feat: add shell completions and man page generation

.gitignore

@@ -1,3 +1,5 @@
 /target
 **/*.rs.bk
 .idea
+/complete
+/man

Cargo.lock

@@ -166,6 +166,15 @@ dependencies = [
  "textwrap",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "3.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df6f3613c0a3cddfd78b41b10203eb322cb29b600cbdf808a7d3db95691b8e25"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "3.1.4"
@@ -179,6 +188,16 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "clap_mangen"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0649fb4156bbd7306896025005596033879a2051f9a3aa7416ab915df1f8fdac"
+dependencies = [
+ "clap",
+ "roff",
+]
+
 [[package]]
 name = "crossbeam-epoch"
 version = "0.9.8"
@@ -754,6 +773,8 @@ dependencies = [
  "axum",
  "chrono",
  "clap",
+ "clap_complete",
+ "clap_mangen",
  "fern",
  "futures",
  "futures-util",
@@ -911,6 +932,12 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "roff"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b833d8d034ea094b1ea68aa6d5c740e0d04bad9d16568d08ba6f76823a114316"
+
 [[package]]
 name = "rustversion"
 version = "1.0.6"

Cargo.toml

@@ -7,6 +7,7 @@ repository = "https://git.jcg.re/jcgruenhage/peshming"
 keywords = ["ping", "icmp", "prometheus"]
 edition = "2018"
 description = "Pings configured hosts in a configurable intervals and exposes metrics for prometheus."
+build = "build.rs"
 
 [dependencies]
 toml = "0.5"
@@ -25,3 +26,8 @@ async-anyhow-logger = "0.1"
 axum = "0.4"
 metrics = "0.18"
 metrics-exporter-prometheus = { version = "0.9", default-features = false }
+
+[build-dependencies]
+clap = { version = "3", features = ["derive", "wrap_help"] }
+clap_mangen = "0.1"
+clap_complete = "3"

README.md

@@ -33,3 +33,9 @@ For configuration options, see the included sample config file.
 There's two endpoints available:
  - `/metrics`, which serves the metrics
  - `/health`, which should always return a 200 status code
+
+### Packaging Notes
+If you're packaging peshming, you might be interested in the env vars
+`PESHMING_MAN_DIR` and `PESHMING_COMPLETIONS_DIR`, which when set, will cause
+cargo to generate a man page and shell completions to the folder passed in
+those variables.

build.rs

@@ -0,0 +1,40 @@
+use std::path::PathBuf;
+
+use clap::{ArgEnum, CommandFactory};
+use clap_complete::{generate_to, Shell};
+
+include!("src/cli.rs");
+
+fn main() -> std::io::Result<()> {
+    let mut cli = Cli::command();
+
+    if let Some(completions_dir) = std::env::var_os("PESHMING_COMPLETIONS_DIR") {
+        let completions_dir: PathBuf = completions_dir.into();
+
+        std::fs::create_dir_all(&completions_dir)
+            .expect("Could not create shell completions output folder.");
+
+        for shell in Shell::value_variants() {
+            generate_to(*shell, &mut cli, "peshming", &completions_dir).unwrap_or_else(|err| {
+                panic!(
+                    "Failed to generate shell completions for {}: {}.",
+                    shell, err
+                )
+            });
+        }
+    }
+
+    if let Some(man_dir) = std::env::var_os("PESHMING_MAN_DIR") {
+        let man_dir: PathBuf = man_dir.into();
+
+        std::fs::create_dir_all(&man_dir).expect("Could not create man page output folder.");
+
+        let man = clap_mangen::Man::new(cli);
+        let mut buffer: Vec<u8> = Default::default();
+        man.render(&mut buffer)?;
+
+        std::fs::write(man_dir.join("peshming.1"), buffer)?;
+    }
+
+    Ok(())
+}

src/cli.rs

@@ -0,0 +1,11 @@
+#[derive(clap::Parser)]
+#[clap(author, version)]
+/// Pings configured hosts in a configurable intervals and exposes metrics for prometheus.
+pub struct Cli {
+    /// Set config file
+    pub config: String,
+    #[clap(short, long, parse(from_occurrences))]
+    /// Be verbose (you can add this up to 4 times for more logs).
+    /// By default, only errors are logged, so no output is a good thing.
+    pub verbose: usize,
+}

src/config.rs

@@ -24,8 +24,11 @@ use metrics::{describe_histogram, register_histogram, Unit};
 use metrics_exporter_prometheus::{Matcher, PrometheusBuilder, PrometheusHandle};
 use serde::Deserialize;
 use serde_with::{serde_as, DurationMilliSeconds};
+
 use std::{collections::HashMap, time::Duration};
 
+use crate::cli::Cli;
+
 pub(crate) struct App {
     pub(crate) config: Config,
     pub(crate) handle: PrometheusHandle,
@@ -75,18 +78,6 @@ impl Default for LogConfig {
     }
 }
 
-#[derive(clap::Parser)]
-#[clap(author, version)]
-/// Pings configured hosts in a configurable intervals and exposes metrics for prometheus.
-pub struct Cli {
-    /// Set config file
-    config: String,
-    #[clap(short, long, parse(from_occurrences))]
-    /// Be verbose (you can add this up to 4 times for more logs).
-    /// By default, only errors are logged, so no output is a good thing.
-    verbose: usize,
-}
-
 fn setup_clap() -> Cli {
     Cli::parse()
 }

src/main.rs

@@ -20,6 +20,7 @@
 use anyhow::Result;
 use async_anyhow_logger::catch;
 
+mod cli;
 mod config;
 mod metrics;
 mod ping;