Containers

The Containers page in OpenPanel allows you to manage Docker services defined via Docker Compose files by your Administrator.

This section provides a clear overview of your containerized services and their resource usage.

Overview​

At the top of the page, you'll see:

• Running Containers / Total Containers – Indicates how many services are currently active.
• Total CPU – Number of CPU cores assigned to your hosting plan.
• Total Memory – Amount of RAM (in GB) assigned to your hosting plan.

You can allocate portions of these total resources to individual services.

Container Table​

Use the Show Columns dropdown above the table to show or hide columns. Name, CPU Usage, Memory Usage, PIDs, Status and Actions are shown by default, Block I/O and Net I/O are hidden.

Each row in the table represents a containerized service and displays:

• Checkbox – Selects the service for bulk actions.
• Name – Name of the Docker service, along with the image used and its tag (version).
• CPU Usage
  • Graph – Real-time usage as a percentage of the allocated CPU.
  • Usage – How much CPU the container is using from its allocated amount.
  • Allocated – Number of CPU cores allocated to the service.
• Memory Usage
  • Graph – Real-time usage as a percentage of the allocated memory.
  • Usage – RAM used by the service from its allocated amount.
  • Allocated – Memory (in GB) allocated to the service.
• PIDs – Processes running in the container and the most it can run.
• Status – A badge showing whether the service is currently Enabled (running) or Disabled (stopped).
• Actions – The ⋮ menu of the service:
  • Start if the service is stopped, or Stop if it's running.
  • Terminal opens a web terminal (podman exec) for that container, and Logs jumps to its log output.
  • Edit and Delete are only shown for services you added yourself, core services (webserver, database, cache, etc.) can't be edited or deleted from this page.

Editing Resources​

To change the CPU, Memory or PIDs limit of a service:

1. Hover over the Allocated value in the table.
2. Click the pencil icon.
3. Adjust the value in the input field.
4. Click Save.

The change is applied immediately to the running container (no restart required). Setting CPU or Memory to 0 removes the limit and falls back to the maximum allowed by your hosting plan, and PIDs 0 means unlimited.

To change the limit of several services at once, use bulk actions.

All limits of a service (CPU, memory and PIDs), along with its image, environment variables, volumes and networks, can also be changed from its Edit page:

Bulk Actions​

Tick the checkbox of one or more services, or the checkbox in the table header to select every service shown by the current search. A bar appears at the bottom of the page with the number of selected services, a Clear link and these actions:

Clicking an action asks you to confirm it first. Edit CPU, Edit RAM and Edit PIDs also ask for the new value, 0 works the same as in Editing Resources, and CPU and memory can't be set higher than your hosting plan allows.

If some of the selected services don't support the action, for example core services with Delete, the confirmation says how many will be skipped and the action runs only on the rest.

Click Confirm and the action runs on the services one after another. When it's done the page reloads with a notice saying whether it succeeded for all of them, or which services failed and why.

Adding New Services​

Click New Service on the Containers page to run any Docker image next to your websites, for example a Redis cache, a queue worker or your own app. The form is split into numbered steps:

1. Image and name

   • Docker image – An image from Docker Hub such as redis:7-alpine, or a full address like ghcr.io/owner/app:1.0. Popular images are suggested as you type. Add a tag to pin the version.
   • Name – Filled in from the image, and changed automatically if that name is already taken. It must start with a letter, contain only lowercase letters and digits, and be at least 3 characters long. Other services reach the container by this name, for example redis:6379.

2. Resources – Pick Small (0.25 CPU, 0.25 GB, 100 processes), Medium (0.5 CPU, 1 GB, 500 processes, the default) or Large (1 CPU, 2 GB, 1000 processes), or type your own values:

   • CPU cores – Maximum CPU the container can use, for example 0.5 or 1.
   • Memory – Maximum memory, always in GB, for example 0.5 or 2.
   • Max processes – The most processes the container can run at once.

   These limits apply to this container only, it can't use more than your hosting plan allows.

3. Networks – Tick one or more networks from your docker-compose.yml. The container can talk to every service on the networks you choose. At least one is required.

4. Storage (optional)

   • Add volume – Pick one of your Docker volumes, enter the path it's mounted at inside the container, and optionally mark it Read-only.
   • + New volume – The last option in the volume list. It switches the row to a name field so you can create a new volume for this container, for example uptimekuma_data. Names are 3 to 64 lowercase letters, digits or _, starting with a letter. The volume is created when you save, and it keeps its data if the container is deleted later.
   • Give access to the Docker socket – Only for tools that manage containers, like Portainer or Watchtower. The container can then control all your other containers. Unchecked by default.

5. Environment variables (optional) – Add a key and value per row, or click Paste as text to paste them as KEY: value lines, one per line. {domain} in a value is replaced with the domain chosen in the next step (or localhost if none), for example WEBHOOK_URL: https://{domain}/.

6. Domain (optional) – Pick one of your domains to make the app reachable from outside, and enter the Container port the app listens on inside the container, for example 3001 for Uptime Kuma. The web server then proxies the whole domain to the container, WebSockets included, so you don't have to edit any web server config yourself. See Pointing a domain to a container.

7. Health check (optional) – A docker compose healthcheck block. Click Insert example to get one that fits the image, for example:

   test: ["CMD", "redis-cli", "ping"]
   interval: 30s
   timeout: 5s
   retries: 3
   

   The Containers page then shows the container as healthy or unhealthy.

Click Create container and the progress of each step is shown on the page:

1. Validating container details – The name, image, limits and networks are checked.
2. Saving container to docker-compose.yml – The service is added to your docker-compose.yml and its limits are saved to .env.
3. Downloading image – The image is pulled, so starting the container later is quick.
4. Starting container – Only when a domain is set.
5. Pointing the domain to the container – Only when a domain is set, the reverse proxy is added to the domain and the web server is restarted.
6. Container created – You're taken back to the Containers page.

If the details are invalid the step turns red with the reason, and Back to the form returns you to the form with everything still filled in. If only the image download fails, the container is already saved, and the error from the registry is shown so you can fix the image from its Edit page.

Each service gets an uppercase prefix for its environment variable keys, and its CPU, memory and process limits are stored as variables in .env. For example, a service named nginx gets:

NGINX_CPU
NGINX_RAM
NGINX_PIDS

Pointing a Domain to a Container​

When a domain is chosen in the Domain step of the form, OpenPanel wires it up for you:

• The container joins the www network, so the web server can reach it by its name.
• A reverse proxy from the domain to name:port is added to the domain's Apache, Nginx, OpenResty or OpenLiteSpeed configuration, with WebSocket support, and the web server is restarted.
• The domain is added to Site Manager as a Docker Containers site. Its Manage button opens the container's Edit page, and Delete deletes the container.

All requests to the domain go to the container, so any website files on that domain are no longer served. A domain can't be used if it already points to another container, has a NodeJS, Python, Ruby, Java or n8n application at its root, or has sites in subfolders.

The Edit page of the container shows which domain and port it's reachable on. A domain can only be set when the container is created.

When the container is deleted, from its Delete button, bulk actions or Site Manager, the reverse proxy is removed from every domain that points to it, not only the one chosen in the form, so no domain is left proxying to a container that no longer exists. Its Site Manager entry is removed too. Volumes created for the container are kept.

Templates​

The Add a container form can be filled in from a link, so an app can be set up in one click. The Auto Installer uses this for its Docker Applications, and you can make your own links:

/containers/new?image=louislam/uptime-kuma:2&name=uptimekuma&cpu=0.5&ram=0.5&volume=uptimekuma_data:/app/data&port=3001

Remember to URL-encode the values, for example {domain} in an env value becomes %7Bdomain%7D. Everything can still be changed on the form before clicking Create container.