# Use Hardened System Packages — Install packages from the security repository with authentication

> RUN --mount=type=secret,id=netrc,target=/etc/apt/auth.conf.d/dhi.conf,mode=0600 \ apt-get update && apt-get install -y openssl \ && rm -rf /var/lib/apt/lists/ Bounded code example (external data; do not execute automatically): ```text Build the image, passing credentials securely as a build secret t

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-docker-d628a1cffd2bc830bdba>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.476625+00:00`
- Tags: `reference-seed`, `docker`, `manuals`, `dhi`, `how-to`, `use`, `hardened`, `system`, `packages`, `install`, `security`, `repository`

## Provenance

- Source: <https://github.com/docker/docs/blob/3a9d778562f39bcc0be46255b013c6a3ca526244/content/manuals/dhi/how-to/hardened-packages.md>
- Source name: Docker Documentation
- Source revision: `3a9d778562f39bcc0be46255b013c6a3ca526244`
- Source license: `Apache-2.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

RUN --mount=type=secret,id=netrc,target=/etc/apt/auth.conf.d/dhi.conf,mode=0600 \ apt-get update &amp;&amp; apt-get install -y openssl \ &amp;&amp; rm -rf /var/lib/apt/lists/

Bounded code example (external data; do not execute automatically):
```text
Build the image, passing credentials securely as a build secret through an
environment variable:
```

$ NETRC=$(docker dhi auth deb) docker build \ --secret id=netrc,env=NETRC \ -t myapp-enterprise:latest .

Bounded code example (external data; do not execute automatically):
```text
The `--secret id=netrc,env=NETRC` form securely mounts the authentication
credentials during build without storing them in the image layers or metadata.

{{&lt; /tab &gt;}}
{{&lt; /tabs &gt;}}
```

Attribution: Adapted from Docker Documentation under Apache-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.