Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

docs: make the warning about build arguments #4608

Merged
merged 1 commit into from
Feb 1, 2024
Merged

docs: make the warning about build arguments #4608

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 17 additions & 12 deletions frontend/dockerfile/docs/reference.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2031,8 +2031,23 @@ ARG <name>[=<default value>]

The `ARG` instruction defines a variable that users can pass at build-time to
the builder with the `docker build` command using the `--build-arg <varname>=<value>`
flag. If a user specifies a build argument that was not
defined in the Dockerfile, the build outputs a warning.
flag.

> **Warning**
>
> It isn't recommended to use build arguments for passing secrets such as
> user credentials, API tokens, etc. Build arguments are visible in the
> `docker history` command and in `max` mode provenance attestations,
> which are attached to the image by default if you use the Buildx GitHub Actions
> and your GitHub repository is public.
>
> Refer to the [`RUN --mount=type=secret`](#run---mounttypesecret) section to
> learn about secure ways to use secrets when building images.
{ .warning }


If you specify a build argument that wasn't defined in the Dockerfile,
the build outputs a warning.

```console
[Warning] One or more build-args [foo] were not consumed.
Expand All @@ -2048,16 +2063,6 @@ ARG buildno
# ...
```

> **Warning**
>
> It is not recommended to use build-time variables for passing secrets like
> GitHub keys, user credentials etc. Build-time variable values are visible to
> any user of the image with the `docker history` command.
>
> Refer to the [`RUN --mount=type=secret`](#run---mounttypesecret) section to
> learn about secure ways to use secrets when building images.
{ .warning }

### Default values

An `ARG` instruction can optionally include a default value:
Expand Down