To use Azure Blob Storage, you'll need your Azure connection string and an existing Blob Storage container name. Set the SCCACHE_AZURE_CONNECTION_STRING
environment variable to your connection string, and SCCACHE_AZURE_BLOB_CONTAINER to the name of the container to use. Note that sccache will not create
the container for you - you'll need to do that yourself.
You can also define a prefix that will be prepended to the keys of all cache objects created and read within the container, effectively creating a scope. To do that use the SCCACHE_AZURE_KEY_PREFIX environment variable. This can be useful when sharing a bucket with another application.
Important: The environment variables are only taken into account when the server starts, i.e. only on the first run.