---
Overmind is a process manager for Procfile-based applications and [tmux](https://tmux.github.io/). With Overmind, you can easily run several processes from your `Procfile` in a single terminal.
Procfile is a simple format to specify types of processes your application provides (such as web application server, background queue process, front-end builder) and commands to run those processes. It can significantly simplify process management for developers and is used by popular hosting platforms, such as Heroku and Deis. You can learn more about the `Procfile` format [here](https://devcenter.heroku.com/articles/procfile).
There are some good Procfile-based process management tools, including [foreman](https://github.com/ddollar/foreman) by David Dollar, which started it all. The problem with most of those tools is that processes you want to manage start to think they are logging their output into a file, and that can lead to all sorts of problems: severe lagging, and losing or breaking colored output. Tools can also add vanity information (unneeded timestamps in logs). Overmind was created to fix those problems once and for all.
See this article for a good intro and all the juicy details! [Introducing
Overmind and Hivemind](https://evilmartians.com/chronicles/introducing-overmind-and-hivemind)
## Overmind features
You may know several Procfile process management tools, but Overmind has some unique, _extraterrestrial_ powers others don't:
* Overmind starts processes in a tmux session, so you can easily connect to any process and gain control over it;
* Overmind can restart a single process on the fly — you don't need to restart the whole stack;
* Overmind allows a specified process to die without interrupting all of the other ones;
* Overmind can restart specified processes automatically when they die;
* Overmind uses tmux's control mode to capture process output — so it won't be clipped, delayed, and it won't break colored output;
* Overmind can read environment variables from a file and use them as parameters so that you can configure Overmind behavior globally and/or per directory.
**If a lot of those features seem like overkill for you, especially the tmux integration, you should take a look at Overmind's little sister — [Hivemind](https://github.com/DarthSim/hivemind)!**
## Installation
**Note:** At the moment, Overmind supports Linux, *BSD, and macOS only.
Overmind works with [tmux](https://tmux.github.io/), so you need to install it first:
```bash
# on macOS (with homebrew)
$ brew install tmux
# on Ubuntu
$ apt-get install tmux
```
**Note:** You can find installation manuals for other systems here: https://github.com/tmux/tmux
There are three ways to install Overmind:
### With Homebrew (macOS)
```bash
brew install overmind
```
### With Ruby
```bash
gem install overmind
```
You can read about installing on Ruby On Rails [here] (https://github.com/DarthSim/overmind/blob/master/packaging/rubygems/README.md)
### Download the latest Overmind release binary
You can download the latest release [here](https://github.com/DarthSim/overmind/releases/latest).
### Build Overmind from source
You need Go 1.21 or later to build the project.
```bash
$ go install github.com/DarthSim/overmind/v2@latest
```
The Overmind binary will be installed to `$(go env GOPATH)/bin`. Make sure that you added it to your `PATH`.
**Note:** You can update Overmind the same way.
## Usage
**In short:** You can get help by running `overmind -h` and `overmind help [command]`.
### Running processes
Overmind reads the list of processes you want to manage from a file named `Procfile`. It may look like this:
```Procfile
web: bin/rails server
worker: bundle exec sidekiq
assets: gulp watch
```
To get started, you just need to run Overmind from your working directory containing a `Procfile`:
```bash
$ overmind start
```
You can also use the short alias:
```bash
$ overmind s
```
#### Specifying a Procfile
If a `Procfile` isn't located in your working directory, you can specify the exact path:
```bash
$ overmind start -f path/to/your/Procfile
$ OVERMIND_PROCFILE=path/to/your/Procfile overmind start
```
#### Specifying the ports
Overmind sets the environment variable `PORT` for each process in your Procfile so that you can do things like this:
```Procfile
web: bin/rails server -p $PORT
```
Overmind assigns the port base (5000 by default) to `PORT` for the first process and increases `PORT` by port step (100 by default) for each subsequent one. You can specify the port base and port step like this:
```bash
$ overmind start -p 3000 -P 10
$ OVERMIND_PORT=3000 OVERMIND_PORT_STEP=10 overmind start
```
#### Disabling `PORT`
If you don't want Overmind to set the `PORT` variable, you can disable it:
```bash
$ overmind start -N
$ OVERMIND_NO_PORT=1 overmind start
```
#### Running only the specified processes
You can specify the names of processes you want to run:
```bash
$ overmind start -l web,sidekiq
$ OVERMIND_PROCESSES=web,sidekiq overmind start
```
#### Not running the specified processes
Similar to the above, if there are some processes in the Procfile that you do not want to run:
```bash
$ overmind start -x web,sidekiq
$ OVERMIND_IGNORED_PROCESSES=web,sidekiq overmind start
```
This takes precedence over the previous `-l` flag. i.e. if you:
```bash
$ overmind start -l web -x web
$ OVERMIND_IGNORED_PROCESSES=web OVERMIND_PROCESSES=web overmind start
```
Nothing will start.
#### Scaling processes (formation)
By default, Overmind starts one instance of each process, but you can set the number of each process instances to run:
```bash
$ overmind start -m web=2,worker=5
$ OVERMIND_FORMATION=web=2,worker=5 overmind start
```
There is a special name `all` that you can use to scale all processes at once:
```bash
$ overmind start -m all=2,worker=5
$ OVERMIND_FORMATION=all=2,worker=5 overmind start
```
If you set instances number of some process to zero, this process won't be run:
```bash
$ overmind start -m some_production_task=0
$ OVERMIND_FORMATION=some_production_task=0 overmind start
```
#### Processes that can die
Usually, when a process dies, Overmind will interrupt all other processes. However, you can specify processes that can die without interrupting all other ones:
```bash
$ overmind start -c assets,npm_install
$ OVERMIND_CAN_DIE=assets,npm_install overmind start
```
Also, you can allow all processes to die:
```bash
$ overmind start --any-can-die
$ OVERMIND_ANY_CAN_DIE=1 overmind start
```
#### Auto-restarting processes
If some of your processes tend to randomly crash, you can tell Overmind to restart them automatically when they die:
```bash
$ overmind start -r rails,webpack
$ OVERMIND_AUTO_RESTART=rails,webpack overmind start
```
The special name `all` can also be used to restart all processes automatically when they die:
```bash
$ overmind start -r all
$ OVERMIND_AUTO_RESTART=all overmind start
```
#### Specifying the colors
Overmind colorizes process names with different colors. It may happen that these colors don't match well with your color scheme. In that case, you can specify your own colors using xterm color codes:
```bash
$ overmind start -b 123,123,125,126,127
$ OVERMIND_COLORS=123,123,125,126,127 overmind start
```
If you want Overmind to always use these colors, you can specify them in the [environment file](https://github.com/DarthSim/overmind#overmind-environment) located in your home directory.
### Show timestamps
By default, Overmind doesn't show timestamps in its output since it expects your processes to add timestamps to their own output. But you can make Overmind to add timestamps to its output:
```bash
$ overmind start -T
$ OVERMIND_SHOW_TIMESTAMPS=1 overmind start
```
### Connecting to a process
If you need to gain access to process input, you can connect to its `tmux` window:
```bash
$ overmind connect
```
You can safely disconnect from the window by hitting `Ctrl b` (or your tmux prefix) and then `d`.
You can omit the process name to connect to the first process defined in the Procfile.
### Restarting a process
You can restart a single process without restarting all the other ones:
```bash
$ overmind restart sidekiq
```
You can restart multiple processes the same way:
```bash
$ overmind restart sidekiq assets
```
It's also possible to use wildcarded process names:
```bash
$ overmind restart 'sidekiq*'
```
When the command is called without any arguments, it will restart all the processes.
### Stopping a process
You can stop a single process without stopping all the other ones:
```bash
$ overmind stop sidekiq
```
You can stop multiple processes the same way:
```bash
$ overmind stop sidekiq assets
```
It's also possible to use wildcarded process names:
```bash
$ overmind stop 'sidekiq*'
```
When the command is called without any arguments, it will stop all the processes without stopping Overmind itself.
### Killing processes
If something goes wrong, you can kill all running processes:
```bash
$ overmind kill
```
### Overmind environment
If you need to set specific environment variables before running a `Procfile`, you can specify them in the `.overmind.env` file in the current working directory, your home directory, or/and in the `.env` file in in the current working directory. The file should contain `variable=value` pairs, one per line:
```
PATH=$PATH:/additional/path
OVERMIND_CAN_DIE=npm_install
OVERMIND_PORT=3000
```
For example, if you want to use a separate `Procfile.dev` by default on a local environment, create `.overmind.env` file with `OVERMIND_PROCFILE=Procfile.dev`. Now, Overmind uses `Procfile.dev` by default.
You can specify additional env files to load with `OVERMIND_ENV` variable:
```bash
$ OVERMIND_ENV=./.env.local,./.env.development overmind s
```
The files will be loaded in the following order:
* `~/.overmind.env`
* `./.overmind.env`
* `./.env`
* `$OVERMIND_ENV`
You can also opt to skip loading the `.env` file entirely (`.overmind.env` will still be read) by setting the variable `OVERMIND_SKIP_ENV`.
#### Running a command in the Overmind environment
Since you set up an environment with `.env` files, you may want to run a command inside this environment. You can do this using `run` command:
```bash
$ overmind run yarn install
```
### Run as a daemon
Overmind can be run as a daemon:
```bash
$ overmind start -D
$ OVERMIND_DAEMONIZE=1 overmind start
```
Use the `echo` command for the logs:
```bash
$ overmind echo
```
You can quit daemonized Overmind with `quit`:
```bash
$ overmind quit
```
### Specifying a socket
Overmind receives commands via a Unix socket. Usually, it opens a socket named `.overmind.sock` in a working directory, but you can specify the full path:
```bash
$ overmind start -s path/to/socket
$ OVERMIND_SOCKET=path/to/socket overmind start
```
All other commands support the same flag:
```bash
$ overmind connect -s path/to/socket web
$ overmind restart -s path/to/socket sidekiq
$ overmind kill -s path/to/socket
```
#### Using TCP network
Overmind can bind its command center to a TCP address instead of Unix socket. This is useful when you run it on a remote machine.
```bash
$ overmind start -s "0.0.0.0:4321" -S "tcp"
$ OVERMIND_SOCKET="0.0.0.0:4321" OVERMIND_NETWORK="tcp" overmind start
```
You need to pass the same flags to other commands:
```bash
$ overmind connect -s "0.0.0.0:4321" -S "tcp" web
```
### Specifying tmux config
Overmind can use a specified tmux config. This is useful if you want to differentiate from your main tmux window, for example adding a custom status line for Overmind or a different prefix key.
```bash
overmind start -F ~/overmind.tmux.conf
OVERMIND_TMUX_CONFIG=~/.overmind.tmux.conf overmind start
```
## Known issues
### Overmind uses the system Ruby/Node/etc instead of a custom-defined one
This may happen if your Ruby/Node/etc version manager isn't configured properly. Make sure that the path to your custom binaries is included in your `PATH` before the system binaries path.
### Overmind does not stop the Docker process properly
Unfortunately, this is how Docker works. When you send `SIGINT` to a `docker run ...` process, it just detaches container and exits. You can solve this by using named containers and signal traps:
```procfile
mydocker: trap 'docker stop mydocker' EXIT > /dev/null; docker run --name mydocker ...
```
### Overmind can't start because of a `bind: invalid argument` error
All operating systems have limits on Unix socket path length. Try to use a shorter socket path.
### Overmind exits after `pg_ctl --wait start` and keeps PostgreSQL server running
Since version 12.0 `pg_ctl --wait start` exits right after starting the server. Just use the `postgres` command directly.
## Author
Sergey "DarthSim" Aleksandrovich
Highly inspired by [Foreman](https://github.com/ddollar/foreman).
Many thanks to @antiflasher for the awesome logo.
## License
Overmind is licensed under the MIT license.
See LICENSE for the full license text.
