feat: precondition checks as a feature (#322)

* feat: preconditions check of disk space

* Merge branch 'main' into preconditions

* fix: use the right term

* fix: merge

uplink/src/collector/mod.rs

@@ -5,6 +5,7 @@ pub mod installer;
 pub mod journalctl;
 #[cfg(target_os = "android")]
 pub mod logcat;
+pub mod preconditions;
 pub mod process;
 pub mod script_runner;
 pub mod simulator;

uplink/src/collector/preconditions.rs

@@ -0,0 +1,84 @@
+use std::{fs::metadata, os::unix::fs::MetadataExt, sync::Arc};
+
+use flume::Receiver;
+use human_bytes::human_bytes;
+use log::debug;
+use serde::Deserialize;
+
+use crate::{base::bridge::BridgeTx, Action, ActionResponse, Config};
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("File io Error: {0}")]
+    Io(#[from] std::io::Error),
+    #[error("Disk space is insufficient: {0}")]
+    InsufficientDisk(String),
+}
+
+#[derive(Deserialize, Clone, PartialEq, Eq, Debug)]
+pub struct Preconditions {
+    #[serde(alias = "content-length")]
+    content_length: usize,
+    #[serde(alias = "uncompressed-size")]
+    uncompressed_length: usize,
+}
+
+pub struct PreconditionChecker {
+    config: Arc<Config>,
+    actions_rx: Receiver<Action>,
+    bridge_tx: BridgeTx,
+}
+
+impl PreconditionChecker {
+    pub fn new(config: Arc<Config>, actions_rx: Receiver<Action>, bridge_tx: BridgeTx) -> Self {
+        Self { config, actions_rx, bridge_tx }
+    }
+
+    #[tokio::main]
+    pub async fn start(self) {
+        while let Ok(action) = self.actions_rx.recv() {
+            let preconditions: Preconditions = match serde_json::from_str(&action.payload) {
+                Ok(c) => c,
+                Err(e) => {
+                    let response = ActionResponse::failure(&action.action_id, e.to_string());
+                    self.bridge_tx.send_action_response(response).await;
+                    continue;
+                }
+            };
+
+            if let Err(e) = self.check_disk_size(preconditions) {
+                let response = ActionResponse::failure(&action.action_id, e.to_string());
+                self.bridge_tx.send_action_response(response).await;
+                continue;
+            }
+
+            let response = ActionResponse::progress(&action.action_id, "Checked OK", 100);
+            self.bridge_tx.send_action_response(response).await;
+        }
+    }
+
+    // Fails if there isn't enough space to download and/or install update
+    // NOTE: both download and installation could happen in the same partition
+    fn check_disk_size(&self, preconditions: Preconditions) -> Result<(), Error> {
+        let disk_free_space =
+            fs2::free_space(&self.config.precondition_checks.as_ref().unwrap().path)? as usize;
+        let mut required_free_space = preconditions.uncompressed_length;
+
+        // Check if download and installation paths are on the same partition, if yes add download file size to required
+        if metadata(&self.config.downloader.path)?.dev()
+            == metadata(&self.config.precondition_checks.as_ref().unwrap().path)?.dev()
+        {
+            required_free_space += preconditions.content_length;
+        }
+
+        let req_size = human_bytes(required_free_space as f64);
+        let free_size = human_bytes(disk_free_space as f64);
+        debug!("The installation requires {req_size}; Disk free space is {free_size}");
+
+        if required_free_space > disk_free_space {
+            return Err(Error::InsufficientDisk(free_size));
+        }
+
+        Ok(())
+    }
+}

uplink/src/config.rs

@@ -233,6 +233,12 @@ impl Default for DeviceShadowConfig {
     }
 }
 
+#[derive(Debug, Clone, Deserialize)]
+pub struct PreconditionCheckerConfig {
+    pub path: PathBuf,
+    pub actions: Vec<ActionRoute>,
+}
+
 #[derive(Debug, Clone, Deserialize, Default)]
 pub struct Config {
     pub project_id: String,
@@ -274,4 +280,5 @@ pub struct Config {
     pub logging: Option<JournalCtlConfig>,
     #[cfg(target_os = "android")]
     pub logging: Option<LogcatConfig>,
+    pub precondition_checks: Option<PreconditionCheckerConfig>,
 }

uplink/src/lib.rs

@@ -67,6 +67,7 @@ use collector::installer::OTAInstaller;
 use collector::journalctl::JournalCtl;
 #[cfg(target_os = "android")]
 use collector::logcat::Logcat;
+use collector::preconditions::PreconditionChecker;
 use collector::process::ProcessHandler;
 use collector::script_runner::ScriptRunner;
 use collector::systemstats::StatCollector;
@@ -294,14 +295,20 @@ impl Uplink {
 
         if !self.config.script_runner.is_empty() {
             let actions_rx = bridge.register_action_routes(&self.config.script_runner)?;
-            let script_runner = ScriptRunner::new(actions_rx, bridge_tx);
+            let script_runner = ScriptRunner::new(actions_rx, bridge_tx.clone());
             spawn_named_thread("Script Runner", || {
                 if let Err(e) = script_runner.start() {
                     error!("Script runner stopped!! Error = {:?}", e);
                 }
             });
         }
 
+        if let Some(checker_config) = &self.config.precondition_checks {
+            let actions_rx = bridge.register_action_routes(&checker_config.actions)?;
+            let checker = PreconditionChecker::new(self.config.clone(), actions_rx, bridge_tx);
+            spawn_named_thread("Logger", || checker.start());
+        }
+
         Ok(())
     }