In order to enable Portainer, the docker-compose.yml and site.conf for Nginx must be modified. 1\. Create a new file `docker-compose.override.yml` in the mailcow-dockerized root folder and insert the following configuration ``` version: '2.1' services: portainer-mailcow: image: portainer/portainer-ce volumes: - /var/run/docker.sock:/var/run/docker.sock - ./data/conf/portainer:/data restart: always dns: - 172.22.1.254 dns_search: mailcow-network networks: mailcow-network: aliases: - portainer ``` 2a\. Create `data/conf/nginx/portainer.conf`: ``` upstream portainer { server portainer-mailcow:9000; } map $http_upgrade $connection_upgrade { default upgrade; '' close; } ``` 2b\. Insert a new location to the default mailcow site by creating the file `data/conf/nginx/site.portainer.custom`: ``` location /portainer/ { proxy_http_version 1.1; proxy_set_header Host $http_host; # required for docker client's sake proxy_set_header X-Real-IP $remote_addr; # pass on real client's IP proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto $scheme; proxy_read_timeout 900; proxy_set_header Connection ""; proxy_buffers 32 4k; proxy_pass http://portainer/; } location /portainer/api/websocket/ { proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection $connection_upgrade; proxy_pass http://portainer/api/websocket/; } ``` 3\. Apply your changes: ``` docker compose up -d && docker compose restart nginx-mailcow ``` Now you can simply navigate to https://${MAILCOW_HOSTNAME}/portainer/ to view your Portainer container monitoring page. You’ll then be prompted to specify a new password for the **admin** account. After specifying your password, you’ll then be able to connect to the Portainer UI.