diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/dns_config.rs | 234 | ||||
| -rw-r--r-- | src/main.rs | 2 |
2 files changed, 173 insertions, 63 deletions
diff --git a/src/dns_config.rs b/src/dns_config.rs index f4a95be..9eb6075 100644 --- a/src/dns_config.rs +++ b/src/dns_config.rs @@ -1,17 +1,21 @@ use std::collections::{HashMap, HashSet}; use std::fmt; +use std::net::{Ipv4Addr, Ipv6Addr}; use std::sync::Arc; -use std::time::Duration; +use std::time::{Duration, SystemTime}; +use anyhow::Result; +use serde::{Deserialize, Serialize}; use tokio::{select, sync::watch}; use tracing::*; use df_consul::*; -const IPV4_TARGET_METADATA_TAG: &str = "public_ipv4"; -const IPV6_TARGET_METADATA_TAG: &str = "public_ipv6"; +const IP_TARGET_METADATA_TAG_PREFIX: &str = "public_"; const CNAME_TARGET_METADATA_TAG: &str = "cname_target"; +const AUTODISCOVERY_CACHE_DURATION: u64 = 600; // 10 minutes + // ---- Extract DNS config from Consul catalog ---- #[derive(Debug, Eq, PartialEq, Default)] @@ -54,86 +58,192 @@ impl DnsConfig { } } -fn parse_d53_tag(tag: &str, node: &catalog::Node) -> Option<(DnsEntryKey, DnsEntryValue)> { - let splits = tag.split(' ').collect::<Vec<_>>(); - if splits.len() != 2 { - return None; - } +// ---- fetcher and autodiscovery cache ---- - let (record_type, targets) = match splits[0] { - "d53-a" => match node.meta.get(IPV4_TARGET_METADATA_TAG) { - Some(tgt) => (DnsRecordType::A, [tgt.to_string()].into_iter().collect()), - None => { - warn!("Got d53-a tag `{}` but node {} does not have a {} metadata value. Tag is ignored.", tag, node.node, IPV4_TARGET_METADATA_TAG); - return None; - } - }, - "d53-aaaa" => match node.meta.get(IPV6_TARGET_METADATA_TAG) { - Some(tgt) => (DnsRecordType::AAAA, [tgt.to_string()].into_iter().collect()), - None => { - warn!("Got d53-aaaa tag `{}` but node {} does not have a {} metadata value. Tag is ignored.", tag, node.node, IPV6_TARGET_METADATA_TAG); - return None; - } - }, - "d53-cname" => match node.meta.get(CNAME_TARGET_METADATA_TAG) { - Some(tgt) => ( - DnsRecordType::CNAME, - [tgt.to_string()].into_iter().collect(), - ), - None => { - warn!("Got d53-cname tag `{}` but node {} does not have a {} metadata value. Tag is ignored.", tag, node.node, CNAME_TARGET_METADATA_TAG); - return None; - } - }, - _ => return None, +pub fn spawn_dns_config_task( + consul: Consul, + must_exit: watch::Receiver<bool>, +) -> watch::Receiver<Arc<DnsConfig>> { + let (tx, rx) = watch::channel(Arc::new(DnsConfig::new())); + + let fetcher = DnsConfigFetcher { + consul, + node_ipv4_cache: HashMap::new(), + node_ipv6_cache: HashMap::new(), }; - Some(( - DnsEntryKey { - dns_path: splits[1].to_string(), - record_type, - }, - DnsEntryValue { targets }, - )) + tokio::spawn(fetcher.task(tx, must_exit)); + + rx } -pub fn spawn_dns_config_task( - consul: &Consul, - mut must_exit: watch::Receiver<bool>, -) -> watch::Receiver<Arc<DnsConfig>> { - let (tx, rx) = watch::channel(Arc::new(DnsConfig::new())); +struct DnsConfigFetcher { + consul: Consul, + node_ipv4_cache: HashMap<String, (u64, Option<Ipv4Addr>)>, + node_ipv6_cache: HashMap<String, (u64, Option<Ipv6Addr>)>, +} - let mut catalog_rx = consul.watch_all_service_health(Duration::from_secs(60)); +impl DnsConfigFetcher { + async fn task( + mut self, + tx: watch::Sender<Arc<DnsConfig>>, + mut must_exit: watch::Receiver<bool>, + ) { + let mut catalog_rx = self + .consul + .watch_all_service_health(Duration::from_secs(60)); - tokio::spawn(async move { while !*must_exit.borrow() { select! { _ = catalog_rx.changed() => (), _ = must_exit.changed() => continue, }; - let services = catalog_rx.borrow_and_update(); + let services = catalog_rx.borrow_and_update().clone(); + match self.parse_catalog(&services).await { + Ok(dns_config) => tx.send(Arc::new(dns_config)).expect("Internal error"), + Err(e) => { + error!("Error when parsing tags: {}", e); + } + }; + } + } - let mut dns_config = DnsConfig::new(); - for (_svc, nodes) in services.iter() { - for node in nodes.iter() { - // Do not take into account backends if any have status critical - if node.checks.iter().any(|x| x.status == "critical") { - continue; + async fn parse_catalog(&mut self, services: &catalog::AllServiceHealth) -> Result<DnsConfig> { + let mut dns_config = DnsConfig::new(); + for (_svc, nodes) in services.iter() { + for node in nodes.iter() { + // Do not take into account backends if any have status critical + if node.checks.iter().any(|x| x.status == "critical") { + continue; + } + for tag in node.service.tags.iter() { + if let Some((k, v)) = self.parse_d53_tag(tag, &node.node).await? { + dns_config.add(k, v); } - for tag in node.service.tags.iter() { - if let Some((k, v)) = parse_d53_tag(tag, &node.node) { - dns_config.add(k, v); + } + } + } + + Ok(dns_config) + } + + async fn parse_d53_tag( + &mut self, + tag: &str, + node: &catalog::Node, + ) -> Result<Option<(DnsEntryKey, DnsEntryValue)>> { + let splits = tag.split(' ').collect::<Vec<_>>(); + if splits.len() != 2 { + return Ok(None); + } + + let (record_type, targets) = match splits[0] { + "d53-a" => match self.get_node_ipv4(&node).await? { + Some(tgt) => (DnsRecordType::A, [tgt.to_string()].into_iter().collect()), + None => { + warn!("Got d53-a tag `{}` but node {} does not appear to have a known public IPv4 address. Tag is ignored.", tag, node.node); + return Ok(None); + } + }, + "d53-aaaa" => match self.get_node_ipv6(&node).await? { + Some(tgt) => (DnsRecordType::AAAA, [tgt.to_string()].into_iter().collect()), + None => { + warn!("Got d53-aaaa tag `{}` but node {} does not appear to have a known public IPv6 address. Tag is ignored.", tag, node.node); + return Ok(None); + } + }, + "d53-cname" => match node.meta.get(CNAME_TARGET_METADATA_TAG) { + Some(tgt) => ( + DnsRecordType::CNAME, + [tgt.to_string()].into_iter().collect(), + ), + None => { + warn!("Got d53-cname tag `{}` but node {} does not have a {} metadata value. Tag is ignored.", tag, node.node, CNAME_TARGET_METADATA_TAG); + return Ok(None); + } + }, + _ => return Ok(None), + }; + + Ok(Some(( + DnsEntryKey { + dns_path: splits[1].to_string(), + record_type, + }, + DnsEntryValue { targets }, + ))) + } + + async fn get_node_ipv4(&mut self, node: &catalog::Node) -> Result<Option<Ipv4Addr>> { + Self::get_node_ip(&self.consul, "ipv4", &mut self.node_ipv4_cache, node).await + } + + async fn get_node_ipv6(&mut self, node: &catalog::Node) -> Result<Option<Ipv6Addr>> { + Self::get_node_ip(&self.consul, "ipv6", &mut self.node_ipv6_cache, node).await + } + + async fn get_node_ip<A>( + consul: &Consul, + family: &str, + cache: &mut HashMap<String, (u64, Option<A>)>, + node: &catalog::Node, + ) -> Result<Option<A>> + where + A: Serialize + for<'de> Deserialize<'de> + std::fmt::Debug + std::str::FromStr + Copy + Eq, + <A as std::str::FromStr>::Err: Send + Sync + std::error::Error + 'static, + { + match cache.get(&node.node) { + Some((t, a)) if timestamp() <= t + AUTODISCOVERY_CACHE_DURATION => Ok(*a), + _ => { + let kv_key = format!("diplonat/autodiscovery/{}/{}", family, node.node); + let autodiscovery = consul.kv_get(&kv_key).await?; + + if let Some(json) = autodiscovery { + let a = serde_json::from_slice::<DiplonatAutodiscoveryResult<A>>(&json)?; + if timestamp() <= a.timestamp + AUTODISCOVERY_CACHE_DURATION { + if cache.get(&node.node).map(|x| x.1) != Some(a.address) { + info!( + "Got {} address for {} from diplonat autodiscovery: {:?}", + family, node.node, a.address + ); } + cache.insert(node.node.clone(), (a.timestamp, a.address)); + return Ok(a.address); + } else { + warn!("{} address for {} from diplonat autodiscovery is outdated (value: {:?}), falling back on value from Consul node meta", family, node.node, a.address); } } - } - tx.send(Arc::new(dns_config)).expect("Internal error"); + let meta_tag = format!("{}{}", IP_TARGET_METADATA_TAG_PREFIX, family); + let a = node.meta.get(&meta_tag).map(|x| x.parse()).transpose()?; + + if cache.get(&node.node).map(|x| x.1) != Some(a) { + info!( + "Got {} address for {} from Consul node meta: {:?}", + family, node.node, a + ); + } + cache.insert(node.node.clone(), (timestamp(), a)); + Ok(a) + } } - }); + } +} - rx +// ---- util for interaction with diplonat ---- + +#[derive(Serialize, Deserialize, Debug)] +pub struct DiplonatAutodiscoveryResult<A> { + pub timestamp: u64, + pub address: Option<A>, +} + +fn timestamp() -> u64 { + SystemTime::now() + .duration_since(SystemTime::UNIX_EPOCH) + .expect("clock error") + .as_secs() } // ---- Display impls ---- diff --git a/src/main.rs b/src/main.rs index 1a41c18..a8a6b36 100644 --- a/src/main.rs +++ b/src/main.rs @@ -111,7 +111,7 @@ async fn main() { .map(ToString::to_string) .collect::<Vec<_>>(); - let rx_dns_config = dns_config::spawn_dns_config_task(&consul, exit_signal.clone()); + let rx_dns_config = dns_config::spawn_dns_config_task(consul, exit_signal.clone()); let updater_task = tokio::spawn(dns_updater::dns_updater_task( rx_dns_config.clone(), |