Factor out part of the provisioning script into a
wait-until-service-is-ready script, and put it unconditionally in
front of ExecStartPost=, so that services that depend on influxdb2 are
not started until influxdb2 responds to requests.
Fixes https://github.com/NixOS/nixpkgs/issues/317017 ("Scrutiny tries to start before influxdb has started")
When `diskImage = null`, the root fs is a tmpfs instead of
`/dev/vda`. Thus, it doesn't have to wait for virtio modules to load
before being mounted. The root fs is a dependency of shared
directories by nature of being their parent directory. Without
depending on `/dev/vda`, these shared directories may attempt to mount
without virtio modules being loaded.
In preparation for the deprecation of `stdenv.isX`.
These shorthands are not conducive to cross-compilation because they
hide the platforms.
Darwin might get cross-compilation for which the continued usage of `stdenv.isDarwin` will get in the way
One example of why this is bad and especially affects compiler packages
https://www.github.com/NixOS/nixpkgs/pull/343059
There are too many files to go through manually but a treewide should
get users thinking when they see a `hostPlatform.isX` in a place where it
doesn't make sense.
```
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv.is" "stdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv'.is" "stdenv'.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "clangStdenv.is" "clangStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "gccStdenv.is" "gccStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenvNoCC.is" "stdenvNoCC.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "inherit (stdenv) is" "inherit (stdenv.hostPlatform) is"
fd --type f "\.nix" | xargs sd --fixed-strings "buildStdenv.is" "buildStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "effectiveStdenv.is" "effectiveStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "originalStdenv.is" "originalStdenv.hostPlatform.is"
```
Unlike regular input-addressed or fixed-output derivations, floating and
deferred derivations do not have their store path available at evaluation time,
so their outPath is a placeholder. The following changes are needed for
replaceDependencies to continue working:
* Detect the placeholder and retrieve the store path using another IFD hack
when collecting the rewrite plan.
* Try to obtain the derivation name needed for replaceDirectDependencies from
the derivation arguments if a placeholder is detected.
* Move the length mismatch detection to build time, since the placeholder has a
fixed length which is unrelated to the store path.
The tests cannot be directly built by Hydra, because replaceDependencies relies
on IFD. Instead, they are put inside a NixOS test where they are built on the
guest.
Move replaceRuntimeDependencies to the replaceDependencies namespace,
where the structure is more consistent with the replaceDependencies
function. This makes space for wiring up cutoffPackages as an option
too.
By default, the system's initrd is excluded. The replacement process does not
work properly anyway due to the structure of the initrd (the files being copied
into it, and it being compressed). In the worst case (which has been observed
to actually occur in practice), a store path makes it into the incompressible
parts of the archive, checksums are broken, and the system won't boot.
Instead of iterating over all replacements and applying them one by one,
use the newly introduced replaceDependencies function to apply them all
at once for replaceRuntimeDependencies. The advantages are twofold in
case there are multiple replacements:
* Performance is significantly improved, because there is only one pass
over the closure to be made.
* Correctness is improved, because replaceDependencies also replaces
dependencies of the replacements themselves if applicable.
Fixes: https://github.com/NixOS/nixpkgs/issues/4336
