1. Install Ubuntu Server

https://ubuntu.com/download/server

2. Nextcloud

3. Install Postgres

❗ LinuxServer.io Nextcloud doesdoes not useuse PostgreSQL environmentenvironment variablesvariables to connect to the databasedatabase.

That’s the issueissue rightright therethere.

UnlikeUnlike the officialofficial nextcloud imageimage, linuxserver/nextcloud doesdoes not read POSTGRES_USER, POSTGRES_PASSWORD, etc. from the environmentenvironment.

InsteadInstead, it expects youyou to configureconfigure the databasedatabase entirelyentirely throughthrough the web UI.


services:
  db:
    image: postgres:16
    container_name: nextcloud-postgres
    environment:
      POSTGRES_DB: nextclouddb
      POSTGRES_USER: nextcloud
      POSTGRES_PASSWORD: MyStrongPassword123!
    volumes:
      - /opt/nextcloud/postgres:/var/lib/postgresql/data
    restart: unless-stopped

  nextcloud:
    image: lscr.io/linuxserver/nextcloud:latest
    container_name: nextcloud
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
    volumes:
      - /opt/nextcloud/config:/config
      - /opt/nextcloud/data:/data
    ports:
      - 443:443
    depends_on:
      - db
    restart: unless-stopped

3. Duck DNS

Errors:

Bad gateway: Because your Portainer HTTPS endpoint is using a self-signed certificate, Cloudflared (by default) will try to validate it—and fail—so you get a 502 even though curl -vk https://127.0.0.1:9443 works locally.

Here’s how to fix that when you’re using the Web Dashboard to manage your tunnel:

Enable “Disable TLS Verification” on the Hostname In the Cloudflare dashboard go to Zero Trust → Access → Tunnels.

Click your tunnel, then open the Public hostnames tab.

Find the row for portainer.kimhungbui.com and click Edit.

Under Origin Connection you should see a toggle or checkbox labeled something like “Disable TLS verification” (or “Skip certificate validation”).

Enable that option and save.

This tells Cloudflared not to reject your Portainer’s self-signed cert.

It work: