chore: introduce promiseall-no-unbounded-parallelism linter rule (#…

…31592)

Since JavaScript is single-threaded, `Promise.all()` will only ever be used for I/O-bound tasks. However, I/O-parallelism isn't free either. Every async I/O-performing task launched will consume some FDs, and their amount is limited. If the amount of promises launched is a function of the input the program runs on, the system FDs might be exhausted. Some concurrency limit must be introduced.

This linter rule exists to remind the programmer of that fact. It triggers on every `Promise.all()` invocation and cannot be resolved; the only solution is to think about it, and then silence this rule as proof that you thought about it.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/cli-integ/lib/with-cdk-app.ts

@@ -529,12 +529,16 @@ export class TestFixture extends ShellHelper {
 
     // Bootstrap stacks have buckets that need to be cleaned
     const bucketNames = stacksToDelete.map(stack => outputFromStack('BucketName', stack)).filter(defined);
+    // Parallelism will be reasonable
+    // eslint-disable-next-line @aws-cdk/promiseall-no-unbounded-parallelism
     await Promise.all(bucketNames.map(b => this.aws.emptyBucket(b)));
     // The bootstrap bucket has a removal policy of RETAIN by default, so add it to the buckets to be cleaned up.
     this.bucketsToDelete.push(...bucketNames);
 
     // Bootstrap stacks have ECR repositories with images which should be deleted
     const imageRepositoryNames = stacksToDelete.map(stack => outputFromStack('ImageRepositoryName', stack)).filter(defined);
+    // Parallelism will be reasonable
+    // eslint-disable-next-line @aws-cdk/promiseall-no-unbounded-parallelism
     await Promise.all(imageRepositoryNames.map(r => this.aws.deleteImageRepository(r)));
 
     await this.aws.deleteStacks(

packages/@aws-cdk-testing/cli-integ/test/resource-pool.test.ts

@@ -51,6 +51,7 @@ test('somewhat balance', async () => {
 
   const keys = Object.keys(counters) as Array<keyof typeof counters> ;
   const pool = ResourcePool.withResources(POOL_NAME, keys);
+  // eslint-disable-next-line @aws-cdk/promiseall-no-unbounded-parallelism
   await Promise.all(Array.from(range(N)).map(() =>
     pool.using(async (x) => {
       counters[x] += 1;

packages/@aws-cdk-testing/framework-integ/test/aws-batch/test/integ.managed-compute-environment.js.snapshot/batch-stack.template.json

@@ -986,112 +986,6 @@
     "UpdatePolicy": {}
    }
   },
-  "noOptimalInstancesForARMSecurityGroup7157B016": {
-   "Type": "AWS::EC2::SecurityGroup",
-   "Properties": {
-    "GroupDescription": "batch-stack/noOptimalInstancesForARM/SecurityGroup",
-    "SecurityGroupEgress": [
-     {
-      "CidrIp": "0.0.0.0/0",
-      "Description": "Allow all outbound traffic by default",
-      "IpProtocol": "-1"
-     }
-    ],
-    "VpcId": {
-     "Ref": "vpcA2121C38"
-    }
-   }
-  },
-  "noOptimalInstancesForARMInstanceProfileRole926AEEC5": {
-   "Type": "AWS::IAM::Role",
-   "Properties": {
-    "AssumeRolePolicyDocument": {
-     "Statement": [
-      {
-       "Action": "sts:AssumeRole",
-       "Effect": "Allow",
-       "Principal": {
-        "Service": "ec2.amazonaws.com"
-       }
-      }
-     ],
-     "Version": "2012-10-17"
-    },
-    "ManagedPolicyArns": [
-     {
-      "Fn::Join": [
-       "",
-       [
-        "arn:",
-        {
-         "Ref": "AWS::Partition"
-        },
-        ":iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role"
-       ]
-      ]
-     }
-    ]
-   }
-  },
-  "noOptimalInstancesForARMInstanceProfile37BE9D32": {
-   "Type": "AWS::IAM::InstanceProfile",
-   "Properties": {
-    "Roles": [
-     {
-      "Ref": "noOptimalInstancesForARMInstanceProfileRole926AEEC5"
-     }
-    ]
-   }
-  },
-  "noOptimalInstancesForARMF146AA4D": {
-   "Type": "AWS::Batch::ComputeEnvironment",
-   "Properties": {
-    "ComputeResources": {
-     "AllocationStrategy": "BEST_FIT_PROGRESSIVE",
-     "Ec2Configuration": [
-      {
-       "ImageIdOverride": {
-        "Ref": "SsmParameterValueawsserviceamiamazonlinuxlatestamznamihvmx8664gp2C96584B6F00A464EAD1953AFF4B05118Parameter"
-       },
-       "ImageType": "ECS_AL2"
-      }
-     ],
-     "InstanceRole": {
-      "Fn::GetAtt": [
-       "noOptimalInstancesForARMInstanceProfile37BE9D32",
-       "Arn"
-      ]
-     },
-     "InstanceTypes": [
-      "a1.large",
-      "m6g"
-     ],
-     "MaxvCpus": 256,
-     "MinvCpus": 0,
-     "SecurityGroupIds": [
-      {
-       "Fn::GetAtt": [
-        "noOptimalInstancesForARMSecurityGroup7157B016",
-        "GroupId"
-       ]
-      }
-     ],
-     "Subnets": [
-      {
-       "Ref": "vpcPrivateSubnet1Subnet934893E8"
-      },
-      {
-       "Ref": "vpcPrivateSubnet2Subnet7031C2BA"
-      }
-     ],
-     "Type": "EC2"
-    },
-    "ReplaceComputeEnvironment": false,
-    "State": "ENABLED",
-    "Type": "managed",
-    "UpdatePolicy": {}
-   }
-  },
   "taggedCESecurityGroup82CCF59F": {
    "Type": "AWS::EC2::SecurityGroup",
    "Properties": {