update boot-instance Occlum to 0.29.7

[mythi]

agent-enclave uses 0.29.5 so it's good for this to follow: https://github.com/confidential-containers/enclave-cc/blob/8164a4cf17c0f9ec7b82b3b61bd55b3607072e99/tools/packaging/build/boot-instance-bundle/Dockerfile#L24-L26

• [x] Change image-rs to use sefs fstype instead of unionfs
• [x] Change runtime boot struct user_rootfs_config
• [x] Update image-rs and change boot-instance/agent-instance Dockerfile to use "upstream" 0.29.6 Occlum

[haosanzi]

Hi. Occlum 0.29.5 does Not support runtime boot. The boot-instance occlum should rebase on occlum NGO which support runtime boot.

[mythi]

@haosanzi this ticket is to get https://github.com/qzheng527/occlum/tree/enclave-cc rebased to 0.29.5 level and .deb packages made available via http://mirrors.openanolis.cn/inclavare-containers/ubuntu20.04 just like we are doing it today.

[mythi]

@haosanzi I think NGO is also OK but I've not seen any activity in the repo since December. What's the NGO status?

[haosanzi]

@mythi hi, ngo has changed to Occlum 1.0, but has no official release yet. The link: https://github.com/occlum/occlum/tree/1.0.0-preview

[mythi]

@haosanzi OK thanks for the NGO update! This issue does not depend on 1.0 though, it's enough we get the 0.29.5 functionality.

[mythi]

I re-titled this to cover 0.29.6 update. Details in #112

[ariel-adam]

@haosanzi is this on track for 0.7.0 (feature freeze 12th of July) or should we move it to 0.8.0 (it's also in status new on our board: https://github.com/orgs/confidential-containers/projects/6/views/17)?

[ariel-adam]

Moving to 0.8.0 given that 0.7.0 feature freeze is happening in 1 week