docs: address issue #23194

This change was automatically generated by the documentation agent team
in response to issue #23194.

🤖 Generated with cagent
This commit is contained in:
github-actions[bot]
2025-12-19 15:04:03 +00:00
committed by David Karlsson
parent 8c3b5db166
commit 02d82e2105

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@@ -77,23 +77,17 @@ dependencies can considerably lower the attack surface.
## Rebuild your images often
Docker images are immutable. Building an image is taking a snapshot of that
image at that moment. That includes any base images, libraries, or other
software you use in your build. To keep your images up-to-date and secure, make
sure to rebuild your image often, with updated dependencies.
Docker images are immutable. Building an image is taking a snapshot of
that image at that moment. That includes any base images, libraries, or
other software you use in your build. To keep your images up-to-date and
secure, rebuild your images regularly with updated dependencies.
To ensure that you're getting the latest versions of dependencies in your build,
you can use the `--no-cache` option to avoid cache hits.
### Use --pull to get fresh base images
```console
$ docker build --no-cache -t my-image:my-tag .
```
The following Dockerfile uses the `24.04` tag of the `ubuntu` image. Over time,
that tag may resolve to a different underlying version of the `ubuntu` image,
as the publisher rebuilds the image with new security patches and updated
libraries. Using the `--no-cache`, you can avoid cache hits and ensure a fresh
download of base images and dependencies.
The following Dockerfile uses the `24.04` tag of the `ubuntu` image.
Over time, that tag may resolve to a different underlying version of the
`ubuntu` image, as the publisher rebuilds the image with new security
patches and updated libraries.
```dockerfile
# syntax=docker/dockerfile:1
@@ -101,6 +95,33 @@ FROM ubuntu:24.04
RUN apt-get -y update && apt-get install -y --no-install-recommends python3
```
To get the latest version of the base image, use the `--pull` flag:
```console
$ docker build --pull -t my-image:my-tag .
```
The `--pull` flag forces Docker to check for and download a newer
version of the base image, even if you have a version cached locally.
### Use --no-cache for clean builds
The `--no-cache` flag disables the build cache, forcing Docker to
rebuild all layers from scratch:
```console
$ docker build --no-cache -t my-image:my-tag .
```
This gets the latest available versions of dependencies from package
managers like `apt-get` or `npm`. However, `--no-cache` doesn't pull a
fresh base image - it only prevents reusing cached layers. For a
completely fresh build with the latest base image, combine both flags:
```console
$ docker build --pull --no-cache -t my-image:my-tag .
```
Also consider [pinning base image versions](#pin-base-image-versions).
## Exclude with .dockerignore
@@ -639,10 +660,10 @@ RUN ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
```
For more information about `ADD` or `COPY`, see the following:
- [Dockerfile reference for the ADD instruction](/reference/dockerfile.md#add)
- [Dockerfile reference for the COPY instruction](/reference/dockerfile.md#copy)
### ENTRYPOINT
The best use for `ENTRYPOINT` is to set the image's main command, allowing that
@@ -695,7 +716,6 @@ fi
exec "$@"
```
This script uses [the `exec` Bash command](https://wiki.bash-hackers.org/commands/builtin/exec) so that the final running application becomes the container's PID 1. This allows the application to receive any Unix signals sent to the container. For more information, see the [`ENTRYPOINT` reference](/reference/dockerfile.md#entrypoint).
In the following example, a helper script is copied into the container and run via `ENTRYPOINT` on