feat: add lambda-prune script

Author: chrispsheehan

.github/workflows/deploy.yml

@@ -121,3 +121,12 @@ jobs:
         with:
           aws_oidc_role_arn: ${{ env.AWS_OIDC_ROLE_ARN }}
           just_action: lambda-deploy
+
+      - name: prune lambda
+        uses: chrispsheehan/just-aws-oidc-action@0.1.3
+        env:
+          FUNCTION_NAME: ${{ steps.get-api-vars.outputs.lambda_function_name }}
+          ALIAS_NAME: ${{ steps.get-api-vars.outputs.lambda_alias_name }}
+        with:
+          aws_oidc_role_arn: ${{ env.AWS_OIDC_ROLE_ARN }}
+          just_action: lambda-prune

justfile

@@ -230,3 +230,30 @@ lambda-deploy:
     echo "❌ Deployment $DEPLOYMENT_ID did not complete within expected time."
     exit 1
 
+
+lambda-prune:
+    #!/usr/bin/env bash
+    KEEP=3
+
+    live_version=$(aws lambda get-alias \
+        --function-name "$FUNCTION_NAME" \
+        --name "$ALIAS_NAME" \
+        --region "$REGION" \
+        | jq -r '.FunctionVersion')
+
+    echo "Alias '$ALIAS_NAME' points to: ${live_version:-<none>}"
+
+    # All published versions (exclude $LATEST), newest first
+    versions=$(aws lambda list-versions-by-function \
+        --function-name "$FUNCTION_NAME" \
+        --region "$AWS_REGION" \
+        | jq -r '.Versions[] | select(.Version != "$LATEST") | .Version' \
+        | sort -nr)
+
+    keep_newest=$(echo "$versions" | head -n "$KEEP")
+    keep_set=$(printf "%s\n%s\n" "$keep_newest" "$live_version" | sort -u)
+    to_delete=$(comm -23 <(echo "$versions" | sort -u) <(echo "$keep_set" | sort -u))
+
+    echo "Keeping:  $(echo "$keep_set" | tr '\n' ' ')"
+    echo "Deleting: $(echo "$to_delete" | tr '\n' ' ')"
+    # aws lambda delete-function --function-name "$FUNCTION_NAME" --qualifier "$v" --region "$REGION"