Upgrades Hydra to the latest master/flake branch. To perform this
upgrade, it's needed to do a non-trivial db-migration which provides a
massive performance-improvement[1].
The basic ideas behind multi-step upgrades of services between NixOS versions
have been gathered already[2]. For further context it's recommended to
read this first.
Basically, the following steps are needed:
* Upgrade to a non-breaking version of Hydra with the db-changes
(columns are still nullable here). If `system.stateVersion` is set to
something older than 20.03, the package will be selected
automatically, otherwise `pkgs.hydra-migration` needs to be used.
* Run `hydra-backfill-ids` on the server.
* Deploy either `pkgs.hydra-unstable` (for Hydra master) or
`pkgs.hydra-flakes` (for flakes-support) to activate the optimization.
The steps are also documented in the release-notes and in the module
using `warnings`.
`pkgs.hydra` has been removed as latest Hydra doesn't compile with
`pkgs.nixStable` and to ensure a graceful migration using the newly
introduced packages.
To verify the approach, a simple vm-test has been added which verifies
the migration steps.
[1] https://github.com/NixOS/hydra/pull/711
[2] https://github.com/NixOS/nixpkgs/pull/82353#issuecomment-598269471
While our ETag patch works pretty fine if it comes to serving data off
store paths, it unfortunately broke something that might be a bit more
common, namely when using regexes to extract path components of
location directives for example.
Recently, @devhell has reported a bug with a nginx location directive
like this:
location ~^/\~([a-z0-9_]+)(/.*)?$" {
alias /home/$1/public_html$2;
}
While this might look harmless at first glance, it does however cause
issues with our ETag patch. The alias directive gets broken up by nginx
like this:
*2 http script copy: "/home/"
*2 http script capture: "foo"
*2 http script copy: "/public_html/"
*2 http script capture: "bar.txt"
In our patch however, we use realpath(3) to get the canonicalised path
from ngx_http_core_loc_conf_s.root, which returns the *configured* value
from the root or alias directive. So in the example above, realpath(3)
boils down to the following syscalls:
lstat("/home", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/home/$1", 0x7ffd08da6f60) = -1 ENOENT (No such file or directory)
During my review[1] of the initial patch, I didn't actually notice that
what we're doing here is returning NGX_ERROR if the realpath(3) call
fails, which in turn causes an HTTP 500 error.
Since our patch actually made the canonicalisation (and thus additional
syscalls) necessary, we really shouldn't introduce an additional error
so let's - at least for now - silently skip return value if realpath(3)
has failed.
However since we're using the unaltered root from the config we have
another issue, consider this root:
/nix/store/...-abcde/$1
Calling realpath(3) on this path will fail (except if there's a file
called "$1" of course), so even this fix is not enough because it
results in the ETag not being set to the store path hash.
While this is very ugly and we should fix this very soon, it's not as
serious as getting HTTP 500 errors for serving static files.
I added a small NixOS VM test, which uses the example above as a
regression test.
It seems that my memory is failing these days, since apparently I *knew*
about this issue since digging for existing issues in nixpkgs, I found
this similar pull request which I even reviewed:
https://github.com/NixOS/nixpkgs/pull/66532
However, since the comments weren't addressed and the author hasn't
responded to the pull request, I decided to keep this very commit and do
a follow-up pull request.
[1]: https://github.com/NixOS/nixpkgs/pull/48337
Signed-off-by: aszlig <aszlig@nix.build>
Reported-by: @devhell
Acked-by: @7c6f434c
Acked-by: @yorickvP
Merges: https://github.com/NixOS/nixpkgs/pull/80671
Fixes: https://github.com/NixOS/nixpkgs/pull/66532
Add a cage module to nixos. This can be used to make kiosk-style
systems that boot directly to a single application. The user (demo by
default) is automatically logged in by this service and the
program (xterm by default) is automatically started.
This is useful for some embedded, single-user systems where we want
automatic booting. To keep the system secure, the user should have
limited privileges.
Based on the service provided in the Cage wiki here:
https://github.com/Hjdskes/cage/wiki/Starting-Cage-on-boot-with-systemd
Co-Authored-By: Florian Klink <flokli@flokli.de>
This fixes the patch for nginx to clear the Last-Modified header if a
static file is served from the Nix store.
So far we only used the ETag from the store path, but if the
Last-Modified header is always set to "Thu, 01 Jan 1970 00:00:01 GMT",
Firefox and Chrome/Chromium seem to ignore the ETag and simply use the
cached content instead of revalidating.
Alongside the fix, this also adds a dedicated NixOS VM test, which uses
WebDriver and Firefox to check whether the content is actually served
from the browser's cache and to have a more real-world test case.
This is what I've suspected a while ago[1]:
> Heads-up everyone: After testing this in a few production instances,
> it seems that some browsers still get cache hits for new store paths
> (and changed contents) for some reason. I highly suspect that it might
> be due to the last-modified header (as mentioned in [2]).
>
> Going to test this with last-modified disabled for a little while and
> if this is the case I think we should improve that patch by disabling
> last-modified if serving from a store path.
Much earlier[2] when I reviewed the patch, I wrote this:
> Other than that, it looks good to me.
>
> However, I'm not sure what we should do with Last-Modified header.
> From RFC 2616, section 13.3.4:
>
> - If both an entity tag and a Last-Modified value have been
> provided by the origin server, SHOULD use both validators in
> cache-conditional requests. This allows both HTTP/1.0 and
> HTTP/1.1 caches to respond appropriately.
>
> I'm a bit nervous about the SHOULD here, as user agents in the wild
> could possibly just use Last-Modified and use the cached content
> instead.
Unfortunately, I didn't pursue this any further back then because
@pbogdan noted[3] the following:
> Hmm, could they (assuming they are conforming):
>
> * If an entity tag has been provided by the origin server, MUST
> use that entity tag in any cache-conditional request (using If-
> Match or If-None-Match).
Since running with this patch in some deployments, I found that both
Firefox and Chrome/Chromium do NOT re-validate against the ETag if the
Last-Modified header is still the same.
So I wrote a small NixOS VM test with Geckodriver to have a test case
which is closer to the real world and I indeed was able to reproduce
this.
Whether this is actually a bug in Chrome or Firefox is an entirely
different issue and even IF it is the fault of the browsers and it is
fixed at some point, we'd still need to handle this for older browser
versions.
Apart from clearing the header, I also recreated the patch by using a
plain "git diff" with a small description on top. This should make it
easier for future authors to work on that patch.
[1]: https://github.com/NixOS/nixpkgs/pull/48337#issuecomment-495072764
[2]: https://github.com/NixOS/nixpkgs/pull/48337#issuecomment-451644084
[3]: https://github.com/NixOS/nixpkgs/pull/48337#issuecomment-451646135
Signed-off-by: aszlig <aszlig@nix.build>
osquery was marked as broken since April.
If somebody steps up to fix it, we can always revive it from the
histroy, but there's not much value in shipping completely broken things
in current master.
cc @ma27
The SLIM project is abandoned and their last release was in 2013.
Because of this it poses a security risk to systems, no one is working
on it or picked up maintenance. It also lacks compatibility with systemd
and logind sessions. For users, there liikely isn't anything like slim
that's as lightweight in terms of dependencies.
The two new options make it possible to create the interface in one namespace
and move it to a different one, as explained at https://www.wireguard.com/netns/.
This is a good example of a package/module that should be distributed
externally (e.g. as a flake [1]): it's not stable yet so anybody who
seriously wants to use it will want to use the upstream repo. Also,
it's highly specialized so NixOS is not really the right place at the
moment (every NixOS module slows down NixOS evaluation for everybody).
[1] https://github.com/edolstra/jormungandr/tree/flake
* lm_sensors: add fancontrol module + nixos test
fancontrol is a small script that checks temperature sensors and adapts
fan speeds accordingly. It reads a text config file that can be
auto-generated by running the pwmconfig wizard on the live system.
