Check if qemu-img is present before startup

virtweb_backend/src/constants.rs

@@ -108,3 +108,6 @@ pub const API_TOKEN_DESCRIPTION_MAX_LENGTH: usize = 30;
 
 /// API token right path max length
 pub const API_TOKEN_RIGHT_PATH_MAX_LENGTH: usize = 255;
+
+/// Qemu image program path
+pub const QEMU_IMAGE_PROGRAM: &str = "/usr/bin/qemu-img";

virtweb_backend/src/main.rs

@@ -28,7 +28,7 @@ use virtweb_backend::controllers::{
 use virtweb_backend::libvirt_client::LibVirtClient;
 use virtweb_backend::middlewares::auth_middleware::AuthChecker;
 use virtweb_backend::nat::nat_conf_mode;
-use virtweb_backend::utils::files_utils;
+use virtweb_backend::utils::{exec_utils, files_utils};
 
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
@@ -43,6 +43,12 @@ async fn main() -> std::io::Result<()> {
     // Load additional config from file, if requested
     AppConfig::parse_env_file().unwrap();
 
+    log::debug!("Checking for required programs");
+    exec_utils::check_program(
+        constants::QEMU_IMAGE_PROGRAM,
+        "QEMU disk image utility is required to manipulate QCow2 files!",
+    );
+
     log::debug!("Create required directory, if missing");
     files_utils::create_directory_if_missing(AppConfig::get().iso_storage_path()).unwrap();
     files_utils::create_directory_if_missing(AppConfig::get().vnc_sockets_path()).unwrap();

virtweb_backend/src/utils/exec_utils.rs

@@ -0,0 +1,10 @@
+use std::path::Path;
+
+/// Check the existence of a required program
+pub fn check_program(name: &str, description: &str) {
+    let path = Path::new(name);
+
+    if !path.exists() {
+        panic!("{name} does not exist! {description}");
+    }
+}

virtweb_backend/src/utils/file_disks_utils.rs

@@ -155,7 +155,7 @@ impl FileDisk {
             }
 
             DiskFormat::QCow2 => {
-                let mut cmd = Command::new("/usr/bin/qemu-img");
+                let mut cmd = Command::new(constants::QEMU_IMAGE_PROGRAM);
                 cmd.arg("create")
                     .arg("-f")
                     .arg("qcow2")
@@ -189,12 +189,13 @@ struct QCowInfoOutput {
 /// Get QCow2 virtual size
 fn qcow_virt_size(path: &str) -> anyhow::Result<usize> {
     // Run qemu-img
-    let mut cmd = Command::new("qemu-img");
+    let mut cmd = Command::new(constants::QEMU_IMAGE_PROGRAM);
     cmd.args(["info", path, "--output", "json", "--force-share"]);
     let output = cmd.output()?;
     if !output.status.success() {
         anyhow::bail!(
-            "qemu-img info failed, status: {}, stderr: {}",
+            "{} info failed, status: {}, stderr: {}",
+            constants::QEMU_IMAGE_PROGRAM,
             output.status,
             String::from_utf8_lossy(&output.stderr)
         );

virtweb_backend/src/utils/mod.rs

@@ -1,3 +1,4 @@
+pub mod exec_utils;
 pub mod file_disks_utils;
 pub mod files_utils;
 pub mod net_utils;