The Minimus gallery of images uses the following system to organize its images:

  • Images - Refers to the image type, as in Nginx, Golang, PHP, Redis, etc.
  • Image lines - Refers to the release branch. That is the upstream’s maintained release lines. Most projects maintain at least 2 lines, often named. For example (current as of March 2025):
    • Nginx has 2 release lines: mainline and stable- 1.27 and 1.26 (ref).
    • MySQL has 3 release lines: innovation (9.2), long term support lts (8.4), and the previous LTS line - 8.0 (ref).
    • Postgres maintains 5 release lines: 13, 14, 15, 16, 17 (ref). They are not named.
    • Python maintains 2 active support lines: 3.13 and 3.12 (ref ). The lines are not named.

Minimus maintains the same release lines as are actively supported by their upstream projects. A release line that is being actively supported by the upstream project means that it actively receives bug reports and security issues and puts out version updates.

  • Image versions - Refers to the version number or release number within the image line.
    • Usually, the image version follows semantic versioning conventions in X.Y.Z format (ref). For example, for the Nginx image, the latest mainline version is 1.27.4 and the latest stable line version is 1.26.3 (as determined on Feb 20, 2025).
    • Minimus follows the release schedule of the upstream projects. Every time a new version is released, Minimus will cut an image of the new version. The version numbers are identical to the upstream project and will be shown in the relevant image line in the Minimus gallery.

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Daily security updates

For every image line, the most recent version is actively maintained by Minimus. This means Minimus builds the most recent image version within every image line every time there is an update in any of the internal packages or their dependencies. Once a new version is published in an image line, active maintenance is transferred to the new version. See architecture

For example, if we look at the last 2 releases of the Nginx mainline, we’ll see that over 2 months passed between them. Version 1.27.4 was released on Feb 5, 2025 and version 1.27.3 was released over 2 months prior, on Nov 26, 2024 (ref). In the time that passed between the two releases, new CVEs were discovered and fixed in internal packages used by the Nginx image. Minimus updates all packages daily, so that no security patches wait too long before they reach you.

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Unique timestamp tag

As a result of its active maintenance policy, Minimus image versions may have several digest IDs, corresponding to the number of times they had internal package updates. Minimus uses a unique timestamp tag to indicate when the build was published, for example:

  • elasticsearch:8.17.2-dev-202503040032 is the tag for the Elasticsearch image version 8.117.2 built on March 4, 2025 at 00:32 UTC.
  • nginx:1.27.4-202503070038 is the tag for the NGINX image version 1.27.4 built on March 7, 2025 at 00:38 UTC.

The unique timestamp tag can help you easily tell apart different builds for the same image version and reliably pull the most recent build for a specific version. The timestamp tag is much like an image digest, only friendlier and human-readable.