feat(relay): Provide a flag to exit container on healthcheck failure

CHANGELOG.md

@@ -15,6 +15,7 @@
 
 - Set `sentry.segment.id` and `sentry.segment.name` attributes on OTLP segment spans. ([#5748](https://github.com/getsentry/relay/pull/5748))
 - Envelope buffer: Add option to disable flush-to-disk on shutdown. ([#5751](https://github.com/getsentry/relay/pull/5751))
+- Healthcheck: Provide a flag to exit container on healthcheck failure. ([#5754](https://github.com/getsentry/relay/pull/5754))
 
 **Internal**:
 

Cargo.lock

@@ -4168,6 +4168,7 @@ dependencies = [
  "hostname 0.4.1",
  "http",
  "mimalloc",
+ "nix",
  "relay-config",
  "relay-kafka",
  "relay-log",

relay/Cargo.toml

@@ -32,4 +32,5 @@ relay-statsd = { workspace = true }
 relay-kafka = { workspace = true, optional = true }
 uuid = { workspace = true }
 reqwest = { workspace = true, features = ["gzip", "native-tls-vendored"] }
+nix = { version = "0.29.0", features = ["signal"] }
 mimalloc = { workspace = true, features = ["v3", "override", "debug_in_debug"] }

relay/src/cliapp.rs

@@ -344,5 +344,12 @@ pub fn make_app() -> Command {
                         .value_parser(clap::value_parser!(SocketAddr))
                         .required(false),
                 )
+                .arg(
+                    Arg::new("kill-on-fail")
+                        .long("kill-on-fail")
+                        .action(ArgAction::SetTrue)
+                        .help("Send SIGTERM to PID 1 if the healthcheck fails.")
+                        .required(false),
+                )
         )
 }

relay/src/healthcheck.rs

@@ -6,6 +6,9 @@ use clap::ArgMatches;
 use relay_config::Config;
 use reqwest::blocking::Client;
 
+use nix::sys::signal::{self, Signal};
+use nix::unistd::Pid;
+
 pub fn healthcheck(config: &Config, matches: &ArgMatches) -> Result<()> {
     let mode = matches
         .get_one::<String>("mode")
@@ -30,12 +33,20 @@ pub fn healthcheck(config: &Config, matches: &ArgMatches) -> Result<()> {
         .get(format!("http://{addr}/api/relay/healthcheck/{mode}/"))
         .send();
 
+    let kill_on_fail = matches.get_flag("kill-on-fail");
+
     match response {
         Ok(response) => {
             if response.status().is_success() {
                 Ok(())
             } else {
                 relay_log::error!("Relay is unhealthy. Status code: {}", response.status());
+                if kill_on_fail {
+                    relay_log::error!("Sending SIGTERM to PID 1 to exit container.");
+                    if let Err(err) = signal::kill(Pid::from_raw(1), Signal::SIGTERM) {
+                        relay_log::error!("Failed to send SIGTERM to PID 1: {err}");
+                    }
+                }
                 Err(format_err!(
                     "Relay is unhealthy. Status code: {}",
                     response.status()
@@ -44,6 +55,12 @@ pub fn healthcheck(config: &Config, matches: &ArgMatches) -> Result<()> {
         }
         Err(err) => {
             relay_log::error!("Relay is unhealthy. Error: {err}");
+            if kill_on_fail {
+                relay_log::error!("Sending SIGTERM to PID 1 to exit container.");
+                if let Err(err) = signal::kill(Pid::from_raw(1), Signal::SIGTERM) {
+                    relay_log::error!("Failed to send SIGTERM to PID 1: {err}");
+                }
+            }
             Err(err.into())
         }
     }