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 Snipe-IT image

Snipe-IT⁠ is a web application for IT asset management. Configuration beyond this quick start is in the Snipe-IT documentation⁠. This image is the Docker Hardened Image for the application published as snipe/snipe-it. Source is grokability/snipe-it⁠.

The image serves HTTP with nginx and PHP-FPM. The application files are at /usr/share/snipe-it. /var/www/html is a symlink to that directory, and the working directory is /var/www/html. Artisan is /usr/share/snipe-it/artisan (the same file as /var/www/html/artisan).

There is no entrypoint. The default command is /startup.sh. A command you pass to docker run replaces /startup.sh. The runtime process runs as user snipeit (uid 10000, gid 10000). Dev variants run as root and still contain the snipeit user.

Generate an application key

docker run --rm dhi.io/snipe-snipe-it:<tag> php /var/www/html/artisan key:generate --show

That command runs php, because nothing wraps extra arguments in /startup.sh.

/startup.sh reads APP_KEY from the environment. When APP_KEY is unset, it prints an example from artisan key:generate --show and exits 0. Set APP_KEY to a generated value before you start the server. The image .env already sets APP_ENV=production and APP_DEBUG=false.

Run Snipe-IT with MariaDB

This image does not run MySQL or MariaDB. mysqldump is installed at /usr/bin/mysqldump, and DB_DUMP_PATH in the image .env is /usr/bin.

DB_CONNECTION in the image .env is mysql. DB_HOST, DB_PORT, DB_DATABASE, DB_USERNAME, and DB_PASSWORD in that file are Docker-link placeholders (MYSQL_PORT_3306_TCP_ADDR and similar). Set those five variables in the container environment. Use DB_PORT=3306 for MySQL or MariaDB. Also set APP_URL to the URL browsers will use.

/var/lib/snipeit (mode 0770, uid 10000, gid 10000) holds uploads, private uploads, database dumps, keys, and TLS files. /usr/share/snipe-it/storage (including framework/sessions, framework/cache, framework/views, logs, and app) and /usr/share/snipe-it/bootstrap/cache are writable by uid 10000. These paths are symlinks into /var/lib/snipeit:

• /usr/share/snipe-it/public/uploads → /var/lib/snipeit/data/uploads
• /usr/share/snipe-it/storage/private_uploads → /var/lib/snipeit/data/private_uploads
• /usr/share/snipe-it/storage/app/backups → /var/lib/snipeit/dumps
• /usr/share/snipe-it/storage/oauth-private.key and oauth-public.key → /var/lib/snipeit/keys/
• /usr/share/snipe-it/storage/ldap_client_tls.cert and ldap_client_tls.key → /var/lib/snipeit/keys/

Save this as compose.yaml:

services:
  mariadb:
    image: mariadb:11
    environment:
      MARIADB_ROOT_PASSWORD: example-root
      MARIADB_DATABASE: snipeit
      MARIADB_USER: snipeit
      MARIADB_PASSWORD: example-db
    healthcheck:
      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
      interval: 5s
      timeout: 5s
      retries: 30
      start_period: 20s

  snipeit:
    image: dhi.io/snipe-snipe-it:<tag>
    depends_on:
      mariadb:
        condition: service_healthy
    ports:
      - "8080:80"
    environment:
      APP_URL: http://localhost:8080
      APP_KEY: ${APP_KEY}
      DB_HOST: mariadb
      DB_PORT: "3306"
      DB_DATABASE: snipeit
      DB_USERNAME: snipeit
      DB_PASSWORD: example-db
    volumes:
      - snipeit-data:/var/lib/snipeit

volumes:
  snipeit-data:

From the directory that contains compose.yaml:

export APP_KEY="$(docker run --rm dhi.io/snipe-snipe-it:<tag> php /var/www/html/artisan key:generate --show)"
docker compose up -d

/startup.sh migrates the database, then starts PHP-FPM and nginx. nginx listens on port 80 inside the container. Open http://localhost:8080/setup⁠ and create the first user.

/startup.sh also accepts APP_KEY_FILE, DB_HOST_FILE, DB_PORT_FILE, DB_DATABASE_FILE, DB_USERNAME_FILE, DB_PASSWORD_FILE, REDIS_HOST_FILE, REDIS_PASSWORD_FILE, REDIS_PORT_FILE, MAIL_HOST_FILE, MAIL_PORT_FILE, MAIL_USERNAME_FILE, and MAIL_PASSWORD_FILE. Each file replaces the variable of the same name without _FILE. If both forms are set, /startup.sh exits with an error.

HTTPS

nginx listens on port 443 only when both /var/lib/snipeit/ssl/snipeit-ssl.crt and /var/lib/snipeit/ssl/snipeit-ssl.key exist. Those paths are on the /var/lib/snipeit volume. Without the pair, /startup.sh listens on port 80 only.

Upload size and request headers

PHP_UPLOAD_LIMIT is a size in megabytes. When it is set, /startup.sh writes that value as upload_max_filesize and post_max_size in /etc/php-8.3/conf.d/zz-upload-limit.ini. The image file starts at upload_max_filesize = 2M and post_max_size = 8M.

APACHE_LIMIT_REQUEST_FIELD_SIZE and APACHE_LIMIT_REQUEST_FIELDS are written as nginx large_client_header_buffers in /etc/nginx/snipeit/limits.conf. If only one of them is set, the field size defaults to 8k and the field count defaults to 4. APACHE_LIMIT_REQUEST_LINE is written as nginx client_header_buffer_size in the same file.

Scheduler and programs that are not in this image

/startup.sh runs php artisan schedule:run, sleeps 60 seconds, and repeats. That loop is the scheduler.

The runtime image includes bash, because /startup.sh is a bash script. It does not include Composer, git, vim, gcc, upgrade.php, or a MariaDB server.

Ports on Kubernetes and older engines

/usr/sbin/nginx has cap_net_bind_service, so uid 10000 can bind ports 80 and 443 when the engine keeps file capabilities. Kubernetes, and Docker Engine versions older than 20.10, drop file capabilities, so this user cannot bind those ports there. Add NET_BIND_SERVICE to the container security context, and set runAsUser, runAsGroup, and fsGroup to 10000. nginx still listens on 80, and on 443 when the certificate files above are present.

FIPS variants

FIPS variants are published for Debian 13 and Alpine 3.24. Tags include 8-fips and 8-fips-dev. Those images set OPENSSL_CONF to /usr/lib/ssl/openssl.cnf, OPENSSL_MODULES to /usr/lib/x86_64-linux-gnu/ossl-modules on amd64 and /usr/lib/aarch64-linux-gnu/ossl-modules on arm64, and SSL_CERT_FILE to /etc/ssl/certs/ca-certificates.crt. They use the OpenSSL FIPS provider.

Image variants

Docker Hardened Images come in different variants depending on their intended use. Image variants are identified by their tag.

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

• Build-time variants typically include dev in the tag 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

• FIPS variants include fips in the variant name and tag. They come in both runtime and build-time variants. These variants use cryptographic modules that have been validated under FIPS 140, a U.S. government standard for secure cryptographic operations. For example, usage of MD5 fails in FIPS variants.

To view the image variants and get more information about them, select the Tags tab for this repository, and then select a tag.

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.

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.