# Colmena
[](https://zhaofengli.github.io/colmena)
[](https://github.com/zhaofengli/colmena/actions/workflows/build.yml)
Colmena is a simple, stateless [NixOS](https://nixos.org) deployment tool modeled after [NixOps](https://github.com/NixOS/nixops) and [morph](https://github.com/DBCDK/morph), written in Rust.
It's a thin wrapper over Nix commands like `nix-instantiate` and `nix-copy-closure`, and supports parallel deployment.
Now with 100% more flakes! See *Tutorial with Flakes* below.
$ colmena apply --on @tag-a
[INFO ] Enumerating nodes...
[INFO ] Selected 7 out of 45 hosts.
(...) ✅ 0s Build successful
sigma 🕗 7s copying path '/nix/store/h6qpk8rwm3dh3zsl1wlj1jharzf8aw9f-unit-haigha-agent.service' to 'ssh://root@sigma.redacted'...
theta ✅ 7s Activation successful
gamma 🕘 8s Starting...
alpha ✅ 1s Activation successful
epsilon 🕗 7s copying path '/nix/store/fhh4rfixny8b21l6jqzk7nqwxva5k20h-nixos-system-epsilon-20.09pre-git' to 'ssh://root@epsilon.redacted'...
beta 🕗 7s removing obsolete file /boot/kernels/z28ayg10kpnlrz0s2qrb9pzv82lc20s2-initrd-linux-5.4.89-initrd
kappa ✅ 2s Activation successful
Colmena is still an early prototype.
## Installation
Colmena doesn't have a stable release yet.
To install the latest development version to the user profile, use `default.nix`:
```
nix-env -if default.nix
```
### Binary Cache
A public binary cache is available at https://colmena.cachix.org, courtesy of Cachix.
## Tutorial
*See Tutorial with Flakes for usage with Nix Flakes.*
Colmena should work with your existing NixOps and morph configurations with minimal modification.
Here is a sample `hive.nix` with two nodes, with some common configurations applied to both nodes:
```nix
{
meta = {
# Override to pin the Nixpkgs version (recommended). This option
# accepts one of the following:
# - A path to a Nixpkgs checkout
# - The Nixpkgs lambda (e.g., import )
# - An initialized Nixpkgs attribute set
nixpkgs = ;
# You can also override Nixpkgs by node!
nodeNixpkgs = {
node-b = ./another-nixos-checkout;
};
# If your Colmena host has nix configured to allow for remote builds
# (for nix-daemon, your user being included in trusted-users)
# you can set a machines file that will be passed to the underlying
# nix-store command during derivation realization as a builders option.
# For example, if you support multiple orginizations each with their own
# build machine(s) you can ensure that builds only take place on your
# local machine and/or the machines specified in this file.
# machinesFile = ./machines.client-a;
};
defaults = { pkgs, ... }: {
# This module will be imported by all hosts
environment.systemPackages = with pkgs; [
vim wget curl
];
# By default, Colmena will replace unknown remote profile
# (unknown means the profile isn't in the nix store on the
# host running Colmena) during apply (with the default goal,
# boot, and switch).
# If you share a hive with others, or use multiple machines,
# and are not careful to always commit/push/pull changes
# you can accidentaly overwrite a remote profile so in those
# scenarios you might want to change this default to false.
# deployment.replaceUnknownProfiles = true;
};
host-a = { name, nodes, ... }: {
# The name and nodes parameters are supported in Colmena,
# allowing you to reference configurations in other nodes.
networking.hostName = name;
time.timeZone = nodes.host-b.config.time.timeZone;
boot.loader.grub.device = "/dev/sda";
fileSystems."/" = {
device = "/dev/sda1";
fsType = "ext4";
};
};
host-b = {
# Like NixOps and morph, Colmena will attempt to connect to
# the remote host using the attribute name by default. You
# can override it like:
deployment.targetHost = "host-b.mydomain.tld";
# It's also possible to override the target SSH port.
# For further customization, use the SSH_CONFIG_FILE
# environment variable to specify a ssh_config file.
deployment.targetPort = 1234;
# Override the default for this target host
deployment.replaceUnknownProfiles = false;
# You can filter hosts by tags with --on @tag-a,@tag-b.
# In this example, you can deploy to hosts with the "web" tag using:
# colmena apply --on @web
# You can use globs in tag matching as well:
# colmena apply --on '@infra-*'
deployment.tags = [ "web" "infra-lax" ];
time.timeZone = "America/Los_Angeles";
boot.loader.grub.device = "/dev/sda";
fileSystems."/" = {
device = "/dev/sda1";
fsType = "ext4";
};
};
}
```
The full set of options can be found in [the manual](https://zhaofengli.github.io/colmena/stable/reference).
Run `colmena build` in the same directory to build the configuration, or do `colmena apply` to build and deploy it to all nodes.
## Tutorial with Flakes
To use with Nix Flakes, create `outputs.colmena` in your `flake.nix`.
Here is a short example:
```nix
{
inputs = {
nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
};
outputs = { nixpkgs, ... }: {
colmena = {
meta = {
nixpkgs = import nixpkgs {
system = "x86_64-linux";
};
};
# Also see the non-Flakes hive.nix example above.
host-a = { name, nodes, pkgs, ... }: {
boot.isContainer = true;
time.timeZone = nodes.host-b.config.time.timeZone;
};
host-b = {
deployment = {
targetHost = "somehost.tld";
targetPort = 1234;
targetUser = "luser";
};
boot.isContainer = true;
time.timeZone = "America/Los_Angeles";
};
};
};
}
```
The full set of options can be found in [the manual](https://zhaofengli.github.io/colmena/stable/reference).
Run `colmena build` in the same directory to build the configuration, or do `colmena apply` to build and deploy it to all nodes.
## Manual
Read [the Colmena Manual](https://zhaofengli.github.io/colmena).
## Environment variables
- `SSH_CONFIG_FILE`: Path to a `ssh_config` file
## Current limitations
- It's required to use SSH keys to log into the remote hosts, and interactive authentication will not work.
- Error reporting is lacking.
## Licensing
Colmena is available under the MIT License.