Introduction

ec2ssh is a ssh_config manager for Amazon EC2.

ec2ssh command adds Host descriptions to ssh_config (~/.ssh/config default). 'Name' tag of instances are used as Host descriptions.

How to use

1. Set 'Name' tag to your instances

eg. Tag 'app-server-1' as 'Name' to an instance i-xxxxx in us-west-1 region.

2. Write ~/.aws/credentials

# ~/.aws/credentials

[default]
aws_access_key_id=...
aws_secret_access_key=...

[myprofile]
aws_access_key_id=...
aws_secret_access_key=...

If you need more details about ~/.aws/credentials, check A New and Standardized Way to Manage Credentials in the AWS SDKs

3. Install ec2ssh

$ gem install ec2ssh

4. Execute ec2ssh init

$ ec2ssh init

5. Edit .ec2ssh

$ vi ~/.ec2ssh
---
profiles 'default', 'myprofile', ...
regions 'us-east-1', 'ap-northeast-1', ...

# Ignore unnamed instances
reject {|instance| !instance.tag('Name') }

# You can specify filters on DescribeInstances (default: lists 'running' instances only)
filters([
  { name: 'instance-state-name', values: ['running', 'stopped'] }
])

# You can use methods of AWS::EC2::Instance and tag(key) method.
# See https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/EC2/Instance.html
host_line <<END
Host <%= tag('Name') %>.<%= placement.availability_zone %>
  HostName <%= public_dns_name || private_ip_address %>
END

6. Execute ec2ssh update

$ ec2ssh update

Then host-names of your instances are generated and wrote to .ssh/config

7. And you can ssh to your instances with your tagged name.

$ ssh app-server-1.us-east-1a

Commands

$ ec2ssh help [TASK]  # Describe available tasks or one specific task
$ ec2ssh init         # Add ec2ssh mark to ssh_config
$ ec2ssh update       # Update ec2 hosts list in ssh_config
$ ec2ssh remove       # Remove ec2ssh mark from ssh_config

Options

--dotfile

Each command can use --dotfile option to set dotfile (.ec2ssh) path. ~/.ec2ssh is default.

$ ec2ssh init --dotfile /path/to/ssh_config

ssh_config and mark lines

ec2ssh init command inserts mark lines your .ssh/config such as:

### EC2SSH BEGIN ###
# Generated by ec2ssh http://github.com/mirakui/ec2ssh
# DO NOT edit this block!
# Updated Sun Dec 05 00:00:14 +0900 2010
### EC2SSH END ###

ec2ssh update command inserts 'Host' descriptions between 'BEGIN' line and 'END' line.

### EC2SSH BEGIN ###
# Generated by ec2ssh http://github.com/mirakui/ec2ssh
# DO NOT edit this block!
# Updated Sun Dec 05 00:00:14 +0900 2010

# section: default
Host app-server-1.us-west-1
  HostName ec2-xxx-xxx-xxx-xxx.us-west-1.compute.amazonaws.com
Host db-server-1.ap-southeast-1
  HostName ec2-xxx-xxx-xxx-xxx.ap-southeast-1.compute.amazonaws.com
    :
    :
### EC2SSH END ###

ec2ssh remove command removes the mark lines.

How to upgrade from 3.x

Dotfile (.ec2ssh) format has been changed from 3.x.

• A instance tag access I/F has been changed from tags['Name'] to tag('Name')
• Aws::EC2::Instance methods have been changed to AWS SDK v3
• The aws_keys structure has been changed
  • aws_keys[profile_name][region] # => Aws::Credentials
  • For example:

aws_keys(
  my_prof1: {
    'ap-northeast-1' => Aws::Credentials.new(ENV['AWS_ACCESS_KEY_ID'], ENV['AWS_SECRET_ACCESS_KEY'])
  }
)

Notice

ec2ssh command updates your .ssh/config file default. You should make a backup of it.

Zsh completion support

Use zsh/_ec2ssh.

License

Copyright (c) 2022 Issei Naruta. ec2ssh is released under the MIT license.