#aws #ec2 #elb #cli #asg

app burnish

Safely deploy code to auto-scaling groups with this Rust-based command line utility

1 unstable release

Uses old Rust 2015

0.1.0 Jan 12, 2020

#453 in Command-line interface

MIT license


Rust 886 SLoC // 0.0% comments HCL 138 SLoC


burnish is a tool to manage deployments of EC2-powered applications.


This project is a rewrite of Golang based tool that my employer uses in production (with their permission). This is another attempt to help me learn how to write command line utilities in Rust. While I believe I have complete feature coverage compared to the original tool, a lot of the work here has not been seriously tested.


burnish is a high-level wrapper of the AWS API. By using burnish, teams can quickly deploy new code releases, view the status of their environments, and modify the state of running applications.

burnish makes certain assumptions about how applications are deployed:

  • Each release is packaged as a single AWS EC2 AMI
  • An application can be deployed to an auto scaling group and registered with an Elastic Load Balancer
  • The application reports health and version information on well-known paths
  • The application uses monotonically-incrementating integer release identifiers, e.g. r41, r42, r43…
  • Two versions of the application can run simultaneously in separate auto scaling groups

In addition to managing deployments, burnish exposes tools to manage creating launch configurations, auto scaling groups, rotating instances in an auto scaling group, measuring ELB statistics, and marking deployment activities in New Relic.

At this time, burnish does not involve itself in:

  • database migrations
  • external notifications (e.g. pinging a Slack channel upon deploy completion)
  • multiple-region application deployments
  • non-EC2 AMI-based applications

This may change in future releases.


You can download a prebuilt binary here.

Configure your AWS resources

burnish relies on a "universe" file that defines the environments and applications that it can deploy. universe.json.example is a barebones example of a universe file. You must have a complete, functional universe file for burnish to function.

burnish does not impose any restrictions on your overall AWS architecture; it only assumes that your application is deployed as a single AMI to an auto scaling group, and is registered with an Elastic Load Balancer. You are free to configure your VPC and related network topology as you see fit.

burnish provides a sample Terraform configuration that defines auto scaling groups, Cloud Watch alarms, and scaling policies. This configuration may be used as the basis for your own configuration, tailored to your application's specific configuration. See the README for instructions on how to use it and the expected output.


ELB Monitoring

Use the burnish elb stats to fetch real-time ELB metrics from CloudWatch.

$ burnish elb stats --name my-example-elb
| Interval | Requests | Requests/sec | 500 Errors | 500 Error % | Connection Errors | Avg. Latency (ms) |
| 1 min    | 395      | 6.58         | 2          | 0.005       | 0                 | 0.190             |
| 5 min    | 1820     | 6.07         | 14         | 0.008       | 0                 | 0.295             |
| 15 min   | 5658     | 6.29         | 48         | 0.008       | 0                 | 0.310             |
| 60 min   | 21650    | 6.01         | 202        | 0.009       | 0                 | 0.289             |

Use burnish elb status to retrieve information about instances registered with a load balancer. Omit --app to list all applications for an environment.

$ burnish elb status --name my-example-elb
+---------------------+-----------+---------------------+-------- +----------------+------------------+--------------------+
| Instance ID         | Health    | Name                | Version | IP Address     | ASG              | Uptime             |
| i-fa2825f154cb662a4 | InService | my-example-instance | r1337   |  | my-example-asg   | 3 days 3 hours ago |
| i-19418f7dabcd27c52 | InService | my-example-instance | r1337   | | my-example-asg   | 3 days 3 hours ago |

Application Deployment

Let's say you want to deploy a new release to production.

  1. Create an AMI. Use packer, Ansible, or another tool to create an AMI with your new application release. burnish is indifferent to how you make an AMI.
  2. Tag your application AMI with app and version tags. The app tag should match the app value in your universe file, and the version should be a meaningful, unique string.
  3. Perform a blue/green deploy of the new code. burnish will use the CLI flags to find the AMI, and then infer environment data (autoscaling groups, load balancers, etc.) from the universe file.
burnish deployment do --app application_name --env dev --version 42

General usage

Use burnish help to see a complete set of command line operations.

    burnish [OPTIONS] [SUBCOMMAND]

    -h, --help       Prints help information
    -V, --version    Prints version information

    -l, --log-level <STRING>    Logging Level: 'debug' for verbose, 'info' for terse (default: 'info')
    -p, --profile <STRING>      AWS Profile (Default: 'default')
    -r, --region <STRING>       AWS Region (Default: 'us-east-1')
    -u, --universe <FILE>       YAML Universe file

    autoscalegroup    create & manipulate autoscale groups
    debug             debug application inventory json
    deployment        perform deployment actions
    help              Prints this message or the help of the given subcommand(s)
    launchconfig      create a new launch config
    loadbalancer      create & manipulate elastic load balancers
    oneoff            launch or terminate a one-off instance


~617K SLoC