Dotnet app from OCI registry

The goal here is to enable dotnet app distribution using an OCI registry. Dotnet apps can be run directly using the dotnet CLI as follow.

dotnet start myregistry.azurecr.io/dotnet-oci-preview-3:app

Building the project

Build and install the tool.

## this builds the tool and installs it into the global tools 
make all

Pushing the sample application

This uses oras - https://github.com/deislabs/oras/

1. Install dotnet preview 3
2. Ensure you have oras binary on your path

# Get the access keys from the registry
export REGISTRY_NAME=<NAME>
az configure --defaults acr=$REGISTRY_NAME
az acr login -n $REGISTRY_NAME
export DOCKER_USERNAME=$(az acr credential show --query username -o tsv)
export DOCKER_PASSWORD=$(az acr credential show --query passwords[0].value  -o tsv)
export REGISTRY=$(az acr show --query loginServer -o tsv)
cd samples/hw-preview-3/
dotnet publish
cd $(git rev-parse --show-toplevel)
./scripts/push-image.sh -p ./samples/hw-preview-3/bin/Debug/netcoreapp3.0/publish/

App cache

The applications are downloaded to a cache and we can make this smarter by indexing by a sha256 digest if needed.

$ tree ~/.dotnet-oras-app/
/Users/sajay/.dotnet-oras-app/
└── sajaywus2.azurecr.io.dotnet-oci-preview-3.app
    ├── hw-preview-3
    ├── hw-preview-3.deps.json
    ├── hw-preview-3.dll
    ├── hw-preview-3.pdb
    └── hw-preview-3.runtimeconfig.json