# Redis

## Description

This Ansible role provides Redis in two interchangeable shapes, selected per consumer with the `shared` flag (mirroring `svc-db-postgres`):

- **Central** (`enabled: true`, `shared: true`): a standalone, manager-pinned Redis stack that many roles share. Each consumer gets its own ACL user restricted to the key-prefix `{entity}:*`.
- **Embedded** (`enabled: true`, `shared: false`): a Redis sidecar rendered into the consumer's own compose stack via `templates/service.yml.j2`.

## Overview

The central stack (`templates/compose.yml.j2`) runs `redis:alpine` with:

- `requirepass` for the `default` (admin) user, sourced from the `REDIS_PASSWORD` credential.
- AOF persistence for cached data.
- A `maxmemory` ceiling derived from the service `mem_limit` with an `allkeys-lru` policy.
- A bind on `127.0.0.1:6379` plus the shared cross-stack overlay network for consumers.

Per-consumer provisioning (`tasks/01_init.yml`) runs with `application_id=svc-db-redis` and `database_consumer_id=<consumer>`; it resolves the consumer's username, password and key-prefix via `lookup('engine', 'redis', <consumer>, ...)` and reconciles an idempotent `ACL SETUSER` restricted to `~{entity}:*`. The ACL users are recreated by the consumer's `01_init` on every deploy, so a container restart that drops the in-memory ACL set is healed on the next run.

The embedded snippet (`templates/service.yml.j2`) keeps the previous single-host behaviour: an unauthenticated in-memory Redis attached to the consumer stack's default network. Its `maxmemory` is 80 % of the consumer's `services.redis.mem_limit`; a consumer that declares none gets 80 % of the limit its container inherits, at most 80 % of this role's own `mem_limit`.

## Cosmos

The diagram places Redis in the Infinito.Nexus cosmos: the components it deploys (capabilities), the central services it consumes (dependencies), and its outward reach (federation and bridged external networks).

```mermaid
flowchart LR
    subgraph deps [Dependencies]
        dep_svc_bkp_volume_2_local["svc-bkp-volume-2-local 💻"]
        dep_svc_net_tor["svc-net-tor 🐳🐝"]
    end
    subgraph role [svc-db-redis 🐳🐝]
        svc_redis["redis"]
        svc_tor["tor"]
        svc_container_backup["container_backup"]
    end
    subgraph dependents [Dependents]
        dpt_web_app_akaunting["web-app-akaunting 🐳🐝"]
        dpt_web_app_baserow["web-app-baserow 🐳🐝"]
        dpt_web_app_bookwyrm["web-app-bookwyrm 🐳🐝"]
        dpt_web_app_decidim["web-app-decidim 🐳🐝"]
        dpt_web_app_discourse["web-app-discourse 🐳🐝"]
        dpt_web_app_erpnext["web-app-erpnext 🐳🐝"]
        dpt_web_app_fider["web-app-fider 🐳🐝"]
        dpt_web_app_flowise["web-app-flowise 🐳🐝"]
        dpt_web_app_funkwhale["web-app-funkwhale 🐳🐝"]
        dpt_web_app_gitea["web-app-gitea 🐳🐝"]
        dpt_web_app_gitlab["web-app-gitlab 🐳🐝"]
        dpt_web_app_magento["web-app-magento 🐳🐝"]
        dpt_more["..."]
    end
    dep_svc_bkp_volume_2_local -- "1:1" --> svc_container_backup
    dep_svc_net_tor -. "0..1" .-> svc_tor
    svc_redis -- "1:1" --> dpt_more
    svc_redis -. "0..1" .-> dpt_web_app_akaunting
    svc_redis -. "0..1" .-> dpt_web_app_baserow
    svc_redis -. "0..1" .-> dpt_web_app_bookwyrm
    svc_redis -. "0..1" .-> dpt_web_app_decidim
    svc_redis -. "0..1" .-> dpt_web_app_discourse
    svc_redis -. "0..1" .-> dpt_web_app_erpnext
    svc_redis -. "0..1" .-> dpt_web_app_fider
    svc_redis -. "0..1" .-> dpt_web_app_flowise
    svc_redis -. "0..1" .-> dpt_web_app_funkwhale
    svc_redis -. "0..1" .-> dpt_web_app_gitea
    svc_redis -. "0..1" .-> dpt_web_app_gitlab
    svc_redis -. "0..1" .-> dpt_web_app_magento
```

Solid `1:1` edges are fixed relationships; dashed `0..1` edges are conditional (enabled only in matching deployments); red `0..0` edges are turned off in this role. Node markers show the role's deploy modes (💻 host, 🐳 compose, 🐝 swarm); ❌ marks a service that is explicitly turned off, and ⚙️ an Ansible role dependency declared in `meta/main.yml`.

## Features

- **Central or embedded** selected per consumer via `services.redis.shared`.
- **ACL isolation** one Redis user per consumer, scoped to `{entity}:*` keys.
- **Idempotent provisioning** ACL users reconciled on every deploy via `ACL SETUSER`.
- **Manager-pinned** central on-disk state stays node-local (never on NFS) in swarm.
- **Built-in healthcheck** authenticated `redis-cli ping`.

## Quick Setup

### Development

Clone, set up the workstation, and deploy Redis onto the local stack:

```bash
git clone https://github.com/infinito-nexus/core.git
cd core
make onboard
make compose-deploy mode=reinstall apps=svc-db-redis full_cycle=false
```

### Production

Run the published image to provision the inventory and deploy Redis to a managed server (the mounted volume persists the inventory):

```bash
APP=svc-db-redis
HOST=<your-server>
DOMAIN=<your-domain>
TLS_MODE=self_signed
SSH_PUBLIC_KEY="<your-ssh-public-key>"

docker run --rm -it \
  -v "$PWD/inventories:/etc/infinito.nexus/inventories" \
  -e APP="$APP" -e HOST="$HOST" -e DOMAIN="$DOMAIN" -e TLS_MODE="$TLS_MODE" -e SSH_PUBLIC_KEY="$SSH_PUBLIC_KEY" \
  ghcr.io/infinito-nexus/core/debian bash -c '
    INVENTORY=/etc/infinito.nexus/inventories/production
    infinito administration inventory provision "$INVENTORY" \
      --inventory-file "$INVENTORY/devices.yml" \
      --host "$HOST" \
      --include "$APP" \
      --vars "{\"TLS_MODE\": \"$TLS_MODE\", \"DOMAIN_PRIMARY\": \"$DOMAIN\", \"users\": {\"administrator\": {\"authorized_keys\": [\"$SSH_PUBLIC_KEY\"]}}}" &&
    infinito administration deploy dedicated "$INVENTORY/devices.yml" \
      --password-file "$INVENTORY/.password" \
      --diff -vv'
```

## Further Resources

- [Official Redis Docker image on Docker Hub](https://hub.docker.com/_/redis)
- [Redis ACL documentation](https://redis.io/docs/latest/operate/oss_and_stack/management/security/acl/)
- [Docker Compose reference](https://docs.docker.com/compose/compose-file/)

## Credits

Implemented by **[Kevin Veen-Birkenbach](https://www.veen.world)**.
Part of the [Infinito.Nexus Project](https://s.infinito.nexus/code) and maintained by [Kevin Veen-Birkenbach](https://www.veen.world).
Licensed under the [Infinito.Nexus Community License (Non-Commercial)](https://s.infinito.nexus/license).