diff --git a/packages/@aws-cdk/aws-cloudformation/test/asset-docker-fixture/Dockerfile b/packages/@aws-cdk/aws-cloudformation/test/asset-docker-fixture/Dockerfile
index 67fd379018917..931518298c332 100644
--- a/packages/@aws-cdk/aws-cloudformation/test/asset-docker-fixture/Dockerfile
+++ b/packages/@aws-cdk/aws-cloudformation/test/asset-docker-fixture/Dockerfile
@@ -1 +1 @@
-FROM alpine
+FROM public.ecr.aws/docker/library/alpine:latest
diff --git a/packages/@aws-cdk/aws-codebuild/test/demo-image/Dockerfile b/packages/@aws-cdk/aws-codebuild/test/demo-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-codebuild/test/demo-image/Dockerfile
+++ b/packages/@aws-cdk/aws-codebuild/test/demo-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-codebuild/test/integ.docker-asset.lit.expected.json b/packages/@aws-cdk/aws-codebuild/test/integ.docker-asset.lit.expected.json
index d3c45a9bee054..e11ff97797ce9 100644
--- a/packages/@aws-cdk/aws-codebuild/test/integ.docker-asset.lit.expected.json
+++ b/packages/@aws-cdk/aws-codebuild/test/integ.docker-asset.lit.expected.json
@@ -146,7 +146,7 @@
                 {
                   "Ref": "AWS::URLSuffix"
                 },
-                "/aws-cdk/assets:4af07cfea2e112710555eb86325bfd4d7d4b97e4fa9f1bf6c053c72f992c7fe5"
+                "/aws-cdk/assets:73ee9c3cafd103104e2a42ee76961a90a2410d0dcad42110343c5fd85ad6db78"
               ]
             ]
           },
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/allow-listed-image/Dockerfile b/packages/@aws-cdk/aws-ecr-assets/test/allow-listed-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/allow-listed-image/Dockerfile
+++ b/packages/@aws-cdk/aws-ecr-assets/test/allow-listed-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile b/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile
+++ b/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile.Custom b/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile.Custom
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile.Custom
+++ b/packages/@aws-cdk/aws-ecr-assets/test/demo-image-custom-docker-file/Dockerfile.Custom
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/demo-image/Dockerfile b/packages/@aws-cdk/aws-ecr-assets/test/demo-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/demo-image/Dockerfile
+++ b/packages/@aws-cdk/aws-ecr-assets/test/demo-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/dockerignore-image/Dockerfile b/packages/@aws-cdk/aws-ecr-assets/test/dockerignore-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/dockerignore-image/Dockerfile
+++ b/packages/@aws-cdk/aws-ecr-assets/test/dockerignore-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/image-asset.test.ts b/packages/@aws-cdk/aws-ecr-assets/test/image-asset.test.ts
index 7640557032510..002e000c89ef2 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/image-asset.test.ts
+++ b/packages/@aws-cdk/aws-ecr-assets/test/image-asset.test.ts
@@ -10,7 +10,7 @@ import { DockerImageAsset, NetworkMode } from '../lib';
 
 /* eslint-disable quote-props */
 
-const DEMO_IMAGE_ASSET_HASH = '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48';
+const DEMO_IMAGE_ASSET_HASH = '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14';
 
 const flags = { [cxapi.DOCKER_IGNORE_SUPPORT]: true };
 
@@ -29,11 +29,11 @@ describe('image asset', () => {
     expect(artifact.assets).toEqual([
       {
         repositoryName: 'aws-cdk/assets',
-        imageTag: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
-        id: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+        imageTag: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
+        id: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
         packaging: 'container-image',
-        path: 'asset.8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
-        sourceHash: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+        path: 'asset.0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
+        sourceHash: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
       },
     ]);
 
@@ -89,29 +89,24 @@ describe('image asset', () => {
     expect(artifact.template).toEqual({});
     expect(artifact.assets).toEqual([
       {
-        'buildArgs': {
-          'a': 'b',
-        },
-        repositoryName: 'aws-cdk/assets',
-        imageTag: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
-        id: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+        buildArgs: { 'a': 'b' },
+        id: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
+        imageTag: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
         packaging: 'container-image',
-        path: 'asset.8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
-        sourceHash: '8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+        path: 'asset.0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
+        repositoryName: 'aws-cdk/assets',
+        sourceHash: '0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
       },
       {
-        'buildArgs': {
-          'a': 'b',
-        },
-        'id': 'd4bbfde4749763cef9707486f81ce1e95d25cedaf4cc34cfcdab7232ec1948ff',
-        'imageTag': 'd4bbfde4749763cef9707486f81ce1e95d25cedaf4cc34cfcdab7232ec1948ff',
-        'packaging': 'container-image',
-        'path': 'asset.d4bbfde4749763cef9707486f81ce1e95d25cedaf4cc34cfcdab7232ec1948ff',
-        'repositoryName': 'aws-cdk/assets',
-        'sourceHash': 'd4bbfde4749763cef9707486f81ce1e95d25cedaf4cc34cfcdab7232ec1948ff',
+        buildArgs: { 'a': 'b' },
+        id: '7f3aa0a36ecd282884e11463b3fde119d25d1ed424f934300f0c7b9cf6f63947',
+        imageTag: '7f3aa0a36ecd282884e11463b3fde119d25d1ed424f934300f0c7b9cf6f63947',
+        packaging: 'container-image',
+        path: 'asset.7f3aa0a36ecd282884e11463b3fde119d25d1ed424f934300f0c7b9cf6f63947',
+        repositoryName: 'aws-cdk/assets',
+        sourceHash: '7f3aa0a36ecd282884e11463b3fde119d25d1ed424f934300f0c7b9cf6f63947',
       },
     ]);
-
   });
 
   testFutureBehavior('with target', flags, App, (app) => {
@@ -355,12 +350,12 @@ describe('image asset', () => {
     const asset5 = new DockerImageAsset(stack, 'Asset5', { directory, file: 'Dockerfile.Custom', target: 'NonDefaultTarget' });
     const asset6 = new DockerImageAsset(stack, 'Asset6', { directory, extraHash: 'random-extra' });
 
-    expect(asset1.assetHash).toEqual('365b5d951fc5f725f78093a07e3e1cc7819b4cbe582ca71a4c344752c23bf409');
-    expect(asset2.assetHash).toEqual('9560a36f786f317c5e1abb986b58269b2453ed1cab16c36fd9b76646c837078c');
-    expect(asset3.assetHash).toEqual('4f4e16f5b0cfab21be4298a04b20f62f63cd91a649ef4620d6d3c948d29f3cb4');
-    expect(asset4.assetHash).toEqual('72b961f96e358b8dad935719cfc2704c3d14a46434871825ac81e3b94caa4853');
-    expect(asset5.assetHash).toEqual('c23d34b3a1dac5a80c42e8fa6c88a0ac697eb709a6f36ebdb6e36ee8c75edc75');
-    expect(asset6.assetHash).toEqual('7e950a9b08c58d371c1658e04d377c0ec59d89a47fc245a86a50525b36a8949b');
+    expect(asset1.assetHash).toEqual('13248c55633f3b198a628bb2ea4663cb5226f8b2801051bd0c725950266fd590');
+    expect(asset2.assetHash).toEqual('36bf205fb9adc5e45ba1c8d534158a0aed96d190eff433af1d90f3b94f96e751');
+    expect(asset3.assetHash).toEqual('4c85bd70e73117b7129c2defbe6dc40a8a3872329f4ddca18d75afa671b38276');
+    expect(asset4.assetHash).toEqual('8a91219a7bb0f58b3282dd84acbf4c03c49c765be54ffb7b125be6a50b6c5645');
+    expect(asset5.assetHash).toEqual('c02bfba13b2e7e1ff5c778a76e10296b9e8d17f7f8252d097f4170ae04ce0eb4');
+    expect(asset6.assetHash).toEqual('3528d6838647a5e9011b0f35aec514d03ad11af05a94653cdcf4dacdbb070a06');
 
   });
 
@@ -371,8 +366,8 @@ describe('image asset', () => {
     const asset1 = new DockerImageAsset(stack, 'Asset1', { directory });
     const asset2 = new DockerImageAsset(stack, 'Asset2', { directory, repositoryName: 'foo' });
 
-    expect(asset1.assetHash).toEqual('b5d181eb114c889020f9d59961ac4ad5d65f49c571c0aafd5ce2be9464bc2d13');
-    expect(asset2.assetHash).toEqual('0b48fa3f7f75365962e6e18f52608ec4e4451f8ecc0b58abdb063c5381569471');
+    expect(asset1.assetHash).toEqual('91cd042be26211c28488a6994327fc579e75e355d9d3bf7043fa6a0bc8ad4265');
+    expect(asset2.assetHash).toEqual('6a6cab989dda908fa3d132d58f402f714d79858f3c89473f2b050096954e6827');
   });
 });
 
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/integ.assets-docker.expected.json b/packages/@aws-cdk/aws-ecr-assets/test/integ.assets-docker.expected.json
index 3f6dd7b36d92e..854d6fab2364f 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/integ.assets-docker.expected.json
+++ b/packages/@aws-cdk/aws-ecr-assets/test/integ.assets-docker.expected.json
@@ -70,7 +70,7 @@
             {
               "Ref": "AWS::URLSuffix"
             },
-            "/aws-cdk/assets:8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48"
+            "/aws-cdk/assets:0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14"
           ]
         ]
       }
diff --git a/packages/@aws-cdk/aws-ecr-assets/test/integ.nested-stacks-docker.expected.json b/packages/@aws-cdk/aws-ecr-assets/test/integ.nested-stacks-docker.expected.json
index 8860ef52935b1..793deb5240d59 100644
--- a/packages/@aws-cdk/aws-ecr-assets/test/integ.nested-stacks-docker.expected.json
+++ b/packages/@aws-cdk/aws-ecr-assets/test/integ.nested-stacks-docker.expected.json
@@ -17,7 +17,7 @@
               },
               "/",
               {
-                "Ref": "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39S3Bucket74894234"
+                "Ref": "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297S3BucketAF5C36E5"
               },
               "/",
               {
@@ -27,7 +27,7 @@
                     "Fn::Split": [
                       "||",
                       {
-                        "Ref": "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39S3VersionKeyD1E9C856"
+                        "Ref": "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297S3VersionKeyEB2E48FF"
                       }
                     ]
                   }
@@ -40,7 +40,7 @@
                     "Fn::Split": [
                       "||",
                       {
-                        "Ref": "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39S3VersionKeyD1E9C856"
+                        "Ref": "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297S3VersionKeyEB2E48FF"
                       }
                     ]
                   }
@@ -55,17 +55,17 @@
     }
   },
   "Parameters": {
-    "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39S3Bucket74894234": {
+    "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297S3BucketAF5C36E5": {
       "Type": "String",
-      "Description": "S3 bucket for asset \"1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39\""
+      "Description": "S3 bucket for asset \"bd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297\""
     },
-    "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39S3VersionKeyD1E9C856": {
+    "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297S3VersionKeyEB2E48FF": {
       "Type": "String",
-      "Description": "S3 key for asset version \"1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39\""
+      "Description": "S3 key for asset version \"bd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297\""
     },
-    "AssetParameters1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39ArtifactHash4D458F5E": {
+    "AssetParametersbd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297ArtifactHashA3886DE7": {
       "Type": "String",
-      "Description": "Artifact hash for asset \"1107443cdc71fce9cccfb7fb4c7c73078878ffb8d631c739c41d45ae40616f39\""
+      "Description": "Artifact hash for asset \"bd34d9d2b847afabcea4ef507c1bdaabe8abdbb75c41b3db3609d371f8626297\""
     }
   }
 }
\ No newline at end of file
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/demo-image/Dockerfile b/packages/@aws-cdk/aws-ecs-patterns/test/demo-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/demo-image/Dockerfile
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/demo-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.asset-image.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.asset-image.expected.json
index 01c7cb601a90c..23fcba8794ced 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.asset-image.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.asset-image.expected.json
@@ -503,7 +503,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48"
+                  "/aws-cdk/assets:0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.circuit-breaker-queue-processing-fargate-service.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.circuit-breaker-queue-processing-fargate-service.expected.json
index 8e44e25a0c5ac..bd451b2c94895 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.circuit-breaker-queue-processing-fargate-service.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.circuit-breaker-queue-processing-fargate-service.expected.json
@@ -460,7 +460,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:d6b024485c22795b5f5379edcd5cd6485f5bec6eb80bd072b20526f8eb2e0c64"
+                  "/aws-cdk/assets:95cefedd43575452a70cdeeeceb0f1c5728fd58c9ff8e81e760c3dac33c46417"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-isolated.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-isolated.expected.json
index 07eefdc4a2629..b351c625b9a04 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-isolated.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-isolated.expected.json
@@ -769,7 +769,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:d6b024485c22795b5f5379edcd5cd6485f5bec6eb80bd072b20526f8eb2e0c64"
+                  "/aws-cdk/assets:95cefedd43575452a70cdeeeceb0f1c5728fd58c9ff8e81e760c3dac33c46417"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.expected.json
index 4994e6d9b015c..be5262a5f25ce 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.expected.json
@@ -18,11 +18,11 @@
     "VPCPublicSubnet1SubnetB4246D30": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.0.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1a",
-        "CidrBlock": "10.0.0.0/19",
         "MapPublicIpOnLaunch": true,
         "Tags": [
           {
@@ -115,11 +115,11 @@
     "VPCPublicSubnet2Subnet74179F39": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.32.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1b",
-        "CidrBlock": "10.0.32.0/19",
         "MapPublicIpOnLaunch": true,
         "Tags": [
           {
@@ -212,11 +212,11 @@
     "VPCPublicSubnet3Subnet631C5E25": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.64.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1c",
-        "CidrBlock": "10.0.64.0/19",
         "MapPublicIpOnLaunch": true,
         "Tags": [
           {
@@ -309,11 +309,11 @@
     "VPCPrivateSubnet1Subnet8BCA10E0": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.96.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1a",
-        "CidrBlock": "10.0.96.0/19",
         "MapPublicIpOnLaunch": false,
         "Tags": [
           {
@@ -371,11 +371,11 @@
     "VPCPrivateSubnet2SubnetCFCDAA7A": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.128.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1b",
-        "CidrBlock": "10.0.128.0/19",
         "MapPublicIpOnLaunch": false,
         "Tags": [
           {
@@ -433,11 +433,11 @@
     "VPCPrivateSubnet3Subnet3EDCD457": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
+        "CidrBlock": "10.0.160.0/19",
         "VpcId": {
           "Ref": "VPCB9E5F0B4"
         },
         "AvailabilityZone": "test-region-1c",
-        "CidrBlock": "10.0.160.0/19",
         "MapPublicIpOnLaunch": false,
         "Tags": [
           {
@@ -609,7 +609,7 @@
                 "CMD-SHELL",
                 "curl -f http://localhost/ || exit 1"
               ],
-              "Interval": 5,
+              "Interval": 6,
               "Retries": 10,
               "Timeout": 5
             },
@@ -628,7 +628,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:d6b024485c22795b5f5379edcd5cd6485f5bec6eb80bd072b20526f8eb2e0c64"
+                  "/aws-cdk/assets:95cefedd43575452a70cdeeeceb0f1c5728fd58c9ff8e81e760c3dac33c46417"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.ts b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.ts
index 495e738d63c38..bc3c9b621309e 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.ts
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service-public.ts
@@ -16,7 +16,7 @@ new QueueProcessingFargateService(stack, 'PublicQueueService', {
   assignPublicIp: true,
   healthCheck: {
     command: ['CMD-SHELL', 'curl -f http://localhost/ || exit 1'],
-    interval: Duration.seconds(5),
+    interval: Duration.seconds(6),
     retries: 10,
   },
 });
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service.expected.json
index 1eab7f10bddc6..9746768edf9fe 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.queue-processing-fargate-service.expected.json
@@ -460,7 +460,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:d6b024485c22795b5f5379edcd5cd6485f5bec6eb80bd072b20526f8eb2e0c64"
+                  "/aws-cdk/assets:95cefedd43575452a70cdeeeceb0f1c5728fd58c9ff8e81e760c3dac33c46417"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.scheduled-fargate-task.lit.expected.json b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.scheduled-fargate-task.lit.expected.json
index 5110af7cc54eb..f0540fcb9044b 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.scheduled-fargate-task.lit.expected.json
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/integ.scheduled-fargate-task.lit.expected.json
@@ -293,7 +293,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48"
+                  "/aws-cdk/assets:0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/sqs-reader/Dockerfile b/packages/@aws-cdk/aws-ecs-patterns/test/sqs-reader/Dockerfile
index e6618640549e2..919fabfc3f637 100644
--- a/packages/@aws-cdk/aws-ecs-patterns/test/sqs-reader/Dockerfile
+++ b/packages/@aws-cdk/aws-ecs-patterns/test/sqs-reader/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 
 RUN pip3 install boto3
 
diff --git a/packages/@aws-cdk/aws-ecs/test/container-definition.test.ts b/packages/@aws-cdk/aws-ecs/test/container-definition.test.ts
index 1aed207c1cdd5..0c428cb23ab84 100644
--- a/packages/@aws-cdk/aws-ecs/test/container-definition.test.ts
+++ b/packages/@aws-cdk/aws-ecs/test/container-definition.test.ts
@@ -1999,7 +1999,7 @@ describe('container definition', () => {
                 { Ref: 'AWS::Region' },
                 '.',
                 { Ref: 'AWS::URLSuffix' },
-                '/aws-cdk/assets:8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+                '/aws-cdk/assets:0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
               ],
             ],
           },
@@ -2055,11 +2055,11 @@ describe('container definition', () => {
     const asm = app.synth();
     expect(asm.getStackArtifact(stack.artifactId).assets[0]).toEqual({
       repositoryName: 'aws-cdk/assets',
-      imageTag: '9d913132f812bc1ad436aeb5a51f9216c5776b8079318c1883ad2f79f0ef1a4b',
-      id: '9d913132f812bc1ad436aeb5a51f9216c5776b8079318c1883ad2f79f0ef1a4b',
+      imageTag: '8b0801d3f897d960240bf5bf3d5a3e367e50a17e04101717320bfd52ebc9d64a',
+      id: '8b0801d3f897d960240bf5bf3d5a3e367e50a17e04101717320bfd52ebc9d64a',
       packaging: 'container-image',
-      path: 'asset.9d913132f812bc1ad436aeb5a51f9216c5776b8079318c1883ad2f79f0ef1a4b',
-      sourceHash: '9d913132f812bc1ad436aeb5a51f9216c5776b8079318c1883ad2f79f0ef1a4b',
+      path: 'asset.8b0801d3f897d960240bf5bf3d5a3e367e50a17e04101717320bfd52ebc9d64a',
+      sourceHash: '8b0801d3f897d960240bf5bf3d5a3e367e50a17e04101717320bfd52ebc9d64a',
       target: 'build-target',
       file: 'index.py',
     });
@@ -2078,7 +2078,7 @@ describe('container definition', () => {
 
     // THEN
     expect(stack.resolve(container.imageName)).toEqual({
-      'Fn::Sub': '${AWS::AccountId}.dkr.ecr.${AWS::Region}.${AWS::URLSuffix}/cdk-hnb659fds-container-assets-${AWS::AccountId}-${AWS::Region}:baa2d6eb2a17c75424df631c8c70ff39f2d5f3bee8b9e1a109ee24ca17300540',
+      'Fn::Sub': '${AWS::AccountId}.dkr.ecr.${AWS::Region}.${AWS::URLSuffix}/cdk-hnb659fds-container-assets-${AWS::AccountId}-${AWS::Region}:aba53d5f05c76afcd7e420dc8cd283ddc31657866bb4ba4ce221e13d8128d92c',
     });
   });
 });
diff --git a/packages/@aws-cdk/aws-ecs/test/demo-image/Dockerfile b/packages/@aws-cdk/aws-ecs/test/demo-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-ecs/test/demo-image/Dockerfile
+++ b/packages/@aws-cdk/aws-ecs/test/demo-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-ecs/test/ec2/ec2-task-definition.test.ts b/packages/@aws-cdk/aws-ecs/test/ec2/ec2-task-definition.test.ts
index 77b1607c13432..fd134d64bbfe6 100644
--- a/packages/@aws-cdk/aws-ecs/test/ec2/ec2-task-definition.test.ts
+++ b/packages/@aws-cdk/aws-ecs/test/ec2/ec2-task-definition.test.ts
@@ -748,7 +748,7 @@ describe('ec2 task definition', () => {
                   {
                     Ref: 'AWS::URLSuffix',
                   },
-                  '/aws-cdk/assets:8c1d9ca9f5d37b1c4870c13a9f855301bb42c1848dbcdd5edc8fe2c6c7261d48',
+                  '/aws-cdk/assets:0a3355be12051c9984bf2b0b2bba4e6ea535968e5b6e7396449701732fe5ed14',
                 ],
               ],
             },
diff --git a/packages/@aws-cdk/aws-events-targets/test/ecs/eventhandler-image/Dockerfile b/packages/@aws-cdk/aws-events-targets/test/ecs/eventhandler-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-events-targets/test/ecs/eventhandler-image/Dockerfile
+++ b/packages/@aws-cdk/aws-events-targets/test/ecs/eventhandler-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-ec2-task.lit.expected.json b/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-ec2-task.lit.expected.json
index 444eaab9f6152..a1423b9e05d3a 100644
--- a/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-ec2-task.lit.expected.json
+++ b/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-ec2-task.lit.expected.json
@@ -698,7 +698,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-fargate-task.expected.json b/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-fargate-task.expected.json
index 9cd668c41aa03..bcfc4ef7fb064 100644
--- a/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-fargate-task.expected.json
+++ b/packages/@aws-cdk/aws-events-targets/test/ecs/integ.event-fargate-task.expected.json
@@ -237,7 +237,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-s3-assets/test/alpine-markdown/Dockerfile b/packages/@aws-cdk/aws-s3-assets/test/alpine-markdown/Dockerfile
index fa7a67678bae9..d0ec147b4a786 100644
--- a/packages/@aws-cdk/aws-s3-assets/test/alpine-markdown/Dockerfile
+++ b/packages/@aws-cdk/aws-s3-assets/test/alpine-markdown/Dockerfile
@@ -1,3 +1,3 @@
-FROM alpine
+FROM public.ecr.aws/docker/library/alpine:latest
 
 RUN apk add markdown
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/batchjob-image/Dockerfile b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/batchjob-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/batchjob-image/Dockerfile
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/batchjob-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.run-batch-job.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.run-batch-job.expected.json
index 94145f863083d..aff74626991ab 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.run-batch-job.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.run-batch-job.expected.json
@@ -869,7 +869,7 @@
                 {
                   "Ref": "AWS::URLSuffix"
                 },
-                "/aws-cdk/assets:3691f011ed75cf0fd05152b8fae3d684323da3da9eaf3be68cba18cb9def2562"
+                "/aws-cdk/assets:8b518243ecbfcfd08b4734069e7e74ff97b7889dfde0a60d16e7bdc96e6c593b"
               ]
             ]
           },
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.submit-job.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.submit-job.expected.json
index 7f48977f12e6c..a722fd182008c 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.submit-job.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/batch/integ.submit-job.expected.json
@@ -869,7 +869,7 @@
                 {
                   "Ref": "AWS::URLSuffix"
                 },
-                "/aws-cdk/assets:3691f011ed75cf0fd05152b8fae3d684323da3da9eaf3be68cba18cb9def2562"
+                "/aws-cdk/assets:8b518243ecbfcfd08b4734069e7e74ff97b7889dfde0a60d16e7bdc96e6c593b"
               ]
             ]
           },
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/eventhandler-image/Dockerfile b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/eventhandler-image/Dockerfile
index 123b5670febc8..235b30e9661ed 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/eventhandler-image/Dockerfile
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/eventhandler-image/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM public.ecr.aws/lambda/python:3.6
 EXPOSE 8000
 WORKDIR /src
 ADD . /src
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-run-task.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-run-task.expected.json
index 4dcc2e6776cca..2beaafbdd6e2a 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-run-task.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-run-task.expected.json
@@ -485,7 +485,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-task.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-task.expected.json
index 558b81faa2897..ed5ada51c4bfa 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-task.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.ec2-task.expected.json
@@ -485,7 +485,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-run-task.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-run-task.expected.json
index ca30cca5b1beb..7cfb1aba285c3 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-run-task.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-run-task.expected.json
@@ -34,7 +34,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-task.expected.json b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-task.expected.json
index d6e61df69d806..4c53cf87e2386 100644
--- a/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-task.expected.json
+++ b/packages/@aws-cdk/aws-stepfunctions-tasks/test/ecs/integ.fargate-task.expected.json
@@ -34,7 +34,7 @@
                   {
                     "Ref": "AWS::URLSuffix"
                   },
-                  "/aws-cdk/assets:3fc39b45c4fd074ceef5d0f8528b74fa7fe6e8fa0aa4a6ffe7fb5e016cf8dc04"
+                  "/aws-cdk/assets:7a4895bc694ae074467753dddb9a798e58f2f5eda62bcce5833d7d356b8a1da2"
                 ]
               ]
             },
diff --git a/packages/@aws-cdk/cx-api/test/fixtures/asset-manifest/docker-asset/Dockerfile b/packages/@aws-cdk/cx-api/test/fixtures/asset-manifest/docker-asset/Dockerfile
index ceaf18ac05257..9b247ee4463fa 100644
--- a/packages/@aws-cdk/cx-api/test/fixtures/asset-manifest/docker-asset/Dockerfile
+++ b/packages/@aws-cdk/cx-api/test/fixtures/asset-manifest/docker-asset/Dockerfile
@@ -1 +1 @@
-FROM ubuntu
+FROM public.ecr.aws/docker/library/ubuntu:latest
diff --git a/packages/@aws-cdk/cx-api/test/fixtures/assets/docker-asset/Dockerfile b/packages/@aws-cdk/cx-api/test/fixtures/assets/docker-asset/Dockerfile
index ceaf18ac05257..9b247ee4463fa 100644
--- a/packages/@aws-cdk/cx-api/test/fixtures/assets/docker-asset/Dockerfile
+++ b/packages/@aws-cdk/cx-api/test/fixtures/assets/docker-asset/Dockerfile
@@ -1 +1 @@
-FROM ubuntu
+FROM public.ecr.aws/docker/library/ubuntu:latest
diff --git a/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile b/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile
index 2f54902fde481..a7e84d32f529d 100644
--- a/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile
+++ b/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile
@@ -1,2 +1,2 @@
-FROM alpine
+FROM public.ecr.aws/docker/library/alpine:latest
 
diff --git a/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile.Custom b/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile.Custom
index 2f54902fde481..a7e84d32f529d 100644
--- a/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile.Custom
+++ b/packages/aws-cdk/test/integ/cli/app/docker/Dockerfile.Custom
@@ -1,2 +1,2 @@
-FROM alpine
+FROM public.ecr.aws/docker/library/alpine:latest