feature/add support to fetch recursively (#6)

* Support recursive option
* Enhance documentation

README.md

@@ -21,6 +21,7 @@ import { PSConfigModule } from 'nestjs-param-store';
     PSConfigModule.register({
       ssmParamStorePath: '/production/services/my-service',
       ssmDecryptParams: true,
+      ssmRecursive: false,
       ssmClientOptions: {
         region: 'us-east-1',
       },
@@ -48,6 +49,7 @@ import { PSConfigModule } from 'nestjs-param-store';
       useFactory: async (config: ConfigService<EnvironmentVariables>) => ({
         ssmParamStorePath: config.get<string>('APP_CONFIG_PATH'),
         ssmDecryptParams: true,
+        ssmRecursive: false,
         ssmClientOptions: {
           region: config.get<string>('AWS_REGION'),
         },
@@ -59,6 +61,15 @@ import { PSConfigModule } from 'nestjs-param-store';
 export class AppModule {}
 ```
 
+## Options
+
+| Option            	| Required 	| Default     	| Description                                                       	|
+|-------------------	|----------	|-------------	|-------------------------------------------------------------------	|
+| ssmParamStorePath 	| Yes      	|             	| The hierarchy for the parameter                                   	|
+| ssmDecryptParams  	| No       	| `false`     	| Retrieve all parameters in a hierarchy with their value decrypted 	|
+| ssmRecursive      	| No       	| `false`     	| Retrieve all parameters within a hierarchy                        	|
+| ssmClientOptions  	| No       	| `undefined` 	| Options to pass to the underlying SSM client                      	|
+
 ## Services
 
 This module exposes the following services.
@@ -172,3 +183,26 @@ Example of output:
   }
 ]
 ```
+
+## Troubleshooting
+
+### Empty list of parameters returned
+
+This happens when `recursive` is `false` and the specified path does not resolve the final level in the hierarchy.
+
+[Reference: GetParametersByPath](https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_GetParametersByPath.html#API_GetParametersByPath_RequestSyntax)
+
+```typescript
+import { Module } from '@nestjs/common';
+import { PSConfigModule } from 'nestjs-param-store';
+
+@Module({
+  imports: [
+    PSConfigModule.register({
+      ssmParamStorePath: '/production',
+      ssmRecursive: true,   // <-- specify recursively
+    }),
+  ],
+})
+export class AppModule {}
+```

lib/interfaces/config-options.interface.ts

@@ -3,5 +3,6 @@ import { SSMClientConfig } from '@aws-sdk/client-ssm';
 export interface PSConfigOptions {
   ssmParamStorePath: string;
   ssmDecryptParams?: boolean;
+  ssmRecursive?: boolean;
   ssmClientOptions?: SSMClientConfig;
 }

lib/providers/config-parameters.provider.ts

@@ -12,6 +12,7 @@ export const configParametersProvider: FactoryProvider<PSConfigParameters> = {
     return psService.getParametersByPath(
       configOptions.ssmParamStorePath,
       configOptions.ssmDecryptParams ?? false,
+      configOptions.ssmRecursive ?? false,
     );
   },
   inject: [PS_CONFIG_OPTIONS, ParameterStoreService],

lib/services/parameter-store.service.ts

@@ -15,6 +15,7 @@ export class ParameterStoreService {
   public async getParametersByPath(
     path: string,
     decrypt = false,
+    recursive = false,
   ): Promise<Parameter[]> {
     let allParameters: Parameter[] = [];
     let nextParametersToken: string | undefined;
@@ -23,6 +24,7 @@ export class ParameterStoreService {
         Path: path,
         WithDecryption: decrypt,
         NextToken: nextParametersToken,
+        Recursive: recursive,
       });
 
       const { Parameters = [], NextToken } = await this.client.send(

package.json

@@ -1,6 +1,6 @@
 {
   "name": "nestjs-param-store",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Configure your NestJS application with AWS Parameter Store",
   "author": "Alberto Menendez Romero <[email protected]>",
   "keywords": [