add unique

cmd/minikube/cmd/start_flags.go

@@ -341,7 +341,7 @@ func generateClusterConfig(cmd *cobra.Command, existing *config.ClusterConfig, k
 
 	// Feed Docker our host proxy environment by default, so that it can pull images
 	// doing this for both new config and existing, in case proxy changed since previous start
-	if _, ok := r.(*cruntime.Docker); ok && !cmd.Flags().Changed("docker-env") {
+	if _, ok := r.(*cruntime.Docker); ok {
 		proxy.SetDockerEnv()
 	}
 

pkg/minikube/proxy/proxy.go

@@ -168,5 +168,17 @@ func SetDockerEnv() []string {
 			config.DockerEnv = append(config.DockerEnv, fmt.Sprintf("%s=%s", k, v))
 		}
 	}
+
+	// remove duplicates
+	seen := map[string]bool{}
+	uniqueEnvs := []string{}
+	for e := range config.DockerEnv {
+		if !seen[config.DockerEnv[e]] {
+			seen[config.DockerEnv[e]] = true
+			uniqueEnvs = append(uniqueEnvs, config.DockerEnv[e])
+		}
+	}
+	config.DockerEnv = uniqueEnvs
+
 	return config.DockerEnv
 }