diff options
Diffstat (limited to 'tvix/nix-compat/src/nixcpp/conf.rs')
| -rw-r--r-- | tvix/nix-compat/src/nixcpp/conf.rs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/tvix/nix-compat/src/nixcpp/conf.rs b/tvix/nix-compat/src/nixcpp/conf.rs new file mode 100644 index 000000000000..6969e05856ac --- /dev/null +++ b/tvix/nix-compat/src/nixcpp/conf.rs @@ -0,0 +1,202 @@ +use std::{fmt::Display, str::FromStr}; + +/// Represents configuration as stored in /etc/nix/nix.conf. +/// This list is not exhaustive, feel free to add more. +#[derive(Clone, Debug, Default, Eq, PartialEq)] +pub struct NixConfig<'a> { + allowed_users: Option<Vec<&'a str>>, + auto_optimise_store: Option<bool>, + cores: Option<u64>, + max_jobs: Option<u64>, + require_sigs: Option<bool>, + sandbox: Option<SandboxSetting>, + sandbox_fallback: Option<bool>, + substituters: Option<Vec<&'a str>>, + system_features: Option<Vec<&'a str>>, + trusted_public_keys: Option<Vec<crate::narinfo::PubKey>>, + trusted_substituters: Option<Vec<&'a str>>, + trusted_users: Option<Vec<&'a str>>, + extra_platforms: Option<Vec<&'a str>>, + extra_sandbox_paths: Option<Vec<&'a str>>, + experimental_features: Option<Vec<&'a str>>, + builders_use_substitutes: Option<bool>, +} + +impl<'a> NixConfig<'a> { + /// Parses configuration from a file like `/etc/nix/nix.conf`, returning + /// a [NixConfig] with all values contained in there. + /// It does not support parsing multiple config files, merging semantics, + /// and also does not understand `include` and `!include` statements. + pub fn parse(input: &'a str) -> Result<Self, Error> { + let mut out = Self::default(); + + for line in input.lines() { + // strip comments at the end of the line + let line = if let Some((line, _comment)) = line.split_once('#') { + line + } else { + line + }; + + // skip comments and empty lines + if line.trim().is_empty() { + continue; + } + + let (tag, val) = line + .split_once('=') + .ok_or_else(|| Error::InvalidLine(line.to_string()))?; + + // trim whitespace + let tag = tag.trim(); + let val = val.trim(); + + #[inline] + fn parse_val<'a>(this: &mut NixConfig<'a>, tag: &str, val: &'a str) -> Option<()> { + match tag { + "allowed-users" => { + this.allowed_users = Some(val.split_whitespace().collect()); + } + "auto-optimise-store" => { + this.auto_optimise_store = Some(val.parse::<bool>().ok()?); + } + "cores" => { + this.cores = Some(val.parse().ok()?); + } + "max-jobs" => { + this.max_jobs = Some(val.parse().ok()?); + } + "require-sigs" => { + this.require_sigs = Some(val.parse().ok()?); + } + "sandbox" => this.sandbox = Some(val.parse().ok()?), + "sandbox-fallback" => this.sandbox_fallback = Some(val.parse().ok()?), + "substituters" => this.substituters = Some(val.split_whitespace().collect()), + "system-features" => { + this.system_features = Some(val.split_whitespace().collect()) + } + "trusted-public-keys" => { + this.trusted_public_keys = Some( + val.split_whitespace() + .map(crate::narinfo::PubKey::parse) + .collect::<Result<Vec<crate::narinfo::PubKey>, _>>() + .ok()?, + ) + } + "trusted-substituters" => { + this.trusted_substituters = Some(val.split_whitespace().collect()) + } + "trusted-users" => this.trusted_users = Some(val.split_whitespace().collect()), + "extra-platforms" => { + this.extra_platforms = Some(val.split_whitespace().collect()) + } + "extra-sandbox-paths" => { + this.extra_sandbox_paths = Some(val.split_whitespace().collect()) + } + "experimental-features" => { + this.experimental_features = Some(val.split_whitespace().collect()) + } + "builders-use-substitutes" => { + this.builders_use_substitutes = Some(val.parse().ok()?) + } + _ => return None, + } + Some(()) + } + + parse_val(&mut out, tag, val) + .ok_or_else(|| Error::InvalidValue(tag.to_string(), val.to_string()))? + } + + Ok(out) + } +} + +#[derive(thiserror::Error, Debug)] +pub enum Error { + #[error("Invalid line: {0}")] + InvalidLine(String), + #[error("Unrecognized key: {0}")] + UnrecognizedKey(String), + #[error("Invalid value '{1}' for key '{0}'")] + InvalidValue(String, String), +} + +/// Valid values for the Nix 'sandbox' setting +#[derive(Clone, Debug, PartialEq, Eq)] +pub enum SandboxSetting { + True, + False, + Relaxed, +} + +impl Display for SandboxSetting { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + SandboxSetting::True => write!(f, "true"), + SandboxSetting::False => write!(f, "false"), + SandboxSetting::Relaxed => write!(f, "relaxed"), + } + } +} + +impl FromStr for SandboxSetting { + type Err = &'static str; + + fn from_str(s: &str) -> Result<Self, Self::Err> { + Ok(match s { + "true" => Self::True, + "false" => Self::False, + "relaxed" => Self::Relaxed, + _ => return Err("invalid value"), + }) + } +} + +#[cfg(test)] +mod tests { + use crate::{narinfo::PubKey, nixcpp::conf::SandboxSetting}; + + use super::NixConfig; + + #[test] + pub fn test_parse() { + let config = NixConfig::parse(include_str!("../../testdata/nix.conf")).expect("must parse"); + + assert_eq!( + NixConfig { + allowed_users: Some(vec!["*"]), + auto_optimise_store: Some(false), + cores: Some(0), + max_jobs: Some(8), + require_sigs: Some(true), + sandbox: Some(SandboxSetting::True), + sandbox_fallback: Some(false), + substituters: Some(vec!["https://nix-community.cachix.org", "https://cache.nixos.org/"]), + system_features: Some(vec!["nixos-test", "benchmark", "big-parallel", "kvm"]), + trusted_public_keys: Some(vec![ + PubKey::parse("cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=") + .expect("failed to parse pubkey"), + PubKey::parse("nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=") + .expect("failed to parse pubkey") + ]), + trusted_substituters: Some(vec![]), + trusted_users: Some(vec!["flokli"]), + extra_platforms: Some(vec!["aarch64-linux", "i686-linux"]), + extra_sandbox_paths: Some(vec![ + "/run/binfmt", "/nix/store/swwyxyqpazzvbwx8bv40z7ih144q841f-qemu-aarch64-binfmt-P-x86_64-unknown-linux-musl" + ]), + experimental_features: Some(vec!["nix-command"]), + builders_use_substitutes: Some(true) + }, + config + ); + + // parse a config file using some non-space whitespaces, as well as comments right after the lines. + // ensure it contains the same data as initially parsed. + let other_config = NixConfig::parse(include_str!("../../testdata/other_nix.conf")) + .expect("other config must parse"); + + assert_eq!(config, other_config); + } +} |