node: Increase process ulimit on start

Users have been having issues with the process soft file limit.
We set that to a reasonably high value to avoid problems.

Cargo.lock

@@ -2361,6 +2361,7 @@ dependencies = [
  "cyphernet",
  "fastrand",
  "git2",
+ "libc",
  "localtime",
  "log",
  "multibase",

radicle-cli/examples/rad-config.md

@@ -25,6 +25,7 @@ $ rad config
       "routingMaxAge": 604800,
       "gossipMaxAge": 1209600,
       "fetchConcurrency": 1,
+      "maxOpenFiles": 4096,
       "rate": {
         "inbound": {
           "fillRate": 0.2,

radicle-httpd/src/api/v1/profile.rs

@@ -94,6 +94,7 @@ mod routes {
                     "routingMaxAge": 604800,
                     "gossipMaxAge": 1209600,
                     "fetchConcurrency": 1,
+                    "maxOpenFiles": 4096,
                     "rate": {
                       "inbound": {
                         "fillRate": 0.2,

radicle-node/src/main.rs

@@ -108,6 +108,10 @@ fn execute() -> anyhow::Result<()> {
         config.listen.clone()
     };
 
+    if let Err(e) = radicle::io::set_file_limit(config.limits.max_open_files as u64) {
+        log::warn!(target: "node", "Unable to set process open file limit: {e}");
+    }
+
     let (notify, signals) = chan::bounded(1);
     signals::install(notify)?;
 

radicle/Cargo.toml

@@ -21,6 +21,7 @@ cyphernet = { version = "0.4.1", features = ["tor", "dns", "p2p-ed25519"] }
 fastrand = { version = "2.0.0" }
 multibase = { version = "0.9.1" }
 localtime = { version = "1.2.0", features = ["serde"] }
+libc = { version = "0.2" }
 log = { version = "0.4.17", features = ["std"] }
 nonempty = { version = "0.8.1", features = ["serialize"] }
 once_cell = { version = "1.13" }

radicle/src/io.rs

@@ -0,0 +1,25 @@
+use std::io;
+
+use libc::{getrlimit, rlimit, setrlimit, RLIMIT_NOFILE};
+
+/// Sets the open file limit to the given value, or the maximum allowed value.
+pub fn set_file_limit(n: u64) -> io::Result<u64> {
+    let mut rlim = rlimit {
+        rlim_cur: 0, // Initial soft limit value
+        rlim_max: 0, // Initial hard limit value
+    };
+    // Get the current limits.
+    unsafe {
+        if getrlimit(RLIMIT_NOFILE, &mut rlim) != 0 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+    // Set the soft limit to the given value, up to the hard limit.
+    rlim.rlim_cur = n.min(rlim.rlim_max);
+    unsafe {
+        if setrlimit(RLIMIT_NOFILE, &rlim as *const rlimit) != 0 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+    Ok(rlim.rlim_cur)
+}

radicle/src/lib.rs

@@ -16,6 +16,7 @@ pub mod collections;
 pub mod explorer;
 pub mod git;
 pub mod identity;
+pub mod io;
 #[cfg(feature = "logger")]
 pub mod logger;
 pub mod node;

radicle/src/node/config.rs

@@ -80,6 +80,8 @@ pub struct Limits {
     pub gossip_max_age: LocalDuration,
     /// Maximum number of concurrent fetches per per connection.
     pub fetch_concurrency: usize,
+    /// Maximum number of open files.
+    pub max_open_files: usize,
     /// Rate limitter settings.
     #[serde(default)]
     pub rate: RateLimits,
@@ -92,6 +94,7 @@ impl Default for Limits {
             routing_max_age: LocalDuration::from_mins(7 * 24 * 60), // One week
             gossip_max_age: LocalDuration::from_mins(2 * 7 * 24 * 60), // Two weeks
             fetch_concurrency: 1,
+            max_open_files: 4096,
             rate: RateLimits::default(),
         }
     }