Merge pull request #2294 from jmccann/keepalive

Add keepalive to agents

cmd/drone-agent/agent.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 
 	"github.com/cncd/pipeline/pipeline"
@@ -75,6 +76,10 @@ func loop(c *cli.Context) error {
 			username: c.String("username"),
 			password: c.String("password"),
 		}),
+		grpc.WithKeepaliveParams(keepalive.ClientParameters{
+			Time: c.Duration("keepalive-time"),
+			Timeout: c.Duration("keepalive-timeout"),
+		}),
 	)
 
 	if err != nil {

cmd/drone-agent/main.go

@@ -80,6 +80,16 @@ func main() {
 			Name:   "healthcheck",
 			Usage:  "enables the healthcheck endpoint",
 		},
+		cli.DurationFlag{
+			EnvVar: "DRONE_KEEPALIVE_TIME",
+			Name:   "keepalive-time",
+			Usage:  "after a duration of this time if the agent doesn't see any activity it pings the server to see if the transport is still alive",
+		},
+		cli.DurationFlag{
+			EnvVar: "DRONE_KEEPALIVE_TIMEOUT",
+			Name:   "keepalive-timeout",
+			Usage:  "after having pinged for keepalive check, the client waits for a duration of Timeout and if no activity is seen even after that the connection is closed.",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {