Prefetch code and packages for offline install

[holgerfriedrich]

Refs: #825

For an "offline install", i.e. first boot of the openHABian image without internet access, we need to cache some code and packages during creation of the image.
I.e. cache ZRAM code repos, cache JAVA, cache essential packages for building ZRAM and all the dependencies.

As this is done during image creation, it cannot use the built-in mechanisms of the target image (apt, ect).

install_zram_code $buildfolder/root/opt/zram
java_zulu_fetch $buildfolder/root
...

List what is required including dependencies, only if not included in the Raspberry Pi OS lite image (make, gcc, git is fine....).

• libattr1-dev

[holgerfriedrich]

@mstormi zram did not work, we have an apt install in install_zram_code

we need to download the deb files manually from correct respian repo and install them during first-boot :-/
This is why I did not like the idea of offline install in the first place.....

zulu java seems to work, azul has the same problem as zram but even worse....

[mstormi]

we have an apt install in install_zram_code

which is just the libattr1-dev that you've asked for (what to install upfront)

zulu java seems to work, azul has the same problem as zram but even worse....

what do you mean ? it works or not ?

[mstormi]

wrong click

[holgerfriedrich]

@mstormi We have to distinguish between build system (the one which executes build.bash) and target image. When I call install_zram_code, the library gets installed on the build system.
I have not way of executing apt of the mounted target image during install.
A simple but ugly way is to wget the correct deb file in install_zram_code and install it during first-boot (I was thinking to create a cache folder and installing all packages during first boot...)

[mstormi]

I think @ecdye worked around exactly that for Zulu, check his code

[ecdye]

No, for Zulu we use the API so we then avoid APT altogether. Honestly, I don't think that an elegant solution for offline install is possible. We may be able to fail gracefully and leave the user with a partial system but not full one.

Zulu offline may not even truly work because the install still has apt packages that it requires as prerequisites.

[mstormi]

Zulu offline may not even truly work because the install still has apt packages that it requires as prerequisites.

which ones? That's Holger's intention of this issue to collect these.

[mstormi]

there's an 'offline' competitor now: https://ubuntu.com/appliance/openhab

[holgerfriedrich]

there's an 'offline' competitor now: https://ubuntu.com/appliance/openhab

Do you know who created this?
Maybe time to start a discussion in maintainers section if we should refocus our efforts.

[mstormi]

Do you know who created this?

No. Canonical I believe.

Maybe time to start a discussion in maintainers section if we should refocus our efforts.

already did: https://github.com/orgs/openhab/teams/openhabian-maintainers/discussions/17

[ecdye]

which ones? That's Holger's intention of this issue to collect these.

The ones listed in java_zulu_prerequisite() being libc, libstdc++, zlib1g

[mstormi]

Holger, any news ?
#986 now hopefully fixed.

[holgerfriedrich]

@mstormi No, sorry. Not even a chance to follow everything you are doing in the meantime. Busy days, so I assume this will take a bit longer....
I have the a really bad feeling when I think about the dependencies of dependencies... We cannot clone the whole apt package repo.... Hm, why not ;-)

[ecdye]

Maybe because we want the resulting image to be a reasonable size. 😉

[mstormi]

It cannot be that many dependencies packages, essentially it's libs only. And why not clone them all?
Come on let's try. This is the only remaining issue to get the image done, isn't it ?