Empty variable is defaulted to empty string. Errors during variable r…

…eplacement can fail the decide process and leave the workflow in a RUNNING state indefinitely
shubham-prasad · Oct 5, 2021 · 49f8882 · 49f8882
1 parent 6d6ab5b
commit 49f8882
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/core/src/main/java/com/netflix/conductor/core/utils/ParametersUtils.java b/core/src/main/java/com/netflix/conductor/core/utils/ParametersUtils.java
@@ -25,6 +25,7 @@
 import com.netflix.conductor.common.run.Workflow;
 import com.netflix.conductor.common.utils.EnvUtils;
 import com.netflix.conductor.common.utils.TaskUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;
@@ -203,12 +204,18 @@ private Object replaceList(List<?> values, String taskId, DocumentContext io) {
     }
 
     private Object replaceVariables(String paramString, DocumentContext documentContext, String taskId) {
-        String[] values = paramString.split("(?=(?<!\\$)\\$\\{)|(?<=\\})");
+        String[] values = paramString.split("(?=(?<!\\$)\\$\\{)|(?<=})");
         Object[] convertedValues = new Object[values.length];
         for (int i = 0; i < values.length; i++) {
             convertedValues[i] = values[i];
             if (values[i].startsWith("${") && values[i].endsWith("}")) {
                 String paramPath = values[i].substring(2, values[i].length() - 1);
+                // if the paramPath is blank, meaning no value in between ${ and }
+                // like ${}, ${  } etc, set the value to empty string
+                if(StringUtils.isBlank(paramPath)) {
+                    convertedValues[i] = "";
+                    continue;
+                }
                 if (EnvUtils.isEnvironmentVariable(paramPath)) {
                     String sysValue = EnvUtils.getSystemParametersValue(paramPath, taskId);
                     if (sysValue != null) {

diff --git a/core/src/test/java/com/netflix/conductor/core/utils/ParametersUtilsTest.java b/core/src/test/java/com/netflix/conductor/core/utils/ParametersUtilsTest.java
@@ -175,6 +175,8 @@ public void testReplaceInputWithMapAndList() throws Exception {
         input.put("k1", "${$.externalId}");
         input.put("k2", "${name}");
         input.put("k3", "${version}");
+        input.put("k4", "${}");
+        input.put("k5", "${    }");
 
         Map<String, String> mapValue = new HashMap<>();
         mapValue.put("name", "${name}");
@@ -195,6 +197,8 @@ public void testReplaceInputWithMapAndList() throws Exception {
         assertEquals("{\"taskRefName\":\"t001\",\"workflowId\":\"w002\"}", replaced.get("k1"));
         assertEquals("conductor", replaced.get("k2"));
         assertEquals(2, replaced.get("k3"));
+        assertEquals("", replaced.get("k4"));
+        assertEquals("", replaced.get("k5"));
 
         Map replacedMap = (Map) replaced.get("map");
         assertEquals("conductor", replacedMap.get("name"));