From 7bbb5a592a41377f7af81c950b180c870dbc65e5 Mon Sep 17 00:00:00 2001
From: Shawn Wang <shawn111@gmail.com>
Date: Thu, 9 May 2024 21:56:42 +0800
Subject: [PATCH] Simple solution to handle ImageIndex

---
 ocipkg/src/distribution/client.rs | 23 +++++++++++++++++++++--
 ocipkg/src/image/artifact.rs      | 13 +++++++++++++
 ocipkg/src/media_types.rs         | 11 +++++++++++
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/ocipkg/src/distribution/client.rs b/ocipkg/src/distribution/client.rs
index a2b2f267..9643f5a7 100644
--- a/ocipkg/src/distribution/client.rs
+++ b/ocipkg/src/distribution/client.rs
@@ -1,5 +1,5 @@
-use crate::distribution::*;
-use anyhow::Result;
+use crate::{distribution::*, media_types};
+use anyhow::{bail, Result};
 use oci_spec::{distribution::*, image::*};
 use url::Url;
 
@@ -106,6 +106,25 @@ impl Client {
                 MediaType::ImageManifest,
             ),
         ))?;
+
+        // simple solution to fetch platform manifest from image index
+        if media_types::is_imageindex(res.content_type()) {
+            log::debug!("media_type is imageindex type: {}", &res.content_type());
+            let mi = ImageIndex::from_reader(res.into_reader())?;
+            let m = mi.manifests().iter().find(|m| {
+                m.platform().as_ref().map_or(false, |platform| {
+                    Arch::default().eq(platform.architecture())
+                })
+            });
+            if let Some(m) = m {
+                return self.get_manifest(&Reference::new(m.digest())?);
+            }
+            bail!(
+                "Found ImageIndex but not supported platform: {}",
+                Arch::default()
+            );
+        }
+
         let manifest = ImageManifest::from_reader(res.into_reader())?;
         Ok(manifest)
     }
diff --git a/ocipkg/src/image/artifact.rs b/ocipkg/src/image/artifact.rs
index 539e6e30..096f286b 100644
--- a/ocipkg/src/image/artifact.rs
+++ b/ocipkg/src/image/artifact.rs
@@ -191,6 +191,15 @@ impl<Base: Image> Artifact<Base> {
                                 files.push(path.to_path_buf());
                             }
                         }
+                        media_type if media_type.to_string().ends_with("gzip") => {
+                            let buf = flate2::read::GzDecoder::new(blob.as_slice());
+                            let mut ar = tar::Archive::new(buf);
+                            for entry in ar.entries()? {
+                                let entry = entry?;
+                                let path = entry.path()?;
+                                files.push(path.to_path_buf());
+                            }
+                        }
                         _ => bail!("Unsupported layer type: {}", desc.media_type()),
                     }
                 }
@@ -231,6 +240,10 @@ impl<Base: Image> Artifact<Base> {
                     let buf = flate2::read::GzDecoder::new(blob.as_slice());
                     tar::Archive::new(buf).unpack(&dest)?;
                 }
+                (ArtifactVersion::V0, media_type) if media_type.to_string().ends_with("gzip") => {
+                    let buf = flate2::read::GzDecoder::new(blob.as_slice());
+                    tar::Archive::new(buf).unpack(&dest)?;
+                }
                 (ArtifactVersion::V1, media_type)
                     if media_type == &media_types::layer_tar_gzip() =>
                 {
diff --git a/ocipkg/src/media_types.rs b/ocipkg/src/media_types.rs
index 34e6176b..943e5ada 100644
--- a/ocipkg/src/media_types.rs
+++ b/ocipkg/src/media_types.rs
@@ -18,3 +18,14 @@ pub fn config_json() -> MediaType {
 pub fn layer_tar_gzip() -> MediaType {
     MediaType::Other("application/vnd.ocipkg.v1.layer.tar+gzip".to_string())
 }
+
+/// Test media_type is imageindex
+///
+/// DockerV2S2 can't directly match by MediaType
+pub fn is_imageindex(media_type: &str) -> bool {
+    matches!(
+        media_type,
+        "application/vnd.docker.distribution.manifest.list.v2+json"
+            | "application/vnd.oci.image.index.v1+json"
+    )
+}