Otherwise, when the port is randomly chosen (e.g. by specifying no port,
or a port of 0), it will just show that the port is 0 and not the port
that is actually serving the metrics.
Periodically, I have seen tests fail because of out of order queue runner behavior:
checking the queue for builds > 0...
loading build 1 (tests:basic:empty_dir)
aborting unsupported build step '...-empty-dir.drv' (type 'x86_64-linux')
marking build 1 as failed
adding new machine ‘localhost’
This patch should prevent the dispatcher from running before any machines are
made available.
In a Hydra instance I saw:
possibly transient failure building ‘/nix/store/X.drv’ on ‘localhost’:
dependency '/nix/store/Y' of '/nix/store/Y.drv' does not exist,
and substitution is disabled
This is confusing because the Hydra in question does have substitution enabled.
This instance uses:
keep-outputs = true
keep-derivations = true
and an S3 binary cache which is not configured as a substituter in the nix.conf.
It appears this instance encountered a situation where store path Y was built
and present in the binary cache, and Y.drv was GC rooted on the instance,
however Y was not on the host.
When Hydra would try to build this path locally, it would look in the binary
cache to see if it was cached:
(nix)
439 bool valid = isValidPathUncached(storePath);
440
441 if (diskCache && !valid)
442 // FIXME: handle valid = true case.
443 diskCache->upsertNarInfo(getUri(), hashPart, 0);
444
445 return valid;
Since it was cached, the store path was considered Valid.
The queue monitor would then not put this input in for substitution, because
the path is valid:
(hydra)
470 if (!destStore->isValidPath(*i.second.path(*localStore, step->drv->name, i.first))) {
471 valid = false;
472 missing.insert_or_assign(i.first, i.second);
473 }
Hydra appears to correctly handle the case of missing paths that need
to be substituted from the binary cache already, but since most
Hydra instances use `keep-outputs` *and* all paths in the binary cache
originate from that machine, it is not common for a path to be cached
and not GC rooted locally.
I'll run Hydra with this patch for a while and see if we run in to the
problem again.
A big thanks to John Ericson who helped debug this particular issue.
When having a builder like this in `/etc/nix/machines`
ssh://mfbuild?remote-store=/home/bosch/store
Hydra cannot build there since it tries to pass the entire value to
`ssh(1)` which doesn't work. Also, an alternate store-location is e.g.
used if the user isn't a trusted user on the remote system and thus
cannot use `/nix/store`.
If such a URI is given, Hydra will now add a `--store /home/bosch/store`
to the `ssh`-command to select the appropriate location remotely.
In Nix the protocol was slightly altered[1] to also contain more
information about realisations. This however wasn't read from the pipe
that was used to read from the store.
After the `cmdBuildDerivation` command which caused this issue, Hydra
will issue a `cmdQueryPathInfos` that tries to read from the remote
store as well. However, there's still left over to read from the
previous command and thus Nix fails to properly allocate the expected
string.
[1] See rev a2b69660a9Fixes#898
Previously, the build ID would never flow through channels which
exited.
This patch tracks the buildOne state as part of State and exits avoids
waiting forever for new work.
The code around buildOnly is a bit rough, making this a bit weird to
implement but since it is only used for testing the value of improving
it on its own is a bit questionable.
The queue runner used to special-case `localhost` as a remote builder:
Rather than using the normal remote-build (using the
`cmdBuildDerivation` command), it was using the (generally less
efficient, except when running against localhost) `cmdBuildPaths`
command because the latter didn't require a privileged Nix user (so made
testing easier − allowing to run hydra in a container in particular).
However:
1. this means that the build loop can follow two discint code paths depending
on the setup, the irony being that the most commonly used one in production
(the “non-localhost” case) isn't the one used in the testsuite (because all
the tests run against a local store);
2. It turns out that the “localhost” version is buggy in relatively obvious
ways − in particular a failure in a fixed-output derivation or a hash
mismatch isn't reported properly;
3. If the “run in a container” use-case is indeed that important, it can be
(partially) restored using a chroot store (which wouldn't behave excactly
the same way of course, but would be more than good-enough for testing)
This would start happening if the network connection between the Hydra
server and the remote build server breaks after sucessfully importing
at least one output of a derivation, but before having finished
importing all outputs.
Fixes#816.
Recently a few internal APIs have changed[1]. The `outputPaths` function
has been removed and a lot of data structures are modeled with
`std::optional` which broke compilation.
This patch updates the code in `hydra-queue-runner` accordingly to make
sure that Hydra compiles again.
[1] https://github.com/NixOS/nix/pull/3883
Graham Christensen