Roadmap

Ideas under consideration for future releases, roughly ordered by expected impact. Items graduate off this page when they ship; the CHANGELOG records what landed.

Native microVM memory snapshots

Filesystem-level checkpoint/restore ships on both backends now (see Checkpoint / Restore): docker via image commit, microsandbox via disk snapshots (stops the sandbox, snapshots its disk, and boots it back from that snapshot under the same name and ports) — boot once, seed once, restore per test instead of re-seeding. What’s left: true MEMORY snapshots, which would resume a sandbox mid-execution — a near-instant restore where a live process’s in-memory state (not just its filesystem) survives too. That still needs upstream microsandbox support.

Self-contained archives

Checkpoint export/import ships now — a checkpoint seeded once in CI can be shipped as a build artifact and restored on a fresh runner instead of re-seeding there too. What’s left: the archive doesn’t bundle the OCI image, so the destination machine still pulls it on the restored container’s first boot — offline restores need the image baked into the archive itself. Blocked upstream: msb 0.6.6’s own --with-image export fails an integrity check on import (“raw manifest digest mismatch”), so this waits on a fix there.

Module breadth

The gaps Testcontainers users will hit first: LocalStack, Elasticsearch / OpenSearch, Vault, MinIO, NATS, Cassandra, MSSQL, Oracle Free, and Ollama (LLM-in-a-box testing, which also fits the isolation story).

Framework integrations

One-annotation setup in the frameworks people actually use: Spring Boot @ServiceConnection-style wiring, Quarkus Dev Services, a pytest-style fixture story, Vitest/Jest global-setup helpers, Axum/sqlx examples.

Building images from code

Define an ad-hoc image inline in the test (Dockerfile-from-code) instead of publishing one — for testing your own service, not just its dependencies.

Host-directory mounts

Start-time host-directory binds (with_copy_file_to_container currently mounts individual files) alongside the existing copy-in. Runtime copy-out already shipped — see Copying Files.

Declarative multi-service groups

A rightsize-native way to declare “these five services, this network, this startup order” as one artifact, serving the docker-compose need without the compose file format.

Warm pools

A background pool of pre-booted sandboxes so start() is near-instant — paired with reuse, this attacks time-to-first-test directly.

Fault injection

The backend controls the virtual NIC: latency, packet loss, partitions between sandboxes, kill-and-revive — first-class API instead of a separate Toxiproxy container.

Time control

A VM owns its clock: advance time inside the guest to test TTLs, certificate expiry, and cron logic faithfully — awkward to impossible on a shared kernel.

Private registry authentication

Pulling from authenticated registries, documented and tested — table stakes for enterprise evaluation.