refactor: the way of plugin initialize load (#2242)

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#### What type of PR is this?
/kind improvement
/area core
/milestone 2.0
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#### What this PR does / why we need it:
1. 优化插件初始化加载方式及 Plugin 自定义模型资源的更新
2. 插件 plugin.yaml 中 license 配置不再支持只配置字符串，而使用如下替代
```yaml
license:
  - name: "MIT"
```
3. 可以在 application.yaml 中配置
```yaml
halo:
  initial-extension-locations:
    - "path/to/extensions/yaml"
```
用于在系统启动时创建或更新自定义模型数据
#### Which issue(s) this PR fixes:

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Fixes #

#### Special notes for your reviewer:
/cc @halo-dev/sig-halo 
#### Does this PR introduce a user-facing change?

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```release-note
None
```

src/main/java/run/halo/app/core/extension/Plugin.java

@@ -1,17 +1,19 @@
 package run.halo.app.core.extension;
 
-import com.fasterxml.jackson.annotation.JsonFormat;
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import io.swagger.v3.oas.annotations.media.Schema;
 import java.time.Instant;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
 import org.pf4j.PluginState;
+import org.springframework.lang.NonNull;
 import run.halo.app.extension.AbstractExtension;
 import run.halo.app.extension.GVK;
 import run.halo.app.plugin.BasePlugin;
@@ -34,6 +36,20 @@ public class Plugin extends AbstractExtension {
 
     private PluginStatus status;
 
+    /**
+     * Gets plugin status.
+     *
+     * @return empty object if status is null.
+     */
+    @NonNull
+    @JsonIgnore
+    public PluginStatus statusNonNull() {
+        if (this.status == null) {
+            return new PluginStatus();
+        }
+        return status;
+    }
+
     @Data
     public static class PluginSpec {
 
@@ -51,7 +67,6 @@ public class Plugin extends AbstractExtension {
 
         private String description;
 
-        @JsonFormat(with = JsonFormat.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY)
         private List<License> license;
 
         /**
@@ -68,6 +83,12 @@ public class Plugin extends AbstractExtension {
         private String settingName;
 
         private String configMapName;
+
+        @NonNull
+        @JsonIgnore
+        public List<String> extensionLocationsNonNull() {
+            return Objects.requireNonNullElseGet(extensionLocations, List::of);
+        }
     }
 
     @Getter
@@ -75,14 +96,6 @@ public class Plugin extends AbstractExtension {
     public static class License {
         private String name;
         private String url;
-
-        public License() {
-        }
-
-        public License(String name) {
-            this.name = name;
-            this.url = "";
-        }
     }
 
     @Data

src/main/java/run/halo/app/core/extension/reconciler/PluginReconciler.java

@@ -10,12 +10,14 @@ import lombok.extern.slf4j.Slf4j;
 import org.pf4j.PluginRuntimeException;
 import org.pf4j.PluginState;
 import org.pf4j.PluginWrapper;
+import org.pf4j.RuntimeMode;
 import run.halo.app.core.extension.Plugin;
 import run.halo.app.extension.ExtensionClient;
 import run.halo.app.extension.controller.Reconciler;
 import run.halo.app.infra.utils.JsonUtils;
 import run.halo.app.plugin.HaloPluginManager;
 import run.halo.app.plugin.PluginStartingError;
+import run.halo.app.plugin.YamlPluginFinder;
 import run.halo.app.plugin.resources.JsBundleRuleProvider;
 import run.halo.app.plugin.resources.ReverseProxyRouterFunctionFactory;
 
@@ -66,7 +68,7 @@ public class PluginReconciler implements Reconciler {
     }
 
     private void reconcilePluginState(Plugin plugin) {
-        Plugin.PluginStatus pluginStatus = plugin.getStatus();
+        Plugin.PluginStatus pluginStatus = plugin.statusNonNull();
         String name = plugin.getMetadata().getName();
         PluginWrapper pluginWrapper = haloPluginManager.getPlugin(name);
         if (pluginWrapper == null) {
@@ -81,6 +83,8 @@ public class PluginReconciler implements Reconciler {
             return;
         }
 
+        ensureSpecUpToDateWhenDevelopmentMode(pluginWrapper, plugin);
+
         if (!Objects.equals(pluginStatus.getPhase(), pluginWrapper.getPluginState())) {
             // Set to the correct state
             pluginStatus.setPhase(pluginWrapper.getPluginState());
@@ -120,14 +124,14 @@ public class PluginReconciler implements Reconciler {
 
     private boolean shouldReconcileStartState(Plugin plugin) {
         return plugin.getSpec().getEnabled()
-            && plugin.getStatus().getPhase() != PluginState.STARTED;
+            && plugin.statusNonNull().getPhase() != PluginState.STARTED;
     }
 
     private void startPlugin(Plugin plugin) {
         String pluginName = plugin.getMetadata().getName();
         PluginState currentState = haloPluginManager.startPlugin(pluginName);
         handleStatus(plugin, currentState, PluginState.STARTED);
-        Plugin.PluginStatus status = plugin.getStatus();
+        Plugin.PluginStatus status = plugin.statusNonNull();
         // TODO Check whether the JS bundle rule exists. If it does not exist, do not populate
         // populate stylesheet path
         String jsBundleRoute = ReverseProxyRouterFunctionFactory.buildRoutePath(pluginName,
@@ -141,7 +145,7 @@ public class PluginReconciler implements Reconciler {
 
     private boolean shouldReconcileStopState(Plugin plugin) {
         return !plugin.getSpec().getEnabled()
-            && plugin.getStatus().getPhase() == PluginState.STARTED;
+            && plugin.statusNonNull().getPhase() == PluginState.STARTED;
     }
 
     private void stopPlugin(Plugin plugin) {
@@ -152,10 +156,7 @@ public class PluginReconciler implements Reconciler {
 
     private void handleStatus(Plugin plugin, PluginState currentState,
         PluginState desiredState) {
-        Plugin.PluginStatus status = plugin.getStatus();
-        if (status == null) {
-            status = new Plugin.PluginStatus();
-        }
+        Plugin.PluginStatus status = plugin.statusNonNull();
         status.setPhase(currentState);
         status.setLastTransitionTime(Instant.now());
         if (desiredState.equals(currentState)) {
@@ -169,4 +170,18 @@ public class PluginReconciler implements Reconciler {
             throw new PluginRuntimeException(startingError.getMessage());
         }
     }
+
+    private void ensureSpecUpToDateWhenDevelopmentMode(PluginWrapper pluginWrapper,
+        Plugin oldPlugin) {
+        if (!RuntimeMode.DEPLOYMENT.equals(pluginWrapper.getRuntimeMode())) {
+            return;
+        }
+        YamlPluginFinder yamlPluginFinder = new YamlPluginFinder();
+        Plugin pluginFromPath = yamlPluginFinder.find(pluginWrapper.getPluginPath());
+        // ensure plugin spec is up to date
+        Plugin.PluginSpec pluginSpec = JsonUtils.deepCopy(pluginFromPath.getSpec());
+        if (!Objects.equals(oldPlugin.getSpec(), pluginSpec)) {
+            oldPlugin.setSpec(pluginSpec);
+        }
+    }
 }

src/main/java/run/halo/app/infra/ExtensionResourceInitializer.java

@@ -0,0 +1,82 @@
+package run.halo.app.infra;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Stream;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
+import org.springframework.lang.NonNull;
+import org.springframework.stereotype.Component;
+import org.springframework.util.CollectionUtils;
+import org.thymeleaf.util.StringUtils;
+import run.halo.app.extension.ExtensionClient;
+import run.halo.app.extension.Unstructured;
+import run.halo.app.infra.properties.HaloProperties;
+import run.halo.app.infra.utils.YamlUnstructuredLoader;
+
+/**
+ * <p>Extension resources initializer.</p>
+ * <p>Check whether {@link HaloProperties#getInitialExtensionLocations()} is configured
+ * When the system ready, and load resources according to it to creates {@link Unstructured}</p>
+ *
+ * @author guqing
+ * @since 2.0.0
+ */
+@Slf4j
+@Component
+public class ExtensionResourceInitializer implements ApplicationListener<ApplicationReadyEvent> {
+    private final HaloProperties haloProperties;
+    private final ExtensionClient extensionClient;
+
+    public ExtensionResourceInitializer(HaloProperties haloProperties,
+        ExtensionClient extensionClient) {
+        this.haloProperties = haloProperties;
+        this.extensionClient = extensionClient;
+    }
+
+    @Override
+    public void onApplicationEvent(@NonNull ApplicationReadyEvent event) {
+        Set<String> extensionLocations = haloProperties.getInitialExtensionLocations();
+        if (!CollectionUtils.isEmpty(extensionLocations)) {
+
+            Resource[] resources = extensionLocations.stream()
+                .map(this::listYamlFiles)
+                .flatMap(List::stream)
+                .toArray(Resource[]::new);
+
+            log.debug("Initialization loaded [{}] resources to establish.", resources.length);
+
+            new YamlUnstructuredLoader(resources).load()
+                .forEach(unstructured -> extensionClient.fetch(unstructured.groupVersionKind(),
+                        unstructured.getMetadata().getName())
+                    .ifPresentOrElse(persisted -> {
+                        unstructured.getMetadata()
+                            .setVersion(persisted.getMetadata().getVersion());
+                        extensionClient.update(unstructured);
+                    }, () -> extensionClient.create(unstructured)));
+        }
+    }
+
+    private List<FileSystemResource> listYamlFiles(String location) {
+        try (Stream<Path> walk = Files.walk(Paths.get(location))) {
+            return walk.filter(this::isYamlFile)
+                .map(path -> new FileSystemResource(path.toFile()))
+                .toList();
+        } catch (IOException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+    private boolean isYamlFile(Path pathname) {
+        Path fileName = pathname.getFileName();
+        return StringUtils.endsWith(fileName, ".yaml")
+            || StringUtils.endsWith(fileName, ".yml");
+    }
+}

src/main/java/run/halo/app/infra/properties/HaloProperties.java

@@ -1,12 +1,16 @@
 package run.halo.app.infra.properties;
 
+import java.util.Set;
+import lombok.Data;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
  * @author guqing
- * @date 2022-04-12
+ * @since 2022-04-12
  */
+@Data
 @ConfigurationProperties(prefix = "halo")
 public class HaloProperties {
 
+    private Set<String> initialExtensionLocations;
 }

src/main/java/run/halo/app/plugin/PluginLoadedListener.java

@@ -1,35 +0,0 @@
-package run.halo.app.plugin;
-
-import org.pf4j.PluginWrapper;
-import org.springframework.context.ApplicationListener;
-import org.springframework.stereotype.Component;
-import run.halo.app.core.extension.Plugin;
-import run.halo.app.extension.ExtensionClient;
-import run.halo.app.plugin.event.HaloPluginLoadedEvent;
-
-/**
- * @author guqing
- * @since 2.0.0
- */
-@Component
-public class PluginLoadedListener implements ApplicationListener<HaloPluginLoadedEvent> {
-    private final ExtensionClient extensionClient;
-
-    public PluginLoadedListener(ExtensionClient extensionClient) {
-        this.extensionClient = extensionClient;
-    }
-
-    @Override
-    public void onApplicationEvent(HaloPluginLoadedEvent event) {
-        PluginWrapper pluginWrapper = event.getPluginWrapper();
-        // TODO: Optimize plugin custom resource loading method
-        // load plugin.yaml
-        YamlPluginFinder yamlPluginFinder = new YamlPluginFinder();
-        Plugin plugin = yamlPluginFinder.find(pluginWrapper.getPluginPath());
-        extensionClient.fetch(Plugin.class, plugin.getMetadata().getName())
-            .ifPresentOrElse(persisted -> {
-                plugin.getMetadata().setVersion(persisted.getMetadata().getVersion());
-                extensionClient.update(plugin);
-            }, () -> extensionClient.create(plugin));
-    }
-}

src/main/java/run/halo/app/plugin/PluginStartedListener.java

@@ -37,8 +37,7 @@ public class PluginStartedListener implements ApplicationListener<HaloPluginStar
         // load unstructured
         DefaultResourceLoader resourceLoader =
             new DefaultResourceLoader(pluginWrapper.getPluginClassLoader());
-        plugin.getSpec().getExtensionLocations()
-            .stream()
+        plugin.getSpec().extensionLocationsNonNull().stream()
             .map(resourceLoader::getResource)
             .filter(Resource::exists)
             .map(resource -> new YamlUnstructuredLoader(resource).load())

src/main/java/run/halo/app/plugin/YamlPluginFinder.java

@@ -47,7 +47,8 @@ import run.halo.app.infra.utils.YamlUnstructuredLoader;
  *   # 'displayName' explains what the plugin does in only a few words
  *   displayName: "a name to show"
  *   description: "Tell me more about this plugin."
- *   license: MIT
+ *   license:
+ *     - name: MIT
  * </pre>
  *
  * @author guqing

src/test/java/run/halo/app/infra/ExtensionResourceInitializerTest.java

@@ -0,0 +1,147 @@
+package run.halo.app.infra;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import org.json.JSONException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import run.halo.app.extension.ExtensionClient;
+import run.halo.app.extension.GroupVersionKind;
+import run.halo.app.extension.Unstructured;
+import run.halo.app.infra.properties.HaloProperties;
+import run.halo.app.infra.utils.JsonUtils;
+
+/**
+ * Tests for {@link ExtensionResourceInitializer}.
+ *
+ * @author guqing
+ * @since 2.0.0
+ */
+@ExtendWith(MockitoExtension.class)
+class ExtensionResourceInitializerTest {
+
+    @Mock
+    private ExtensionClient extensionClient;
+    @Mock
+    private HaloProperties haloProperties;
+    @Mock
+    private ApplicationReadyEvent applicationReadyEvent;
+
+    private ExtensionResourceInitializer extensionResourceInitializer;
+
+    @BeforeEach
+    void setUp() throws IOException {
+        extensionResourceInitializer =
+            new ExtensionResourceInitializer(haloProperties, extensionClient);
+
+        Path tempDirectory = Files.createTempDirectory("extension-resource-initializer-test");
+        Path multiDirectory = Files.createDirectories(tempDirectory.resolve("a/b/c"));
+        Files.writeString(tempDirectory.resolve("hello.yml"), """
+                kind: FakeExtension
+                apiVersion: v1
+                metadata:
+                  name: fake-extension
+                spec:
+                  hello: world
+                """,
+            StandardCharsets.UTF_8);
+
+        Files.writeString(multiDirectory.getParent().resolve("fake-1.txt"), """
+                kind: FakeExtension
+                name: fake-extension
+                """,
+            StandardCharsets.UTF_8);
+        Files.writeString(multiDirectory.resolve("fake.yaml"), """
+                kind: FakeExtension
+                apiVersion: v1
+                metadata:
+                  name: fake-extension
+                spec:
+                  hello: world
+                """,
+            StandardCharsets.UTF_8);
+
+        // test file in directory
+        Path filePath = Files.createTempDirectory("extension-resource-file-test")
+            .resolve("good.yml");
+        Files.writeString(filePath, """
+                kind: FakeExtension
+                apiVersion: v1
+                metadata:
+                  name: config-file-is-ok
+                spec:
+                  key: value
+                """,
+            StandardCharsets.UTF_8);
+
+        when(haloProperties.getInitialExtensionLocations())
+            .thenReturn(Set.of(tempDirectory.toString(), filePath.toString()));
+    }
+
+    @Test
+    void onApplicationEvent() throws JSONException {
+        ArgumentCaptor<Unstructured> argumentCaptor = ArgumentCaptor.forClass(Unstructured.class);
+
+        when(extensionClient.fetch(any(GroupVersionKind.class), any()))
+            .thenReturn(Optional.empty());
+
+        extensionResourceInitializer.onApplicationEvent(applicationReadyEvent);
+
+        verify(extensionClient, times(3)).create(argumentCaptor.capture());
+
+        List<Unstructured> values = argumentCaptor.getAllValues();
+        assertThat(values).isNotNull();
+        assertThat(values).hasSize(3);
+        JSONAssert.assertEquals("""
+            [
+                 {
+                     "kind": "FakeExtension",
+                     "apiVersion": "v1",
+                     "metadata": {
+                         "name": "config-file-is-ok"
+                     },
+                     "spec": {
+                         "key": "value"
+                     }
+                 },
+                 {
+                     "kind": "FakeExtension",
+                     "apiVersion": "v1",
+                     "metadata": {
+                         "name": "fake-extension"
+                     },
+                     "spec": {
+                         "hello": "world"
+                     }
+                 },
+                 {
+                     "kind": "FakeExtension",
+                     "apiVersion": "v1",
+                     "metadata": {
+                         "name": "fake-extension"
+                     },
+                     "spec": {
+                         "hello": "world"
+                     }
+                 }
+            ]
+            """, JsonUtils.objectToJson(values), false);
+    }
+}

src/test/java/run/halo/app/plugin/YamlPluginFinderTest.java

@@ -88,7 +88,7 @@ class YamlPluginFinderTest {
                         "license": [
                             {
                                 "name": "MIT",
-                                "url": ""
+                                "url": null
                             }
                         ],
                         "requires": ">=2.0.0",
@@ -124,50 +124,6 @@ class YamlPluginFinderTest {
             .hasMessage("Unable to find plugin descriptor file: plugin.yaml");
     }
 
-    @Test
-    void acceptArrayLicense() throws JSONException {
-        Resource pluginResource = new InMemoryResource("""
-            apiVersion: v1
-            kind: Plugin
-            metadata:
-              name: plugin-1
-            spec:
-              license: "MIT"
-            """);
-        Plugin plugin = pluginFinder.unstructuredToPlugin(pluginResource);
-        assertThat(plugin.getSpec()).isNotNull();
-        JSONAssert.assertEquals("""
-            [{
-                "name": "MIT",
-                "url": ""
-            }]
-            """, JsonUtils.objectToJson(plugin.getSpec().getLicense()), false);
-    }
-
-    @Test
-    void acceptMultipleItemArrayLicense() throws JSONException {
-        Resource pluginResource = new InMemoryResource("""
-            apiVersion: v1
-            kind: Plugin
-            metadata:
-              name: plugin-1
-            spec:
-              license: ["MIT", "Apache-2.0"]
-            """);
-        Plugin plugin = pluginFinder.unstructuredToPlugin(pluginResource);
-        assertThat(plugin.getSpec()).isNotNull();
-        JSONAssert.assertEquals("""
-            [{
-                "name": "MIT",
-                "url": ""
-            },
-            {
-                "name": "Apache-2.0",
-                "url": ""
-            }]
-            """, JsonUtils.objectToJson(plugin.getSpec().getLicense()), false);
-    }
-
     @Test
     void acceptArrayObjectLicense() throws JSONException {
         Resource pluginResource = new InMemoryResource("""

src/test/resources/plugin/plugin.yaml

@@ -13,4 +13,5 @@ spec:
   homepage: https://github.com/guqing/halo-plugin-1
   displayName: "a name to show"
   description: "Tell me more about this plugin."
-  license: MIT
+  license:
+    - name: MIT