Use workflow template for workflow model_dir (deepjavalibrary#1612)

serving/docs/workflow_templates.md

@@ -31,8 +31,8 @@ Example:
 To add a new template, begin by creating the template JSON file.
 This mostly matches the standard format of a [workflow](workflows.md).
 However, your template can indicate variable sections of the template to be replaced.
-This is done by prefixing the name to replace with a `$`.
-So, a parameter `param` would replace the value `$param` within the template.
+This is done by surrounding the name with curly braces.
+So, a parameter `param` would replace the value `{param}` within the template.
 This replacement is directly in place, so if your parameter is a string you will still have to surround it with quotation marks.
 
 Then, you must register your new workflow template.

serving/src/main/java/ai/djl/serving/workflow/WorkflowDefinition.java

@@ -102,12 +102,19 @@ public static WorkflowDefinition parse(Path path) throws IOException {
      * @throws IOException if read from uri failed
      */
     public static WorkflowDefinition parse(String name, URI uri) throws IOException {
-        return parse(name, uri, null);
+        return parse(name, uri, new ConcurrentHashMap<>());
     }
 
     static WorkflowDefinition parse(String name, URI uri, Map<String, String> templateReplacements)
             throws IOException {
         String type = FilenameUtils.getFileExtension(Objects.requireNonNull(uri.toString()));
+
+        // Default model_dir template replacement
+        if (templateReplacements == null) {
+            templateReplacements = new ConcurrentHashMap<>();
+        }
+        templateReplacements.put("model_dir", getWorkflowDir(uri.toString()));
+
         try (InputStream is = uri.toURL().openStream();
                 Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
             WorkflowDefinition wd = parse(type, reader, templateReplacements);
@@ -133,7 +140,7 @@ private static WorkflowDefinition parse(
                                                 templateReplacements.entrySet()) {
                                             l =
                                                     l.replace(
-                                                            "$" + replacement.getKey(),
+                                                            "{" + replacement.getKey() + "}",
                                                             replacement.getValue());
                                         }
                                         return l;
@@ -221,14 +228,12 @@ public static URI toWorkflowUri(String link) {
      * @throws BadWorkflowException if the workflow could not be parsed successfully
      */
     public Workflow toWorkflow() throws BadWorkflowException {
-        int pos = baseUri.lastIndexOf('/');
-        String workflowDir = baseUri.substring(0, pos);
+        String workflowDir = getWorkflowDir(baseUri);
 
         if (models != null) {
             for (Entry<String, ModelInfo<Input, Output>> emd : models.entrySet()) {
                 ModelInfo<Input, Output> md = emd.getValue();
                 md.setId(emd.getKey());
-                md.postWorkflowParsing(workflowDir);
             }
         }
 
@@ -266,6 +271,11 @@ public Workflow toWorkflow() throws BadWorkflowException {
         return new Workflow(name, version, wpcs, expressions, configs, loadedFunctions);
     }
 
+    private static String getWorkflowDir(String uri) {
+        int pos = uri.lastIndexOf('/');
+        return uri.substring(0, pos);
+    }
+
     private static final class ModelDefinitionDeserializer
             implements JsonDeserializer<ModelInfo<Input, Output>> {
 

serving/src/main/resources/workflowTemplates/adapter.json

@@ -1,18 +1,18 @@
 {
-  "name": "$adapter",
+  "name": "{adapter}",
   "version": "0.1",
   "models": {
-    "m": "$model"
+    "m": "{model}"
   },
   "configs": {
     "adapters": {
-      "$adapter": {
+      "{adapter}": {
         "model": "m",
-        "src": "$url"
+        "src": "{url}"
       }
     }
   },
   "workflow": {
-    "out": ["adapter", "$adapter", "in"]
+    "out": ["adapter", "{adapter}", "in"]
   }
 }

wlm/src/main/java/ai/djl/serving/wlm/ModelInfo.java

@@ -40,8 +40,6 @@
 import ai.djl.util.Utils;
 import ai.djl.util.cuda.CudaUtils;
 
-import com.google.gson.JsonParseException;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -194,18 +192,6 @@ public ModelInfo(
         dimension = new Dimension("Model", id);
     }
 
-    /**
-     * Performs post workflow parsing initialization.
-     *
-     * @param workflowDir the workflow parent directory
-     */
-    public void postWorkflowParsing(String workflowDir) {
-        if (modelUrl == null) {
-            throw new JsonParseException("modelUrl is required in workflow definition.");
-        }
-        modelUrl = modelUrl.replaceAll("\\{model_dir}", workflowDir);
-    }
-
     /**
      * Returns the properties of the model.
      *