Ansible Kamal

ansible-kamal

Scaffolds a full Ansible + Kamal 2 infrastructure tree for a Rails app on a single Ubuntu VPS. Generates:

• Root Makefile — make deploy ENV=…, make db-restore-from-vps ENV=…, make build, make run-local, make mailhog.
• Root scripts/ — kamal-deploy-from-pass.sh, db-restore-from-vps.sh (provider-agnostic — works with Hetzner, DigitalOcean, OVH, Hostinger, AWS Lightsail, etc., as long as the Ansible inventory points at the box).
• infra/ansible/ — playbooks (bootstrap, site, dump_db, restore_db), roles (common, users, ssh_bootstrap, firewall, fail2ban, docker, postgresql, traefik, opt), inventory, Makefile (setup, test, bootstrap, ansible), README.
• infra/kamal/README.md — secrets / pass / GitHub Actions guide.
• config/deploy.yml (+ config/deploy.staging.yml if staging is enabled).
• .kamal/secrets, .kamal/secrets-common (+ .kamal/secrets.staging if enabled).

When to Use

• A new Rails project that needs a single Ubuntu VPS with Kamal 2 + host PostgreSQL 16.
• An existing project missing infra/ansible/ where you want the same hardened baseline (UFW, fail2ban, sshd drop-in, Docker, PG on host).

Do NOT use when the project already has infra/ansible/ — diff manually instead, this skill overwrites.

Inputs to ask the user (in this order)

1. App slug (snake_case) — e.g. myapp, petshop. Used for DB names (<slug>_production, <slug>_staging), DB users (<slug>_prod_user, <slug>_staging_user), and env var prefix (POSTGRES_<SLUG_UPPER>_PROD_PASSWORD).
2. Service name (kebab-case) — Kamal service: and image name. Default = slug with _→- (e.g. my-app).
3. Image repo — e.g. myorg/<service> for GHCR.
4. VPS IP (IPv4) — host key in inventory/production.yml and config/deploy.yml servers.web.hosts.
5. Inventory group name — Ansible group; default = slug (e.g. myapp).
6. Environment mode — ONE of:
   • staging+production — two Kamal destinations, two DBs, two domains (recommended for production apps).
   • single — only one domain / DB / Kamal destination, no staging plumbing emitted.
7. Production domain — e.g. example.com.
8. Staging domain — only if staging+production. Default = staging.<production_domain>.
9. Let's Encrypt email — for kamal-proxy ACME (and Traefik if ever enabled).
10. Deploy user — Linux user Ansible (site.yml) + Kamal SSH as. Default = <slug>_deploy. Must NOT be root.
11. Pass backend — custom (uses a custom PASSWORD_STORE_DIR, e.g. ~/.password-store-custom) or pass (default ~/.password-store).
12. Pass namespace — e.g. infra/myapp. Default = infra/<inventory_group>.

Variable map

After collecting inputs, derive:

How to scaffold

Run the render script from the target project root (the repo to scaffold INTO):

APP_SLUG=myapp \
APP_SERVICE=my-app \
APP_SLUG_UPPER=MYAPP \
INVENTORY_GROUP=myapp \
VPS_IP=203.0.113.10 \
DOMAIN_PROD=example.com \
DOMAIN_STAGING=staging.example.com \
LETSENCRYPT_EMAIL=admin@example.com \
DEPLOY_USER=myapp_deploy \
IMAGE_REPO=myorg/my-app \
PASS_BACKEND=custom \
PASS_STORE_DIR='$(HOME)/.password-store-custom' \
PASS_NAMESPACE=infra/myapp \
ENV_MODE=staging+production \
TARGET_DIR=. \
~/.claude/skills/ansible-kamal/scripts/render.sh

For ENV_MODE=single leave DOMAIN_STAGING empty (or unset). PASS_STORE_DIR may be empty when PASS_BACKEND=pass.

The script:

1. Walks templates/, applies placeholder substitution.
2. Strips blocks fenced by # >>> staging-only / # <<< staging-only when ENV_MODE=single.
3. Skips files matching *.staging.* and secrets.staging when ENV_MODE=single.
4. Renames *.tmpl → no suffix.
5. Refuses to overwrite existing infra/ansible/ unless FORCE=1.

After scaffold

Tell the user, in order:

1. cd infra/ansible && make setup && make test — bootstraps venv + galaxy collections + lints.
2. Generate deploy SSH key pair, pass insert -m __PASS_NAMESPACE__/deploy_ssh_{private,public}_key.
3. Generate DB passwords: openssl rand -base64 32, store at __PASS_NAMESPACE__/postgres___APP_SLUG___prod_password (and _staging_ if applicable).
4. DNS A records: __DOMAIN_PROD__ (+ __DOMAIN_STAGING__) → __VPS_IP__.
5. Open the VPS provider's firewall (or ufw): allow 22/80/443 from anywhere (or your IP for 22).
6. Run DEPLOY_SSH_KEY="$(pass show __PASS_NAMESPACE__/deploy_ssh_public_key)" make bootstrap (root reachable).
7. Run make ansible (loads PG passwords from pass and provisions site.yml as __DEPLOY_USER__).
8. Wire GitHub Environments + secrets per infra/kamal/README.md.
9. bundle exec kamal setup (production) and bundle exec kamal setup -d staging (if staging).

Known constraints baked in

• PostgreSQL on host, not Docker accessory. Containers reach it via host.docker.internal (add-host: host.docker.internal:host-gateway in deploy.yml).
• kamal-proxy owns 80/443 (Traefik role disabled by default; kept in tree).
• UFW runs in bootstrap.yml only, with MANAGE_BUILTINS=yes and DEFAULT_FORWARD_POLICY=ACCEPT so SSH survives Docker's iptables hooks. Includes nft INPUT rehook task to recover from Docker orphaning UFW jumps.
• sshd drop-in 05-ansible-sshd-hardening.conf in bootstrap; cloud-init 50- and 60- removed.
• Deploy user sudo restricted to systemctl, apt, apt-get. No /etc/ssh editing.
• Docker daemon MTU 1450 for Let's Encrypt egress on cloud bridges.

Files emitted (full list)

Makefile                          # root: deploy, db-restore-from-vps, build, run-local, mailhog
scripts/kamal-deploy-from-pass.sh
scripts/db-restore-from-vps.sh
infra/README.md
infra/ansible/ansible.cfg
infra/ansible/Makefile            # ansible: setup, test, bootstrap, ansible
infra/ansible/README.md
infra/ansible/requirements.txt
infra/ansible/requirements.yml
infra/ansible/playbooks/{bootstrap,site,dump_db,restore_db}.yml
infra/ansible/inventory/production.yml
infra/ansible/inventory/group_vars/all.yml
infra/ansible/roles/common/tasks/main.yml
infra/ansible/roles/users/tasks/main.yml
infra/ansible/roles/users/library/managed_authorized_key.py     # idempotent single-key authorized_keys module
infra/ansible/roles/ssh_bootstrap/{tasks/main.yml,templates/sshd_ansible_hardening.conf.j2,handlers/main.yml}
infra/ansible/roles/firewall/tasks/{main,nft_input_rehook}.yml
infra/ansible/roles/fail2ban/{tasks/main.yml,handlers/main.yml}
infra/ansible/roles/docker/{tasks/main.yml,templates/daemon.json.j2,handlers/main.yml}
infra/ansible/roles/postgresql/{tasks/{main,discover,ufw}.yml,templates/{postgresql.conf,pg_hba.conf,create_databases.sql}.j2,handlers/main.yml}
infra/ansible/roles/opt/tasks/main.yml
infra/ansible/roles/traefik/{tasks/main.yml,templates/{traefik.yml,docker-compose.yml}.j2}
infra/kamal/README.md
config/deploy.yml
config/deploy.staging.yml         # only if ENV_MODE=staging+production
.kamal/secrets
.kamal/secrets-common
.kamal/secrets.staging            # only if ENV_MODE=staging+production

Common mistakes