Overcast is a simple terminal-based cloud management tool that was designed to make it easy to spin up and manage clusters of servers in a consistent, scriptable way. Inspired by Packer.io.
Define clusters using the command line or manually by editing a JSON file.
$ overcast cluster create db
$ overcast cluster create app
Create, snapshot and destroy instances on DigitalOcean.
# Create a new Ubuntu 12.04 instance:
$ overcast instance create db.01 --cluster=db
# Install/configure the instance to your liking:
$ overcast run db.01 install/core install/redis
$ overcast expose db.01 22 6379
# Shutdown the instance and create a snapshot:
$ overcast digitalocean shutdown db.01
$ overcast digitalocean snapshot db.01 my.db.snapshot
# Spin up a cluster using your snapshot:
$ overcast instance create db.02 --cluster=db --image-name=my.db.snapshot
$ overcast instance create db.03 --cluster=db --image-name=my.db.snapshot
$ overcast instance create db.04 --cluster=db --image-name=my.db.snapshot
EC2/Linode support is on the roadmap.
Import existing instances located anywhere to a cluster.
$ overcast instance import app.01 --cluster=app --ip=127.0.0.2 \
--ssh-port=22222 --ssh-key=$HOME/.ssh/id_rsa
$ overcast instance import app.02 --cluster=app --ip=127.0.0.3 \
--ssh-port=22222 --ssh-key=$HOME/.ssh/id_rsa
Run commands or script files on an instance, a cluster, or all clusters, sequentially or in parallel.
$ overcast run db install/core install/redis
$ overcast run all uptime "free-m" "df -h" --parallel
Push and pull files between your local machine and an instance, a cluster, or all clusters. Dynamically rewrite file paths to include the instance name.
$ overcast push app nginx/myapp.conf /etc/nginx/sites-enabled/myapp.conf
$ overcast pull all /etc/nginx/sites-enabled/myapp.conf nginx/{instance}.myapp.conf
Overcast is a thin wrapper around your native SSH client, and doesn't install or leave anything on the servers you communicate with.
A script library is included to make it easy to install common software components in a modular fashion. The library is tailored to Ubuntu 12.04, but could easily be extended to include other distributions/versions.
There are a number of server management frameworks out there already (Chef, Puppet, Ansible, Salt), but all involve either a complicated server/client implementation, a steep learning curve or a giant, monolithic conceptual framework.
I wanted something that is conceptually simple and easy to use, that is only concerned with programmatic communication with clusters of servers, that leaves problems like process/state management and monitoring to other tools.
Install Node.js if not already installed.
Install Overcast using npm.
$ npm -g install overcast
You can now use Overcast from any directory.
$ overcast help
Overcast looks for an .overcast directory in the current directory, or in some parent directory, otherwise falling back to $HOME/.overcast. This allows you to have multiple configurations, and to check your cluster definitions and scripts into a repo, like source code.
The command overcast init will create a new configuration in the current directory. The config directory looks like this:
.overcast
/files # Files to be copied to instances
/keys # SSH keys. Can be your own or auto-generated by overcast
/scripts # Scripts to be run on instances
/clusters.json # Cluster/instance definitions (see example.clusters.json)
/variables.json # API keys, etc (see example.variables.json)
overcast cluster create [name]
Creates a new cluster.
Example:
$ overcast cluster create db
overcast cluster rename [name] [new-name]
Renames a cluster.
Example:
$ overcast cluster rename app-cluster app-cluster-old
overcast cluster remove [name]
Removes a cluster from the index. If the cluster has any instances
attached to it, they will be moved to the "orphaned" cluster.
Example:
$ overcast cluster remove db
These functions require the following values set in .overcast/variables.json:
DIGITALOCEAN_CLIENT_ID
DIGITALOCEAN_API_KEY
overcast digitalocean destroy [instance]
Destroys a DigitalOcean droplet and removes it from your account.
This is irreversible.
Example:
$ overcast digitalocean destroy app.01
overcast digitalocean droplets
List all DigitalOcean droplets in your account.
overcast digitalocean images
List all available DigitalOcean images. Includes snapshots.
overcast digitalocean reboot [instance]
Reboots a DigitalOcean droplet. According to their API docs: "this is the
preferred method to use if a server is not responding."
Example:
$ overcast digitalocean reboot app.01
overcast digitalocean rebuild [instance] [options]
Rebuild a DigitalOcean droplet using a specified image name, slug or ID.
According to the API docs, "This is useful if you want to start again but
retain the same IP address for your droplet."
Option | Default
--image-slug=SLUG | ubuntu-12-04-x64
--image-name=NAME |
--image-id=ID |
Example:
$ overcast digitalocean rebuild app.01 --name=my.app.snapshot
overcast digitalocean regions
List available DigitalOcean regions (nyc2, sfo1, etc).
overcast digitalocean sizes
List available DigitalOcean sizes (512mb, 1gb, etc).
overcast digitalocean shutdown [instance]
Shut down a DigitalOcean droplet.
Example:
$ overcast digitalocean shutdown app.01
overcast digitalocean snapshot [instance] [snapshot-name]
Creates a named snapshot of a droplet. Returns a snapshot object,
which you can use to create a new instance. This may cause a reboot.
Example:
$ overcast digitalocean snapshot app.01
overcast digitalocean snapshots
Lists available snapshots in your DigitalOcean account.
overcast expose [instance|cluster|all] [port...]
Reset the exposed ports on the instance or cluster using iptables.
This will fail if you don't include the current SSH port.
Expects an Ubuntu server, untested on other distributions.
Examples:
$ overcast expose redis 22 6379
$ overcast expose mysql 22 3306
$ overcast expose app 22 80 443
overcast exposed [instance|cluster|all]
List the exposed ports on the instance or cluster.
Expects an Ubuntu server, untested on other distributions.
Overcast v0.1.8
Code repo, issues, pull requests:
https://github.com/andrewchilds/overcast
Usage:
overcast [command] [options...]
Help:
overcast help
overcast help [command]
overcast [command] help
Commands:
overcast cluster list
overcast cluster create [name]
overcast cluster rename [name] [new-name]
overcast cluster remove [name]
overcast digitalocean destroy [instance]
overcast digitalocean droplets
overcast digitalocean images
overcast digitalocean reboot [instance]
overcast digitalocean rebuild [instance] [options]
overcast digitalocean regions
overcast digitalocean sizes
overcast digitalocean shutdown [instance]
overcast digitalocean snapshot [instance] [snapshot-name]
overcast digitalocean snapshots
overcast expose [instance|cluster|all] [port...]
overcast exposed [instance|cluster|all]
overcast info
overcast init
overcast instance create [name] [options]
overcast instance import [name] [options]
overcast instance remove [name]
overcast list
overcast ping [instance|cluster|all]
overcast port [instance|cluster|all] [port]
overcast pull [instance|cluster|all] [source] [dest]
overcast push [instance|cluster|all] [source] [dest]
overcast run [instance|cluster|all] [command...]
overcast run [instance|cluster|all] [file...]
overcast ssh [instance]
Config directory:
/path/to/.overcast
overcast info
Pretty-prints the complete clusters.json file, stored here:
/path/to/.overcast/clusters.json
overcast init
Create an .overcast config directory in the current working directory.
No action taken if one already exists.
overcast instance create [name] [options]
Creates a new instance on a hosting provider. You'll need to add your API
credentials to the .overcast/variables.json file for this to work.
See the .overcast/example.variables.json file for reference.
The instance will start out using the auto-generated SSH key found here:
/path/to/.overcast/keys/overcast.key.pub
You can specify region, image, and size of the droplet using -id or -slug.
You can also specify an image or snapshot using --image-name.
Option | Default
--cluster=CLUSTER |
--provider=NAME | digitalocean
--ssh-port=PORT | 22
--region-slug=NAME | nyc2
--region-id=ID |
--image-slug=NAME | ubuntu-12-04-x64
--image-id=ID |
--image-name=NAME |
--size-slug=NAME | 512mb
--size-id=ID |
Example:
$ overcast instance create db.01 --cluster=db --host=digitalocean
overcast instance import [name] [options]
Imports an existing instance to a cluster.
Option | Default
--cluster=CLUSTER |
--ip=IP |
--ssh-port=PORT | 22
--ssh-key=PATH | .overcast/keys/overcast.key
--user=USERNAME | root
Example:
$ overcast instance import app.01 --cluster=app --ip=127.0.0.1 \
--ssh-port=22222 --ssh-key=$HOME/.ssh/id_rsa
overcast instance remove [name]
Removes an instance from the index.
The server itself is not affected by this action.
Example:
$ overcast instance remove app.01
overcast list
Short list of your cluster and instance definitions, stored here:
/path/to/.overcast/clusters.json
overcast ping [instance|cluster|all]
Ping an instance or cluster.
Option | Default
--count=N | 3
Examples:
$ overcast ping app.01
$ overcast ping db --count=5
overcast port [instance|cluster|all] [port]
Change the SSH port for an instance or a cluster.
Careful, this port should already be open!
Examples:
$ overcast port app.01 22222
$ overcast port db 22222
overcast pull [instance|cluster|all] [source] [dest]
Pull a file or directory from an instance or cluster using scp. Source is absolute.
Destination can be absolute or relative to the .overcast/files directory.
Any reference to {instance} in the destination will be replaced with the instance name.
Example:
Assuming instances "app.01" and "app.02", this will expand to:
- .overcast/files/nginx/app.01.myapp.conf
- .overcast/files/nginx/app.02.myapp.conf
$ overcast pull app /etc/nginx/sites-enabled/myapp.conf nginx/{instance}.myapp.conf
overcast push [instance|cluster|all] [source] [dest]
Push a file or directory to an instance or cluster using scp. Source can be
absolute, or relative to the .overcast/files directory. Destination is absolute.
Any reference to {instance} in the source will be replaced with the instance name.
Example:
Assuming instances "app.01" and "app.02", this will expand to:
- .overcast/files/nginx/app.01.myapp.conf
- .overcast/files/nginx/app.02.myapp.conf
$ overcast push app nginx/{instance}.myapp.conf /etc/nginx/sites-enabled/myapp.conf
overcast run [instance|cluster|all] [command...]
Runs a command or series of commands on an instance or cluster.
Commands will run sequentially unless you use the --parallel flag,
in which case each command will run on all instances simultanously.
Option
--env="KEY=VAL KEY='1 2 3'"
--parallel -p
Examples:
$ overcast run app --env="foo='bar bar' testing=123" env
$ overcast run all uptime "free -m" "df -h"
overcast run [instance|cluster|all] [file...]
Executes a script file or files on an instance or cluster.
Script files can be either absolute or relative path.
Script files will run sequentially unless you use the --parallel flag,
in which case each file will execute on all instances simultanously.
Option
--env="KEY=VAL KEY='1 2 3'"
--parallel -p
Relative paths are relative to this directory:
/path/to/.overcast/scripts
Example:
$ overcast run db install/core install/redis
overcast ssh [instance]
Opens an SSH connection to an instance.
npm install
npm test
npm -g update overcast
Configuration files are left alone during an upgrade.
Contributions are very welcome. If you've got an idea for a feature or found a bug, please open an issue. If you're a developer and want to help make Overcast better, open a pull request with your changes.
MIT. Copyright © 2014 Andrew Childs.
FAQs
A simple command line program that makes it easy to spin up, configure, and manage virtual machines over SSH.
The npm package overcast receives a total of 23 weekly downloads. As such, overcast popularity was classified as not popular.
We found that overcast demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 0 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Research
Security News
Socket researchers uncover a malicious npm package posing as a tool for detecting vulnerabilities in Etherium smart contracts.
Security News
Research
A supply chain attack on Rspack's npm packages injected cryptomining malware, potentially impacting thousands of developers.
Research
Security News
Socket researchers discovered a malware campaign on npm delivering the Skuld infostealer via typosquatted packages, exposing sensitive data.