springload / ecs-tool

What is it?

ecs-tool can run commands on an ECS cluster. There are some tools available, like official: ecs-cli, awscli, and custom ones like ecs-deploy.

However, they have too many flags to just do one thing: run a command. Also, those tools don't give the command output, and there are different flags or even tools to get it.

So what if there was a project- and environment-specific config with all the settings, so that you can concentrate only on a command you want to run?

There it is

So that's it:

$ecs-tool run -h
Runs the specified command on an ECS cluster, optionally catching its output.

It can modify the container command.

Usage:
  ecs-tool run [flags]

Flags:
      --container_name string   Name of the container to modify parameters for
  -h, --help                    help for run
  -l, --log_group string        Name of the log group to get output

Global Flags:
  -c, --cluster string           name of cluster (required)
      --config string            config file to use. Overrides -e/--environment lookup
  -e, --environment string       look up config based on the environment flag. It looks for ecs-$environment.toml config in infra folder.
  -p, --profile string           name of profile to use
  -t, --task_definition string   name of task definition to use (required)

There are a couple of required flags, but they can be set either via enviromental variables or in the config. It is possible to define a specific config by using --config flag, or rely on ecs-tool to look it up based on --environment flag. The tool then will search for infra/ecs-$environment.toml file.

Just try running ecs-tool envs in a project folder to discover available environments.

It is as simple as this (while being in the project folder /Users/user/company/project_name):

$ecs-tool run -e production -- uptime
2018/07/26 09:52:24  info Using config file: /Users/user/company/project_name/infra/ecs-production.toml
2018/07/26 09:52:26  info waiting for the task to finish task_definition=project_name-production-app
 21:52:28 up 16 days, 10:45,  load average: 0.00, 0.02, 0.00

Even more, it is possible to configure ecs-tool via environmental variables instead of using config. Every flag has to be uppercased and prefixed by ECS_. So that --cluster can be set by ECS_CLUSTER environmental variable, or --task_definition by ECS_TASK_DEFINITION.

Also, ecs-tool exit code is the same as the container exit code.

SSH

'SSH' access availabe to developers using ecs-tool ssh

$ecs-tool ssh -e preview
  INFO[0000] Using config file: ecs-preview.toml
  INFO[0000] Looking for ECS Task...   task_definition=test-preview-app
  INFO[0001] Looking for EC2 Instance... task_arn=arn:aws:ecs:ap-southeast-2:123456789:task/00000000-0000-0000-0000-000000 task_definition=test-preview-app
  INFO[0001] Pushing SSH key...        instance_id=i-12345678888765432 task_definition=test-preview-app
  INFO[0002] Connecting to container... instance_id=i-12345678888765432 task_definition=test-preview-app
root@d00e0c978012:/app# ls
Gemfile  Gemfile.lock  Guardfile  LICENSE  README.md  Rakefile  api_testing_examples.md  app  bin  config  config.ru  db  
docker  docker-compose.yml  infra  lib  log  model_testing_examples.md  public  spec  tmp
root@d00e0c978012:/app#

AWS Authentication

It is handled by aws-sdk-go and supports all standard methods: env vars, ~/.aws/credential and ~/.aws/config.

Installation

There are deb and rpm packages and binaries for those who don't use packages. Just head up to the releases page.

For Mac users there is one simple command: brew install springload/tools/ecs-tool.