This is the first step towards a more granular build process where
some of the build responsibility moves into the server component.
Rather than assembling all layers inside of Nix, it will only create
the symlink forest and return information about the runtime paths
required by the image.
The server is then responsible for grouping these paths into layers,
and assembling the layers themselves.
Relates to #50.
Fixes two launch script compatibility issues with other container
runtimes (such as gvisor):
* don't fail if /tmp already exists
* don't fail if the environment becomes unset
Instead of dumping all Nix output as one at the end of the build
process, stream it live as the lines come in.
This is a lot more useful for debugging stuff like where manifest
retrievals get stuck.
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.
Use the PackageSource.CacheKey function introduced in the previous
commit to determine the key at which a manifest should be cached in
the local cache.
Due to this change, manifests for moving target sources are no longer
cached and the recency threshold logic has been removed.
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.
Adds a NIX_TIMEOUT environment variable which can be set to a number
of seconds that is the maximum allowed time each Nix builder can run.
By default this is set to 60 seconds, which should be plenty for most
use-cases as Nixery is not expected to be performing builds of
uncached binaries in most production cases.
Currently the errors Nix throws on a build timeout are not separated
from other types of errors, meaning that users will see a generic 500
server error in case of a timeout.
This fixes#47
Moves the relevant parts of the customisation layer construction from
dockerTools.mkCustomisationLayer into the Nixery code base.
The version in dockerTools builds additional files (including via
hashing of potentially large files) which are not required when
serving an image over the registry protocol.
This package is used by a variety of programs that users may want to
embed into Nixery in addition, for example cachix, but those packages
don't refer to it explicitly.
This is required by git in cases where Nixery is configured with a
custom git repository.
I've also added a shell back into the image to make debugging a
running Nixery easier. It turns out some of the dependencies already
pull in bash anyways, so this is just surfacing it to $PATH.
Before this change, Nixery would pass on the image name unmodified to
Nix which would lead it to cache-bust the manifest and configuration
layers for images that are content-identical but have different
package ordering.
This fixes#38.
This test, after performing the usual Nixery build, loads the built
image into Docker, runs it, pulls an image from Nixery and runs that
image.
To make this work, there is some configuration on the Travis side.
Most importantly, the following environment variables have special
values:
* `GOOGLE_KEY`: This is set to a base64-encoded service account key to
be used in the test.
* `GCS_SIGNING_PEM`: This is set to a base64-encoded signing key (in
PEM) that is used for signing URLs.
Both of these are available to all branches in the Nixery repository.
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.
Some upcoming changes might require the Nix build to be split into
multiple separate nix-build invocations of different expressions, thus
splitting this out is useful.
It also fixes an issue where `build-image/default.nix` might be called
in an environment where no Nix channels are configured.
ALl the ones except for build-image.nix are considered trivial. On the
latter, nixfmt makes some useful changes but by-and-large it is not
ready for that code yet.
Removes usage of the old layering algorithm and replaces it with the
new one.
Apart from the new layer layout this means that each layer is now
built in a separate derivation, which hopefully leads to better
cacheability.
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`.
This commit adds the actual logic for extracting layer groupings and
merging them until the layer budget is satisfied.
The implementation conforms to the design doc as of the time of this
commit.
This script generates an entry in a text file for each time a
derivation is referred to by another in nixpkgs.
For initial testing, this output can be turned into group-layers
compatible JSON with this *trivial* invocation:
cat output | awk '{ print "{\"" $2 "\":" $1 "}"}' | jq -s '. | add | with_entries(.key |= sub("/nix/store/[a-z0-9]+-";""))' > test-data.json
As described in the design document, this adds considerations for
closure size and popularity. All closures meeting a certain threshold
for either value will have an extra edge from the image root to
themselves inserted in the graph, which will cause them to be
considered for inclusion in a separate layer.
This is preliminary because popularity is considered as a boolean
toggle (the input I generated only contains the top ~200 most popular
packages), but it should be using either absolute popularity values or
percentiles (needs some experimentation).
