Merge pull request #15127 from AndriiLandiak/rest-api-node-body-template

Added request body template support for REST API call node

rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/util/TbNodeUtils.java

@@ -15,6 +15,7 @@
  */
 package org.thingsboard.rule.engine.api.util;
 
+import com.fasterxml.jackson.core.io.JsonStringEncoder;
 import com.fasterxml.jackson.databind.JsonNode;
 import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.rule.engine.api.TbNodeConfiguration;
@@ -57,8 +58,12 @@ public final class TbNodeUtils {
     }
 
     public static String processPattern(String pattern, TbMsg tbMsg) {
+        return processPattern(pattern, tbMsg, false);
+    }
+
+    public static String processPattern(String pattern, TbMsg tbMsg, boolean escapeJsonValues) {
         try {
-            String result = processPattern(pattern, tbMsg.getMetaData());
+            String result = processPattern(pattern, tbMsg.getMetaData(), escapeJsonValues);
             JsonNode json = JacksonUtil.toJsonNode(tbMsg.getData());
 
             result = result.replace(ALL_DATA_TEMPLATE, JacksonUtil.toString(json));
@@ -79,7 +84,11 @@ public final class TbNodeUtils {
                     }
 
                     if (jsonNode != null && jsonNode.isValueNode()) {
-                        result = result.replace(formatDataVarTemplate(group), jsonNode.asText());
+                        String value = jsonNode.asText();
+                        if (escapeJsonValues) {
+                            value = escapeJsonValue(value);
+                        }
+                        result = result.replace(formatDataVarTemplate(group), value);
                     }
                 }
             }
@@ -89,22 +98,31 @@ public final class TbNodeUtils {
         }
     }
 
-    private static String processPattern(String pattern, TbMsgMetaData metaData) {
+    private static String processPattern(String pattern, TbMsgMetaData metaData, boolean escapeJsonValues) {
         String replacement = metaData.isEmpty() ? "{}" : JacksonUtil.toString(metaData.getData());
         pattern = pattern.replace(ALL_METADATA_TEMPLATE, replacement);
-        return processTemplate(pattern, metaData.values());
+        return processTemplate(pattern, metaData.values(), escapeJsonValues);
+    }
+
+    private static String processPattern(String pattern, TbMsgMetaData metaData) {
+        return processPattern(pattern, metaData, false);
     }
 
     public static String processTemplate(String template, Map<String, String> data) {
+        return processTemplate(template, data, false);
+    }
+
+    private static String processTemplate(String template, Map<String, String> data, boolean escapeJsonValues) {
         String result = template;
         for (Map.Entry<String, String> kv : data.entrySet()) {
-            result = processVar(result, kv.getKey(), kv.getValue());
+            String value = escapeJsonValues ? escapeJsonValue(kv.getValue()) : kv.getValue();
+            result = result.replace(formatMetadataVarTemplate(kv.getKey()), value);
         }
         return result;
     }
 
-    private static String processVar(String pattern, String key, String val) {
+    private static String escapeJsonValue(String value) {
-        return pattern.replace(formatMetadataVarTemplate(key), val);
+        return new String(JsonStringEncoder.getInstance().quoteAsString(value));
     }
 
     static String formatDataVarTemplate(String key) {

rule-engine/rule-engine-api/src/test/java/org/thingsboard/rule/engine/api/util/TbNodeUtilsTest.java

@@ -305,6 +305,50 @@ public class TbNodeUtilsTest {
         assertThat(actual, is(expected));
     }
 
+    @Test
+    public void testProcessPatternWithJsonEscaping() {
+        String pattern = "{\"name\":\"${user}\",\"desc\":\"$[description]\"}";
+        TbMsgMetaData md = new TbMsgMetaData();
+        md.putValue("user", "John \"Doe\"");
+
+        ObjectNode node = JacksonUtil.newObjectNode();
+        node.put("description", "line1\nline2");
+
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(TenantId.SYS_TENANT_ID)
+                .copyMetaData(md)
+                .data(JacksonUtil.toString(node))
+                .build();
+
+        String result = TbNodeUtils.processPattern(pattern, msg, true);
+        Assertions.assertEquals("{\"name\":\"John \\\"Doe\\\"\",\"desc\":\"line1\\nline2\"}", result);
+
+        // Verify the result is valid JSON
+        Assertions.assertDoesNotThrow(() -> JacksonUtil.toJsonNode(result));
+    }
+
+    @Test
+    public void testProcessPatternWithoutJsonEscaping() {
+        String pattern = "Hello ${user}, desc: $[description]";
+        TbMsgMetaData md = new TbMsgMetaData();
+        md.putValue("user", "John \"Doe\"");
+
+        ObjectNode node = JacksonUtil.newObjectNode();
+        node.put("description", "line1\nline2");
+
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(TenantId.SYS_TENANT_ID)
+                .copyMetaData(md)
+                .data(JacksonUtil.toString(node))
+                .build();
+
+        // Without escaping, raw values are substituted as-is
+        String result = TbNodeUtils.processPattern(pattern, msg, false);
+        Assertions.assertEquals("Hello John \"Doe\", desc: line1\nline2", result);
+    }
+
     @Test
     public void testMixedAllDataMetadataAndNormalTemplates() {
         // GIVEN

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/rest/TbHttpClient.java

@@ -55,6 +55,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Properties;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
@@ -182,10 +183,7 @@ public class TbHttpClient {
     }
 
     EventLoopGroup getSharedOrCreateEventLoopGroup(EventLoopGroup eventLoopGroupShared) {
-        if (eventLoopGroupShared != null) {
+        return Objects.requireNonNullElseGet(eventLoopGroupShared, () -> this.eventLoopGroup = new NioEventLoopGroup());
-            return eventLoopGroupShared;
-        }
-        return this.eventLoopGroup = new NioEventLoopGroup();
     }
 
     private void checkSystemProxyProperties() throws TbNodeException {
@@ -243,7 +241,7 @@ public class TbHttpClient {
             if ((HttpMethod.POST.equals(method) || HttpMethod.PUT.equals(method) ||
                     HttpMethod.PATCH.equals(method) || HttpMethod.DELETE.equals(method)) &&
                     !config.isIgnoreRequestBody()) {
-                request.body(BodyInserters.fromValue(getData(msg, config.isParseToPlainText())));
+                request.body(BodyInserters.fromValue(getRequestBody(msg)));
             }
 
             request
@@ -268,6 +266,11 @@ public class TbHttpClient {
                     });
         } catch (InterruptedException e) {
             log.warn("Timeout during waiting for reply!", e);
+        } catch (Exception e) {
+            if (semaphore != null) {
+                semaphore.release();
+            }
+            onFailure.accept(msg, e);
         }
     }
 
@@ -275,7 +278,7 @@ public class TbHttpClient {
         if (origin instanceof WebClientResponseException restClientResponseException
                 && restClientResponseException.getStatusCode().is2xxSuccessful()) {
             // return cause instead of original exception in case 2xx status code
-            // this will provide meaningful error message to the user
+            // this will provide a meaningful error message to the user
             return new RuntimeException(restClientResponseException.getCause());
         }
         return origin;
@@ -340,6 +343,22 @@ public class TbHttpClient {
         return UriComponentsBuilder.fromUriString(endpointUrl).build().encode().toUri();
     }
 
+    private Object getRequestBody(TbMsg msg) {
+        if (StringUtils.isNotBlank(config.getRequestBodyTemplate())) {
+            boolean escapeJson = !config.isParseToPlainText();
+            String processedTemplate = TbNodeUtils.processPattern(config.getRequestBodyTemplate(), msg, escapeJson);
+            if (config.isParseToPlainText()) {
+                return processedTemplate;
+            }
+            try {
+                return JacksonUtil.toJsonNode(processedTemplate);
+            } catch (Exception e) {
+                throw new RuntimeException("Request body template produced invalid JSON: " + processedTemplate, e);
+            }
+        }
+        return getData(msg, config.isParseToPlainText());
+    }
+
     private Object getData(TbMsg tbMsg, boolean parseToPlainText) {
         String data = tbMsg.getData();
         return parseToPlainText ? JacksonUtil.toPlainText(data) : JacksonUtil.toJsonNode(data);
@@ -363,7 +382,7 @@ public class TbHttpClient {
         headers.forEach((key, values) -> {
             if (values != null && !values.isEmpty()) {
                 if (values.size() == 1) {
-                    consumer.accept(key, values.get(0));
+                    consumer.accept(key, values.getFirst());
                 } else {
                     consumer.accept(key, JacksonUtil.toString(values));
                 }

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/rest/TbRestApiCallNode.java

@@ -41,7 +41,9 @@ import static org.thingsboard.server.dao.service.ConstraintValidator.validateFie
         version = 4,
         nodeDescription = "Invoke REST API calls to external REST server",
         nodeDetails = "Will invoke REST API call <code>GET | POST | PUT | DELETE</code> to external REST server. " +
-                "Message payload added into Request body. Configured attributes can be added into Headers from Message Metadata." +
+                "Message payload is used as the request body by default. " +
+                "Optionally, a request body template can be configured with <code>${metadataKey}</code> and <code>$[messageKey]</code> placeholders. " +
+                "Configured attributes can be added into Headers from Message Metadata." +
                 " Outbound message will contain response fields " +
                 "(<code>status</code>, <code>statusCode</code>, <code>statusReason</code> and response <code>headers</code>) in the Message Metadata." +
                 " Response body saved in outbound Message payload. " +
@@ -56,6 +58,7 @@ public class TbRestApiCallNode extends TbAbstractExternalNode {
 
     static final String PARSE_TO_PLAIN_TEXT = "parseToPlainText";
     static final String MAX_IN_MEMORY_BUFFER_SIZE_IN_KB = "maxInMemoryBufferSizeInKb";
+    static final String REQUEST_BODY_TEMPLATE = "requestBodyTemplate";
     static final String TRIM_DOUBLE_QUOTES = "trimDoubleQuotes";
     protected TbHttpClient httpClient;
 
@@ -110,12 +113,16 @@ public class TbRestApiCallNode extends TbAbstractExternalNode {
                     ((ObjectNode) oldConfiguration).put(MAX_IN_MEMORY_BUFFER_SIZE_IN_KB, 256);
                 }
             case 3:
+                if (!oldConfiguration.has(REQUEST_BODY_TEMPLATE)) {
+                    hasChanges = true;
+                    ((ObjectNode) oldConfiguration).putNull(REQUEST_BODY_TEMPLATE);
+                }
                 Set<String> knownProperties = Set.of(
                         "restEndpointUrlPattern", "requestMethod", "headers",
                         "readTimeoutMs", "maxParallelRequestsCount", "parseToPlainText",
                         "enableProxy", "useSystemProxyProperties", "proxyHost", "proxyPort",
                         "proxyUser", "proxyPassword", "credentials", "ignoreRequestBody",
-                        "maxInMemoryBufferSizeInKb"
+                        "requestBodyTemplate", "maxInMemoryBufferSizeInKb"
                 );
                 Iterator<String> fieldNames = oldConfiguration.fieldNames();
                 while (fieldNames.hasNext()) {

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/rest/TbRestApiCallNodeConfiguration.java

@@ -51,6 +51,7 @@ public class TbRestApiCallNodeConfiguration implements NodeConfiguration<TbRestA
     private String proxyPassword;
     private ClientCredentials credentials;
     private boolean ignoreRequestBody;
+    private String requestBodyTemplate;
     private int maxInMemoryBufferSizeInKb;
 
     @JsonIgnore

rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/rest/TbHttpClientTest.java

@@ -569,8 +569,8 @@ public class TbHttpClientTest {
         Map<String, String> data = metaData.getData();
 
         Assertions.assertEquals(2, data.size());
-        Assertions.assertEquals(data.get("Content-Type"), "binary");
+        Assertions.assertEquals("binary", data.get("Content-Type"));
-        Assertions.assertEquals(data.get("Set-Cookie"), "[\"sap-context=sap-client=075; path=/\",\"sap-token=sap-client=075; path=/\"]");
+        Assertions.assertEquals("[\"sap-context=sap-client=075; path=/\",\"sap-token=sap-client=075; path=/\"]", data.get("Set-Cookie"));
     }
 
 }

rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/rest/TbRestApiCallNodeTest.java

@@ -16,13 +16,9 @@
 package org.thingsboard.rule.engine.rest;
 
 import com.datastax.oss.driver.api.core.uuid.Uuids;
-import org.apache.http.HttpException;
-import org.apache.http.HttpRequest;
-import org.apache.http.HttpResponse;
 import org.apache.http.config.SocketConfig;
 import org.apache.http.impl.bootstrap.HttpServer;
 import org.apache.http.impl.bootstrap.ServerBootstrap;
-import org.apache.http.protocol.HttpContext;
 import org.apache.http.protocol.HttpRequestHandler;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -52,11 +48,14 @@ import org.thingsboard.server.common.msg.TbMsgMetaData;
 import org.thingsboard.server.exception.DataValidationException;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Stream;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
@@ -71,19 +70,17 @@ import static org.mockito.Mockito.verify;
 @ExtendWith(MockitoExtension.class)
 public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
 
-    private RuleNode ruleNode;
-
     @Spy
     private TbRestApiCallNode restNode;
 
     @Mock
     private TbContext ctx;
 
-    private EntityId originator = new DeviceId(Uuids.timeBased());
+    private final EntityId originator = new DeviceId(Uuids.timeBased());
-    private TbMsgMetaData metaData = new TbMsgMetaData();
+    private final TbMsgMetaData metaData = new TbMsgMetaData();
 
-    private RuleChainId ruleChainId = new RuleChainId(Uuids.timeBased());
+    private final RuleChainId ruleChainId = new RuleChainId(Uuids.timeBased());
-    private RuleNodeId ruleNodeId = new RuleNodeId(Uuids.timeBased());
+    private final RuleNodeId ruleNodeId = new RuleNodeId(Uuids.timeBased());
 
     private HttpServer server;
 
@@ -108,7 +105,7 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
 
     @BeforeEach
     public void setup() {
-        ruleNode = new RuleNode();
+        RuleNode ruleNode = new RuleNode();
         ruleNode.setId(ruleNodeId);
         ruleNode.setName("Test REST API call node");
         lenient().when(ctx.getSelf()).thenReturn(ruleNode);
@@ -217,22 +214,17 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
     public void deleteRequestWithoutBody() throws IOException, InterruptedException {
         final CountDownLatch latch = new CountDownLatch(1);
         final String path = "/path/to/delete";
-        setupServer("*", new HttpRequestHandler() {
+        setupServer("*", (request, response, _) -> {
-
+            try {
-            @Override
+                assertEquals(path, request.getRequestLine().getUri(), "Request path matches");
-            public void handle(HttpRequest request, HttpResponse response, HttpContext context)
+                assertTrue(request.containsHeader("Foo"), "Custom header included");
-                    throws HttpException, IOException {
+                assertEquals("Bar", request.getFirstHeader("Foo").getValue(), "Custom header value");
-                try {
+                response.setStatusCode(200);
-                    assertEquals(request.getRequestLine().getUri(), path, "Request path matches");
+                latch.countDown();
-                    assertTrue(request.containsHeader("Foo"), "Custom header included");
+            } catch (Exception e) {
-                    assertEquals("Bar", request.getFirstHeader("Foo").getValue(), "Custom header value");
+                System.out.println("Exception handling request: " + e);
-                    response.setStatusCode(200);
+                e.printStackTrace();
-                    latch.countDown();
+                latch.countDown();
-                } catch (Exception e) {
-                    System.out.println("Exception handling request: " + e.toString());
-                    e.printStackTrace();
-                    latch.countDown();
-                }
             }
         });
 
@@ -269,28 +261,23 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
     public void deleteRequestWithBody() throws IOException, InterruptedException {
         final CountDownLatch latch = new CountDownLatch(1);
         final String path = "/path/to/delete";
-        setupServer("*", new HttpRequestHandler() {
+        setupServer("*", (request, response, _) -> {
-
+            try {
-            @Override
+                assertEquals(path, request.getRequestLine().getUri(), "Request path matches");
-            public void handle(HttpRequest request, HttpResponse response, HttpContext context)
+                assertTrue(request.containsHeader("Content-Type"), "Content-Type included");
-                    throws HttpException, IOException {
+                assertEquals("application/json",
-                try {
+                        request.getFirstHeader("Content-Type").getValue(), "Content-Type value");
-                    assertEquals(path, request.getRequestLine().getUri(), "Request path matches");
+                assertTrue(request.containsHeader("Content-Length"), "Content-Length included");
-                    assertTrue(request.containsHeader("Content-Type"), "Content-Type included");
+                assertEquals("2",
-                    assertEquals("application/json",
+                        request.getFirstHeader("Content-Length").getValue(), "Content-Length value");
-                            request.getFirstHeader("Content-Type").getValue(), "Content-Type value");
+                assertTrue(request.containsHeader("Foo"), "Custom header included");
-                    assertTrue(request.containsHeader("Content-Length"), "Content-Length included");
+                assertEquals("Bar", request.getFirstHeader("Foo").getValue(), "Custom header value");
-                    assertEquals("2",
+                response.setStatusCode(200);
-                            request.getFirstHeader("Content-Length").getValue(), "Content-Length value");
+                latch.countDown();
-                    assertTrue(request.containsHeader("Foo"), "Custom header included");
+            } catch (Exception e) {
-                    assertEquals("Bar", request.getFirstHeader("Foo").getValue(), "Custom header value");
+                System.out.println("Exception handling request: " + e);
-                    response.setStatusCode(200);
+                e.printStackTrace();
-                    latch.countDown();
+                latch.countDown();
-                } catch (Exception e) {
-                    System.out.println("Exception handling request: " + e.toString());
-                    e.printStackTrace();
-                    latch.countDown();
-                }
             }
         });
 
@@ -323,6 +310,143 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
         assertEquals(TbMsg.EMPTY_JSON_OBJECT, dataCaptor.getValue());
     }
 
+    @Test
+    public void postRequestWithBodyTemplate() throws IOException, InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final String path = "/api/token";
+        final AtomicReference<String> capturedBody = new AtomicReference<>();
+        setupServerWithBodyCapture(capturedBody, latch);
+
+        TbRestApiCallNodeConfiguration config = new TbRestApiCallNodeConfiguration().defaultConfiguration();
+        config.setRequestMethod("POST");
+        config.setRequestBodyTemplate("{\"grant_type\":\"client_credentials\",\"client_id\":\"${clientId}\",\"value\":\"$[token]\"}");
+        config.setRestEndpointUrlPattern(String.format("http://localhost:%d%s", server.getLocalPort(), path));
+        initWithConfig(config);
+
+        metaData.putValue("clientId", "my-client-123");
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(originator)
+                .copyMetaData(metaData)
+                .dataType(TbMsgDataType.JSON)
+                .data("{\"token\":\"abc-xyz\"}")
+                .ruleChainId(ruleChainId)
+                .ruleNodeId(ruleNodeId)
+                .build();
+        restNode.onMsg(ctx, msg);
+
+        assertTrue(latch.await(10, TimeUnit.SECONDS), "Server handled request");
+        assertEquals("{\"grant_type\":\"client_credentials\",\"client_id\":\"my-client-123\",\"value\":\"abc-xyz\"}", capturedBody.get());
+    }
+
+    @Test
+    public void postRequestWithBodyTemplateAndParseToPlainText() throws IOException, InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final String path = "/api/text";
+        final AtomicReference<String> capturedBody = new AtomicReference<>();
+        setupServerWithBodyCapture(capturedBody, latch);
+
+        TbRestApiCallNodeConfiguration config = new TbRestApiCallNodeConfiguration().defaultConfiguration();
+        config.setRequestMethod("POST");
+        config.setParseToPlainText(true);
+        config.setRequestBodyTemplate("Hello ${name}, your token is $[token]!");
+        config.setRestEndpointUrlPattern(String.format("http://localhost:%d%s", server.getLocalPort(), path));
+        initWithConfig(config);
+
+        metaData.putValue("name", "World");
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(originator)
+                .copyMetaData(metaData)
+                .dataType(TbMsgDataType.JSON)
+                .data("{\"token\":\"abc-xyz\"}")
+                .ruleChainId(ruleChainId)
+                .ruleNodeId(ruleNodeId)
+                .build();
+        restNode.onMsg(ctx, msg);
+
+        assertTrue(latch.await(10, TimeUnit.SECONDS), "Server handled request");
+        assertEquals("Hello World, your token is abc-xyz!", capturedBody.get());
+    }
+
+    @Test
+    public void postRequestWithBodyTemplateEscapesJsonSpecialChars() throws IOException, InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final String path = "/api/token";
+        final AtomicReference<String> capturedBody = new AtomicReference<>();
+        setupServerWithBodyCapture(capturedBody, latch);
+
+        TbRestApiCallNodeConfiguration config = new TbRestApiCallNodeConfiguration().defaultConfiguration();
+        config.setRequestMethod("POST");
+        config.setRequestBodyTemplate("{\"name\":\"${userName}\",\"desc\":\"$[description]\"}");
+        config.setRestEndpointUrlPattern(String.format("http://localhost:%d%s", server.getLocalPort(), path));
+        initWithConfig(config);
+
+        metaData.putValue("userName", "John \"Doe\"");
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(originator)
+                .copyMetaData(metaData)
+                .dataType(TbMsgDataType.JSON)
+                .data("{\"description\":\"line1\\nline2\"}")
+                .ruleChainId(ruleChainId)
+                .ruleNodeId(ruleNodeId)
+                .build();
+        restNode.onMsg(ctx, msg);
+
+        assertTrue(latch.await(10, TimeUnit.SECONDS), "Server handled request");
+        assertEquals("{\"name\":\"John \\\"Doe\\\"\",\"desc\":\"line1\\nline2\"}", capturedBody.get());
+    }
+
+    @Test
+    public void postRequestWithEmptyBodyTemplateUsesMessageData() throws IOException, InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(1);
+        final String path = "/api/data";
+        final AtomicReference<String> capturedBody = new AtomicReference<>();
+        setupServerWithBodyCapture(capturedBody, latch);
+
+        TbRestApiCallNodeConfiguration config = new TbRestApiCallNodeConfiguration().defaultConfiguration();
+        config.setRequestMethod("POST");
+        // requestBodyTemplate is null by default — should use msg.getData()
+        config.setRestEndpointUrlPattern(String.format("http://localhost:%d%s", server.getLocalPort(), path));
+        initWithConfig(config);
+
+        TbMsg msg = TbMsg.newMsg()
+                .type(TbMsgType.POST_TELEMETRY_REQUEST)
+                .originator(originator)
+                .copyMetaData(metaData)
+                .dataType(TbMsgDataType.JSON)
+                .data("{\"temperature\":25}")
+                .ruleChainId(ruleChainId)
+                .ruleNodeId(ruleNodeId)
+                .build();
+        restNode.onMsg(ctx, msg);
+
+        assertTrue(latch.await(10, TimeUnit.SECONDS), "Server handled request");
+
+        ArgumentCaptor<TbMsg> msgCaptor = ArgumentCaptor.forClass(TbMsg.class);
+        ArgumentCaptor<TbMsgMetaData> metadataCaptor = ArgumentCaptor.forClass(TbMsgMetaData.class);
+        ArgumentCaptor<String> dataCaptor = ArgumentCaptor.forClass(String.class);
+        verify(ctx, timeout(10_000)).transformMsg(msgCaptor.capture(), metadataCaptor.capture(), dataCaptor.capture());
+        assertEquals("{\"temperature\":25}", capturedBody.get());
+    }
+
+    private void setupServerWithBodyCapture(AtomicReference<String> capturedBody, CountDownLatch latch) throws IOException {
+        setupServer("*", (request, response, _) -> {
+            try {
+                if (request instanceof org.apache.http.HttpEntityEnclosingRequest entityRequest) {
+                    InputStream is = entityRequest.getEntity().getContent();
+                    capturedBody.set(new String(is.readAllBytes(), StandardCharsets.UTF_8));
+                }
+                response.setStatusCode(200);
+                latch.countDown();
+            } catch (Exception e) {
+                e.printStackTrace();
+                latch.countDown();
+            }
+        });
+    }
+
     private static Stream<Arguments> givenFromVersionAndConfig_whenUpgrade_thenVerifyHasChangesAndConfig() {
         return Stream.of(
                 Arguments.of(0,
@@ -339,7 +463,7 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
                                 "\"proxyPort\": 0,\"proxyUser\": null,\"proxyPassword\": null,\"readTimeoutMs\": 0," +
                                 "\"maxParallelRequestsCount\": 0,\"headers\": {\"Content-Type\": \"application/json\"}," +
                                 "\"credentials\": {\"type\": \"anonymous\"}," +
-                                "\"maxInMemoryBufferSizeInKb\": 256}"),
+                                "\"maxInMemoryBufferSizeInKb\": 256,\"requestBodyTemplate\": null}"),
                 Arguments.of(1,
                         "{\"restEndpointUrlPattern\":\"http://localhost/api\",\"requestMethod\": \"POST\"," +
                                 "\"useSimpleClientHttpFactory\": false,\"parseToPlainText\": false,\"ignoreRequestBody\": false," +
@@ -355,7 +479,7 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
                                 "\"proxyPort\": 0,\"proxyUser\": null,\"proxyPassword\": null,\"readTimeoutMs\": 0," +
                                 "\"maxParallelRequestsCount\": 0,\"headers\": {\"Content-Type\": \"application/json\"}," +
                                 "\"credentials\": {\"type\": \"anonymous\"}," +
-                                "\"maxInMemoryBufferSizeInKb\": 256}"),
+                                "\"maxInMemoryBufferSizeInKb\": 256,\"requestBodyTemplate\": null}"),
                 Arguments.of(2,
                         "{\"restEndpointUrlPattern\":\"http://localhost/api\",\"requestMethod\": \"POST\"," +
                                 "\"useSimpleClientHttpFactory\": false,\"parseToPlainText\": false,\"ignoreRequestBody\": false," +
@@ -370,7 +494,7 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
                                 "\"proxyPort\": 0,\"proxyUser\": null,\"proxyPassword\": null,\"readTimeoutMs\": 0," +
                                 "\"maxParallelRequestsCount\": 0,\"headers\": {\"Content-Type\": \"application/json\"}," +
                                 "\"credentials\": {\"type\": \"anonymous\"}," +
-                                "\"maxInMemoryBufferSizeInKb\": 256}"),
+                                "\"maxInMemoryBufferSizeInKb\": 256,\"requestBodyTemplate\": null}"),
                 Arguments.of(3, """
                                 {
                                     "restEndpointUrlPattern": "http://localhost/api",
@@ -419,6 +543,7 @@ public class TbRestApiCallNodeTest extends AbstractRuleNodeUpgradeTest {
                                     "credentials": {
                                         "type": "anonymous"
                                     },
+                                    "requestBodyTemplate": null,
                                     "maxInMemoryBufferSizeInKb": 256
                                 }""")
         );

rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/rest/TbSendRestApiCallReplyNodeTest.java

@@ -51,7 +51,7 @@ public class TbSendRestApiCallReplyNodeTest {
 
     private TbSendRestApiCallReplyNode node;
     private TbSendRestApiCallReplyNodeConfiguration config;
-    
+
     @Mock
     private TbContext ctxMock;
     @Mock
@@ -140,4 +140,5 @@ public class TbSendRestApiCallReplyNodeTest {
                         TbMsg.EMPTY_STRING, "Request body is empty!")
         );
     }
+
 }

ui-ngx/src/app/modules/home/components/rule-node/external/rest-api-call-config.component.html

@@ -138,10 +138,21 @@
             </div>
           </mat-slide-toggle>
         </div>
-        <div class="tb-form-row">
+        <div class="tb-form-panel stroked column">
           <mat-slide-toggle class="mat-slide fixed-title-width" formControlName="ignoreRequestBody">
             {{ 'rule-node-config.ignore-request-body' | translate }}
           </mat-slide-toggle>
+          @if(!restApiCallConfigForm.get('ignoreRequestBody').value) {
+            <div class="tb-form-hint tb-primary-fill mb-4" [innerHTML]="'rule-node-config.request-body-template-hint' | translate | safe: 'html'"></div>
+            <mat-form-field class="mat-block" subscriptSizing="dynamic" appearance="outline" floatLabel="always">
+              <mat-label translate>rule-node-config.request-body-template</mat-label>
+              <textarea matInput
+                        formControlName="requestBodyTemplate"
+                        class="tb-enable-vertical-resize"
+                        cdkTextareaAutosize
+                        cdkAutosizeMinRows="3"></textarea>
+            </mat-form-field>
+          }
         </div>
         <mat-form-field class="mat-block" subscriptSizing="dynamic" appearance="outline">
           <mat-label translate>rule-node-config.read-timeout</mat-label>

ui-ngx/src/app/modules/home/components/rule-node/external/rest-api-call-config.component.scss

@@ -26,4 +26,7 @@
       }
     }
   }
+  textarea.tb-enable-vertical-resize {
+    resize: vertical;
+  }
 }

ui-ngx/src/app/modules/home/components/rule-node/external/rest-api-call-config.component.ts

@@ -51,6 +51,7 @@ export class RestApiCallConfigComponent extends RuleNodeConfigurationComponent {
       requestMethod: [configuration ? configuration.requestMethod : null, [Validators.required]],
       parseToPlainText: [configuration ? configuration.parseToPlainText : false, []],
       ignoreRequestBody: [configuration ? configuration.ignoreRequestBody : false, []],
+      requestBodyTemplate: [configuration ? configuration.requestBodyTemplate : null, []],
       enableProxy: [configuration ? configuration.enableProxy : false, []],
       useSystemProxyProperties: [configuration ? configuration.enableProxy : false, []],
       proxyHost: [configuration ? configuration.proxyHost : null, []],

ui-ngx/src/assets/locale/locale.constant-en_US.json

@@ -5521,8 +5521,10 @@
         "endpoint-url-pattern-required": "Endpoint URL pattern is required",
         "request-method": "Request method",
         "ignore-request-body": "Without request body",
+        "request-body-template": "Request body template",
+        "request-body-template-hint": "Use <code><span style=\"color: #000;\">$&#123;</span>metadataKey<span style=\"color: #000;\">&#125;</span></code> for metadata, <code><span style=\"color: #000;\">$[</span>messageKey<span style=\"color: #000;\">]</span></code> for message values. If empty, the message payload is used as the request body. For non-JSON payloads, enable 'Parse to plain text'.",
         "parse-to-plain-text": "Parse to plain text",
-        "parse-to-plain-text-hint": "If selected, request body message payload will be transformed from JSON string to plain text, e.g. msg = \"Hello,\\t\"world\"\" will be parsed to Hello, \"world\"",
+        "parse-to-plain-text-hint": "If selected, the request body (message payload or body template result) will be sent as a plain text string instead of being parsed as JSON, e.g. msg = \"Hello,\\t\"world\"\" will be parsed to Hello, \"world\"",
         "read-timeout": "Read timeout in millis",
         "read-timeout-hint": "The value of 0 means an infinite timeout",
         "max-parallel-requests-count": "Max number of parallel requests",