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-rw-r--r--src/dns_config.rs234
1 files changed, 172 insertions, 62 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 ----
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-19 16:58:41 +0000