chore!: refactor config file format

There are substructs for the different parts of the config now, as a
preparation of a larger refactor coming in.

BREAKING CHANGE: config file format changed

Cargo.lock

@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -352,6 +354,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
  "cfg-if",
+ "serde",
 ]
 
 [[package]]

Cargo.toml

@@ -17,7 +17,7 @@ futures = "0.3"
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "time"] }
 clap = "2"
 fern = "0.6"
-log = "0.4"
+log = { version = "0.4", features = ["serde"] }
 chrono = "0.4"
 serde = { version = "1", features = ["derive"] }
 tokio-icmp-echo = "0.4"

config.toml.sample

@@ -6,6 +6,11 @@ listener = "[::]:9898"
 # The format here is `"host" = interval in milliseconds`, so these examples
 # will ping the primary and secondary IP of cloudflare's 1.1.1.1 DNS service
 # every 500ms, or twice per second.
-[hosts]
+[ping.hosts]
 "1.1.1.1" = 500
 "1.0.0.1" = 500
+
+# Configure logging is also possible here instead of using the CLI. If both are
+# specified, the more verbose of the two will be used.
+# [log]
+# level = "ERROR"

src/config.rs

@@ -20,15 +20,35 @@
 use anyhow::{Context, Result};
 use clap::{clap_app, crate_authors, crate_description, crate_name, crate_version};
 use log::info;
-use serde::{Deserialize, Serialize};
+use serde::Deserialize;
 use std::collections::HashMap;
 
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Deserialize, Clone)]
 pub(crate) struct Config {
     pub(crate) listener: std::net::SocketAddr,
+    pub(crate) ping: PingConfig,
+    #[serde(default)]
+    pub(crate) log: LogConfig,
+}
+
+#[derive(Deserialize, Clone)]
+pub(crate) struct PingConfig {
     pub(crate) hosts: HashMap<std::net::IpAddr, u64>,
 }
 
+#[derive(Deserialize, Clone)]
+pub(crate) struct LogConfig {
+    pub(crate) level: log::LevelFilter,
+}
+
+impl Default for LogConfig {
+    fn default() -> Self {
+        Self {
+            level: log::LevelFilter::Error,
+        }
+    }
+}
+
 fn setup_clap() -> clap::ArgMatches<'static> {
     clap_app!(myapp =>
         (name: crate_name!())
@@ -42,14 +62,7 @@ fn setup_clap() -> clap::ArgMatches<'static> {
     .get_matches()
 }
 
-fn setup_fern(level: u64) {
-    let level = match level {
-        0 => log::LevelFilter::Error,
-        1 => log::LevelFilter::Warn,
-        2 => log::LevelFilter::Info,
-        3 => log::LevelFilter::Debug,
-        _ => log::LevelFilter::Trace,
-    };
+fn setup_fern(level: log::LevelFilter) {
     match fern::Dispatch::new()
         .format(|out, message, record| {
             out.finish(format_args!(
@@ -77,9 +90,22 @@ fn read_config(path: &str) -> Result<Config> {
 
 pub(crate) fn setup_app() -> Result<Config> {
     let clap = setup_clap();
-    setup_fern(clap.occurrences_of("v"));
     let config_path = clap
         .value_of("config")
         .context("Got no config file. clap should've catched this")?;
-    Ok(read_config(config_path).context("Couldn't read config file!")?)
+    let config = read_config(config_path).context("Couldn't read config file!")?;
+    setup_fern(determine_level(clap.occurrences_of("v"), config.log.level));
+    Ok(config)
+}
+
+fn determine_level(verbose_occurrences: u64, config_level: log::LevelFilter) -> log::LevelFilter {
+    let cli_level = match verbose_occurrences {
+        0 => log::LevelFilter::Error,
+        1 => log::LevelFilter::Warn,
+        2 => log::LevelFilter::Info,
+        3 => log::LevelFilter::Debug,
+        _ => log::LevelFilter::Trace,
+    };
+
+    Ord::max(cli_level, config_level)
 }

src/ping.rs

@@ -44,7 +44,7 @@ lazy_static! {
 pub(crate) async fn start_pinging_hosts(config: &Config) -> Result<()> {
     let pinger = Pinger::new().await.context("Couldn't create pinger")?;
     let mut handles = vec![];
-    for (host, interval) in config.hosts.clone() {
+    for (host, interval) in config.ping.hosts.clone() {
         info!("Spawn ping task for {}", host);
         handles.push(tokio::spawn(ping_host(pinger.clone(), host, interval)));
     }