feat(core): add a randomPort pebble function

core/src/main/java/io/kestra/core/runners/pebble/Extension.java

@@ -151,6 +151,7 @@ public Map<String, Function> getFunctions() {
             functions.put("errorLogs", errorLogsFunction);
         }
         functions.put("randomInt", new RandomIntFunction());
+        functions.put("randomPort", new RandomPortFunction());
         return functions;
     }
 

core/src/main/java/io/kestra/core/runners/pebble/functions/RandomPortFunction.java

@@ -0,0 +1,32 @@
+package io.kestra.core.runners.pebble.functions;
+
+import io.pebbletemplates.pebble.error.PebbleException;
+import io.pebbletemplates.pebble.extension.Function;
+import io.pebbletemplates.pebble.template.EvaluationContext;
+import io.pebbletemplates.pebble.template.PebbleTemplate;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.util.List;
+import java.util.Map;
+
+public class RandomPortFunction implements Function {
+  @Override
+  public Object execute(Map<String, Object> args, PebbleTemplate self, EvaluationContext context, int lineNumber) {
+      try (ServerSocket tempSocket = new ServerSocket(0)) {
+          return tempSocket.getLocalPort();
+      } catch (IOException e) {
+          throw new PebbleException(
+              e,
+              "Unable to get random port",
+              lineNumber,
+              self.getName()
+          );
+      }
+  }
+
+  @Override
+  public List<String> getArgumentNames() {
+    return List.of();
+  }
+}

core/src/test/java/io/kestra/core/runners/pebble/functions/RandomPortFunctionTest.java

@@ -0,0 +1,23 @@
+package io.kestra.core.runners.pebble.functions;
+
+import io.kestra.core.exceptions.IllegalVariableEvaluationException;
+import io.kestra.core.junit.annotations.KestraTest;
+import io.kestra.core.runners.VariableRenderer;
+import jakarta.inject.Inject;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+
+@KestraTest
+class RandomPortFunctionTest {
+    @Inject VariableRenderer variableRenderer;
+
+    @Test
+    void checkIsDefined() throws IllegalVariableEvaluationException {
+        String rendered = variableRenderer.render("{{ randomPort() }}", Collections.emptyMap());
+        assertThat(Integer.parseInt(rendered), greaterThanOrEqualTo(0));
+    }
+}