Makes use of the `.WithError` and `.WithField` convenience functions
in logrus to simplify log statement construction.
This has the added benefit of making it easier to correctly log
errors.
This rewrites all existing log statements into the structured logrus
format. For consistency, all errors are always logged separately from
the primary message in a field called `error`.
Only the "info", "error" and "warn" severities are used.
Uses a hash of Nixery's sources as the version displayed when Nixery
launches or logs an error. This makes it possible to distinguish
between errors logged from different versions.
The source hashes should be reproducible between different checkouts
of the same source tree.
Implements a local manifest cache that uses the temporary directory to
cache manifest builds.
This is necessary due to the size of manifests: Keeping them entirely
in-memory would quickly balloon the memory usage of Nixery, unless
some mechanism for cache eviction is implemented.
The state type contains things such as the bucket handle and Nixery's
configuration which need to be passed around in the builder.
This is only added for convenience.
Caches manifests under `manifests/$cacheKey` in the GCS bucket and
introduces two-tiered retrieval of manifests from the caches (local
first, bucket second).
There is some cleanup to be done in this code, but the initial version
works.
Introduces three new types representing each of the possible package
sources and moves the logic for specifying the package source to the
server.
Concrete changes:
* Determining whether a specified git reference is a commit vs. a
branch/tag is now done in the server, and is done more precisely by
using a regular expression.
* Package sources now have a new `CacheKey` function which can be used
to retrieve a key under which a build manifest can be cached *if*
the package source is not a moving target (i.e. a full git commit
hash of either nixpkgs or a private repository).
This function is not yet used.
* Users *must* now specify a package source, Nixery no longer defaults
to anything and will fail to launch if no source is configured.
Implements a cache that keeps track of:
a) Manifests that have already been built (for up to 6 hours)
b) Layers that have already been seen (and uploaded to GCS)
This significantly speeds up response times for images that are full
or partial matches with previous images served by an instance.
Instead of requiring the server component to be made aware of the
location of the Nix builder via environment variables, this commit
introduces a wrapper script for the builder that can simply exist on
the builders $PATH.
This is one step towards a slightly nicer out-of-the-box experience
when using `nix-build -A nixery-bin`.
