feat(foundryup): add foundryup self-update

[9547]

Motivation

Add a --self-update command to update foundryup itself.

Solution

[zerosnacks]

Thanks @9547!

cc @grandizzy what do you think of adding this into the installer?

It would make upgrading foundryup easier for end users and the functionality is in line with rustup.

One concern is that where the rest of the Bash script is highly flexible in allowing users to install from forks we would limit foundryup to be updated only from the source repo. This makes sense from a security standpoint.

Another concern is that it is possible a failure case (e.g. partial download) could possibly brick foundryup. One way to address this is to avoid writing directly to the final location, and instead first write to a temporary location, perform a sanity check and then move it to the final location.

cc @sambacha do you have opinions or concerns regarding this proposed update?

[grandizzy]

One concern is that where the rest of the Bash script is highly flexible in allowing users to install from forks we would limit foundryup to be updated only from the source repo. This makes sense from a security standpoint.

Yep, agree is better to update only from the source repo.

Another concern is that it is possible a failure case (e.g. partial download) could possibly brick foundryup. One way to address this is to avoid writing directly to the final location, and instead first write to a temporary location, perform a sanity check and then move it to the final location.

That would be nice to have, though probably unlikely to happen given foundryup size (and could happen also in the current way to update foundryup, by rerunning curl -L https://foundry.paradigm.xyz | bash), I don't have a strong opinion if we should add or not.

[DaniPopes]

Downloading to a temp file first is required with bash script because the interpreter (bash) is not guaranteed to buffer the entire file in memory when executing. This means that modifying the file while it's running it could cause inconsistencies and weird errors.

[zerosnacks]

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