Use clap for command line arguments

To support command line arguments `clap` is used. This adds following
argument `--config`/`-c` to provide a different path for the
configurationf file and the subcommand `configtest` which parses and
loads the configuration and exits.

Cargo.lock

@@ -164,6 +164,38 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "clap"
+version = "3.0.0-beta.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bd1061998a501ee7d4b6d449020df3266ca3124b941ec56cf2005c3779ca142"
+dependencies = [
+ "atty",
+ "bitflags",
+ "clap_derive",
+ "indexmap",
+ "lazy_static",
+ "os_str_bytes",
+ "strsim",
+ "termcolor",
+ "textwrap",
+ "unicode-width",
+ "vec_map",
+]
+
+[[package]]
+name = "clap_derive"
+version = "3.0.0-beta.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "370f715b81112975b1b69db93e0b56ea4cd4e5002ac43b2da8474106a54096a1"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2 1.0.27",
+ "quote 1.0.9",
+ "syn 1.0.72",
+]
+
 [[package]]
 name = "cookie"
 version = "0.11.4"
@@ -353,6 +385,15 @@ version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 
+[[package]]
+name = "heck"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
+dependencies = [
+ "unicode-segmentation",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.18"
@@ -572,6 +613,12 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
+[[package]]
+name = "os_str_bytes"
+version = "2.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "afb2e1c3ee07430c2cf76151675e583e0f19985fa6efae47d6848a3e2c824f85"
+
 [[package]]
 name = "pear"
 version = "0.1.4"
@@ -623,6 +670,30 @@ version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2 1.0.27",
+ "quote 1.0.9",
+ "syn 1.0.72",
+ "version_check 0.9.3",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2 1.0.27",
+ "quote 1.0.9",
+ "version_check 0.9.3",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "0.4.30"
@@ -927,6 +998,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "subtle"
 version = "2.4.0"
@@ -970,6 +1047,15 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "textwrap"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "203008d98caf094106cfaba70acfed15e18ed3ddb7d94e49baec153a2b462789"
+dependencies = [
+ "unicode-width",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.25"
@@ -1069,6 +1155,18 @@ dependencies = [
  "tinyvec",
 ]
 
+[[package]]
+name = "unicode-segmentation"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
+
 [[package]]
 name = "unicode-xid"
 version = "0.1.0"
@@ -1118,6 +1216,12 @@ dependencies = [
  "log 0.4.14",
 ]
 
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
 [[package]]
 name = "version_check"
 version = "0.1.5"
@@ -1141,6 +1245,7 @@ name = "webhookey"
 version = "0.1.0-rc.2"
 dependencies = [
  "anyhow",
+ "clap",
  "dirs",
  "env_logger",
  "hex",

Cargo.toml

@@ -27,6 +27,7 @@ hex = "0.4"
 ipnet = { version = "2.3", features = ["serde"] }
 thiserror = "1.0"
 run_script = "0.7"
+clap = "3.0.0-beta.2"
 
 [package.metadata.deb]
 extended-description = "Webhookey receives requests in form of a so called Webhook as for example sent by Gitea. Those requests are matched against configured filters, if a filter matches, values from the header and the body can be passed to scripts as parameters which are then executed subsequently."

src/main.rs

@@ -1,6 +1,7 @@
 #![feature(proc_macro_hygiene, decl_macro)]
 
 use anyhow::{anyhow, bail, Result};
+use clap::{app_from_crate, App, Arg};
 use hmac::{Hmac, Mac, NewMac};
 use ipnet::IpNet;
 use log::{debug, error, info, trace, warn};
@@ -474,10 +475,34 @@ fn get_config() -> Result<File> {
 fn main() -> Result<()> {
     env_logger::init();
 
-    let config: Config = serde_yaml::from_reader(BufReader::new(get_config()?))?;
+    let cli = app_from_crate!()
+        .arg(
+            Arg::new("config")
+                .short('c')
+                .long("config")
+                .takes_value(true)
+                .value_name("FILE")
+                .about("Provide a path to the configuration file"),
+        )
+        .subcommand(
+            App::new("configtest")
+                .about("Verifies if the configuration can be parsed without errors."),
+        )
+        .get_matches();
+
+    let config: Config = match cli.value_of("config") {
+        Some(config) => serde_yaml::from_reader(BufReader::new(File::open(config)?))?,
+        _ => serde_yaml::from_reader(BufReader::new(get_config()?))?,
+    };
 
     trace!("Parsed configuration:\n{}", serde_yaml::to_string(&config)?);
 
+    if let Some(_) = cli.subcommand_matches("configtest") {
+        debug!("Configtest succeded.");
+        println!("Config is OK");
+        return Ok(())
+    }
+
     rocket::ignite()
         .mount("/", routes![receive_hook])
         .attach(AdHoc::on_attach("webhookey config", move |rocket| {