* Ignition and Cloud config templates can reference selector
key/value pairs by lowercase key name
* Metadata endpoint will provide metadata and selector key/val
pairs for the matching machine group
* All Groups retrieved from FileStore's GroupGet (via ParseGroup)
should have normalized selectors since end-users may write Group
definitions with MAC addresses which don't match Go's format
* Change assets download location to examples/assets
* FileStore should default to /var/lib/bootcfg/{profiles,groups,
ignition,cloud}
* Assets location should default to /var/lib/bootcfg/assets
* Fix -rpcAddress flag to be -rpc-address
* Split config.yaml files into JSON groups files
* Update examples to use folders of mountable groups files
* Stop reading groups from a -config config.yaml file
* Add RichGroup JSON <-> Protobuf Serialize Group
* Defining protobuf messages with protobuf rpc services resulted
in generated code which depended upon the gRPC package. This meant
the core server lib depended on gPRC and thus, so did the HTTP
server.
* Move rpc service protobuf definitions under bootcfg/rpc, so the
bootcfg/server package no longer depends on grpc.
* Simplify server lib responses so HTTP server components don't
have to unwrap protobuf Response types intended for gRPC uses
* Wrap server lib responses in protobuf Response types in the
rpc package
* The etcd clusters use static address assignment so dynamic metadata
isn't needed for this case. Custom metadata is useful for fetching
custom data on each boot, to configure units.
* Add gRPC SelectGroup and SelectProfile service endpoints
* HTTP and gRPC servers should both allow labels to be resolved to the
matching Group or Profile. Move logic to bootcfg core server.
* Add gRPC wrapper selectServer to avoid cluttering core server with
response types which are currently only useful for gRPC
* FileStore should manage resources found in type named directories
since this is similar to a traditional table-DB layout and to how
an EtcdStore would work
* http.Dir securely restricts accesses to a filesystem directory to
support http FileServe, which is why this type was used previously
* Dir copies the sanatization behavior of http.Dir verbatim, but
provides ioutil-like write and directory access within the directory
* Why: Safe FileStore writes need to be possible and also, storage
should not have a dependency on net/http just for its http.Dir
* Run k8stls.service to fetch TLS assets if path is missing
* Make Kubelet depend upon a kubelet.path path unit
* Fixes to file mode (octal allowed in YAML)
