How to use the @pulumi/pulumi.concat function in @pulumi/pulumi

// limitations under the License.

import * as pulumi from "@pulumi/pulumi";
import * as k8s from "@pulumi/kubernetes";
import * as random from "@pulumi/random"

//
// To allow parallel test runs, generate a namespace name with a random suffix.
//

let randomSuffix = new random.RandomString("random-suffix", {
    length: 6,
    special: false,
    upper: false
});
let nsName = pulumi.concat(`test-namespace-`, randomSuffix.result);

//
// Tests that if we force a `Pod` to be created before the `Namespace` it is supposed to exist in,
// it will retry until created.
//

new k8s.core.v1.Pod("nginx", {
    metadata: {
        namespace: nsName,
        name: "nginx"
    },
    spec: {
        containers: [
            {
                name: "nginx",
                image: "nginx:1.7.9",

periodSeconds: 10,
                                    successThreshold: 1,
                                    failureThreshold: 3,
                                },
                                lifecycle: {
                                  preStop: {
                                    exec: {
                                      command: ["sleep", "20"],
                                    },
                                  },
                                },
                                // For more info on all CLI args available:
                                // https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/cli-arguments.md
                                args: pulumi.all([
                                    "/nginx-ingress-controller",
                                    pulumi.concat("--configmap=$(POD_NAMESPACE)/", args.configMapName),
                                    // NGINX service name is fixed vs auto-named & ref'd in order for
                                    // nginx-ing-cntlr arg --publish-service to work.
                                    pulumi.concat("--publish-service=$(POD_NAMESPACE)/", name),
                                    "--annotations-prefix=nginx.ingress.kubernetes.io",
                                    "--ingress-class=" + args.ingressClass,
                                    "--v=2",
                                ]),
                            },
                        ],
                    },
                },
            },
        },
        {
            provider: args.provider,
        },

},
                                lifecycle: {
                                  preStop: {
                                    exec: {
                                      command: ["sleep", "20"],
                                    },
                                  },
                                },
                                // For more info on all CLI args available:
                                // https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/cli-arguments.md
                                args: pulumi.all([
                                    "/nginx-ingress-controller",
                                    pulumi.concat("--configmap=$(POD_NAMESPACE)/", args.configMapName),
                                    // NGINX service name is fixed vs auto-named & ref'd in order for
                                    // nginx-ing-cntlr arg --publish-service to work.
                                    pulumi.concat("--publish-service=$(POD_NAMESPACE)/", name),
                                    "--annotations-prefix=nginx.ingress.kubernetes.io",
                                    "--ingress-class=" + args.ingressClass,
                                    "--v=2",
                                ]),
                            },
                        ],
                    },
                },
            },
        },
        {
            provider: args.provider,
        },
    );
}