Skip to content

Fix a grammar mistake in serialization.md and don't imply _ is valid in dns hostnames #163

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

Closed
wants to merge 1 commit into from
Closed

Fix a grammar mistake in serialization.md and don't imply _ is valid in dns hostnames #163

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
2 changes: 1 addition & 1 deletion serialization.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -75,7 +75,7 @@ This specification uses the following terms:
A collection of tags grouped under a common prefix (the name component before <code>:</code>).
For example, in an image tagged with the name <code>my-app:3.1.4</code>, <code>my-app</code> is the <i>Repository</i> component of the name.
A repository name is made up of slash-separated name components, optionally prefixed by a DNS hostname.
The hostname must follow comply with standard DNS rules, but may not contain <code>_</code> characters.
The hostname must comply with standard DNS rules that apply to IDNA labels as defined in <a href="https://tools.ietf.org/html/rfc5890#section-2.3">RFC 5890</a>.
Copy link
Contributor

@wking wking Aug 24, 2016

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think we want to explicitly list A-label, U-label, or NR-LDH label. Searching the spec for a definition for “IDNA labels” turned up this:

IDNA labels come in two flavors: an ACE-encoded form and a Unicode (native character) form. These are referred to as A-labels and U-labels, respectively…

But I think we want to allow NR-LDH labels as well, because U-labels must contain at least one non-ASCII character, and I'm fine with all-ASCII, non-A label, repository names.

If a hostname is present, it may optionally be followed by a port number in the format <code>:8080</code>.
Name components may contain lowercase characters, digits, and separators.
A separator is defined as a period, one or two underscores, or one or more dashes.
Expand Down