From 678218f2be830b6011728d42a72a35714f423bcf Mon Sep 17 00:00:00 2001 From: CrazyMax Date: Wed, 4 May 2022 15:02:47 +0200 Subject: [PATCH] Note about image name and tag sanitization Signed-off-by: CrazyMax --- README.md | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/README.md b/README.md index 06590a47b..0d8f41fc4 100644 --- a/README.md +++ b/README.md @@ -31,6 +31,7 @@ ___ * [`type=raw`](#typeraw) * [`type=sha`](#typesha) * [Notes](#notes) + * [Image name and tag sanitization](#image-name-and-tag-sanitization) * [Latest tag](#latest-tag) * [Global expressions](#global-expressions) * [`{{branch}}`](#branch) @@ -625,6 +626,22 @@ tags: | ## Notes +### Image name and tag sanitization + +In order to comply with [the specification](https://docs.docker.com/engine/reference/commandline/tag/#extended-description), +the image name components may contain lowercase letters, digits and separators. +A separator is defined as a period, one or two underscores, or one or more +dashes. A name component may not start or end with a separator. + +A tag name must be a valid ASCII chars sequences and may contain lowercase and +uppercase letters, digits, underscores, periods and dashes. A tag name may not +start with a period or a dash and may contain a maximum of 128 characters. + +To ease the integration in your workflow, this action will automatically: + +* Lowercase the image name +* Replace invalid chars sequences with `-` for tags + ### Latest tag `latest` tag is handled through the [`flavor` input](#flavor-input). It will be generated by default (`auto` mode) for: