UserNotes:lalyos

my initial use-cases for cmd.io:

• listing/filtering cloud resources (aws/gcloud/digitalocean ...)
• one single instance list across all supported clouds (cost control)
• sigil playground:
  • template from stdin (for example create a custom sigil from a PR branch, check before merging)
  • git push based template generation, no local sigil install needed

List AWS resources

This is the most common use-case, so lets start implementing it with cmd.io. Simple aws-cli wrapping is fine, but lets take it a bit further:

• cross region resource listing
• configurable fields to display (to fit narrow terminal with most important data)
• filtering based on Tags (you can rely your own internal tagging policies, like prod/test)

Ec2-list Command

install and configure the command

ssh cmd :add ec2-list lalyos/cmd-aws
ssh cmd ec2-list:config set \
  AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
  AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
  AWS_ROLE_ARN=$AWS_ROLE_ARN

Changing the fields

You can use the image locally as well, and tune the QUERY env var until you get it right:

QUERY='id: InstanceId, region: Placement.AvailabilityZone, started: LaunchTime, pubIp: PublicIpAddress'
docker run -it \
  -e AWS_ROLE_ARN=$AWS_ROLE_ARN \
  -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
  -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
  -e "QUERY=$QUERY" \
  lalyos/cmd-aws

Complex fields

awscli uses JMesPath for restricting fields, filtering/sorting arrays. But it uses all quotation marks: single, double even backtick. So if you want to pass a complicated awscli query parameter for example which includes space and backtick, you are entering the quotation hell. Or use QUERY_BASE64 which will be bas64 decoded in the containers entrypoint script.

QUERY='id: InstanceId, region: Placement.AvailabilityZone, started: LaunchTime, pubIp: PublicIpAddress, stack: join(``, Tags[?Key==`aws:cloudformation:stack-name`].Value || `[]`), name: join(``, Tags[?Key==`Name`].Value || `[]`), owner: join(``, Tags[?(Key==`owner` || Key==`Owner`)].Value || `[]`) '
QUERY='id: InstanceId, region: Placement.AvailabilityZone, started: LaunchTime, pubIp: PublicIpAddress,  name: join(``, Tags[?Key==`Name`].Value || `[]`)'
QUERY_BASE64=$(base64 <<< $QUERY)

docker run -it \
  -e AWS_ROLE_ARN=$AWS_ROLE_ARN \
  -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
  -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
  -e QUERY_BASE64=$(base64 <<< $QUERY) \
  lalyos/cmd-aws

SSH setup

You can type less (obviously you can create an alias as well), but ssh ControlMaster makes accelerated cmd.io commands after initial connection.

Create ssh config for cmd.io which reuses a "background" ssh connection

cat >> ~/.ssh/config <<EOF
Host cmd
    Hostname alpha.cmd.io
    User yourgithubname
    ControlMaster auto
    ControlPath /tmp/%r@%h:%p
    ControlPersist yes
EOF

Custom Docker Image

built by using: https://github.com/lalyos/docker-cmd-aws