apptainer(1)

💅 apptainer(1) — the manual page, bestie edition 🎀

okay so you've stumbled into the apptainer(1) manual and specifically the registry login page, and honestly? you're in the right place. pull up a chair, grab a strawberry 🍓, and let's get you logged in. no cap, this one's short and sweet.

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✨ NAME ✨

okay so the actual full name of this command is apptainer-registry-login — it's the part of apptainer that lets you login to an OCI/Docker registry. that's the whole vibe. she logs you in. 🫶

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🌸 SYNOPSIS 🌸

apptainer registry login [login options...]

literally just that. command, subcommand, and then your options go bopping along after it. iconic.

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🦋 DESCRIPTION 🦋

so the 'registry login' command is the one that lets you login to a specific OCI/Docker registry. that's it, that's the whole description, and honestly she ate. 💅 think of it as showing your ID at the door of the container registry club — once you're in, you're in.

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✨ OPTIONS ✨

here's the whole menu of flags, no skips, all of them, in order:

• --authfile="" — the Docker-style authentication file to use for writing/reading OCI registry credentials. default is empty, i.e. "". your little credential locker, basically. 🎀
• -h, --help[=false] — help for login. default is false. when in doubt, ask for help, bestie. it's giving "just read the instructions" energy and we love that for us.
• -p, --password="" — the password / token to authenticate with. default "".
• --password-stdin[=false] — take the password from standard input. default is false. lowkey the safer vibe, iykyk. 🔥
• -u, --username="" — the username to authenticate with, and heads up: this is required for Docker/OCI registry login. default "". yes, even when you're using a token. more on that below. 👀

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🧚 EXAMPLE 🧚

okay so the original example, verbatim, because precision is the moment:

To login in to a docker/OCI registry:
$ apptainer registry login --username foo docker://docker.io
$ apptainer registry login --username foo oras://myregistry.example.com

so you've got your docker:// registries and your oras:// registries, and either way you're passing --username foo. cute. simple. slay.

⚠️ and now the important part, bestie, read this twice:

many cloud OCI registries use token-based authentication. the token should be specified as the password for login. and even then — a username is still required. no username, no entry, periodt. 😭

so like, for the record: when using a standard Azure identity and token to login to an ACR registry, the username '00000000-0000-0000-0000-000000000000' is required. yes that's a real string, yes you have to type it exactly, no you can't skip it. 💀

and obviously consult your provider's documentation for the details concerning their specific login requirements — every registry's got its own little rules and honestly they all think they're the main character.

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👑 SEE ALSO 👑

• apptainer-registry(1) — go read the parent page too, the whole registry family is right there ✨

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🎀 HISTORY 🎀

22-Oct-2026 — Auto generated by spf13/cobra. so yeah, this page literally wrote itself. auto-generated and still serving looks. 🌈

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and that's the whole page! 💖 big sign-off energy: this beauty was Auto generated by spf13/cobra and dated Oct 2026, with apptainer(1) living up there in the corner the whole time. go log in, bestie, you're gonna do amazing 🦋🌟