github-to-sops 1.4.1

Standalone (no-dependencies beyond Python) script fetches SSH keys of GitHub repository contributors and generates SOPS-compatible SSH key files.

github-to-sops integrates SOPS with github team/user identities. Use sops + github instead of having to operate Hashicorp Vault, AWS Secret Manager or just stuffing everything into github action secrets, or fighting with GPG.

Why?

I think SOPS is the simplest way to manage secrets for team and individual projects, especially when combined with github as a key distribution mechanism.

This script makes it easy to setup SOPS as a lightweight gitops alternative to AWS Secrets Manager, AWS KMS, Hashicorp Vault.

SOPS is helpful to avoid the push-and-pray (https://dagger.io/ came up with this term and solution for it) pattern where all secrets for github actions are stored in Github Secrets such that nobody can repro stuff locally. With sops one can give github actions a single age private key and share all the development keys with rest of team on equal footing with CI/CD env.

Requirements

• sops
• https://github.com/Mic92/ssh-to-age/ (until the SOPS ssh backend lands).
• Python3
• pip

Installation

The latest version of github-to-sops can be cloned locally or installed using pip:

pip install github-to-sops

On Mac or Linux you can install sops, ssh-to-age using:

github-to-sops install-binaries

Implementation

This generates a nice .sops.yaml file with comments indicating where the keys came from to make key rotation easier.

Idea for this originated in https://github.com/tarasglek/chatcraft.org/pull/319 after I got sick of devising a secure secret distribution scheme for every small project.

Contributions Welcome

• Tests
• Binary build for python-less environments
• Would be nice to add is ACLs and an integrity check to keys being used.

Examples:

I wrote an indepth explanation and screencasts on my blog post introducing github-to-sops.

Env vars:

• GITHUB_TOKEN: optional github token which helps avoid rate limiting.

I tried to make the code work without github tokens, but github requires them for private repos and does aggressive rate-limiting without them. See github docs on how to obtain GITHUB_TOKEN https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens

Example workflow for secrets with github

Import all public keys for contributors from an existing github project

./github-to-sops import-keys  > .sops.yaml

of if your repo isn't published to github or you aren't working inside a git checkout

./github-to-sops import-keys  --github-url https://github.com/tarasglek/chatcraft.org

lets see

cat .sops.yaml

creation_rules:
  - key_groups:
      - age:
        - age19j4d6v9j7rx5fs629fu387qz4zmlpsqjexa4s08tkfrrmfdl5cwqjlaupd # humphd
        - age13runq29jhy9kfpaegczrzttykerswh0qprq59msgd754yermtfmsa3hwg2 # tarasglek

Put a sample secret in yaml

echo -e "secrets:\n  SECRET_KEY: dontlook" | sops --input-type yaml --output-type yaml  -e /dev/stdin > secrets.enc.yaml

Lets take a peek

head -n 9 secrets.enc.yaml

secrets:
    SECRET_KEY: ENC[AES256_GCM,data:MKKR6B0h1iA=,iv:KegjC62NQxich1dtodVF3aVnchf/fB+KQbtETh+4CaY=,tag:2+5mk4YMKKxLqaCOpZVNSA==,type:str]
sops:
    kms: []
    gcp_kms: []
    azure_kv: []
    hc_vault: []
    age:
        - recipient: age19j4d6v9j7rx5fs629fu387qz4zmlpsqjexa4s08tkfrrmfdl5cwqjlaupd

^ is safe to commit!

Decrypting secrets using ssh keys

Easy way:

github-to-sops sops -d secrets.enc.yaml

More complicated details:

export SOPS_AGE_KEY=$(ssh-to-age -private-key < ~/.ssh/id_ed25519)

Lets extract our secret in a way that's useful for automation

sops --extract '["secrets"]["SECRET_KEY"]' -d secrets.env.yaml

dontlook

sops -i secrets.env.yaml is useful for interactive editing.

Bulk-updating secrets+keys when someone is added/removed from project

github-to-sops refresh-secrets

Usage:

./github-to-sops -h
usage: github-to-sops [-h] {import-keys,refresh-secrets,sops} ...

Manage GitHub SSH keys and generate SOPS-compatible SSH key files.

options:
  -h, --help            show this help message and exit

Commands:
  {import-keys,refresh-secrets,sops}
    sops                Run sops with SOPS_AGE_KEY set from ~/.ssh/id_ed25519
    import-keys         Import SSH keys of GitHub repository contributors or specified github users and output that info into a useful format like sops or ssh authorized_keys
    refresh-secrets     Find all .sops.yaml files in the repo that are managed by git and run `import-keys --inplace-edit .sops.yaml` on them.

Example invocations:
- `./github-to-sops import-keys --github-url https://github.com/tarasglek/chatcraft.org --key-types ssh-ed25519 --format sops`
- `./github-to-sops import-keys --github-url https://github.com/tarasglek/chatcraft.org --format authorized_keys`
- `./github-to-sops import-keys --local-github-checkout . --format sops --known-hosts ~/.ssh/known_hosts --key-types ssh-ed25519`
- `./github-to-sops refresh-secrets`