allow use prometheus service discovery files as params

Cargo.lock

@@ -704,6 +704,7 @@ dependencies = [
  "prometheus-edge-detector 0.1.0 (git+https://github.com/icewind1991/prometheus-edge-detector)",
  "reqwest 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

Cargo.toml

@@ -16,6 +16,7 @@ toml = "0.5"
 log = "0.4"
 env_logger = "0.7"
 err-derive = "0.2.1"
+serde_json = "1.0.45"
 
 [dev-dependencies]
 maplit = "1.0.2"

src/config.rs

@@ -9,6 +9,12 @@ pub enum ParameterError {
     MdnsError(#[error(source)] mdns::Error),
     #[error(display = "requested mdns host not found")]
     MdnsHostNotFound,
+    #[error(display = "error reading file: {}", _0)]
+    FilesystemError(#[error(source)] std::io::Error),
+    #[error(display = "malformed service file: {}", _0)]
+    Service(#[error(source)] serde_json::Error),
+    #[error(display = "requested service not found")]
+    ServiceNotFound,
 }
 
 #[derive(Debug, Clone, Deserialize)]
@@ -22,6 +28,11 @@ pub enum Parameter {
     Value {
         value: String,
     },
+    Service {
+        file: String,
+        key: String,
+        value: String,
+    },
 }
 
 impl Parameter {
@@ -36,7 +47,19 @@ impl Parameter {
                     None => Err(ParameterError::MdnsHostNotFound)
                 }
             }
-            Parameter::Value { value } => Ok(value.clone())
+            Parameter::Value { value } => Ok(value.clone()),
+            Parameter::Service {
+                file, key, value
+            } => {
+                let content = tokio::fs::read(file).await?;
+                let services: Vec<Service> = serde_json::from_slice(&content)?;
+                services.into_iter().find_map(|service| {
+                    service.labels.get(key)
+                        .filter(|val| *val == value)
+                        .and_then(|_| service.targets.get(0))
+                        .cloned()
+                }).ok_or(ParameterError::ServiceNotFound)
+            }
         }
     }
 }
@@ -83,3 +106,9 @@ pub enum Method {
     Put,
     Post,
 }
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct Service {
+    targets: Vec<String>,
+    labels: HashMap<String, String>,
+}

src/main.rs

@@ -12,7 +12,10 @@ mod trigger;
 async fn main() -> Result<(), MainError> {
     env_logger::init();
 
-    if let Some(path) = std::env::args().nth(1) {
+    let mut args = std::env::args();
+    let bin = args.next().unwrap();
+
+    if let Some(path) = args.next() {
         let mut file = File::open(path).await?;
 
         let mut contents = vec![];
@@ -22,7 +25,7 @@ async fn main() -> Result<(), MainError> {
 
         Ok(trigger_manager.run_triggers().await?)
     } else {
-        println!("Usage {} config.toml", std::env::args().next().unwrap());
+        println!("Usage {} config.toml", bin);
         return Ok(());
     }
 }

src/trigger.rs

@@ -6,7 +6,7 @@ use futures_util::future::try_join_all;
 use std::time::{Duration, SystemTime};
 use reqwest::Client;
 use tokio::time::delay_for;
-use log::{info, warn};
+use log::{info, error};
 use err_derive::Error;
 
 pub struct TriggerManager {
@@ -70,12 +70,12 @@ impl TriggerManager {
                         Ok(Some(new_edge)) if new_edge == edge => {
                             info!("[{}] Edge still valid, triggering", trigger.name);
                             if let Err(e) = run_action(&trigger.action, &self.http_client).await {
-                                warn!("[{}]: {}", trigger.name, e);
+                                error!("[{}]: {}", trigger.name, e);
                             }
                             delay_for(delay_duration).await;
                         }
                         Err(e) => {
-                            warn!("[{}]: {}", trigger.name, e);
+                            error!("[{}]: {}", trigger.name, e);
                             delay_for(error_delay).await;
                         }
                         _ => {
@@ -88,7 +88,7 @@ impl TriggerManager {
                     delay_for(delay_duration).await;
                 }
                 Err(e) => {
-                    warn!("[{}]: {}", trigger.name, e);
+                    error!("[{}]: {}", trigger.name, e);
                     delay_for(error_delay).await;
                 }
             }