Move latest backup download feature to Discord commands processing lambda (#53)

Author: 314pies

lambda/discord_command_processer/index.ts

@@ -77,18 +77,28 @@ exports.handler = async (event: any, context: Context) => {
   }
 
   if (commandName == 'mc_backup_download') {
-    try {
-      const result = await sendCommands([
-        'cd /opt/minecloud/',
-        'sudo ./get_latest_server_backup.sh'
-      ]);
-      console.log('mc_backup_download result: ', result);
-      await sendDeferredResponse('OK, contacting server instance!');
-    } catch (err) {
-      console.error(`mc_backup error: \n`, err);
+    const s3 = new AWS.S3({ signatureVersion: 'v4' });
+
+    const bucketName: string = process.env.BACKUP_BUCKET_NAME as string;
+    const s3Objects = await s3.listObjectsV2({ Bucket: bucketName }).promise();
+
+    if (s3Objects.Contents && s3Objects.Contents.length > 0) {
+      let s3ObjectKeys = s3Objects.Contents.map((x) => x.Key);
+      s3ObjectKeys = s3ObjectKeys.sort((a, b) => (a! > b! ? -1 : 1));
+
+      const latestBackupKey = s3ObjectKeys[0];
+
+      const params = {
+        Bucket: bucketName,
+        Key: latestBackupKey,
+        Expires: 3600
+      };
+      const preSignedUrl = await s3.getSignedUrl('getObject', params);
       await sendDeferredResponse(
-        getAWSErrorMessageTemplate('getting latest backup', err)
+        `Here's the download link for ${latestBackupKey}:\n ${preSignedUrl}`
       );
+    } else {
+      await sendDeferredResponse('Hmm... looks like there is no backup yet~');
     }
   }
 

lib/discord-interactions-endpoint-construct.ts

@@ -10,11 +10,13 @@ import { PolicyStatement, Policy } from 'aws-cdk-lib/aws-iam';
 import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs';
 import { Duration } from 'aws-cdk-lib';
 import { DISCORD_APP_ID } from '../minecloud_configs/MineCloud-Configs';
+import { Bucket } from 'aws-cdk-lib/aws-s3';
 
 export interface DiscordInteractionsEndpointConstructProps {
   instanceId: string;
   ec2Region: string;
   discordPublicKey: string;
+  backUpBucket: Bucket;
 }
 
 export class DiscordInteractionsEndpointConstruct extends Construct {
@@ -61,12 +63,14 @@ export class DiscordInteractionsEndpointConstruct extends Construct {
         environment: {
           INSTANCE_ID: props.instanceId,
           EC2_REGION: props.ec2Region,
-          APP_ID: DISCORD_APP_ID
+          APP_ID: DISCORD_APP_ID,
+          BACKUP_BUCKET_NAME: props.backUpBucket.bucketName
         },
         timeout: Duration.seconds(15)
       }
     );
     this.discordCommandProcesser.grantInvoke(this.discordInteractionsEndpoint);
+    props.backUpBucket.grantReadWrite(this.discordCommandProcesser);
 
     const ec2Policy = new PolicyStatement({
       actions: ['ec2:*'],

lib/instance-init.ts

@@ -58,8 +58,7 @@ export function getInitConfig(backupBucketName: string) {
         'setupDiscordMessaging',
         'setupMineCloudService',
         'setupBackupScripts',
-        'setupAutoShutdown',
-        'setupGetLatestBackupScript'
+        'setupAutoShutdown'
       ]
     },
     configs: {
@@ -170,13 +169,6 @@ export function getInitConfig(backupBucketName: string) {
           `(crontab -l 2>/dev/null; echo "*/30 * * * * ${MINECLOUD_BASE_DIR}/check_user_conn.sh") | crontab -`
         )
       ]),
-      setupGetLatestBackupScript: new InitConfig([
-        ...setUpShellScript(
-          MINECLOUD_BASE_DIR,
-          'get_latest_server_backup.sh',
-          'server_init_assets/get_latest_server_backup.sh'
-        )
-      ]),
       noAction: new InitConfig([])
     }
   });

lib/mine-cloud-stack.ts

@@ -83,7 +83,8 @@ export class MineCloud extends Stack {
         {
           instanceId: this.ec2Instance.instanceId,
           ec2Region: this.region,
-          discordPublicKey: DISCORD_PUBLIC_KEY
+          discordPublicKey: DISCORD_PUBLIC_KEY,
+          backUpBucket: this.backupBucket
         }
       );
     this.discordInteractionsEndpointLambda.node.addDependency(this.ec2Instance);