Encouraging to put container elements on their own lines to minimize
diffs, merge conflicts and making re-ordering easier.
Nix doesn't suffer the restrictions of other languages where commas are
used to separate list items.
First of all, this makes the existing documentation a bit more clear on
what autoPatchelfHook is all about, because after discussing with
@svanderburg - who wrote a similar implementation - the rationale about
autoPatchelfHook wasn't very clear in the documentation.
I also added the recent changes around being able to use autoPatchelf
manually and the new --no-recurse flag.
Signed-off-by: aszlig <aszlig@nix.build>
It's incorrect (preferLocalBuild does not prevent uploading to binary
caches) and is not a stdenv attribute (it's already documented in the
Nix manual).
Python 3.4 will receive it's final patch release in March 2019 and there won't
be any releases anymore after that, so also not during NixOS 2019.03.
Python 3.4 is not used anymore in Nixpkgs. In any case, migrating code from
3.4 to 3.4+ is trivial.
This commit renames the pythondaemon module to match its module name, github
name, and pypi name, which makes it easier to find and reference. In order to
avoid breaking any external users, I've left an alias with a deprecated warning.
Rationale
---------
Currently, tests are hard to discover. For instance, someone updating
`dovecot` might not notice that the interaction of `dovecot` with
`opensmtpd` is handled in the `opensmtpd.nix` test.
And even for someone updating `opensmtpd`, it requires manual work to go
check in `nixos/tests` whether there is actually a test, especially
given not so many packages in `nixpkgs` have tests and this is thus most
of the time useless.
Finally, for the reviewer, it is much easier to check that the “Tested
via one or more NixOS test(s)” has been checked if the file modified
already includes the list of relevant tests.
Implementation
--------------
Currently, this commit only adds the metadata in the package. Each
element of the `meta.tests` attribute is a derivation that, when it
builds successfully, means the test has passed (ie. following the same
convention as NixOS tests).
Future Work
-----------
In the future, the tools could be made aware of this `meta.tests`
attribute, and for instance a `--with-tests` could be added to
`nix-build` so that it also builds all the tests. Or a `--without-tests`
to build without all the tests. @Profpatsch described in his NixCon talk
such systems.
Another thing that would help in the future would be the possibility to
reasonably easily have cross-derivation nix tests without the whole
NixOS VM stack. @7c6f434c already proposed such a system.
This RFC currently handles none of these concerns. Only the addition of
`meta.tests` as metadata to be used by maintainers to remember to run
relevant tests.
The `name` arg of `vim_configurable.customize` does not only determine
the package name, but also the name of the command/ executable to be
called.
In my opinion this is not documented properly and finding that out took
me several hours.
Allows for adding Perl libraries in the same way as for Python. Doesn't
really need to be a function, since there's only one perlPackages in
nixpkgs, but I went for consistency with the python plugin.
This touches up a handful of places in the python documentation to try to make
the current best-practices more obvious. In particular, I often find the
function signatures (what to pass, what not to pass) confusing and have added
them to the docs.
Also updated the metas to be more consistent with the most frequently used
modern style.
Hydra passes the full revision in to the input, which we pass through.
If we don't get this ,we try to get it from other sources, or default to
master which should have the definition in a close-ish location.
All published docs should have theURL resolve properly, only local
hackers will have the link break.
Create a many-layered Docker Image.
Implements much less than buildImage:
- Doesn't support specific uids/gids
- Doesn't support runninng commands after building
- Doesn't require qemu
- Doesn't create mutable copies of the files in the path
- Doesn't support parent images
If you want those feature, I recommend using buildLayeredImage as an
input to buildImage.
Notably, it does support:
- Caching low level, common paths based on a graph traversial
algorithm, see referencesByPopularity in
0a80233487993256e811f566b1c80a40394c03d6
- Configurable number of layers. If you're not using AUFS or not
extending the image, you can specify a larger number of layers at
build time:
pkgs.dockerTools.buildLayeredImage {
name = "hello";
maxLayers = 128;
config.Cmd = [ "${pkgs.gitFull}/bin/git" ];
};
- Parallelized creation of the layers, improving build speed.
- The contents of the image includes the closure of the configuration,
so you don't have to specify paths in contents and config.
With buildImage, paths referred to by the config were not included
automatically in the image. Thus, if you wanted to call Git, you
had to specify it twice:
pkgs.dockerTools.buildImage {
name = "hello";
contents = [ pkgs.gitFull ];
config.Cmd = [ "${pkgs.gitFull}/bin/git" ];
};
buildLayeredImage on the other hand includes the runtime closure of
the config when calculating the contents of the image:
pkgs.dockerTools.buildImage {
name = "hello";
config.Cmd = [ "${pkgs.gitFull}/bin/git" ];
};
Minor Problems
- If any of the store paths change, every layer will be rebuilt in
the nix-build. However, beacuse the layers are bit-for-bit
reproducable, when these images are loaded in to Docker they will
match existing layers and not be imported or uploaded twice.
Common Questions
- Aren't Docker layers ordered?
No. People who have used a Dockerfile before assume Docker's
Layers are inherently ordered. However, this is not true -- Docker
layers are content-addressable and are not explicitly layered until
they are composed in to an Image.
- What happens if I have more than maxLayers of store paths?
The first (maxLayers-2) most "popular" paths will have their own
individual layers, then layer #(maxLayers-1) will contain all the
remaining "unpopular" paths, and finally layer #(maxLayers) will
contain the Image configuration.
The `overrideScope` bound by `makeScope` (via special `callPackage`)
took an override in the form `super: self { … }`. But this is
dangerously close to the `self: super { … }` form used by *everything*
else, even other definitions of `overrideScope`! Since that
implementation did not even share any code either until I changed it
recently in 3cf43547f4, this inconsistency
is almost certainly an oversight and not intentional.
Unfortunately, just as the inconstency is hard to debug if one just
assumes the conventional order, any sudden fix would break existing
overrides in the same hard-to-debug way. So instead of changing the
definition a new `overrideScope'` with the conventional order is added,
and old `overrideScope` deprecated with a warning saying to use
`overrideScope'` instead. That will hopefully get people to stop using
`overrideScope`, freeing our hand to change or remove it in the future.
For technical reasons, we cannot easily add a warning to top-level
definitions, so 2a6e4ae49a and
e51f736076 reverted the deprecation. But
we can still remove mention of the would-be deprecated definitions to
steer people towards using the preferred alternatives.
