Refine public key usage when remote

* Move all public key handling into one AuthMethod. Prioritize ssh-agent
  keys over identity files.
* Cache server connection when tunneling, saves one RoundTrip on ssh
  handshake

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

1 files changed, 22 insertions, 2 deletions

diff --git a/pkg/domain/infra/runtime_tunnel.go b/pkg/domain/infra/runtime_tunnel.go
index 6c85e837e..3fddf577c 100644
--- a/pkg/domain/infra/runtime_tunnel.go
+++ b/pkg/domain/infra/runtime_tunnel.go
@@ -5,18 +5,38 @@ package infra
 import (
 	"context"
 	"fmt"
+	"sync"
 
 	"github.com/containers/podman/v2/pkg/bindings"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/domain/infra/tunnel"
 )
 
+var (
+	connectionMutex = &sync.Mutex{}
+	connection      *context.Context
+)
+
+func newConnection(uri string, identity string) (context.Context, error) {
+	connectionMutex.Lock()
+	defer connectionMutex.Unlock()
+
+	if connection == nil {
+		ctx, err := bindings.NewConnectionWithIdentity(context.Background(), uri, identity)
+		if err != nil {
+			return ctx, err
+		}
+		connection = &ctx
+	}
+	return *connection, nil
+}
+
 func NewContainerEngine(facts *entities.PodmanConfig) (entities.ContainerEngine, error) {
 	switch facts.EngineMode {
 	case entities.ABIMode:
 		return nil, fmt.Errorf("direct runtime not supported")
 	case entities.TunnelMode:
-		ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.URI, facts.Identity)
+		ctx, err := newConnection(facts.URI, facts.Identity)
 		return &tunnel.ContainerEngine{ClientCxt: ctx}, err
 	}
 	return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)
@@ -28,7 +48,7 @@ func NewImageEngine(facts *entities.PodmanConfig) (entities.ImageEngine, error)
 	case entities.ABIMode:
 		return nil, fmt.Errorf("direct image runtime not supported")
 	case entities.TunnelMode:
-		ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.URI, facts.Identity)
+		ctx, err := newConnection(facts.URI, facts.Identity)
 		return &tunnel.ImageEngine{ClientCxt: ctx}, err
 	}
 	return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)