system-config-api: add syslog feature

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

proxmox-system-config-api/Cargo.toml

@@ -18,6 +18,7 @@ serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 nix = { workspace = true, optional = true }
 libc = { workspace = true, optional = true }
+log = { workspace = true, optional = true }
 
 proxmox-sys = { workspace = true, optional = true }
 proxmox-schema = { workspace = true, features = ["api-macro", "api-types"] }
@@ -51,3 +52,8 @@ network-impl = [
     "dep:libc",
     "dep:proxmox-sys",
 ]
+syslog = []
+syslog-impl = [
+    "syslog",
+    "dep:log",
+]

proxmox-system-config-api/src/lib.rs

@@ -6,3 +6,6 @@ pub mod network;
 
 #[cfg(feature = "time")]
 pub mod time;
+
+#[cfg(feature = "syslog")]
+pub mod syslog;

proxmox-system-config-api/src/syslog/api_types.rs

@@ -0,0 +1,58 @@
+use serde::{Deserialize, Serialize};
+
+use proxmox_schema::api;
+use proxmox_schema::api_types::SYSTEMD_DATETIME_FORMAT;
+
+#[api(
+    properties: {
+        start: {
+            type: Integer,
+            description: "Start line number.",
+            minimum: 0,
+            optional: true,
+        },
+        limit: {
+            type: Integer,
+            description: "Max. number of lines.",
+            optional: true,
+            minimum: 0,
+        },
+        since: {
+            type: String,
+            optional: true,
+            description: "Display all log since this date-time string.",
+	        format: &SYSTEMD_DATETIME_FORMAT,
+        },
+        until: {
+            type: String,
+            optional: true,
+            description: "Display all log until this date-time string.",
+	        format: &SYSTEMD_DATETIME_FORMAT,
+        },
+        service: {
+            type: String,
+            optional: true,
+            description: "Service ID.",
+            max_length: 128,
+        },
+    },
+)]
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+/// Syslog filtering options.
+pub struct SyslogFilter {
+    pub start: Option<u64>,
+    pub limit: Option<u64>,
+    pub since: Option<String>,
+    pub until: Option<String>,
+    pub service: Option<String>,
+}
+
+#[api]
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+/// Syslog line with line number.
+pub struct SyslogLine {
+    /// Line number.
+    pub n: u64,
+    /// Line text.
+    pub t: String,
+}

proxmox-system-config-api/src/syslog/journal.rs

@@ -0,0 +1,73 @@
+use std::process::{Command, Stdio};
+
+use anyhow::Error;
+
+use super::{SyslogFilter, SyslogLine};
+
+pub fn dump_journal(filter: SyslogFilter) -> Result<(u64, Vec<SyslogLine>), Error> {
+    let mut args = vec!["-o", "short", "--no-pager"];
+
+    if let Some(service) = &filter.service {
+        args.extend(["--unit", service]);
+    }
+    if let Some(since) = &filter.since {
+        args.extend(["--since", since]);
+    }
+    if let Some(until) = &filter.until {
+        args.extend(["--until", until]);
+    }
+
+    let mut lines: Vec<SyslogLine> = Vec::new();
+    let mut limit = filter.limit.unwrap_or(50);
+    let start = filter.start.unwrap_or(0);
+    let mut count: u64 = 0;
+
+    let mut child = Command::new("journalctl")
+        .args(&args)
+        .stdout(Stdio::piped())
+        .spawn()?;
+
+    use std::io::{BufRead, BufReader};
+
+    if let Some(ref mut stdout) = child.stdout {
+        for line in BufReader::new(stdout).lines() {
+            match line {
+                Ok(line) => {
+                    count += 1;
+                    if count < start {
+                        continue;
+                    };
+                    if limit == 0 {
+                        continue;
+                    };
+
+                    lines.push(SyslogLine { n: count, t: line });
+
+                    limit -= 1;
+                }
+                Err(err) => {
+                    log::error!("reading journal failed: {}", err);
+                    let _ = child.kill();
+                    break;
+                }
+            }
+        }
+    }
+
+    let status = child.wait().unwrap();
+    if !status.success() {
+        log::error!("journalctl failed with {}", status);
+    }
+
+    // HACK: ExtJS store.guaranteeRange() does not like empty array
+    // so we add a line
+    if count == 0 {
+        count += 1;
+        lines.push(SyslogLine {
+            n: count,
+            t: String::from("no content"),
+        });
+    }
+
+    Ok((count, lines))
+}

proxmox-system-config-api/src/syslog/mod.rs

@@ -0,0 +1,8 @@
+mod api_types;
+pub use api_types::*;
+
+
+#[cfg(feature = "syslog-impl")]
+mod journal;
+#[cfg(feature = "syslog-impl")]
+pub use journal::dump_journal;