containerd/leases/grpc.go
Derek McGowan e13894bb7a
Add leases api
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
2017-11-07 12:54:22 -08:00

42 lines
957 B
Go

package leases
import (
"golang.org/x/net/context"
"google.golang.org/grpc/metadata"
)
const (
// GRPCHeader defines the header name for specifying a containerd lease.
GRPCHeader = "containerd-lease"
)
func withGRPCLeaseHeader(ctx context.Context, lid string) context.Context {
// also store on the grpc headers so it gets picked up by any clients
// that are using this.
txheader := metadata.Pairs(GRPCHeader, lid)
md, ok := metadata.FromOutgoingContext(ctx) // merge with outgoing context.
if !ok {
md = txheader
} else {
// order ensures the latest is first in this list.
md = metadata.Join(txheader, md)
}
return metadata.NewOutgoingContext(ctx, md)
}
func fromGRPCHeader(ctx context.Context) (string, bool) {
// try to extract for use in grpc servers.
md, ok := metadata.FromIncomingContext(ctx)
if !ok {
return "", false
}
values := md[GRPCHeader]
if len(values) == 0 {
return "", false
}
return values[0], true
}