Pushing template engine prototype as-is, so work can be picked up in …

…other time zones.

aspire4j/aspire4j-extensions-azure-storage/src/main/java/com/microsoft/aspire/extensions/azure/storage/resources/AzureStorageResource.java

@@ -5,26 +5,22 @@
 import com.microsoft.aspire.resources.properties.EndpointReference;
 import com.microsoft.aspire.DistributedApplicationHelper;
 import com.microsoft.aspire.resources.traits.ResourceWithEndpoints;
+import com.microsoft.aspire.utils.templates.TemplateEngine;
 
-import java.io.IOException;
-import java.io.InputStream;
+import java.nio.file.Path;
 import java.util.List;
+import java.util.Map;
 
 public class AzureStorageResource extends AzureBicepResource<AzureStorageResource>
                                   implements ResourceWithEndpoints<AzureStorageResource> {
     private static final ResourceType AZURE_STORAGE = ResourceType.fromString("azure.storage.v0");
 
-    private static final String BICEP_TEMPLATE_FILE = "templates/bicep/storage.module.bicep";
-    private static final String BICEP_OUTPUT_FILE = "%s.module.bicep";
-
-    private final String bicepOutputFilename;
-
     public AzureStorageResource(String name) {
         super(AZURE_STORAGE, name);
 
         // This is the path to the output bicep file
-        bicepOutputFilename = String.format(BICEP_OUTPUT_FILE, name);
-        withPath(bicepOutputFilename);
+//        bicepOutputFilename = String.format(BICEP_OUTPUT_FILE, name);
+//        withPath(bicepOutputFilename);
 
         // FIXME just here because I saw other samples with it
 //        withParameter("principalId", "");
@@ -43,20 +39,18 @@ public List<EndpointReference> getEndpoints() {
     }
 
     @Override
-    public List<TemplateFileOutput> processTemplate() {
-        // read the file from our local resources directory
-        InputStream resourceAsStream = AzureStorageResource.class.getResourceAsStream(BICEP_TEMPLATE_FILE);
-        if (resourceAsStream == null) {
-            throw new RuntimeException("Resource file not found: " + BICEP_TEMPLATE_FILE);
-        }
-        try {
-            String bicepTemplate = new String(resourceAsStream.readAllBytes());
-
-            // If necessary, modify template variables
-
-            return List.of(new TemplateFileOutput(bicepOutputFilename, bicepTemplate));
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+    public List<TemplateFileOutput> processTemplate(Path outputPath) {
+        List<TemplateDescriptor> templateFiles = List.of(
+            new TemplateDescriptor("/templates/bicep/storage.module.bicep", "${name}.module.bicep")
+        );
+
+        List<TemplateFileOutput> templateOutput = TemplateEngine.process(AzureStorageResource.class, templateFiles, Map.of(
+            "name", getName()
+        ));
+
+        // we know that we need to get the output filename from the first element, and set that as the path
+        withPath(outputPath.toString());
+
+        return templateOutput;
     }
 }

aspire4j/aspire4j-extensions-azure-storage/src/main/java/module-info.java

@@ -4,10 +4,13 @@
     requires transitive com.microsoft.aspire;
 
     exports com.microsoft.aspire.extensions.azure.storage;
+    exports com.microsoft.aspire.extensions.azure.storage.resources;
 
     opens com.microsoft.aspire.extensions.azure.storage to org.hibernate.validator, com.fasterxml.jackson.databind;
-    exports com.microsoft.aspire.extensions.azure.storage.resources;
     opens com.microsoft.aspire.extensions.azure.storage.resources to com.fasterxml.jackson.databind, org.hibernate.validator;
 
+    // We conditionally open up the template files to the apphost, so it can write them out
+    opens templates.bicep to com.microsoft.aspire;
+
     provides com.microsoft.aspire.Extension with AzureStorageExtension;
 }

aspire4j/aspire4j-extensions-azure-storage/src/main/resources/templates/bicep/storage.module.bicep

@@ -11,7 +11,7 @@ param principalType string
 
 
 resource storageAccount_1XR3Um8QY 'Microsoft.Storage/storageAccounts@2022-09-01' = {
-  name: toLower(take('storage${uniqueString(resourceGroup().id)}', 24))
+  name: toLower(take('storage${r"${uniqueString(resourceGroup().id)"}}', 24))
   location: location
   tags: {
     'aspire-resource-name': 'storage'

aspire4j/aspire4j-extensions-spring/src/main/java/com/microsoft/aspire/extensions/spring/resources/EurekaServiceDiscovery.java

@@ -1,27 +1,57 @@
 package com.microsoft.aspire.extensions.spring.resources;
 
 import com.microsoft.aspire.resources.DockerFile;
-import com.microsoft.aspire.resources.ResourceType;
 import com.microsoft.aspire.resources.traits.ResourceWithTemplate;
+import com.microsoft.aspire.utils.templates.TemplateEngine;
 
+import java.nio.file.Path;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
-public class EurekaServiceDiscovery extends DockerFile<EurekaServiceDiscovery>
-                                    implements ResourceWithTemplate<EurekaServiceDiscovery> {
+public final class EurekaServiceDiscovery extends DockerFile<EurekaServiceDiscovery>
+                                          implements ResourceWithTemplate<EurekaServiceDiscovery> {
+
+    private final String PROPERTY_NAME = "name";
+    private final String PROPERTY_PORT = "port";
+    private final String PROPERTY_REGISTER_WITH_EUREKA = "registerWithEureka";
+    private final String PROPERTY_FETCH_REGISTRY = "fetchRegistry";
+
+    private final Map<String, Object> properties;
 
     public EurekaServiceDiscovery(String name) {
-        super(ResourceType.fromString("spring.eureka.server.v0"), name);
+        super(name);
+
+        this.properties = new HashMap<>();
+        this.properties.put(PROPERTY_NAME, name);
+        this.properties.put(PROPERTY_PORT, 8761);
+        this.properties.put(PROPERTY_REGISTER_WITH_EUREKA, false);
+        this.properties.put(PROPERTY_FETCH_REGISTRY, false);
+    }
 
-        // TODO
-        // We have a template for the eureka server, consisting of a minimal Spring Boot application, as well as
-        // pom.xml, configuration file, and a Dockerfile to build the image. We need to allow for the template properties
-        // to be set by the user, such as the port, the name of the service, etc, and then we need to write these out
-        // to a temporary location, and then build the image from that location.
+    public EurekaServiceDiscovery withPort(int port) {
+        this.properties.put(PROPERTY_PORT, port);
+        return this;
     }
 
     @Override
-    public List<TemplateFileOutput> processTemplate() {
-        return List.of();
+    public List<TemplateFileOutput> processTemplate(Path outputPath) {
+        final String inPrefix = "/templates/eureka/";
+        final String outPrefix = "eureka/";
+        List<TemplateDescriptor> templateFiles = List.of(
+            new TemplateDescriptor(inPrefix+"pom.xml", outPrefix+"pom.xml"),
+            new TemplateDescriptor(inPrefix+"Dockerfile", outPrefix+"Dockerfile"),
+            new TemplateDescriptor(inPrefix+"EurekaServerApplication.java", outPrefix+"src/main/java/com/microsoft/aspire/spring/eureka/EurekaServerApplication.java"),
+            new TemplateDescriptor(inPrefix+"application.yaml", outPrefix+"src/main/resources/application.yaml")
+        );
+
+        List<TemplateFileOutput> templateOutput = TemplateEngine.process(EurekaServiceDiscovery.class, templateFiles, properties);
+
+        // TODO we know that we need to get the output filename from the first element, and set that as the path
+        withPath(outputPath.resolve(templateOutput.get(0).filename()).toString());
+        withContext(outputPath.resolve(templateOutput.get(0).filename()).getParent().toString());
+
+        return templateOutput;
     }
 
     @Override

aspire4j/aspire4j-extensions-spring/src/main/java/module-info.java

@@ -7,10 +7,12 @@
     requires java.logging;
 
     exports com.microsoft.aspire.extensions.spring;
-
-    opens com.microsoft.aspire.extensions.spring to org.hibernate.validator, com.fasterxml.jackson.databind;
     exports com.microsoft.aspire.extensions.spring.resources;
+    opens com.microsoft.aspire.extensions.spring to org.hibernate.validator, com.fasterxml.jackson.databind;
     opens com.microsoft.aspire.extensions.spring.resources to com.fasterxml.jackson.databind, org.hibernate.validator;
 
+    // We conditionally open up the template files to the apphost, so it can write them out
+    opens templates.eureka to com.microsoft.aspire;
+
     provides com.microsoft.aspire.Extension with SpringExtension;
 }

aspire4j/aspire4j-extensions-spring/src/main/resources/templates/eureka/application.yaml

@@ -0,0 +1,9 @@
+spring:
+  application:
+    name: ${name}
+server:
+  port: ${port?c}
+eureka:
+  client:
+    register-with-eureka: ${registerWithEureka?string("true", "false")}
+    fetch-registry: ${fetchRegistry?string("true", "false")}

aspire4j/aspire4j-extensions-spring/src/main/resources/templates/eureka/pom.xml

@@ -35,7 +35,7 @@
             <dependency>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-dependencies</artifactId>
-                <version>${spring-cloud.version}</version>
+                <version>${r"${spring-cloud.version}"}</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>

aspire4j/aspire4j/pom.xml

@@ -32,6 +32,18 @@
             <artifactId>expressly</artifactId>
             <version>5.0.0</version>
         </dependency>
+
+        <!-- Template engine -->
+<!--        <dependency>-->
+<!--            <groupId>org.apache.velocity</groupId>-->
+<!--            <artifactId>velocity-engine-core</artifactId>-->
+<!--            <version>2.3</version>-->
+<!--        </dependency>-->
+        <dependency>
+            <groupId>org.freemarker</groupId>
+            <artifactId>freemarker</artifactId>
+            <version>2.3.33</version>
+        </dependency>
     </dependencies>
 
     <build>

aspire4j/aspire4j/src/main/java/com/microsoft/aspire/ManifestGenerator.java

@@ -5,14 +5,11 @@
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.*;
-import java.util.List;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.microsoft.aspire.implementation.json.RelativePathSerializer;
-import com.microsoft.aspire.resources.AzureBicepResource;
-import com.microsoft.aspire.resources.Resource;
 import com.microsoft.aspire.resources.traits.ResourceWithTemplate;
 import jakarta.validation.ConstraintViolation;
 import jakarta.validation.Validation;
@@ -28,19 +25,24 @@ class ManifestGenerator {
     void generateManifest(AppHost appHost, Path outputPath) {
         this.outputPath = outputPath;
 
+        File outputDir = outputPath.toFile();
+        if (!outputDir.exists()) {
+            outputDir.mkdirs();
+        }
+
         DistributedApplication app = new DistributedApplication();
         appHost.configureApplication(app);
         app.performResourceIntrospection();
-        processTemplates(app);
+        processTemplates(app, outputPath);
         writeManifest(app);
     }
 
-    private void processTemplates(DistributedApplication app) {
+    private void processTemplates(DistributedApplication app, Path outputPath) {
         LOGGER.info("Processing templates...");
         app.manifest.getResources().values().stream()
             .filter(r -> r instanceof ResourceWithTemplate<?>)
             .map(r -> (ResourceWithTemplate<?>) r)
-            .map(ResourceWithTemplate::processTemplate)
+            .map(r -> r.processTemplate(outputPath))
             .forEach(templateFiles -> templateFiles.forEach(this::writeTemplateFile));
         LOGGER.info("Templates processed");
     }
@@ -70,11 +72,6 @@ private void writeManifest(DistributedApplication app) {
             LOGGER.info("Models validated...Writing manifest to file");
         }
 
-        File outputDir = outputPath.toFile();
-        if (!outputDir.exists()) {
-            outputDir.mkdirs();
-        }
-
         // Set the outputDir in the RelativePathSerializer
         RelativePathSerializer.setOutputPath(outputPath);
 
@@ -84,7 +81,7 @@ private void writeManifest(DistributedApplication app) {
 
         try {
             objectMapper.writerWithDefaultPrettyPrinter()
-                    .writeValue(new File(outputDir, "aspire-manifest.json"), app.manifest);
+                    .writeValue(new File(outputPath.toFile(), "aspire-manifest.json"), app.manifest);
         } catch (IOException e) {
             e.printStackTrace();
         }
@@ -93,29 +90,13 @@ private void writeManifest(DistributedApplication app) {
 
     private void writeTemplateFile(ResourceWithTemplate.TemplateFileOutput templateFile) {
         try {
-            Files.write(Paths.get(outputPath.toString() + "/" + templateFile.filename()), templateFile.content().getBytes());
+            Path path = Paths.get(outputPath.toString() + "/" + templateFile.filename());
+
+            // ensure the parent directories exist
+            Files.createDirectories(path.getParent());
+            Files.write(path, templateFile.content().getBytes());
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
-
-//    private void writeBicep(DistributedApplication app) {
-//        LOGGER.info("Writing Bicep files...");
-//
-//        // iterate through the resources in the app, and for any that are of type AzureBicep, give them the opportunity
-//        // to write their bicep file to the output directory.
-//        for (Resource resource : app.manifest.getResources().values()) {
-//            if (resource instanceof AzureBicepResource azureBicepResource) {
-//                List<ResourceWithTemplate.TemplateFileOutput> bicepFiles = azureBicepResource.getBicepFiles();
-//
-//                for (ResourceWithTemplate.TemplateFileOutput bicepFile : bicepFiles) {
-//                    try {
-//                        Files.write(Paths.get(outputPath.toString() + "/" + bicepFile.filename()), bicepFile.content().getBytes());
-//                    } catch (IOException e) {
-//                        e.printStackTrace();
-//                    }
-//                }
-//            }
-//        }
-//    }
 }

aspire4j/aspire4j/src/main/java/com/microsoft/aspire/resources/traits/ResourceWithTemplate.java

@@ -1,5 +1,6 @@
 package com.microsoft.aspire.resources.traits;
 
+import java.nio.file.Path;
 import java.util.List;
 
 /**
@@ -12,10 +13,12 @@
  */
 public interface ResourceWithTemplate<T extends ResourceWithTemplate<T>> {
 
-    List<TemplateFileOutput> processTemplate();
+    List<TemplateFileOutput> processTemplate(Path outputPath);
 
     T self();
 
+    record TemplateDescriptor(String inputFilename, String outputFilename) {   }
+
     // FIXME at some point string content won't be sufficient, and we will want to support binary content too
     record TemplateFileOutput(String filename, String content) {    }
 }

aspire4j/aspire4j/src/main/java/com/microsoft/aspire/utils/templates/FreeMarkerTemplateProcessor.java

@@ -0,0 +1,29 @@
+package com.microsoft.aspire.utils.templates;
+
+import freemarker.template.Configuration;
+import freemarker.template.Template;
+import freemarker.template.TemplateException;
+import freemarker.template.Version;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.util.Map;
+
+public class FreeMarkerTemplateProcessor implements TemplateEngine {
+
+    @Override
+    public String processTemplate(String templateContent, Map<String, Object> context) {
+        Configuration cfg = new Configuration(new Version("2.3.31"));
+        StringWriter out = new StringWriter();
+
+        try {
+            Template template = new Template("template", new StringReader(templateContent), cfg);
+            template.process(context, out);
+        } catch (IOException | TemplateException e) {
+            throw new RuntimeException(e);
+        }
+
+        return out.toString();
+    }
+}