Peek inside your AWS CloudFormation Deployments with timeline view

AWS CloudFormation makes it easy to model and provision your cloud application infrastructure as code. CloudFormation templates can be written directly in JSON or YAML, or they can be generated by tools like the AWS Cloud Development Kit (CDK). These templates are submitted to the CloudFormation service and the resources are deployed together as stacks, in dependency order. Stack events can be viewed in a tabular format in the console, which provides fine-grained details about each event. And now there is a new feature that offers a more visually intuitive view of the events called the deployment timeline view, which provides a visualization of the sequence of actions CloudFormation took in a stack operation. This visual timeline shows you the exact order in which resources are provisioned, dependencies between resources, provisioning times, and likely root causes for any deployment failures. It complements the existing tabular stack events view by giving you additional context and visibility into what happens behind the scenes during deployments.

Figure 1: CloudFormation deployment timeline view feature overview

To use the new deployment timeline view, simply initiate a stack create, update, or delete operation. In the AWS CloudFormation Console, choose the Events tab, then click the Timeline view tab next to Table View. As CloudFormation begins provisioning the resources defined in your template, you’ll see each resource operation appear as a bar in the timeline view. The resources are organized in a vertical stack, chronologically ordered with the most recent resource operation at the top. Each resource action is visualized horizontally, segmented by different color bars for each resource action:

In dark mode, in-progress rollback and completed rollback switch colors.

You can hover over any bar to see additional details like the full resource name and the start/end times of the resource action. If a deployment fails, CloudFormation will highlight the resource operation that was the likely root cause node in a red-and-white striped bar, which you can hover over to see the specific failure reason.

Create a simple stack using CloudFormation Console. You will initiate a deployment and then explore the visual timeline view.

1. From the CloudFormation console, click Create stack and then choose with new resources.

Figure 2: CloudFormation’s create stack console button 

2. In the Create stack wizard, click Choose an existing template and then choose Upload a template file. Click Choose file to select and upload the template file of the stack to deploy. In this blog you will use the template available here. Download the template or you can use your own template. If you decide to use your own template, it will result in a different deployment timeline view.

Figure 3: CloudFormation’s create stack console wizard

The application stack includes the following key resources: Amazon EC2 instance (AWS::EC2::Instance), an Amazon VPC (AWS::EC2::VPC) and related VPC resources like subnets (AWS::EC2::Subnet) and an internet gateway (AWS::EC2::InternetGateway).

3. Once the template is uploaded to S3, click Next, then provide a stack name and parameters if needed. Complete the remaining stack deployment configuration steps, then initiate the stack creation operation.

4. On the stack events page, click the Deployment timeline tab next to Events.

You should now see the deployment timeline view rendering in real-time as CloudFormation provisions the VPC networking resources first, followed by the security group, subnet, and lastly, the EC2 instance.

Figure 4: Real-time CloudFormation in-progress deployment timeline view 

5. The timeline refreshes every five seconds to update the deployment progress. Five seconds later you have the below timeline view.

Figure 5: Updated CloudFormation deployment timeline after five second

Figure 6: CloudFormation completed deployment timeline view 

The above timeline shows, from the bottom to the top, bars representing each resource CloudFormation provisioned, with virtual vertical dependency lines showing the orders in which each resource operation occurred. The bars change colors as operations progress from blue (in-progress), to yellow consistency check, green (success) or red (failed).

Figure 7: CloudFormation deployment timeline view – resource detail popover

Hover over any bar to see details like the start/end time of each deployment phase and the full resource name. The detailed information in the graph’s popover shows that CloudFormation created the InternetGateway resource in two seconds, then waited for 15-seconds to check if the resource was fully operational before marking as complete. This phase is called the resource consistency check phase, also known as the resource stabilization phase. It allows CloudFormation and other Infrastructure as Code (IaC) tools to ensure resilient deployments. To learn more, read this post about CloudFormation optimistic stabilization strategy.

When a stack deployment fails, CloudFormation rolls your stack back to its initial stable state before the current stack operation. The deployment timeline view below shows a failed stack operation in a complete rollback state. You can see the likely root cause resource highlighted in a red-and-white striped color so you can instantly identify it and start troubleshooting.

Figure 8: Deployment timeline view of a stack in rollback complete

The new CloudFormation deployment timeline view provides visibility into the orchestration flow and dependencies involved when CloudFormation provisions resources defined in your infrastructure-as-code templates. With this visual timeline view, you can quickly identify the root cause of deployment failures before operations complete and better understand the provisioning process. This feature is available now in all AWS regions where CloudFormation is supported. Visit the CloudFormation console to start using deployment timeline view.

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