To those self-hosters who are out there curious if there exists a faster Nextcloud-like alternative without all the bells and whistles. I present to you, OCIS! This howto assumes that you're running a Linux OS and that you have a reverse proxy like caddy running. To the guy who I suggested checking out OCIS, I wrote this guide for you ;)

1. Download the OCIS binary:

sudo wget -O /usr/bin/ocis https://download.owncloud.com/ocis/ocis/stable/3.0.0/ocis-3.0.0-linux-amd64

The above downloads the latest stable version.

2. Make the downloaded binary executable:

sudo chmod +x /usr/bin/ocis

3. Create a systemd unit file to start OCIS automatically:

Description=OCIS server

[Service]
Type=simple
User=ocis
Group=ocis
EnvironmentFile=/etc/ocis/ocis.env
ExecStart=ocis server
Restart=always

[Install]
WantedBy=multi-user.target

4. Create the ocis user:

sudo useradd --system --no-create-home --shell=/sbin/nologin ocis

5. Create the necessary directories:

sudo mkdir -p /etc/ocis /var/lib/ocis

6. Grant ownership of created directories above to the ocis user:

sudo chown -R ocis:ocis /etc/ocis/ /var/lib/ocis

7. Create the environment file for running OCIS:

sudo nano /etc/ocis/ocis.env and paste the lines below - edit the domain accordingly:

OCIS_URL=https://ocis.your.domain.org
PROXY_TLS=false
OCIS_INSECURE=true
OCIS_LOG_LEVEL=error
OCIS_CONFIG_DIR=/etc/ocis
OCIS_BASE_DATA_PATH=/var/lib/ocis
PROXY_HTTP_ADDR=0.0.0.0:9200
PROXY_USER_OIDC_CLAIM=preferred_username
PROXY_USER_CS3_CLAIM=username
PROXY_ENABLE_BASIC_AUTH=true

8. Initialize your OCIS install:

sudo -u ocis ocis init --config-path /etc/ocis

That's it! Visiting the url https://ocis.your.domain.org should present you with OCIS login page. To access the webdav endpoint via something like Cx Explorer or Gnome files, use: https://ocis.your.domain.org/remote.php/webdav

Depending on your setup, you might have to add the ocis domain above to your hosts file. A line like 127.0.0.1 ocis.your.domain.org to the /etc/hosts file.

If you don't have a reverse proxy but would still like to check out OCIS, use the environment file below:

OCIS_URL=https://192.168.x.x:9200
PROXY_TLS=true
OCIS_INSECURE=true
OCIS_LOG_LEVEL=error
OCIS_CONFIG_DIR=/etc/ocis
OCIS_BASE_DATA_PATH=/var/lib/ocis
PROXY_HTTP_ADDR=0.0.0.0:9200
PROXY_USER_OIDC_CLAIM=preferred_username
PROXY_USER_CS3_CLAIM=username
PROXY_ENABLE_BASIC_AUTH=true

I tried mine with keli.local:9200 and it worked just fine- make sure you have avahi-daemon installed!

Edit: If you're using a reverse proxy, your proxy address should be localhost:9200. For caddy, this would mean an entry like:

ocis.your.domain.org {
    reverse_proxy localhost:9200
}