHeaders = customHeaderParams.isEmpty()
+                ? null : convertMapToHeaders(customHeaderParams);
+
         return clientTypeBuilder()
                 .withURL(url)
                 .withSSL(ssl)
                 .withConnectionTimeout(connectionTimeout)
                 .withReceiveTimeout(receiveTimeout)
+                .withCustomHTTPHeader(customHeaders)
                 .build();
 
     }
@@ -243,6 +253,10 @@ public class ConfigUtil {
             builder.withReceiveTimeout(primary.getReceiveTimeout());
         }
 
+        if (primary.getCustomHTTPHeader() != null) {
+            builder.withCustomHTTPHeader(merge(primary.getCustomHTTPHeader(), fallback.getCustomHTTPHeader()));
+        }
+
         return builder.build();
     }
 
@@ -282,6 +296,26 @@ public class ConfigUtil {
 
     }
 
+    private List<CustomHTTPHeaderType> merge(List<CustomHTTPHeaderType> primary, List<CustomHTTPHeaderType> fallback) {
+
+        if (fallback == null) return primary;
+
+        var primaryMap = convertHeadersToMap(primary);
+        var fallbackMap = convertHeadersToMap(fallback);
+
+        Map<String, String> mergedMap = Stream.of(fallbackMap, primaryMap)
+                .flatMap(map -> map.entrySet().stream())
+                .collect(toMap(
+                        Map.Entry::getKey,
+                        entry -> entry.getValue().get(0),
+                        (v1, v2) -> v2
+                ));
+
+        return convertMapToHeaders(mergedMap);
+
+    }
+
+
     private MsgResponseSinksType merge(MsgResponseSinksType primary, MsgResponseSinksType fallback) {
 
         if (fallback == null) {
@@ -340,4 +374,32 @@ public class ConfigUtil {
 
     }
 
+    /**
+     * Convert a Map that is indexed by header names into a List of CustomHTTPHeaders.
+     * @param customHeaderMap map of headers, indexed by header names.
+     * @return List of CustomHTTPHeaders
+     */
+    public List<CustomHTTPHeaderType> convertMapToHeaders(Map<String, String> customHeaderMap) {
+        return customHeaderMap.entrySet().stream()
+                .map(e -> customHTTPHeaderTypeBuilder()
+                        .withName(e.getKey())
+                        .withValue(e.getValue())
+                        .build())
+                .collect(toList());
+    }
+
+
+    /**
+     * Convert a List of CustomHTTPHeaders into a Map that is indexed by the header names. Values are wrapped in Lists.
+     * @param customHeaders List of CustomHTTPHeaders
+     * @return Map of headers, indexed by header names.
+     */
+    public Map<String, List<String>> convertHeadersToMap(List<CustomHTTPHeaderType> customHeaders) {
+        return customHeaders
+                .stream()
+                .collect(toMap(
+                        h -> h.getName(),
+                        h -> List.of(h.getValue())));
+    }
+
 }