---
url: /bupha/how-to/sccache-backend.md
---
# How-to: sccache backend

sccache's backend is decoupled via an env file — set
`[cache] conf` to a `KEY=VAL` file (mounted into containers as
a secret). Without it, sccache uses a local cache volume.

## Local S3 (garage)

```
docker run -d --name garage --restart always \
  -v $HOME/bupha-data/garage:/data \
  -v $HOME/bupha-data/garage.toml:/etc/garage.toml \
  -p 9100:9100 dxflrs/garage:v1.x.x
```

Then in the garage CLI: `bucket create bupha-ci` → `key create sccache`
→ `bucket allow --read --write --owner bupha-ci --key sccache`.

Env file:

```
SCCACHE_ENDPOINT=http://<docker-gateway>:9100
SCCACHE_BUCKET=bupha-ci
SCCACHE_REGION=garage
SCCACHE_S3_USE_SSL=false
AWS_ACCESS_KEY_ID=...
AWS_SECRET_ACCESS_KEY=...
```

## Migrating to hosted S3 (R2 / AWS)

Same file, new values — `SCCACHE_ENDPOINT` to the provider URL, real
region, new creds. No code changes; that's the point of the env file.