How to use this image

All examples in this guide use the public image. If you've mirrored the repository for your own use (for example, to your Docker Hub namespace), update your commands to reference the mirrored image instead of the public one.

For example:

• Public image: dhi.io/<repository>:<tag>
• Mirrored image: <your-namespace>/dhi-<repository>:<tag>

For the examples, you must first use docker login dhi.io to authenticate to the registry to pull the images.

Start a metabase instance

Run the following command and replace <tag> with the image variant you want to run.

docker run --rm -p 127.0.0.1:3000:3000 dhi.io/metabase:<tag>

Open http://localhost:3000 in your browser to reach the setup wizard. The first boot takes a minute or more while Metabase runs its application database migrations, so wait for the container logs to settle before loading the page.

The example publishes the port on loopback only. Until the setup wizard is completed, whoever reaches the port first claims the admin account, so widen the binding to -p 3000:3000 only once setup is finished and the instance sits behind your own network controls.

By default Metabase stores its application data in an embedded H2 database inside the container. Without a mounted volume or an external database, this data is lost when the container is removed. See the following use cases for persisting data.

Common metabase use cases

Persist the embedded H2 database

The image stores the embedded H2 database in the /metabase.db directory (MB_DB_FILE=/metabase.db/metabase.db), the same location the upstream image uses after its first-boot migration. Mount a volume there so the database survives container restarts and recreation:

docker run -d \
  --name metabase \
  -p 127.0.0.1:3000:3000 \
  -v mb-data:/metabase.db \
  dhi.io/metabase:<tag>

To store the database somewhere else, set MB_DB_FILE to a path on a writable mounted volume.

Production deployment with PostgreSQL

For production use, point Metabase at an external PostgreSQL or MySQL application database instead of the embedded H2 database. The following compose.yml example starts Metabase alongside a PostgreSQL application database:

services:
  postgres:
    image: dhi.io/postgres:<tag>
    environment:
      - POSTGRES_DB=metabase
      - POSTGRES_USER=metabase
      - POSTGRES_PASSWORD=metabasepass
    volumes:
      - postgres_data:/var/lib/postgresql/data

  metabase:
    image: dhi.io/metabase:<tag>
    ports:
      - "127.0.0.1:3000:3000"
    environment:
      - MB_DB_TYPE=postgres
      - MB_DB_DBNAME=metabase
      - MB_DB_PORT=5432
      - MB_DB_USER=metabase
      - MB_DB_PASS=metabasepass
      - MB_DB_HOST=postgres
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/api/health"]
      interval: 15s
      timeout: 5s
      retries: 20
    depends_on:
      - postgres

volumes:
  postgres_data:

Pass database credentials with Docker secrets

Swap any MB_DB_* credential variable above for its _FILE form (for example MB_DB_PASS_FILE=/run/secrets/mb_db_pass) and the entrypoint reads the value from the file instead of the environment, so Docker secrets work without running as root. See the Metabase environment variable reference⁠ for the full list.

Install a third-party database driver

Metabase loads driver jars it finds in /plugins at startup. The drivers it ships with are loaded from inside the uberjar, so /plugins holds only the extracted sample database until you add something.

Create the host directory, copy the driver jar (for example, a ClickHouse or Snowflake driver) into it, and make it writable by the container's user. Metabase also extracts its sample database into /plugins, so the mount has to be writable:

mkdir -p drivers
cp /path/to/driver.jar drivers/
chown 2000:2000 drivers

Then mount it to /plugins:

docker run -d \
  --name metabase \
  -p 127.0.0.1:3000:3000 \
  -v "$(pwd)/drivers:/plugins" \
  dhi.io/metabase:<tag>

Advanced configuration

For single sign-on (SAML, JWT, LDAP), static and interactive embedding, serialization for moving dashboards and questions between environments, and migrating from the embedded H2 database to PostgreSQL or MySQL with load-from-h2, see the Metabase documentation⁠.

Non-hardened images vs. Docker Hardened Images

The DHI metabase runtime variants always run as the nonroot metabase user on uid/gid 2000, the same ids upstream's run_metabase.sh creates on first boot. An existing H2 or /plugins volume written by the upstream image therefore works here as-is, with no chown step. Note that upstream reaches those ids by starting as root and self-dropping, chowning application paths on the way; the DHI runtime variants never run as root, so that bootstrap branch never executes and a volume owned by any other uid has to be made writable by uid/gid 2000 before you mount it. Because the account is baked into the image, upstream's MUID and MGID variables have no effect.

The hardened system package installs the entrypoint script at /usr/bin/run_metabase.sh and the jar at /usr/share/metabase/metabase.jar, and the image keeps upstream's /app/run_metabase.sh and /app/metabase.jar as symlinks onto them, so the entrypoint and the /app-based layout stay where a migrating user expects them. /opt/java/openjdk also stays as a symlink to the JDK so commands written against upstream's layout keep working. MB_DB_FILE defaults to /metabase.db/metabase.db — the same directory layout upstream's first-boot migration produces — and /metabase.db ships writable by the metabase user.

The dev variants run as root and do take upstream's bootstrap branch, so they set MB_DB_FILE=/metabase.db and let the script derive that same layout. Run the dev variants as root; running one as a nonroot user needs an explicit MB_DB_FILE=/metabase.db/metabase.db.

The runtime variants keep bash, the core utilities the entrypoint script invokes, and curl for the upstream-documented health check (see Image variants below), but contain no package manager.

Image variants

Docker Hardened Images come in different variants depending on their intended use.

• Runtime variants are designed to run your application in production. These images are intended to be used either directly or as the FROM image in the final stage of a multi-stage build. These images typically:

  • Run as the nonroot user
  • Do not include a shell or a package manager
  • Contain only the minimal set of libraries needed to run the app

  metabase is an exception: its entrypoint run_metabase.sh is a shell script, so the runtime variants include bash and the core utilities it invokes, plus curl for the upstream-documented health check. They still run as the nonroot user and contain no package manager.

• Build-time variants typically include dev in the variant name and are intended for use in the first stage of a multi-stage Dockerfile. These images typically:

  • Run as the root user
  • Include a shell and package manager
  • Are used to build or compile applications

Migrate to a Docker Hardened Image

To migrate your application to a Docker Hardened Image, you must update your Dockerfile. At minimum, you must update the base image in your existing Dockerfile to a Docker Hardened Image. This and a few other common changes are listed in the following table of migration notes.

The following steps outline the general migration process.

1. Find hardened images for your app.

   A hardened image may have several variants. Inspect the image tags and find the image variant that meets your needs.

2. Update the base image in your Dockerfile.

   Update the base image in your application's Dockerfile to the hardened image you found in the previous step. For framework images, this is typically going to be an image tagged as dev because it has the tools needed to install packages and dependencies.

3. For multi-stage Dockerfiles, update the runtime image in your Dockerfile.

   To ensure that your final image is as minimal as possible, you should use a multi-stage build. All stages in your Dockerfile should use a hardened image. While intermediary stages will typically use images tagged as dev, your final runtime stage should use a non-dev image variant.

4. Install additional packages

   Docker Hardened Images contain minimal packages in order to reduce the potential attack surface. You may need to install additional packages in your Dockerfile. Inspect the image variants to identify which packages are already installed.

   Only images tagged as dev typically have package managers. You should use a multi-stage Dockerfile to install the packages. Install the packages in the build stage that uses a dev image. Then, if needed, copy any necessary artifacts to the runtime stage that uses a non-dev image.

   For Alpine-based images, you can use apk to install packages. For Debian-based images, you can use apt-get to install packages.

Troubleshooting migration

The following are common issues that you may encounter during migration.

General debugging

The hardened images intended for runtime don't contain a shell nor any tools for debugging. The recommended method for debugging applications built with Docker Hardened Images is to use Docker Debug⁠ to attach to these containers. Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

Permissions

By default image variants intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user. You may need to copy files to different directories or change permissions so your application running as the nonroot user can access them.

Privileged ports

Non-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10. To avoid issues, configure your application to listen on port 1025 or higher inside the container, even if you map it to a lower port on the host. For example, docker run -p 80:8080 my-image will work because the port inside the container is 8080, and docker run -p 80:81 my-image won't work because the port inside the container is 81.

No shell

By default, image variants intended for runtime don't contain a shell. Use dev images in build stages to run shell commands and then copy any necessary artifacts into the runtime stage. In addition, use Docker Debug to debug containers with no shell. metabase is an exception: its entrypoint is a shell script, so the runtime variants keep a shell.

Entry point

Docker Hardened Images may have different entry points than images such as Docker Official Images. Use docker inspect to inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.