Add VarlinkCall.RequiresUpgrade() type and method

Type varlinkapi.VarlinkCall currently only used as receiver for
RequiresUpgrade() future helpers could be added to this type.

RequiresUpgrade() verifies caller has given correct options to the call
for the given operation.

Signed-off-by: Jhon Honce <jhonce@redhat.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/pkg/varlinkapi/util.go b/pkg/varlinkapi/util.go
index 8716c963a..a9f1e20a1 100644
--- a/pkg/varlinkapi/util.go
+++ b/pkg/varlinkapi/util.go
@@ -13,6 +13,11 @@ import (
 	"github.com/containers/libpod/cmd/podman/varlink"
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/storage/pkg/archive"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrUpgradedConnectionRequired = errors.New("peer must use upgraded connection for operation")
 )
 
 // getContext returns a non-nil, empty context
@@ -195,3 +200,13 @@ func makePsOpts(inOpts iopodman.PsOpts) shared.PsOptions {
 		Sync:      derefBool(inOpts.Sync),
 	}
 }
+
+// RequiresUpgrade tests if varlink connection has been marked for upgrade.
+func (v *VarlinkCall) RequiresUpgrade() error {
+	if v.WantsUpgrade() {
+		// A nil is sent to the peer as required by the varlink protocol.
+		return v.Reply(nil)
+	} else {
+		return ErrUpgradedConnectionRequired
+	}
+}