Search PATH for docker executable

main.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"os/exec"
 	"os/user"
+	"runtime"
 	"strconv"
 	"strings"
 	"syscall"
@@ -169,10 +170,15 @@ func Run(detach bool, mounts []string, command []string) error {
 	}
 
 	home := os.Getenv("HOME")
-	hostOS := "darwin"
+	hostOS := runtime.GOOS
+
+	dockerBin, err := exec.LookPath("docker")
+	if err != nil {
+		return err
+	}
 
 	dockerCommand := []string{
-		"/bin/docker", "run", "--network=host",
+		dockerBin, "run", "--network=host",
 		"--workdir=" + workDir,
 		"--rm",
 		"-e", "WORKSPACE_OS=" + hostOS,