refactor: simplify launcher image validation by accepting manifest digest directly by barakeinav1 · Pull Request #2785 · near/mpc

barakeinav1 · 2026-04-09T14:24:48Z

Summary

Remove the Docker registry API from the tee-launcher. The approved hashes file now contains manifest digests, so the launcher can docker pull image@sha256:<digest> directly without querying the registry.

Removed (~630 lines):

registry.rs entirely — Docker registry auth, manifest fetching, retry/backoff, multi-platform resolution, config digest matching
oci-client, backon, rustls, rstest dependencies
All registry-related error variants
rustls crypto provider setup in main.rs
external-services-tests feature flag

Simplified:

validation.rs: 79 → 33 lines (just docker pull + verify exit code)
error.rs: 90 → 65 lines
lib.rs: now emits manifest digest to RTMR3 (not config digest)

Note: LauncherConfig still accepts rpc_* fields for backward compat with existing TOML configs. They are unused — removal is a follow-up.

Closes #2627. Plan and research in the issue comment.

Requires coordination

The approved hashes file must contain manifest digests (not config digests)
The contract/node side needs to store and propagate manifest digests — tracked separately
Build script must output manifest digests ([build] Switch MPC node image push to skopeo with --preserve-digests #2778)

Test plan

cargo check -p tee-launcher passes
cargo test -p tee-launcher passes (30 tests)

… manifest digest Remove the Docker registry API interaction from the launcher. The approved hashes file now contains manifest digests (instead of config digests), so the launcher can pull directly with `docker pull image@sha256:<digest>` without querying the registry to resolve config digest -> manifest digest. Removed: - registry.rs (~430 lines) -- Docker registry auth, manifest fetching, retry logic, multi-platform resolution, config digest matching - oci-client, backon, rustls, rstest dependencies - Registry-related error variants - rustls crypto provider setup in main.rs - external-services-tests feature flag Simplified: - validation.rs: 79 lines -> 33 lines (just docker pull + verify) - error.rs: 90 lines -> 65 lines - lib.rs: emits manifest digest (not config digest) to RTMR3 Closes #2627

claude · 2026-04-09T14:25:46Z

Code Review

Clean simplification. The removal of the OCI registry client in favor of direct docker pull image@sha256:<digest> is straightforward and correct. No critical issues found.

Minor observations (non-blocking):

The sync pull_and_verify call inside the async run() is fine here since this is a sequential launcher binary (and other calls like launch_mpc_container are already sync in the same context).
The PR description notes that LauncherConfig still has unused rpc_* fields for backward compat — the follow-up cleanup is tracked.

✅ Approved

Copilot

Pull request overview

This PR refactors tee-launcher image validation to accept and operate directly on manifest digests, removing the OCI/Docker registry API client and associated retry/auth logic so the launcher can docker pull <image>@sha256:<digest> without registry lookups.

Changes:

Replace registry-based digest resolution with a direct docker pull by manifest digest (pull_and_verify).
Remove the registry.rs module and drop related dependencies (oci-client, backon, rustls, rstest) and error variants.
Emit the selected manifest digest to dstack (RTMR3) and propagate it through tee config / compose launch.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
`crates/tee-launcher/src/validation.rs`	Replaces async registry+inspect validation with a minimal pull-by-digest check.
`crates/tee-launcher/src/registry.rs`	Deletes the registry client, digest resolution logic, and related tests.
`crates/tee-launcher/src/main.rs`	Removes rustls crypto provider initialization that was required for prior TLS usage.
`crates/tee-launcher/src/lib.rs`	Switches selection/validation flow to manifest digests and emits manifest digest to RTMR3.
`crates/tee-launcher/src/error.rs`	Simplifies error enums by removing registry-related variants and tightening run/pull errors.
`crates/tee-launcher/Cargo.toml`	Removes registry/test-related features and dependencies.
`Cargo.lock`	Removes transitive packages no longer needed after dropping the registry client stack.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-04-09T14:31:27Z

crates/tee-launcher/Cargo.toml

 [[bin]]
 name = "tee-launcher"
 path = "src/main.rs"

-[features]
-external-services-tests = []
-
 [dependencies]
-backon = { workspace = true }
 clap = { workspace = true }
 dstack-sdk = { workspace = true }


Removing the external-services-tests feature flag will break existing CI/docs that still run cargo nextest ... -p tee-launcher --features external-services-tests (e.g. .github/workflows/external-services-tests.yml). Either keep this feature as a no-op for compatibility, or update the workflow/docs to stop passing the feature for tee-launcher.

Copilot · 2026-04-09T14:31:28Z

crates/tee-launcher/src/lib.rs

+    // The approved hashes file now contains manifest digests.
+    // We can pull directly by digest without querying the Docker registry API.
+    let manifest_digest = select_image_hash(
        approved_hashes_on_disk.as_ref(),
        &args.default_image_digest,
        config.launcher_config.mpc_hash_override.as_ref(),
    )?;

-    let manifest_digest = validate_image_hash(&config.launcher_config, image_hash.clone()).await?;
+    pull_and_verify(&config.launcher_config.image_name, &manifest_digest)?;



pull_and_verify is invoked with only launcher_config.image_name, and launcher_config.registry is no longer used anywhere. Configs/docs currently model non-DockerHub registries as registry=<host> + image_name=<repo>, which would now attempt to pull from the default registry instead of the configured one. Consider constructing a fully-qualified image reference (or explicitly requiring image_name to include the registry host) and using that consistently for both pull and compose launch.

Copilot · 2026-04-09T14:31:28Z

crates/tee-launcher/src/validation.rs

        .map_err(|e| ImageDigestValidationFailed::DockerPullFailed(e.to_string()))?;

-    let pull_failed = !pull.status.success();
-    if pull_failed {
-        return Err(ImageDigestValidationFailed::DockerPullFailed(
-            "docker pull terminated with unsuccessful status".to_string(),
-        ));
-    }
-
-    // Verify that the pulled image ID matches the expected config digest.
-    // `docker inspect .ID` returns the image ID, which equals the config digest
-    // (i.e. the sha256 of the image config blob).
-    let inspect = Command::new("docker")
-        .args([
-            "image",
-            "inspect",
-            "--format",
-            "{{index .ID}}",
-            &name_and_digest,
-        ])
-        .output()
-        .map_err(|e| ImageDigestValidationFailed::DockerInspectFailed(e.to_string()))?;
-
-    let docker_inspect_failed = !inspect.status.success();
-    if docker_inspect_failed {
-        return Err(ImageDigestValidationFailed::DockerInspectFailed(
-            "docker inspect terminated with unsuccessful status".to_string(),
-        ));
-    }
-
-    let pulled_image_id: DockerSha256Digest = String::from_utf8_lossy(&inspect.stdout)
-        .trim()
-        .to_string()
-        .parse()
-        .map_err(|e| {
-            ImageDigestValidationFailed::DockerInspectFailed(format!(
-                "docker inspect returned invalid image ID: {e}"
-            ))
-        })?;
-
-    if pulled_image_id != image_hash {
-        return Err(
-            ImageDigestValidationFailed::PulledImageHasMismatchedDigest {
-                pulled_image_id,
-                expected_image_id: image_hash,
-            },
-        );
+    if !pull.status.success() {
+        let stderr = String::from_utf8_lossy(&pull.stderr);
+        return Err(ImageDigestValidationFailed::DockerPullFailed(format!(
+            "docker pull {reference} failed: {stderr}"
+        )));


The current error formatting will duplicate text ("docker pull failed: docker pull ... failed: ...") and only includes stderr, which can hide useful diagnostics if Docker writes details to stdout (or if stderr includes trailing newlines). Consider adjusting ImageDigestValidationFailed::DockerPullFailed to carry structured info (reference, exit status, stdout/stderr) and format it once, with trimmed output.

Simplify LauncherConfig to use a single 'image' field that is the full Docker image reference (e.g., 'nearone/mpc-node' for Docker Hub or 'ghcr.io/nearone/mpc-node' for other registries). Removed fields: image_tags, image_name, registry, rpc_request_timeout_secs, rpc_request_interval_secs, rpc_max_attempts (all were only used by the now-deleted registry API code). Updated README and tests to reflect the new config format.

barakeinav1 · 2026-04-09T14:37:40Z

crates/tee-launcher/README.md

-| `rpc_request_timeout_secs` | Yes | Per-request timeout for registry API calls (seconds) |
-| `rpc_request_interval_secs` | Yes | Initial retry interval for registry API calls (seconds) |
-| `rpc_max_attempts` | Yes | Maximum registry API retry attempts |
+| `image` | Yes | Full Docker image reference. Include registry prefix for non-Docker Hub registries. Examples: `"nearone/mpc-node"` (Docker Hub), `"ghcr.io/nearone/mpc-node"` |


The registry, image_name, and image_tags fields were replaced with a single image field. These fields existed
because the old code needed to construct Docker registry API URLs separately
(https://{registry}/v2/{image_name}/manifests/{tag}). Now that we pull directly with docker pull
image@sha256:, Docker handles registry resolution natively from the image reference. A single image field
(e.g., nearone/mpc-node or ghcr.io/nearone/mpc-node) is all that's needed and matches standard Docker conventions.
The rpc_* fields (timeout, interval, max_attempts) were also removed as they only controlled the now-deleted
registry retry logic.

I am not 100% about this, but of course could be certainly the case

barakeinav1 · 2026-04-09T14:40:31Z

crates/tee-launcher/README.md

 ## Supported Registries

-The launcher uses the [OCI Distribution Specification](https://github.com/opencontainers/distribution-spec) for registry communication. Auth endpoints are discovered automatically via the `WWW-Authenticate` challenge on `/v2/`, so there is no hard-coded auth URL.
+The launcher pulls images using `docker pull <image>@sha256:<digest>`. Any registry that Docker supports works out of the box. Set the `image` field to include the registry prefix:


Note on removing the OCI Distribution Spec client (oci-client):

The old code used oci-client to interact with registries directly via the OCI Distribution Spec. This gave us: (1)
automatic auth challenge discovery via WWW-Authenticate, (2) multi-platform manifest resolution to amd64/linux, and
(3) config digest verification inside the manifest before pulling.

With the new docker pull image@sha256:<manifest_digest> approach, all of this is handled by Docker itself:

Auth: Docker uses its credential helpers (~/.docker/config.json), which actually supports private registries —
the old code only supported anonymous/public images

Multi-platform: Not needed — we pull by exact manifest digest, which already points to a single-platform manifest
(platform was resolved at build time)

Digest verification: Docker verifies the pulled content matches the digest — if it doesn't, the pull fails

Net result: same guarantees, 430 fewer lines, and we gained private registry support.

… digests Update image hash inspection, voting, and verification sections to reflect the switch from config digests (docker inspect .ID) to manifest digests (skopeo inspect .Digest / build script output).

barakeinav1 requested a review from Copilot April 9, 2026 14:25

Copilot started reviewing on behalf of barakeinav1 April 9, 2026 14:26 View session

Copilot AI reviewed Apr 9, 2026

View reviewed changes

barakeinav1 commented Apr 9, 2026

View reviewed changes

barakeinav1 marked this pull request as draft April 9, 2026 14:42

docs: update operator guide to use manifest digests instead of config…

3d61145

… digests Update image hash inspection, voting, and verification sections to reflect the switch from config digests (docker inspect .ID) to manifest digests (skopeo inspect .Digest / build script output).

barakeinav1 force-pushed the barak/simplify-image-validation branch from 839a7d3 to 3d61145 Compare April 10, 2026 07:27

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

refactor: simplify launcher image validation by accepting manifest digest directly#2785

refactor: simplify launcher image validation by accepting manifest digest directly#2785
barakeinav1 wants to merge 3 commits intomainfrom
barak/simplify-image-validation

barakeinav1 commented Apr 9, 2026

Uh oh!

claude bot commented Apr 9, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Apr 9, 2026

Uh oh!

Copilot AI Apr 9, 2026

Uh oh!

Copilot AI Apr 9, 2026

Uh oh!

barakeinav1 Apr 9, 2026

Uh oh!

gilcu3 Apr 9, 2026

Uh oh!

barakeinav1 Apr 9, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

barakeinav1 commented Apr 9, 2026

Summary

Requires coordination

Test plan

Uh oh!

claude bot commented Apr 9, 2026

Code Review

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

barakeinav1 Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

gilcu3 Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

barakeinav1 Apr 9, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants