> ## Documentation Index
> Fetch the complete documentation index at: https://docs.codeant.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Best practice

<AccordionGroup>
  <Accordion title="missing-dnf-clean-all">
    This dnf command does not end with '&& dnf clean all'. Running 'dnf clean all' will remove cached data and reduce package size. (This must be performed in the same RUN step.)
  </Accordion>

  <Accordion title="prefer-json-notation">
    Prefer JSON notation when using CMD or ENTRYPOINT. This allows signals to be passed from the OS.
  </Accordion>

  <Accordion title="use-either-wget-or-curl">
    'wget' and 'curl' are similar tools. Choose one and do not install the other to decrease image size.
  </Accordion>

  <Accordion title="nonsensical-command">
    Some commands such as `$CMD` do not make sense in a container. Do not use these.
  </Accordion>

  <Accordion title="avoid-zypper-update">
    Packages in base images should be up-to-date, removing the need for 'zypper update'. If packages are out-of-date, consider contacting the base image maintainer.
  </Accordion>

  <Accordion title="missing-image-version">
    Detected docker image with no explicit version attached. Images should be tagged with an explicit version to produce deterministic container images -- attach a version when using  `FROM <image>`.
  </Accordion>

  <Accordion title="avoid-dnf-update">
    Packages in base images should be up-to-date, removing the need for 'dnf update'. If packages are out-of-date, consider contacting the base image maintainer.
  </Accordion>

  <Accordion title="missing-apk-no-cache">
    This apk command is missing '--no-cache'. This forces apk to use a package index instead of a local package cache, removing the need for '--update' and the deletion of '/var/cache/apk/\*'. Add '--no-cache' to your apk command.
  </Accordion>

  <Accordion title="missing-pip-no-cache-dir">
    This '\$PIP install' is missing '--no-cache-dir'. This flag prevents package archives from being kept around, thereby reducing image size. Add '--no-cache-dir'.
  </Accordion>

  <Accordion title="prefer-copy-over-add">
    The ADD command will accept and include files from a URL and automatically extract archives. This potentially exposes the container to a man-in-the-middle attack or other attacks if a malicious actor can tamper with the source archive. Since ADD can have this and other unexpected side effects, the use of the more explicit COPY command is preferred.
  </Accordion>

  <Accordion title="remove-package-lists">
    The package lists were not deleted after running 'apt-get update', which increases the size of the image. Remove the package lists by appending '&& rm -rf /var/lib/apt/lists/\*' at the end of apt-get command chain.
  </Accordion>

  <Accordion title="remove-package-cache">
    The package cache was not deleted after running 'apt-get update', which increases the size of the image. Remove the package cache by appending '&& apt-get clean' at the end of apt-get command chain.
  </Accordion>

  <Accordion title="avoid-platform-with-from">
    Using '--platform' with FROM restricts the image to build on a single platform. Further, this must be the same as the build platform. If you intended to specify the target platform, use the utility 'docker buildx --platform=' instead.
  </Accordion>

  <Accordion title="missing-zypper-clean">
    This zypper command does not end with '&& zypper clean'. Running 'zypper clean' will remove cached data and reduce package size. (This must be performed in the same RUN step.)
  </Accordion>

  <Accordion title="avoid-latest-version">
    Images should be tagged with an explicit version to produce deterministic container images. The 'latest' tag may change the base container without warning.
  </Accordion>

  <Accordion title="prefer-apt-get">
    'apt-get' is preferred as an unattended tool for stability. 'apt' is discouraged.
  </Accordion>

  <Accordion title="set-pipefail">
    Only the exit code from the final command in this RUN instruction will be evaluated unless 'pipefail' is set. If you want to fail the command at any stage in the pipe, set 'pipefail' by including 'SHELL \["/bin/bash", "-o", "pipefail", "-c"] before the command. If you're using alpine and don't have bash installed, communicate this explicitly with `SHELL ["/bin/ash"]`.
  </Accordion>

  <Accordion title="avoid-yum-update">
    Packages in base images should be up-to-date, removing the need for 'yum update'. If packages are out-of-date, consider contacting the base image maintainer.
  </Accordion>

  <Accordion title="maintainer-is-deprecated">
    MAINTAINER has been deprecated.
  </Accordion>

  <Accordion title="use-shell-instruction">
    Use the SHELL instruction to set the default shell instead of overwriting '/bin/sh'.
  </Accordion>

  <Accordion title="avoid-apt-get-upgrade">
    Packages in base containers should be up-to-date, removing the need to upgrade or dist-upgrade. If a package is out of date, contact the maintainers.
  </Accordion>

  <Accordion title="avoid-apk-upgrade">
    Packages in base images should be up-to-date, removing the need for 'apk upgrade'. If packages are out-of-date, consider contacting the base image maintainer.
  </Accordion>

  <Accordion title="missing-no-install-recommends">
    This 'apt-get install' is missing '--no-install-recommends'. This prevents unnecessary packages from being installed, thereby reducing image size. Add '--no-install-recommends'.
  </Accordion>

  <Accordion title="use-workdir">
    As recommended by Docker's documentation, it is best to use 'WORKDIR' instead of 'RUN cd ...' for improved clarity and reliability. Also, 'RUN cd ...' may not work as expected in a container.
  </Accordion>

  <Accordion title="missing-dnf-assume-yes-switch">
    This 'dnf install' is missing the '-y' switch. This might stall builds because it requires human intervention. Add the '-y' switch.
  </Accordion>

  <Accordion title="missing-yum-assume-yes-switch">
    This 'yum install' is missing the '-y' switch. This might stall builds because it requires human intervention. Add the '-y' switch.
  </Accordion>
</AccordionGroup>