Previously this function didn't actually have a lot of effect. If a
build A had a dependency B, Hydra would start B first. But on the
next scan through the queue, it would start A anyway, because of the
"busy => 0" restriction.
Now the queue runner won't start a build if a dependency is already
running. (This is not necessarily optimal, since the build may have
other dependencies that don't correspond to a build in the queue but
could run. One day we'll start all Hydra builds in parallel...)
Also, for performance, use computeFSClosure instead of "nix-store
-qR". And don't bother with topological sorting because it didn't
have an effect anyway since the database returns dependencies in
arbitrary order.
This allows checking a jobset (say) at most once a day. It's also
possible to disable polling by setting the interval to 0. This is
useful for jobsets that use push notification or are manually
evaluated.
This is a followup to commit
10882a1ffd ("Add multiple output
support").
* src/script/hydra-eval-guile-jobs.in (job-evaluations->sxml): Return
several `output' tags in the body, and remove the `outPath' attribute
of `job'.
Note that on machines that support multiple system types, EACH system type gets the full number of build slots, which is almost certainly not what we want.
External machines can now notify Hydra that it should check a
repository by sending a GET or PUSH request to /api/push, providing a
list of jobsets to be checked and/or a list of repository URLs. In
the latter case, all jobsets that have any of the specified
repositories as an input will be checked.
For instance, you can configure GitHub or BitBucket to send a request
to the URL
http://hydra.example.org/api/push?repos=git://github.com/NixOS/nixpkgs.git
to trigger evaluation of all jobsets that have
git://github.com/NixOS/nixpkgs.git as an input, or to the URL
http://hydra.example.org/api/push?jobsets=patchelf:trunk,nixpkgs:trunk
to trigger evaluation of just the specified jobsets.
It's pointless to store these, since Nix knows where the logs are.
Also handle (in fact require) Nix's new log storage scheme. Also some
cleanups in the build page.
If a build has ‘preferLocalBuilds = true’ (or we're not using remote
building), and the build has a non-permanent failure, then the build
status should be "Aborted" rather than "Failed". This is denoted by
an exit status of 100 from nix-store.
This happened in a pathological case in Nixpkgs: the "grub" job is
evaluated for i686-linux and x86_64-linux, but in the latter case it
returns the same derivation as in the former case. So only one build
should be added.
This gets rid of the openHydraDB function and ensures that we
open the database in a consistent way.
Also drop the PostgreSQL sequence hacks. They don't seem to be
necessary anymore.
When checking whether the jobset is unchanged, we need to compare with
the previous JobsetEval regardless of whether it had new builds.
Otherwise we'll keep adding new JobsetEval rows.
This isn't perfect because it doesn't handle the case where a
previous build hasn't finished yet. But at least it won't send mail
for old builds that fail while a newer build has already succeeded.
* Don't use isCurrent anymore; instead look up builds in the previous
jobset evaluation. (The isCurrent field is still maintained because
it's still used in some other places.)
* To determine whether to perform an evaluation, compare the hash of
the current inputs with the inputs of the previous jobset
evaluation, rather than checking if there was ever an evaluation
with those inputs. This way, if the inputs of an evaluation change
back to a previous state, we get a new jobset evaluation in the
database (and thus the latest jobset evaluation correctly represents
the latest state of the jobset).
* Improve performance by removing some unnecessary operations and
adding an index.
