From c9d850287cb8516158cfc7d9d9f9f5a27933e15f Mon Sep 17 00:00:00 2001
From: Navid Yaghoobi <navidys@fedoraproject.org>
Date: Sun, 18 Aug 2024 18:41:30 +1000
Subject: [PATCH] added /proc/<pid>/ns

Signed-off-by: Navid Yaghoobi <navidys@fedoraproject.org>
---
 FEATURES.md            |   1 +
 examples/process_ns.rs |  14 ++++++
 src/lib.rs             |   1 +
 src/process_ns.rs      | 102 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 examples/process_ns.rs
 create mode 100644 src/process_ns.rs

diff --git a/FEATURES.md b/FEATURES.md
index 92ebe21..aa40b10 100644
--- a/FEATURES.md
+++ b/FEATURES.md
@@ -9,6 +9,7 @@ Supported Features
     * io
     * limits
     * root
+    * ns
 
 * ✅ `/proc/buddyinfo`
 
diff --git a/examples/process_ns.rs b/examples/process_ns.rs
new file mode 100644
index 0000000..95eb1e6
--- /dev/null
+++ b/examples/process_ns.rs
@@ -0,0 +1,14 @@
+use procsys::process;
+
+fn main() {
+    let sys_proc = process::collect(2).expect("system proc 2");
+    let sys_proc_ns = sys_proc.namespaces().expect("system proc 2 namespaces");
+
+    match serde_json::to_string_pretty(&sys_proc_ns) {
+        Ok(output) => println!("{}", output),
+        Err(err) => {
+            log::error!("{}", err);
+            std::process::exit(1);
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index fc3cbcc..4d06aa0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,6 +13,7 @@ pub mod process;
 pub mod process_cgroup;
 pub mod process_io;
 pub mod process_limits;
+pub mod process_ns;
 pub mod swaps;
 pub mod sysfs;
 pub mod utils;
diff --git a/src/process_ns.rs b/src/process_ns.rs
new file mode 100644
index 0000000..353dde4
--- /dev/null
+++ b/src/process_ns.rs
@@ -0,0 +1,102 @@
+use std::{collections::HashMap, fs::read_link};
+
+use serde::Serialize;
+
+use crate::{
+    error::{CollectResult, MetricError},
+    process::Process,
+    utils,
+};
+
+/// ProcessNamespace represents a single namespace of a process
+#[derive(Debug, Serialize, Clone, Default)]
+pub struct ProcessNamespace {
+    pub ns_type: String,
+    pub inode: u32,
+}
+
+impl ProcessNamespace {
+    pub fn new() -> Self {
+        Default::default()
+    }
+}
+
+impl Process {
+    /// Namespaces reads from /proc/\<pid\>/ns/* to get the namespaces of which the process is a member
+    pub fn namespaces(&self) -> CollectResult<HashMap<String, ProcessNamespace>> {
+        let mut proc_namespaces: HashMap<String, ProcessNamespace> = HashMap::new();
+
+        let mut proc_ns_path = self.path();
+        proc_ns_path.push("ns");
+
+        for ns_item in utils::list_dir_content(&proc_ns_path, "", "ns") {
+            let mut ns_item_path = proc_ns_path.clone();
+            ns_item_path.push(&ns_item);
+
+            match read_link(&ns_item_path) {
+                Ok(c) => {
+                    let item_fields: Vec<&str> = c
+                        .to_str()
+                        .unwrap_or_default()
+                        .trim()
+                        .split(':')
+                        .filter(|s| !s.is_empty())
+                        .collect();
+
+                    if item_fields.len() != 2 {
+                        return Err(MetricError::InvalidFieldNumberError(
+                            "process ns item".to_string(),
+                            item_fields.len(),
+                            c.to_str().unwrap_or_default().to_string(),
+                        ));
+                    }
+
+                    let mut proc_ns = ProcessNamespace::new();
+                    let proc_ns_inode = item_fields[1].trim().trim_matches('[').trim_matches(']');
+
+                    proc_ns.ns_type = item_fields[0].trim().to_string();
+                    proc_ns.inode = proc_ns_inode.parse::<u32>().unwrap_or_default();
+
+                    proc_namespaces.insert(ns_item, proc_ns);
+                }
+                Err(e) => return Err(MetricError::IOError(ns_item_path, e)),
+            }
+        }
+
+        Ok(proc_namespaces)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::path::Path;
+
+    use crate::process::*;
+
+    #[test]
+    fn proc_ns() {
+        let proc_path = Path::new("test_data/fixtures/proc");
+        let sys_proc = collect_from(proc_path, 26231).expect("running proc 26231");
+        let sys_proc_ns = sys_proc
+            .namespaces()
+            .expect("running proc 26231 namespaces");
+
+        assert_eq!(sys_proc_ns.len(), 2);
+        assert_eq!(sys_proc_ns.contains_key("mnt"), true);
+        assert_eq!(sys_proc_ns.contains_key("net"), true);
+
+        for (key, proc_ns) in &sys_proc_ns {
+            match key.as_str() {
+                "mnt" => {
+                    assert_eq!(proc_ns.ns_type, "mnt");
+                    assert_eq!(proc_ns.inode, 4026531840);
+                }
+                "net" => {
+                    assert_eq!(proc_ns.ns_type, "net");
+                    assert_eq!(proc_ns.inode, 4026531993);
+                }
+                _ => panic!("invalid namespace key: {}", key),
+            }
+        }
+    }
+}