Remove seed generation task and seed from YAML files (airbytehq#5335)

## What
- This is the first PR for airbytehq#4890.
  - This PR does not remove the config volume.
  - This PR does not mount the directories for the local connectors.
- Resolves airbytehq#5373.

## How
-  Previously the seed container copies the configs to the storage root, it may take some time for the operation to complete and for the `CONFIG_DIR` to show up. So we cannot infer anything based on the existence of this directory. Now this seed generation step has been removed. So we can tell immediately whether `CONFIG_DIR` exists or not.
  - If `CONFIG_DIR` exists, it means the user has just migrated Airbyte from an old version that uses this file system config persistence.
  - Otherwise, we can seed the config persistence from the YAML files.

airbyte-config/init/build.gradle

@@ -7,42 +7,3 @@ dependencies {
 
     implementation project(':airbyte-config:models')
 }
-
-// generate seed for each yaml file.
-task generateSeed {
-    def seeds = [
-            [
-                "sourceDefinitionId",
-                new File(project.projectDir, '/src/main/resources/seed/source_definitions.yaml'),
-                new File(project.projectDir, '/src/main/resources/config/STANDARD_SOURCE_DEFINITION')
-            ],
-            [
-                "destinationDefinitionId",
-                new File(project.projectDir, '/src/main/resources/seed/destination_definitions.yaml'),
-                new File(project.projectDir, '/src/main/resources/config/STANDARD_DESTINATION_DEFINITION')
-            ],
-    ]
-    seeds.each{val ->
-        def name = val[0]
-        def taskName = "generateSeed$name"
-        dependsOn taskName
-        task "$taskName"(type: JavaExec) {
-            classpath = sourceSets.main.runtimeClasspath
-
-            main = 'io.airbyte.config.init.SeedRepository'
-
-            // arguments to pass to the application
-            args '--id-name'
-            args val[0]
-            args '--input-path'
-            args val[1]
-            args '--output-path'
-            args val[2]
-        }
-    }
-}
-
-// we only want to attempt generateSeed if tests have passed.
-generateSeed.dependsOn(check)
-generateSeed.dependsOn(assemble)
-build.dependsOn(generateSeed)

airbyte-config/init/src/main/java/io/airbyte/config/init/SeedType.java

@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 Airbyte
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package io.airbyte.config.init;
+
+public enum SeedType {
+
+  STANDARD_SOURCE_DEFINITION("/seed/source_definitions.yaml", "sourceDefinitionId"),
+  STANDARD_DESTINATION_DEFINITION("/seed/destination_definitions.yaml", "destinationDefinitionId");
+
+  final String resourcePath;
+  // ID field name
+  final String idName;
+
+  SeedType(String resourcePath, String idName) {
+    this.resourcePath = resourcePath;
+    this.idName = idName;
+  }
+
+  public String getResourcePath() {
+    return resourcePath;
+  }
+
+  public String getIdName() {
+    return idName;
+  }
+
+}

airbyte-config/persistence/src/main/java/io/airbyte/config/persistence/ConfigPersistenceBuilder.java

@@ -68,11 +68,13 @@ public static ConfigPersistence getDbPersistence(Configs configs) throws IOExcep
    * Otherwise, seed the database from the yaml files.
    */
   ConfigPersistence create() throws IOException, InterruptedException {
-    // Uncomment this branch in a future version when config volume is removed.
-    // if (configs.getConfigRoot() == null) {
-    // return getDbPersistenceWithYamlSeed();
-    // }
-    return getDbPersistenceWithFileSeed();
+    if (FileSystemConfigPersistence.hasExistingConfigs(configs.getConfigRoot())) {
+      LOGGER.info("There is existing local config directory");
+      return getDbPersistenceWithFileSeed();
+    } else {
+      LOGGER.info("There is no existing local config directory");
+      return getDbPersistenceWithYamlSeed();
+    }
   }
 
   /**
@@ -81,7 +83,7 @@ ConfigPersistence create() throws IOException, InterruptedException {
    */
   ConfigPersistence getDbPersistenceWithYamlSeed() throws IOException {
     LOGGER.info("Creating db-based config persistence, and loading initial seed from YAML files");
-    ConfigPersistence seedConfigPersistence = new YamlSeedConfigPersistence();
+    ConfigPersistence seedConfigPersistence = YamlSeedConfigPersistence.get();
     return getDbPersistence(seedConfigPersistence);
   }