allow output to file

Cargo.lock

@@ -8,6 +8,16 @@ dependencies = [
  "nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "atomicwrites"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "autocfg"
 version = "0.1.6"
@@ -311,6 +321,18 @@ dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "nix"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "nodrop"
 version = "0.1.13"
@@ -365,6 +387,7 @@ dependencies = [
 name = "prometheus-mdns-sd-rs"
 version = "0.1.0"
 dependencies = [
+ "atomicwrites 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
  "maplit 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "mdns 0.3.1 (git+https://github.com/bkchr/mdns?branch=tokio_rewrite)",
@@ -386,6 +409,18 @@ dependencies = [
  "proc-macro2 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand"
 version = "0.6.5"
@@ -490,6 +525,14 @@ dependencies = [
  "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "remove_dir_all"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.16"
@@ -584,6 +627,15 @@ dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "tempdir"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "tokio"
 version = "0.1.22"
@@ -763,6 +815,11 @@ name = "version_check"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
@@ -803,6 +860,7 @@ dependencies = [
 
 [metadata]
 "checksum arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "b8d73f9beda665eaa98ab9e4f7442bd4e7de6652587de55b2525e52e29c1b0ba"
+"checksum atomicwrites 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c4e1aa99513c90202b4b04cfbe3c9d51dd914f2e26215a4caa76574b00bb6393"
 "checksum autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "b671c8fb71b457dd4ae18c4ba1e59aa81793daacc361d82fcd410cef0d491875"
 "checksum backtrace 0.3.37 (registry+https://github.com/rust-lang/crates.io-index)" = "5180c5a20655b14a819b652fd2378fa5f1697b6c9ddad3e695c2f9cedf6df4e2"
 "checksum backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "82a830b4ef2d1124a711c71d263c5abdc710ef8e907bd508c88be475cebc422b"
@@ -841,6 +899,7 @@ dependencies = [
 "checksum mio-uds 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)" = "966257a94e196b11bb43aca423754d87429960a768de9414f3691d6957abf125"
 "checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
 "checksum net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"
+"checksum nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6c722bee1037d430d0f8e687bbdbf222f27cc6e4e68d5caf630857bb2b6dbdce"
 "checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
 "checksum num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bcef43580c035376c0705c42792c294b66974abbfd2789b511784023f71f3273"
 "checksum owning_ref 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "49a4b8ea2179e6a2e27411d3bca09ca6dd630821cf6894c6c7c8467a8ee7ef13"
@@ -849,6 +908,7 @@ dependencies = [
 "checksum proc-macro2 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e98a83a9f9b331f54b924e68a66acb1bb35cb01fb0a23645139967abefb697e8"
 "checksum quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9274b940887ce9addde99c4eee6b5c44cc494b182b97e73dc8ffdcb3397fd3f0"
 "checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+"checksum rand 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "552840b97013b1a26992c11eac34bdd778e464601a4c2054b5f0bff7c6761293"
 "checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
 "checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
 "checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
@@ -860,6 +920,7 @@ dependencies = [
 "checksum rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
 "checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+"checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
 "checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum ryu 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c92464b447c0ee8c4fb3824ecc8383b81717b9f1e74ba2e72540aef7b9f82997"
@@ -874,6 +935,7 @@ dependencies = [
 "checksum smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ab606a9c5e214920bb66c458cd7be8ef094f813f20fe77a54cc7dbfff220d4b7"
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "66850e97125af79138385e9b88339cbcd037e3f28ceab8c5ad98e64f0f1f80bf"
+"checksum tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "15f2b5fb00ccdf689e0149d1b1b3c03fead81c2b37735d812fa8bddbbf41b6d8"
 "checksum tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)" = "5a09c0b5bb588872ab2f09afa13ee6e9dac11e10a0ec9e8e3ba39a5a5d530af6"
 "checksum tokio-codec 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5c501eceaf96f0e1793cf26beb63da3d11c738c4a943fdf3746d81d64684c39f"
 "checksum tokio-current-thread 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "d16217cad7f1b840c5a97dfb3c43b0c871fef423a6e8d2118c604e843662a443"
@@ -889,6 +951,7 @@ dependencies = [
 "checksum tokio-uds 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "037ffc3ba0e12a0ab4aca92e5234e0dedeb48fddf6ccd260f1f150a36a9f2445"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"

Cargo.toml

@@ -3,8 +3,10 @@ name = "prometheus-mdns-sd-rs"
 version = "0.1.0"
 authors = ["Robin Appelman <robin@icewind.nl>"]
 edition = "2018"
-
+description = "mDNS service discovery for prometherus"
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/icewind1991/prometheus-mdns-rs"
 
 [dependencies]
 mdns = { version = "0.3", git = "https://github.com/bkchr/mdns", branch = "tokio_rewrite" }
@@ -13,3 +15,4 @@ tokio = "0.1.21"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 maplit = "1.0"
+atomicwrites = "0.2"

src/main.rs

@@ -1,8 +1,11 @@
+use atomicwrites::{AllowOverwrite, AtomicFile};
 use futures::{Future, Stream};
 use maplit::hashmap;
 use mdns::{Record, RecordKind};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
+use std::env;
+use std::io::Write;
 use std::sync::mpsc;
 use std::sync::mpsc::Sender;
 use std::thread;
@@ -38,8 +41,14 @@ impl From<&Service> for PrometheusService {
 }
 
 const TIMEOUT: Duration = Duration::from_secs(60);
+const INTERVAL: Duration = Duration::from_secs(15);
 
 fn main() {
+    let out = env::args()
+        .skip(1)
+        .next()
+        .map(|path| AtomicFile::new(path, AllowOverwrite));
+
     let (tx, rx) = mpsc::channel();
 
     thread::spawn(move || {
@@ -62,18 +71,25 @@ fn main() {
         let removed_count = services.len();
 
         if start_count != added_count || added_count != removed_count {
-            let output: Vec<PrometheusService> =
+            let output_services: Vec<PrometheusService> =
                 services.iter().map(|(_, service)| service.into()).collect();
-            println!("{}", serde_json::to_string(&output).unwrap());
+            let output = serde_json::to_string(&output_services).unwrap();
+
+            match &out {
+                Some(path) => {
+                    let _ = path.write(|f| f.write_all(output.as_bytes()));
+                }
+                None => println!("{}", output),
+            }
         }
 
-        sleep(Duration::from_secs(15));
+        sleep(INTERVAL);
     }
 }
 
 fn discover(tx: Sender<Service>) {
     tokio::run(
-        mdns::discover::all(SERVICE_NAME, Duration::from_secs(15))
+        mdns::discover::all(SERVICE_NAME, INTERVAL)
             .unwrap()
             .for_each(move |response| {
                 if response
@@ -84,8 +100,6 @@ fn discover(tx: Sender<Service>) {
                     let port = response.records().filter_map(self::to_port).next();
                     let name = response.records().filter_map(self::to_name).next();
 
-                    dbg!(response);
-
                     if let (Some(addr), Some(name), Some(port)) = (addr, name, port) {
                         let _ = tx.send(Service {
                             name,