Addressing comments

src/cli/install.rs

@@ -22,7 +22,7 @@ use crate::{
     container,
 };
 
-/// Install FastFreeze, mostly to setup virtualization
+/// Install FastFreeze, required when namespaces are not available (e.g., Docker).
 #[derive(StructOpt, PartialEq, Debug, Serialize)]
 pub struct Install {
     /// Verbosity. Can be repeated
@@ -37,7 +37,7 @@ pub struct Install {
 
 pub fn is_ff_installed() -> Result<bool> {
     Ok(match LD_SYSTEM_PATH.read_link() {
-        Ok(path) => path.to_string_lossy().contains("virtcpuid"),
+        Ok(path) => path.eq(&*LD_VIRTCPUID_PATH),
         // EINVAL means the file is not a symlink.
         Err(e) if e.kind() == ErrorKind::InvalidInput => false,
         Err(e) => Err(e).with_context(||

src/cli/main.rs

@@ -35,7 +35,7 @@ use super::{
     // subcommand version is not useful, disable it.
     global_setting(AppSettings::VersionlessSubcommands),
 )]
-#[structopt(after_help("    restore-only is achived by using \
+#[structopt(after_help("    restore-only is achieved by using \
 the `run` subcommand without passing the application command-line arguments"
 ))]
 pub struct Opts {

src/cli/mod.rs

@@ -13,11 +13,11 @@
 //  limitations under the License.
 
 pub mod run;
-pub mod checkpoint;
-pub mod extract;
-pub mod wait;
+mod checkpoint;
+mod extract;
+mod wait;
 pub mod install;
-pub mod main;
+mod main;
 
 use crate::consts::*;
 

src/cli/run.rs

@@ -85,10 +85,8 @@ pub struct Run {
 
     /// Application command, used when running the app from scratch.
     /// When absent, FastFreeze runs in restore-only mode.
-    // Note: Type should be OsString, but structopt doesn't like it
-    // Also, we wish to pass min_values=1, but it's not working.
     #[structopt()]
-    app_args: Vec<String>,
+    app_args: Vec<OsString>,
 
     /// Shell command to run once the application is running.
     // Note: Type should be OsString, but structopt doesn't like it
@@ -444,7 +442,7 @@ fn ensure_non_conflicting_pid() -> Result<()> {
 
 fn do_run(
     image_url: ImageUrl,
-    app_args: Option<Vec<String>>,
+    app_args: Option<Vec<OsString>>,
     preserved_paths: HashSet<PathBuf>,
     passphrase_file: Option<PathBuf>,
     no_restore: bool,
@@ -507,28 +505,31 @@ fn do_run(
     Ok(())
 }
 
-fn default_image_name(app_args: &[String]) -> String {
+fn default_image_name(app_args: &[OsString]) -> Result<String> {
     use std::collections::hash_map::DefaultHasher;
     use std::hash::{Hash, Hasher};
 
-    fn program_name(cmd: &str) -> String {
-        // unwrap() is fine, we'll error earlier if cmd is empty.
-        cmd.split('/').last().unwrap().to_string()
+    fn program_name(cmd: &OsString) -> Result<String> {
+        Ok(Path::new(cmd)
+            .file_name().ok_or_else(||
+                anyhow!("Failed to determine program name from command name. \
+                         Please use `--image-url` to specify the image URL"))?
+            .to_string_lossy().into_owned())
     }
 
-    match app_args {
+    Ok(match app_args {
         [] => unreachable!(),
-        [app_name] => program_name(app_name),
+        [app_name] => program_name(app_name)?,
         _ =>  {
             let hash = {
                 let mut hasher = DefaultHasher::new();
                 app_args.hash(&mut hasher);
                 hasher.finish()
             };
 
-            format!("{}-{:04x}", program_name(&app_args[0]), hash & 0xFFFF)
+            format!("{}-{:04x}", program_name(&app_args[0])?, hash & 0xFFFF)
         }
-    }
+    })
 }
 
 impl super::CLI for Run {
@@ -554,7 +555,7 @@ impl super::CLI for Run {
                 (None, None) =>
                     bail!("--image-url is necessary when running in restore-only mode"),
                 (None, Some(app_args)) => {
-                    let image_path = DEFAULT_IMAGE_DIR.join(default_image_name(app_args));
+                    let image_path = DEFAULT_IMAGE_DIR.join(default_image_name(app_args)?);
                     let image_url = format!("file:{}", image_path.display());
                     info!("image-url is {}", image_url);
                     image_url