s0me1newithhand7s/system-manager
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Impprove error messages when a wrong flake attr was specified.

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r-vdp 2023-04-06 13:19:57 +02:00
parent fd2168914e
commit 5b4e7938f5
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1 changed files with 37 additions and 33 deletions
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70
src/generate.rs
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@ -1,6 +1,5 @@
use anyhow::{Context, Result};
use anyhow::{anyhow, Context, Result};
use serde::{Deserialize, Serialize};
use std::borrow::Cow;
use std::collections::HashMap;
use std::fs::DirBuilder;
use std::path::Path;
@ -62,48 +61,53 @@ pub fn build(flake_uri: &str) -> Result<StorePath> {
Ok(store_path)
}
fn find_flake_attr(flake_uri: &str) -> Result<Cow<'_, str>> {
let flake_uri = flake_uri.trim_end_matches('#');
let hash_count = flake_uri.match_indices('#').count();
if hash_count > 1 {
anyhow::bail!("Invalid flake URI!");
fn find_flake_attr(flake_uri: &str) -> Result<String> {
fn full_uri(flake: &str, attr: &str) -> String {
format!("{flake}#{FLAKE_ATTR}.{attr}")
}
if hash_count == 1 {
return if try_flake_attr(flake_uri)? {
Ok(flake_uri.into())
let flake_uri = flake_uri.trim_end_matches('#');
let mut splitted = flake_uri.split('#');
let flake = splitted
.next()
.ok_or_else(|| anyhow!("Invalid flake URI: {flake_uri}"))?;
let attr = splitted.next();
if splitted.next().is_some() {
anyhow::bail!("Invalid flake URI, too many '#'s: {flake_uri}");
}
if let Some(attr) = attr {
if try_flake_attr(flake, attr)? {
return Ok(full_uri(flake, attr));
} else {
anyhow::bail!(
"Explicitly provided flake URI {} does not seem to point to a valid system-manager configuration.",
flake_uri
"Explicitly provided flake URI does not point to a valid system-manager configuration: {}",
format!("{flake}#{attr}")
)
};
}
}
let hostname = nix::unistd::gethostname()?;
let full_uri = format!("{flake_uri}#{FLAKE_ATTR}.{}", hostname.to_string_lossy());
let hostname_os = nix::unistd::gethostname()?;
let hostname = hostname_os.to_string_lossy();
let default = "default";
if try_flake_attr(&full_uri)? {
return Ok(full_uri.into());
} else {
let full_uri = format!("{flake_uri}#{FLAKE_ATTR}.default");
if try_flake_attr(&full_uri)? {
return Ok(full_uri.into());
};
if try_flake_attr(flake, &hostname)? {
return Ok(full_uri(flake, &hostname));
} else if try_flake_attr(flake, default)? {
return Ok(full_uri(flake, default));
};
anyhow::bail!("No suitable flake attribute found, giving up.");
}
// TODO handle errors better.
// E.g. when we refer to an unexisting module in the systemConfig definition.
fn try_flake_attr(flake_uri: &str) -> Result<bool> {
log::info!("Trying flake URI: {flake_uri}...");
let status = try_nix_eval(flake_uri)?;
fn try_flake_attr(flake: &str, attr: &str) -> Result<bool> {
let full_uri = format!("{flake}#{FLAKE_ATTR}.{attr}");
log::info!("Trying flake URI: {full_uri}...");
let status = try_nix_eval(flake, attr)?;
if status {
log::info!("Success, using {flake_uri}");
log::info!("Success, using {full_uri}");
} else {
log::info!("Attribute {flake_uri} not found in flake.");
log::info!("Attribute {full_uri} not found in flake.");
};
Ok(status)
}
@ -150,13 +154,13 @@ fn run_nix_build(flake_uri: &str) -> Result<process::Output> {
Ok(output)
}
fn try_nix_eval(flake_uri: &str) -> Result<bool> {
fn try_nix_eval(flake: &str, attr: &str) -> Result<bool> {
let output = nix_cmd()
.arg("eval")
.arg(flake_uri)
.arg(format!("{flake}#{FLAKE_ATTR}"))
.arg("--json")
.arg("--apply")
.arg("a: a ? outPath")
.arg(format!("a: a ? {attr}"))
.output()?;
if output.status.success() {
let stdout = String::from_utf8(output.stdout)?;