# Host a library

A podcast app downloads each episode from `<base_url>/audio/<name>.mp3`. A library can live on any service that makes a folder's files available at URLs like that, with no login.


# Services that work

| Service | `base_url` looks like |
|----|----|
| pCloud public folder | `https://filedn.com/XXXX/earmark` |
| Cloudflare R2, public bucket | `https://pub-xxxx.r2.dev` |
| Backblaze B2, public bucket | `https://f000.backblazeb2.com/file/my-bucket` |
| AWS S3 or another S3-compatible bucket | `https://my-bucket.s3.amazonaws.com/audio` |
| Your own web server | `https://example.com/audio` |
| GitHub Pages, Netlify, Cloudflare Pages | `https://you.github.io/audio` |

**Dropbox, Box, Google Drive, OneDrive and iCloud Drive do not work.** They give a separate share link for each file. They do not serve a folder at one URL.


# A synced folder: nothing more to do

If the library is in a folder that the service syncs to the web, such as a pCloud public folder, then `earmark publish` is complete when the MP3 is written. Set `base_url` to the public URL of that folder.


# Anything else: upload with `after_publish`

If the library is not in a public folder, set `after_publish` in `earmark.toml`. It is one shell command that earmark runs in the library after each publish:

``` toml
after_publish = "rclone sync . r2:my-bucket/audio"

[feed]
base_url = "https://pub-xxxx.r2.dev"
```

| Host | `after_publish` |
|----|----|
| S3, R2, B2 (with [rclone](https://rclone.org)) | `rclone sync . r2:my-bucket/audio` |
| Your own server | `rsync -a --delete . me@host:/var/www/audio/` |
| A GitHub Pages repo | `git add -A && git commit -m earmark && git push` |

Set `base_url` to the URL where the files arrive, not to the local folder.


# Check the URLs

An incorrect `base_url` causes no error. The feed looks correct, but the app shows no episodes. To test that the feed, the cover and the newest episodes download:

``` bash
earmark feed --check
```