From 2ff606a30a09b09baa605f8b8cf3fd8c42731a1b Mon Sep 17 00:00:00 2001
From: Tim Buckley <timothyb89@gmail.com>
Date: Wed, 30 Dec 2020 19:11:50 -0700
Subject: [PATCH] Partial exporter impl

---
 src/bin/metriful_exporter.rs | 143 ++++++++++++++++++++++++++++++++++-
 1 file changed, 142 insertions(+), 1 deletion(-)

diff --git a/src/bin/metriful_exporter.rs b/src/bin/metriful_exporter.rs
index e493bfa..014ed08 100644
--- a/src/bin/metriful_exporter.rs
+++ b/src/bin/metriful_exporter.rs
@@ -1,4 +1,111 @@
-fn main() {
+use std::path::PathBuf;
+use std::sync::{Arc, RwLock};
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::thread;
+use std::time::Duration;
+use std::sync::mpsc::channel;
+
+use color_eyre::eyre::{Result, Error, Context, eyre};
+use log::*;
+use metriful::{Metriful, CyclePeriod, metric::METRIC_COMBINED_ALL};
+use serde_json::{self, json};
+use simple_prometheus_exporter::{Exporter, export};
+use structopt::StructOpt;
+use warp::Filter;
+
+fn try_from_hex_arg(s: &str) -> Result<u16> {
+  if s.starts_with("0x") {
+    u16::from_str_radix(&s[2..], 16).with_context(|| format!("invalid hex: {}", s))
+  } else {
+    s.parse().with_context(|| format!("invalid int: {}", s))
+  }
+}
+
+fn parse_duration_secs(s: &str) -> Result<Duration> {
+  Ok(Duration::from_secs(
+    s.parse().wrap_err_with(|| format!("invalid seconds value: {}", s))?
+  ))
+}
+
+#[derive(Debug, Clone, StructOpt)]
+#[structopt(name = "metriful-exporter")]
+struct Options {
+  /// system i2c device, e.g. /dev/i2c-1
+  #[structopt(
+    long, short,
+    parse(from_os_str),
+    default_value = "/dev/i2c-1",
+    global = true,
+    env = "METRIFUL_I2C_DEVICE"
+  )]
+  device: PathBuf,
+
+  /// Metriful device i2c address; usually 0x71, or 0x71 if the solder bridge is
+  /// closed. Can specify a plain base-10 int or hex with a `0x` prefix.
+  #[structopt(
+    long,
+    parse(try_from_str = try_from_hex_arg),
+    default_value = "0x71",
+    global = true,
+    env = "METRIFUL_I2C_ADDRESS"
+  )]
+  i2c_address: u16,
+
+  /// GPIO number for the ready signal. Note that this is a GPIO number, not a
+  /// physical pin number - the mapping between the two numbers varies by
+  /// device.
+  #[structopt(
+    long,
+    default_value = "11",
+    env = "METRIFUL_GPIO_READY",
+    global = true
+  )]
+  gpio_ready: u64,
+
+  /// Global timeout for any individual sensor command in seconds.
+  #[structopt(
+    long,
+    parse(try_from_str = parse_duration_secs),
+    global = true,
+    env = "METRIFUL_TIMEOUT"
+  )]
+  timeout: Option<Duration>,
+
+  /// Cycle period, one of: 0 (3s), 1 (100s), 2 (300s)
+  #[structopt(long, short, default_value = "3s", env = "METRIFUL_INTERVAL")]
+  interval: CyclePeriod,
+
+  /// HTTP server port
+  #[structopt(long, short, default_value = "8083", env = "METRIFUL_PORT")]
+  port: u16,
+}
+
+fn export_reading(
+  exporter: &Exporter,
+  reading: &Reading,
+  error_count: &Arc<AtomicUsize>,
+  fatal_error_count: &Arc<AtomicUsize>
+) -> String {
+  let mut s = exporter.session();
+
+  match reading {
+    Some(r) => {
+      // TODO
+      //export!(s, "metriful_temperature", r.temperature.value, unit = "c");
+    },
+    None => ()
+  };
+
+  export!(s, "metriful_error_count", error_count.load(Ordering::Relaxed) as f64);
+  export!(s, "metriful_fatal_error_count", fatal_error_count.load(Ordering::Relaxed) as f64);
+
+  s.to_string()
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+  color_eyre::install()?;
+
   let env = env_logger::Env::default()
     .filter_or("METRIFUL_LOG", "info")
     .write_style_or("METRIFUL_STYLE", "always");
@@ -7,4 +114,38 @@ fn main() {
     .target(env_logger::Target::Stderr)
     .init();
 
+  let opts = Options::from_args();
+  let port = opts.port;
+
+  let latest_reading_lock = Arc::new(RwLock::new(None));
+  let error_count = Arc::new(AtomicUsize::new(0));
+  let fatal_error_count = Arc::new(AtomicUsize::new(0));
+
+  let json_lock = Arc::clone(&latest_reading_lock);
+  let r_json = warp::path("json").map(move || {
+    match *json_lock.read().unwrap() {
+      Some(ref r) => warp::reply::json()),
+      None => warp::reply::json(&json!(null))
+    }
+  });
+
+  let exporter = Arc::new(Exporter::new());
+  let metrics_lock = Arc::clone(&latest_reading_lock);
+  let metrics_error_count = Arc::clone(&error_count);
+  let metrics_fatal_error_count = Arc::clone(&fatal_error_count);
+  let r_metrics = warp::path("metrics").map(move || {
+    export_reading(
+      &exporter,
+      &*metrics_lock.read().unwrap(),
+      &metrics_error_count,
+      &metrics_fatal_error_count
+    )
+  });
+
+  info!("starting exporter on port {}", port);
+
+  let routes = warp::get().and(r_json).or(r_metrics);
+  warp::serve(routes).run(([0, 0, 0, 0], port)).await;
+
+  Ok(())
 }