[install.bundles] fails to mount airgap bundle.tar with K3s image + Helm binary (compressed assets): “too big” warning prevents mounting

[jarrillaga]

Hi Kairos community 👋

I’ve successfully installed K3s using a custom bundle image, following the approach described in the Kairos Airgap example. After a few minor adjustments, everything worked as expected: K3s loads the image correctly from the persistent path, and the system boots and runs without issues.

However, I’m running into a consistent problem when trying to include the Helm binary in addition to K3s, either as part of the same bundle or as a separate one.

I've tried the following:

• Packing both k3s-airgap-images-amd64.tar.gz and helm.tar.gz into a single bundle.tar
• Creating two separate bundles: bundle-k3s.tar and bundle-helm.tar

In both cases, when installing from the LiveCD and the Kairos Agent reaches the install.bundles phase, I consistently see errors like:

• bundle.tar: too big

---

• bundle-k3s.tar: too big
• bundle-helm.tar: too big

And although run.sh does get executed, /assets/ is not mounted, so neither K3s nor Helm gets copied into the persistent path, which breaks the airgap setup.

This seems related to RAM constraints in the initramfs environment. During the install phase (from the LiveCD), bundles are mounted into memory from /run/initramfs/live/, and if they exceed a certain threshold, they're skipped. Adding a second asset like Helm, even if small, appears to tip the system over that limit.

• Is there a hard or soft limit on bundle size during install.bundles pointing to /run/initramfs/live/
• Is there a recommended workaround to ensure both K3s, Helm and other assets can be delivered in an airgap installation?

Thanks in advance for your help, this is key for us. If Kairos only supports a k3s bundle due to size constraints, it severely limits the ability to build reliable immutable images for airgapped environments.

Happy to help contribute improvements to the docs based on whatever we find here.

[jarrillaga]

Quick follow-up on this: after further testing, I’ve confirmed that the issue was not related to the bundle size, as I initially suspected.

I made a fix, and both K3s and Helm bundles load and install correctly, even when combined.

[jimmykarily]

Happy to hear it's working for you @jarrillaga ! In any case, consider sharing what the actual problem was in case someone faces the same problem. I've found myself following a google result that matches my problem perfectly, only to find that the reporter didn't share the fix :D .