Update version to 22 and enhance README

Dockerfile

@@ -1 +1 @@
-FROM nextcloud:18.0.12-apache
+FROM nextcloud:22-apache

README.md

@@ -1,58 +1,106 @@
-# Nextcloud on Dokku
-> This is a complete overhaul of the initial fork from @dionysio that has been tested, confirmed working and used in production for Nextcloud 18.
+# Nextcloud 22 on Dokku
 
-With recent versions of Nextcloud, it became super easy to run `nextcloud` under dokku:
+With recent versions of Nextcloud, it became super easy to run it under
+[Dokku](https://dokku.com/) using [Nextcloud Docker
+image](https://hub.docker.com/_/nextcloud).
+
+## Requirements
+
+You'll need access a server where you have Dokku installed with
+[dokku-postgres](https://github.com/dokku/dokku-postgres) and
+[dokku-letsencrypt](https://github.com/dokku/dokku-letsencrypt) plugins
+enabled.
+
+## Installtion
+
+Connect to your Dokku server and set the following environment variables with
+the values for your deployment:
 
 ```sh
-dokku postgres:create nextcloud
-dokku apps:create nextcloud
-dokku postgres:link nextcloud nextcloud
+# Execute on SERVER
+
+APP_NAME="nextcloud"
+PG_SERVICE_NAME="pg_${APP_NAME}"
+APP_DOMAIN="nextcloud.example.com"
+ADMIN_EMAIL="[email protected]"
+DATA_PATH="/var/lib/dokku/data/storage/${APP_NAME}"
 ```
 
-Then, from your machine, after cloning this repo and adding `dokku` as a remote:
+Now, execute the following commands:
 
 ```sh
-git push dokku
+# Execute on SERVER
+
+dokku apps:create $APP_NAME
+dokku postgres:create $PG_SERVICE_NAME
+dokku postgres:link $PG_SERVICE_NAME $APP_NAME
 ```
 
-Now back to your dokku server!
+Then, from your machine, add a `dokku` remote pointing to your server/app and
+do the first push:
 
 ```sh
-dokku domains:add nextcloud <your domain>
-dokku letsencrypt nextcloud
-# Replace this path with where you want to store user files (can be a network disk).
-mkdir -p /var/lib/dokku/data/storage/nextcloud/data
-chown www-data:www-data /var/lib/dokku/data/storage/nextcloud/data
+# Execute on CLIENT (env vars set on server are not available here, so replace
+# <...> with the correct values)
 
-# Replace this path with where you want to store Nextcloud config (can be a network disk, but this'll make serving webpages much slower)
-mkdir -p /var/lib/dokku/data/storage/nextcloud/config
-chown www-data:www-data /var/lib/dokku/data/storage/nextcloud/config
+git clone <this-repo-url>
+cd dokku-nextcloud
+git remote add dokku dokku@<your-server>:<your-app-name>
+git push dokku main
+```
 
-dokku storage:mount nextcloud /var/lib/dokku/data/storage/nextcloud/data:/var/www/html/data
-dokku storage:mount nextcloud /var/lib/dokku/data/storage/nextcloud/config:/var/www/html/config
-# required to create the mount files (we pushed earlier)
-dokku ps:restart nextcloud
+[comment]: <> (TODO: we may change to the docker image deployment instead of git repository)
 
-```
-You're nearly done! Visit `<your domain>` to finish configuration.
+Now back to your dokku server to finish the configuration!
 
-Set up an admin account.
-Click on "Storage & database".
-Leave the data folder unchanged (`/var/www/html/data`)
-For the database, **select Postgres**; you'll find the database credentials by running `dokku config nextcloud` and looking for DATABASE_URL: it'll look like postgres://USER:PASSWORD@HOST:PORT/DBNAME, just fill-in the fields on the webpage.
+```sh
+# Execute on SERVER
 
-For instance, with `postgres://postgres:ae9e02101f9977e1fabb19f09605e486@dokku-postgres-nextcloud:5432/nextcloud`:
+dokku domains:add $APP_NAME $APP_DOMAIN
+dokku config:set $APP_NAME DOKKU_LETSENCRYPT_EMAIL=$ADMIN_EMAIL
+dokku letsencrypt:enable $APP_NAME
 
-* Database user: postgres
-* Database password: ae9e02101f9977e1fabb19f09605e486
-* Database name: nextcloud
-* Database host: dokku-postgres-nextcloud:5432
+for directory in config custom_apps data; do
+	mkdir -p "$DATA_PATH/$directory"
+	chown www-data:www-data "$DATA_PATH/$directory"
+	dokku storage:mount $APP_NAME "$DATA_PATH/$directory:/var/www/html/$directory"
+done
 
-Click on finish setup.
+dokku ps:restart $APP_NAME
+```
+
+You're nearly done! Now:
+- Visit `<your domain>` to finish configuration.
+- Set up an admin account.
+- Click on "Storage & database".
+- Leave the data folder unchanged (`/var/www/html/data`)
+- For the database, **select Postgres**; you'll find the database credentials
+  by running `dokku config $PG_SERVICE_NAME` and looking for DATABASE_URL:
+  it'll look like `postgres://USER:PASSWORD@HOST:PORT/DBNAME`, just fill-in the
+  fields on the webpage. For instance, with
+  `postgres://postgres:ae9e02101f9977e1fabb19f09605e486@dokku-postgres-nextcloud:5432/nextcloud`:
+  - Database user: `postgres`
+  - Database password: `ae9e02101f9977e1fabb19f09605e486`
+  - Database name: `nextcloud`
+  - Database host: `dokku-postgres-nextcloud:5432`
+- Click on **finish setup**.
 
 
 ## Tweaks
-If you're planning to use desktop client,  because you're running with Dokku as a reverse proxy, you'll need to change your config.php file under `/var/lib/dokku/data/storage/nextcloud/config` to add this:
+
+### Cache
+
+You can make pages load faster (and save some CPU cycles) by adding a cache
+layer to Nextcloud. It can be done by running [Redis](https://redis.io/) via
+[dokku-redis](https://github.com/dokku/dokku-redis).
+
+[comment]: <> (TODO: add commands to install redis plugin, create a Redis instance, link to the app and configure it on Nextcloud)
+
+### Upload size
+
+If you're planning to use desktop client, because you're running with Dokku as
+a reverse proxy, you'll need to change your `config.php` file under
+`$CONFIG_PATH` to add this:
 
 ```
 'overwriteprotocol' => 'https'
@@ -63,17 +111,55 @@ Make sure the value for `'overwrite.cli.url'` starts with https.
 You'll also need to allow large uploads to your server:
 
 ```sh
-mkdir /home/dokku/nextcloud/nginx.conf.d/
-echo 'client_max_body_size 50000m;' > /home/dokku/nextcloud/nginx.conf.d/upload.conf
-echo 'proxy_read_timeout 600s;' >> /home/dokku/nextcloud/nginx.conf.d/upload.conf
-chown dokku:dokku /home/dokku/nextcloud/nginx.conf.d/upload.conf
+mkdir /home/dokku/$APP_NAME/nginx.conf.d/
+echo 'client_max_body_size 50000m;' > /home/dokku/$APP_NAME/nginx.conf.d/upload.conf
+echo 'proxy_read_timeout 600s;' >> /home/dokku/$APP_NAME/nginx.conf.d/upload.conf
+chown dokku:dokku /home/dokku/$APP_NAME/nginx.conf.d/upload.conf
 service nginx reload
 ```
 
+### Cron
+
+For some tasks you'll need to install a crontab. For this to work, you must
+create an `app.json` file inside this repository, commit it and push to dokku's
+app repository on your server. Check [Dokku docs on how to configure a cron
+job](https://dokku.com/docs/processes/scheduled-cron-tasks/#dokku-managed-cron).
+
+[comment]: <> (TODO: add sample `app.json`)
+[comment]: <> (TODO: may use <https://github.com/crisward/dokku-require> and provide a sample app.json)
+
+### Executing `occ` command
+
+```sh
+# Execute on the SERVER
+
+container_id=$(docker ps | grep dokku/${APP_NAME}:latest | awk '{print $1}')
+docker exec -it --user www-data $container_id php occ ...
+```
+
 ## Uninstalling
+
 If you're unhappy with your setup, this'll remove everything *forever*:
+
+```sh
+dokku apps:destroy $APP_NAME
+dokku postgres:destroy $APP_NAME
+rm -rf "$DATA_PATH" "$CONFIG_PATH"
 ```
-dokku apps:destroy nextcloud
-dokku postgres:destroy nextcloud
-rm -rf  /var/lib/dokku/data/storage/nextcloud
-```
+
+### Possible problems
+
+#### Invalid private key
+
+If the users are getting the annoying message "Invalid private key for
+encryption app", update your private key password in your personal settings to
+recover access to your encrypted files", look at [this issue
+comment](https://github.com/nextcloud/server/issues/8546#issuecomment-371795233).
+
+
+#### Could not establish a connection
+
+If the users are getting the message "Could not establish a connection with at
+least one participant" during videoconferences, then a TURN server might be
+needed for your scenario, check more details at [Nextcloud TURN
+docs](https://nextcloud-talk.readthedocs.io/en/latest/TURN.html).