This is an oci store implementation
It's made of a base store on top of which additional stores can be built (perhaps also an appc store). The oci store adds OCI specific functions (primarily blobs GC) to the base store.
Tha base store is a CAS store with additional features required to handle multiple requirements (access from multiple processes, access from multiple goroutine using the same store instance, indexing, additional blob data, key/value data):
- The store data can be concurrently accessed by multiple processes and multiple goroutines (like CoreOS rkt) (locally since it's not meant to be used as a multi host shared store)
- Store data (blobs) is indexed to be easily listed and searched (for example to resolve partial digests)
- Every blob can be augmented with additional data (useful to save additional informations (like last accessed time etc...)
- Additional key/value data (the can optionally reference a blob) can be added (useful for oci references to descriptors and for the appc spec remote caching data)
The oci store use this base store and implements OCI specific functions:
- Garbage collection of unreferenced manifests, configs, layers
- A check for verifying that all the blobs needed by a name reference are available in the store (TODO)
Its base comes from the experience in the CoreOS rkt store and uses big part of it.
NOTE: This is a work in progress and before a initial release I'll squash and force push to avoid multiple unuseful commits.
A simple test client has been created to test different features.
It can import and export a directory containing a oci image layout and list references
Build the example client
cd examples/client cd oci-fetch go install
Create an oci image layout dir:
go get github.com/sgotti/oci-fetch # temporary fixes to be merged in github.com/containers/oci-fetch oci-fetch docker://registry-1.docker.io/library/nginx:latest nginx.oci mkdir nginx; cd nginx tar xvf ../nging.oci
Import from oci image layout ref latest with name
nginx in the oci store
./client import --sref latest --dref nginx:latest nginx/
List oci store manifest references
Export image nginx with rev latest to an oci image layout in out/ dir
./client export --sref nginx:latest --dref latest out/
Remove image nginx with rev latest from the store
./client rm --ref nginx:latest
Garbage collect unreferenced blobs