paramedic

Paramedic

Paramedic is a tool to diagnose and remediate instances, using Amazon EC2 Systems Manager.

With Paramedic:

• can cancel a running command by sending SIGTERM
• can see output of running commands in near-realtime, using Kinesis Streams
• Operations can be delegated to specific users or groups, using IAM policy
• Operations stored as documents can be used repeatedly
• Operations can be reviewed as a code, using a platform like GitHub Pull Requests

Setup

TODO

Configure Kinesis Streams

Create a stream named paramedic-logs and configure subscription from CloudWatch Logs: http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/SubscriptionFilters.html#DestinationKinesisExample

Note that the filter pattern should be empty.

Usage

Prepare YAML file which defines a document to be run:

# reload-nginx.yaml
name: reload-nginx # Optional
description: Reload nginx via systemctl
scriptFile: reload-nginx

Save a script named reload-yaml:

#!/bin/bash
exec systemctl reload nginx

Upload a document to SSM:

$ paramedic documents upload reload-nginx.yaml

Run a command:

$ paramedic commands run --document-name=reload-nginx --tags=Env=dev,Role=app
2017/09/27 13:26:19 [INFO] This command will be executed on the following instances
2017/09/27 13:26:19 [INFO]   app-i-aaa (i-aaa)
2017/09/27 13:26:19 [INFO]   app-i-bbb (i-bbb)
Are you sure to continue? (y/N): y
2017/09/27 13:26:20 [INFO] A command '...' started
2017/09/27 13:26:20 [INFO] To see the command status, run 'paramedic commands show --command-id=...'
2017/09/27 13:26:20 [INFO] Output logs will be shown below
[2017-09-27T13:26:21+09:00] [i-aaa] [exit status: 0]
[2017-09-27T13:26:21+09:00] [i-bbb] [exit status: 0]

app-i-aaa (i-aaa) Success
app-i-bbb (i-bbb) Success

Development

Adding a subcommand

$ go get github.com/spf13/cobra/cobra
$ cobra add newcommand