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Forgot to add this when moving it out of my //users directory.
Change-Id: If6d30a2a58a6bd73e160706cb706e3b2e100e909
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2754
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
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So here is what has been keeping me up at night: At some point I
realized that nix actually made a somewhat passable language for CGI
programming:
* That `builtins.getEnv` exists as one of the impurities of Nix is
perfect as environment variables are the main way of communication
from the web server to the CGI application.
* We can actually read from the filesystem via builtins.readDir and
builtins.readFile with bearable overhead if we avoid importing the
used paths into the nix store.
* Templating and routing are convenient to implement via indented strings
and attribute sets respectively.
Of course there are obvious limitation:
* The overhead of derivations is probably much to great for them to be
useful via IfD.
* Even without derivations, nix evaluation is very slow to the point
were a trivial application takes between 100ms and 400ms to produce a
response.
* We can't really cause effects other than producing a response which
makes it not viable for a lot of applications. There are some ways
around this:
* With a custom interpreter we could have streaming and multiplexed
I/O (using lazy lists emulated via attrsets) to cause such effects,
but it would probably perform terribly.
* We can use builtins.fetchurl to call other HTTP-based microservices,
but only in very limited constraints, i. e. only GET, no headers,
and only if the tarball ttl is set to 0 in the global nix.conf.
* Terrible error handling capabilities because builtins.tryEval actually
doesn't catch a lot of errors.
To prove that it actually works, there are some demo applications,
which I invite you to run and potentially break horribly:
nix-build -A web.bubblegum.examples && ./result
# navigate to http://localhost:9000
The setup uses thttpd and executes the nix CGI scripts using
users.sterni.nint which automatically passed `depot`, so they can
import the cgi library.
Change-Id: I3a22a749612211627e5f8301c31ec2e7a872812c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2746
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
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nint (short for nix interpreter) is a tiny wrapper around nix-instantiate
which allows to run nix scripts, i. e. nix expressions that conform to
a certain calling convention. A nix script runnable using nint must
conform to the following constraints:
* It must evaluate to a function which has a set pattern with an
ellipsis as the single argument.
* It must produce a string as a return value or fail.
When invoked, a the expression receives the following arguments:
* `currentDir`: the current working directory as a nix path
* `argv`: a list of strings containing `argv` including `argv[0]`
* extra arguments which are manually specified which allows for
passing along dependencies or libraries, for example:
nint --arg depot '(import /depot {})' my-prog.nix [ argv[1] … ]
would pass along depot to be used in `my-prog.nix`.
Such nix scripts are purely functional in a sense: The way inputs can be
taken is very limited and causing effects is also only possible in a
very limited sense (using builtins.fetchurl if TARBALL_TTL is 0,
adding files and directories to the nix store, realising derivations).
As an approximation, a program executed using nint can be thought of
as a function with the following signature:
λ :: environment → working directory → argv → stdout
where environment includes:
* the time at the start of the program (`builtins.currentTime`)
* other information about the machine (`builtins.currentSystem` …)
* environment variables (`builtins.getEnv`)
* the file system (`builtins.readDir`, `builtins.readFile`, …) which
is the biggest input impurity as it may change during evaluation
Additionally import from derivation and builtin fetchers are available
which introduce further impurities to be utilized.
Future work:
* Streaming I/O via lazy lists. This would allow usage of
stdin and output before the program terminates. However this would
require using libexpr directly or writing a custom nix interpreter.
A description of how this would work can be found on the website of the
esoteric programming language Lazy K: https://tromp.github.io/cl/lazy-k.html
* An effect system beyond stdin / stdout.
* Better error handling, support setting exit codes etc.
These features would require either using an alternative or custom
interpreter for nix (tvix or hnix) or to link against libexpr directly
to have more control over evaluation.
Change-Id: I61528516eb418740df355852f23425acc4d0656a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2745
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
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Change-Id: I8baf2404f0f6e9c4fad767911646cdc55051dd2e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2753
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
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Change-Id: I41d71f9aae7e64bdfef8f2b7142d13009b216eaa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2752
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
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Getting `lib` from `stdenv.lib` is deprecated, and throws warnings.
Change-Id: Ic925818c1b5a67d15d6d40ad784554328cd603e0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2751
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: glittershark <grfn@gws.fyi>
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
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This also looks much cleaner than before.
Change-Id: I767b881c73699151afc03746c04e413e74f30387
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2750
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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This modifies the capture regex executed by `jq` to capture the TODO
text itself as a separate capture group, which is then used for the
content of the TODO listing.
The web listing looks much cleaner this way.
Change-Id: I00a14da57b315a353f700c112ba33f38e16f1f85
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2749
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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Change-Id: Iba48c8ac8c45075ecb9741572bca9cea4f8b0f9d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2748
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI
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The way this loads the api key is a hack, but also... I don't care!
Change-Id: I4d417b1a824007620661188b60b21a1f73867dca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2747
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI
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