install: Drop support for old skopeo

Let's just hard require a skopeo that can fetch from `containers-storage`.
Motivated by containers#263 which
was moving this code around.

Signed-off-by: Colin Walters <walters@verbum.org>

lib/src/install.rs

@@ -232,8 +232,6 @@ pub(crate) struct State {
     pub(crate) source: SourceInfo,
     /// Force SELinux off in target system
     pub(crate) override_disable_selinux: bool,
-    /// True if the skoepo on host supports containers-storage:
-    pub(crate) skopeo_supports_containers_storage: bool,
     #[allow(dead_code)]
     pub(crate) setenforce_guard: Option<crate::lsm::SetEnforceGuard>,
     #[allow(dead_code)]
@@ -569,21 +567,14 @@ async fn initialize_ostree_root_from_self(
         ..Default::default()
     };
 
-    let mut temporary_dir = None;
-    let src_imageref = if state.skopeo_supports_containers_storage {
+    let src_imageref = {
         // We always use exactly the digest of the running image to ensure predictability.
         let spec =
             crate::utils::digested_pullspec(&state.source.imageref.name, &state.source.digest);
         ostree_container::ImageReference {
             transport: ostree_container::Transport::ContainerStorage,
             name: spec,
         }
-    } else {
-        let td = tempfile::tempdir_in("/var/tmp")?;
-        let path: &Utf8Path = td.path().try_into().unwrap();
-        let r = copy_to_oci(&state.source.imageref, path)?;
-        temporary_dir = Some(td);
-        r
     };
     let src_imageref = ostree_container::OstreeImageReference {
         // There are no signatures to verify since we're fetching the already
@@ -610,8 +601,6 @@ async fn initialize_ostree_root_from_self(
     println!("Installed: {target_image}");
     println!("   Digest: {digest}");
 
-    drop(temporary_dir);
-
     // Write the entry for /boot to /etc/fstab.  TODO: Encourage OSes to use the karg?
     // Or better bind this with the grub data.
     sysroot.load(cancellable)?;
@@ -656,32 +645,6 @@ async fn initialize_ostree_root_from_self(
     Ok(aleph)
 }
 
-#[context("Copying to oci")]
-fn copy_to_oci(
-    src_imageref: &ostree_container::ImageReference,
-    dir: &Utf8Path,
-) -> Result<ostree_container::ImageReference> {
-    tracing::debug!("Copying {src_imageref}");
-    let src_imageref = src_imageref.to_string();
-    let dest_imageref = ostree_container::ImageReference {
-        transport: ostree_container::Transport::OciDir,
-        name: dir.to_string(),
-    };
-    let dest_imageref_str = dest_imageref.to_string();
-    Task::new_cmd(
-        "Copying to temporary OCI (skopeo is too old)",
-        run_in_host_mountns("skopeo"),
-    )
-    .args([
-        "copy",
-        // TODO: enable this once ostree is fixed "--dest-oci-accept-uncompressed-layers",
-        src_imageref.as_str(),
-        dest_imageref_str.as_str(),
-    ])
-    .run()?;
-    Ok(dest_imageref)
-}
-
 /// Run a command in the host mount namespace
 pub(crate) fn run_in_host_mountns(cmd: &str) -> Command {
     let mut c = Command::new("/proc/self/exe");
@@ -927,6 +890,9 @@ async fn prepare_install(
 
     let skopeo_supports_containers_storage = skopeo_supports_containers_storage()
         .context("Failed to run skopeo (it currently must be installed in the host root)")?;
+    if !skopeo_supports_containers_storage {
+        anyhow::bail!("skopeo is too old");
+    }
 
     let source = SourceInfo::from_container(&container_info)?;
 
@@ -982,7 +948,6 @@ async fn prepare_install(
     // combines our command line options along with some bind mounts from the host.
     let state = Arc::new(State {
         override_disable_selinux,
-        skopeo_supports_containers_storage,
         setenforce_guard,
         source,
         config_opts,