path: root/src/consul.rs

use std::collections::HashMap;

use anyhow::Result;
use bytes::Bytes;
use log::*;
use reqwest::StatusCode;
use serde::{Deserialize, Serialize};

// ---- Watch and retrieve Consul catalog ----

#[derive(Serialize, Deserialize, Debug)]
pub struct ConsulServiceEntry {
	#[serde(rename = "Address")]
	pub address: String,

	#[serde(rename = "Port")]
	pub port: u16,

	#[serde(rename = "Tags")]
	pub tags: Vec<String>,
}

#[derive(Serialize, Deserialize, Debug)]
pub struct ConsulNodeCatalog {
	#[serde(rename = "Services")]
	pub services: HashMap<String, ConsulServiceEntry>,
}

#[derive(Clone)]
pub struct Consul {
	client: reqwest::Client,
	url: String,
	kv_prefix: String,
	idx: Option<u64>,
}

impl Consul {
	pub fn new(url: &str, kv_prefix: &str) -> Self {
		return Self {
			client: reqwest::Client::new(),
			url: url.to_string(),
			kv_prefix: kv_prefix.to_string(),
			idx: None,
		};
	}

	pub fn watch_node_reset(&mut self) -> () {
		self.idx = None;
	}

	pub async fn watch_node(&mut self, host: &str) -> Result<ConsulNodeCatalog> {
		let url = match self.idx {
			Some(i) => format!("{}/v1/catalog/node/{}?index={}", self.url, host, i),
			None => format!("{}/v1/catalog/node/{}", self.url, host),
		};

		let http = self.client.get(&url).send().await?;
		self.idx = match http.headers().get("X-Consul-Index") {
			Some(v) => Some(v.to_str()?.parse::<u64>()?),
			None => return Err(anyhow!("X-Consul-Index header not found")),
		};

		let resp: ConsulNodeCatalog = http.json().await?;
		return Ok(resp);
	}

	pub async fn kv_get(&self, key: &str) -> Result<Option<Bytes>> {
		debug!("kv_get {}", key);

		let url = format!("{}/v1/kv/{}{}?raw", self.url, self.kv_prefix, key);
		let http = self.client.get(&url).send().await?;
		match http.status() {
			StatusCode::OK => Ok(Some(http.bytes().await?)),
			StatusCode::NOT_FOUND => Ok(None),
			_ => Err(anyhow!(
				"Consul request failed: {:?}",
				http.error_for_status()
			)),
		}
	}

	pub async fn kv_get_json<T: for<'de> Deserialize<'de>>(&self, key: &str) -> Result<Option<T>> {
		debug!("kv_get_json {}", key);

		let url = format!("{}/v1/kv/{}{}?raw", self.url, self.kv_prefix, key);
		let http = self.client.get(&url).send().await?;
		match http.status() {
			StatusCode::OK => Ok(Some(http.json().await?)),
			StatusCode::NOT_FOUND => Ok(None),
			_ => Err(anyhow!(
				"Consul request failed: {:?}",
				http.error_for_status()
			)),
		}
	}

	pub async fn kv_put(&self, key: &str, bytes: Bytes) -> Result<()> {
		debug!("kv_put {}", key);

		let url = format!("{}/v1/kv/{}{}", self.url, self.kv_prefix, key);
		let http = self.client.put(&url).body(bytes).send().await?;
		http.error_for_status()?;
		Ok(())
	}

	pub async fn kv_put_json<T: Serialize>(&self, key: &str, value: &T) -> Result<()> {
		debug!("kv_put_json {}", key);

		let url = format!("{}/v1/kv/{}{}", self.url, self.kv_prefix, key);
		let http = self.client.put(&url).json(value).send().await?;
		http.error_for_status()?;
		Ok(())
	}

	pub async fn kv_delete(&self, key: &str) -> Result<()> {
		let url = format!("{}/v1/kv/{}{}", self.url, self.kv_prefix, key);
		let http = self.client.delete(&url).send().await?;
		http.error_for_status()?;
		Ok(())
	}
}