Upgrade to newer version of config crate.

Cargo.lock

@@ -62,12 +62,6 @@ version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4c527152e37cf757a3f78aae5a06fbeefdb07ccc535c980a3208ee3060dd544"
 
-[[package]]
-name = "arrayvec"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
-
 [[package]]
 name = "arti"
 version = "0.0.4"
@@ -628,12 +622,14 @@ dependencies = [
 
 [[package]]
 name = "config"
-version = "0.11.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b1b9d958c2b1368a663f05538fc1b5975adce1e19f435acceae987aceeeb369"
+checksum = "54ad70579325f1a38ea4c13412b82241c5900700a69785d73e2736bd65a33f86"
 dependencies = [
+ "async-trait",
  "lazy_static",
  "nom",
+ "pathdiff",
  "serde",
  "toml",
 ]
@@ -1561,19 +1557,6 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
-[[package]]
-name = "lexical-core"
-version = "0.7.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6607c62aa161d23d17a9072cc5da0be67cdfc89d3afb1e8d9c842bebc2525ffe"
-dependencies = [
- "arrayvec",
- "bitflags",
- "cfg-if 1.0.0",
- "ryu",
- "static_assertions",
-]
-
 [[package]]
 name = "libc"
 version = "0.2.115"
@@ -1678,6 +1661,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "minimal-lexical"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
 [[package]]
 name = "miniz_oxide"
 version = "0.4.4"
@@ -1797,12 +1786,12 @@ dependencies = [
 
 [[package]]
 name = "nom"
-version = "5.1.2"
+version = "7.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ffb4262d26ed83a1c0a33a38fe2bb15797329c85770da05e6b828ddb782627af"
+checksum = "1b1d11e1ef389c76fe5b81bcaf2ea32cf88b62bc494e19f493d0b30e7a930109"
 dependencies = [
- "lexical-core",
  "memchr",
+ "minimal-lexical",
  "version_check",
 ]
 
@@ -2007,6 +1996,12 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "pathdiff"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8835116a5c179084a830efb3adc117ab007512b535bc1a21c991d3b32a6b44dd"
+
 [[package]]
 name = "pem-rfc7468"
 version = "0.2.4"
@@ -2868,9 +2863,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-util"
-version = "0.6.9"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e99e1983e5d376cd8eb4b66604d2e99e79f5bd988c3055891dcd8c9e2604cc0"
+checksum = "64910e1b9c1901aaf5375561e35b9c057d95ff41a44ede043a03e09279eabaf1"
 dependencies = [
  "bytes",
  "futures-core",

crates/arti-bench/src/main.rs

@@ -46,6 +46,7 @@ use rand::distributions::Standard;
 use rand::Rng;
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
+use std::convert::TryInto;
 use std::fmt;
 use std::fmt::Formatter;
 use std::future::Future;

crates/arti-config/Cargo.toml

@@ -14,7 +14,7 @@ repository="https://gitlab.torproject.org/tpo/core/arti.git/"
 arti-client = { package="arti-client", path = "../arti-client", version = "0.0.4"}
 tor-circmgr = { package="tor-circmgr", path="../tor-circmgr", version = "0.0.4"}
 tor-config = { package="tor-config", path = "../tor-config", version = "0.0.4", features = ["expand-paths"]}
-config = { version = "0.11.0", default-features = false, features = ["toml"] }
+config = { version = "0.12.0", default-features = false, features = ["toml"] }
 once_cell = "1"
 serde = { version = "1.0.103", features = ["derive"] }
 toml = "0.5"

crates/arti-config/src/lib.rs

@@ -51,6 +51,11 @@ pub use options::{
 };
 use tor_config::CfgPath;
 
+/// The synchronous configuration builder type we use.
+///
+/// (This is a type alias that config should really provide.)
+type ConfigBuilder = config::builder::ConfigBuilder<config::builder::DefaultState>;
+
 use std::path::{Path, PathBuf};
 
 /// A description of where to find our configuration options.
@@ -116,38 +121,41 @@ impl ConfigurationSources {
 
     /// Load the configuration into a new [`config::Config`].
     pub fn load(&self) -> Result<config::Config, config::ConfigError> {
-        let mut config = config::Config::new();
-        config.merge(config::File::from_str(
+        let mut builder = config::Config::builder();
+        builder = builder.add_source(config::File::from_str(
             options::ARTI_DEFAULTS,
             config::FileFormat::Toml,
-        ))?;
-        load_mut(&mut config, &self.files, &self.options)?;
-        Ok(config)
+        ));
+        builder = add_sources(builder, &self.files, &self.options);
+        builder.build()
     }
 }
 
-/// As [`ConfigurationSources::load()`], but load into a mutable `Config`
-/// object.
-fn load_mut<P: AsRef<Path>>(
-    cfg: &mut config::Config,
+/// Add every file and commandline source to `builder`, returning a new
+/// builder.
+fn add_sources<P>(
+    mut builder: ConfigBuilder,
     files: &[(P, MustRead)],
     opts: &[String],
-) -> Result<(), config::ConfigError> {
+) -> ConfigBuilder
+where
+    P: AsRef<Path>,
+{
     for (path, must_read) in files {
         // Not going to use File::with_name here, since it doesn't
         // quite do what we want.
-        let f: config::File<_> = path.as_ref().into();
+        let f: config::File<_, _> = path.as_ref().into();
         let required = must_read == &MustRead::MustRead;
-        cfg.merge(f.format(config::FileFormat::Toml).required(required))?;
+        builder = builder.add_source(f.format(config::FileFormat::Toml).required(required));
     }
 
     let mut cmdline = CmdLine::new();
     for opt in opts {
         cmdline.push_toml_line(opt.clone());
     }
-    cfg.merge(cmdline)?;
+    builder = builder.add_source(cmdline);
 
-    Ok(())
+    builder
 }
 
 /// Return a filename for the default user configuration file.
@@ -167,13 +175,21 @@ world = \"stuff\"
 friends = 4242
 ";
 
+    /// Load from a set of files and option strings, without taking
+    /// the arti defaults into account.
+    fn load_nodefaults<P: AsRef<Path>>(
+        files: &[(P, MustRead)],
+        opts: &[String],
+    ) -> Result<config::Config, config::ConfigError> {
+        add_sources(config::Config::builder(), files, opts).build()
+    }
+
     #[test]
     fn non_required_file() {
         let td = tempdir().unwrap();
         let dflt = td.path().join("a_file");
         let files = vec![(dflt, MustRead::TolerateAbsence)];
-        let mut c = config::Config::new();
-        load_mut(&mut c, &files, Default::default()).unwrap();
+        load_nodefaults(&files, Default::default()).unwrap();
     }
 
     static EX2_TOML: &str = "
@@ -186,13 +202,12 @@ world = \"nonsense\"
         let td = tempdir().unwrap();
         let dflt = td.path().join("a_file");
         let cf = td.path().join("other_file");
-        let mut c = config::Config::new();
         std::fs::write(&cf, EX2_TOML).unwrap();
         let files = vec![(dflt, MustRead::TolerateAbsence), (cf, MustRead::MustRead)];
-        load_mut(&mut c, &files, Default::default()).unwrap();
+        let c = load_nodefaults(&files, Default::default()).unwrap();
 
-        assert!(c.get_str("hello.friends").is_err());
-        assert_eq!(c.get_str("hello.world").unwrap(), "nonsense".to_string());
+        assert!(c.get_string("hello.friends").is_err());
+        assert_eq!(c.get_string("hello.world").unwrap(), "nonsense".to_string());
     }
 
     #[test]
@@ -200,16 +215,15 @@ world = \"nonsense\"
         let td = tempdir().unwrap();
         let cf1 = td.path().join("a_file");
         let cf2 = td.path().join("other_file");
-        let mut c = config::Config::new();
         std::fs::write(&cf1, EX_TOML).unwrap();
         std::fs::write(&cf2, EX2_TOML).unwrap();
         let v = vec![(cf1, MustRead::TolerateAbsence), (cf2, MustRead::MustRead)];
         let v2 = vec!["other.var=present".to_string()];
-        load_mut(&mut c, &v, &v2).unwrap();
+        let c = load_nodefaults(&v, &v2).unwrap();
 
-        assert_eq!(c.get_str("hello.friends").unwrap(), "4242".to_string());
-        assert_eq!(c.get_str("hello.world").unwrap(), "nonsense".to_string());
-        assert_eq!(c.get_str("other.var").unwrap(), "present".to_string());
+        assert_eq!(c.get_string("hello.friends").unwrap(), "4242".to_string());
+        assert_eq!(c.get_string("hello.world").unwrap(), "nonsense".to_string());
+        assert_eq!(c.get_string("other.var").unwrap(), "present".to_string());
     }
 
     #[test]

crates/arti-config/src/options.rs

@@ -10,6 +10,7 @@ use arti_client::config::{
 use derive_builder::Builder;
 use serde::Deserialize;
 use std::collections::HashMap;
+use std::convert::TryFrom;
 use tor_config::{CfgPath, ConfigBuildError};
 
 /// Default options to use for our configuration.
@@ -288,6 +289,13 @@ pub struct ArtiConfig {
     system: SystemConfig,
 }
 
+impl TryFrom<config::Config> for ArtiConfig {
+    type Error = config::ConfigError;
+    fn try_from(cfg: config::Config) -> Result<ArtiConfig, Self::Error> {
+        cfg.try_deserialize()
+    }
+}
+
 impl From<ArtiConfig> for TorClientConfigBuilder {
     fn from(cfg: ArtiConfig) -> TorClientConfigBuilder {
         let mut builder = TorClientConfig::builder();
@@ -570,6 +578,7 @@ impl From<ArtiConfig> for ArtiConfigBuilder {
 mod test {
     #![allow(clippy::unwrap_used)]
 
+    use std::convert::TryInto;
     use std::time::Duration;
 
     use super::*;
@@ -577,12 +586,13 @@ mod test {
     #[test]
     fn default_config() {
         // TODO: this is duplicate code.
-        let mut cfg = config::Config::new();
-        cfg.merge(config::File::from_str(
-            ARTI_DEFAULTS,
-            config::FileFormat::Toml,
-        ))
-        .unwrap();
+        let cfg = config::Config::builder()
+            .add_source(config::File::from_str(
+                ARTI_DEFAULTS,
+                config::FileFormat::Toml,
+            ))
+            .build()
+            .unwrap();
 
         let parsed: ArtiConfig = cfg.try_into().unwrap();
         let default = ArtiConfig::default();

crates/arti/Cargo.toml

@@ -28,7 +28,7 @@ arti-config = { path="../arti-config", version = "0.0.4"}
 
 anyhow = "1.0.23"
 async-ctrlc = { version = "1.2.0", optional = true }
-config = { version = "0.11.0", default-features = false }
+config = { version = "0.12.0", default-features = false }
 cfg-if = "1.0.0"
 futures = "0.3.14"
 tracing = "0.1.18"

crates/arti/src/main.rs

@@ -101,6 +101,8 @@ use anyhow::{Context, Result};
 use clap::{App, AppSettings, Arg, SubCommand};
 use tracing::{info, warn};
 
+use std::convert::TryInto;
+
 /// Run the main loop of the proxy.
 async fn run<R: Runtime>(
     runtime: R,

crates/arti/src/watch_cfg.rs

 //! Code to watch configuration files for any changes.
 
 use std::collections::HashSet;
+use std::convert::TryInto;
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::channel as std_channel;
 use std::time::Duration;