AWS cdk documentation change

Service: cdk · 2025-03-02 · Documentation low

File: cdk/v2/guide/ref-cli-cmd-diff.md

Summary

Added detailed documentation about CDK CLI diff output symbols and provided an example of a Lambda function diff.

Security assessment

The changes are purely about improving documentation for the CDK CLI diff command and its output format. There is no security-related content in these changes.

Diff

diff --git a/cdk/v2/guide/ref-cli-cmd-diff.md
index c5315f2db..4480e3e90 100644
--- a/cdk/v2/guide/ref-cli-cmd-diff.md
+++ b/cdk/v2/guide/ref-cli-cmd-diff.md
@@ -104,0 +105,52 @@ The path to the CloudFormation template to compare a CDK stack with.
+The CDK CLI uses the following symbols in the diff output:
+
+  * `[+]` – Identifies code or resources that will be added if you deploy your changes.
+
+  * `[-]` – Identifies code or resources that will be removed if you deploy your changes.
+
+  * `[~]` – Identifies a resource or property that will be modified if you deploy your changes.
+
+
+
+
+The following is an example that shows a diff of local changes to a Lambda function:
+    
+    
+    $ cdk diff MyStackName
+    start: Building asset-hash:account-Region
+    success: Built asset-hash:account-Region
+    start: Publishing asset-hash:account-Region
+    success: Published asset-hash:account-Region
+    Hold on while we create a read-only change set to get a diff with accurate replacement information (use --no-change-set to use a less accurate but faster template-only diff)
+    Stack MyStackName
+    Resources
+    [~] AWS::Lambda::Function HelloWorldFunction resource-logical-ID
+     └─ [~] Code
+         └─ [~] .ZipFile:
+             ├─ [-] 
+            exports.handler = async function(event) {
+              return {
+                statusCode: 200,
+                body: JSON.stringify('Hello World!'),
+              };
+            };
+          
+             └─ [+] 
+            exports.handler = async function(event) {
+              return {
+                statusCode: 200,
+                body: JSON.stringify('Hello from CDK!'),
+              };
+            };
+          
+    
+    
+    ✨  Number of stacks with differences: 1
+
+A `[~]` indicator for resources that will be modified does not always mean a full resource replacement:
+
+  * Some resource properties, like `Code`, will update the resource.
+
+  * Some resource properties, like `FunctionName`, may cause a full resource replacement.
+
+
@@ -106 +157,0 @@ The path to the CloudFormation template to compare a CDK stack with.
-    $ cdk diff MyStackName --app='node bin/main.js'