Add Bazel files to support Bazel integration

[joyanta55]

Added BUILD file in the kubernetes c client repository that helps integrating the library to external Bazel users.
Following are the changes needed from the external Bazel users to do.

WORKSPACE file:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
     name = "kubernetes_c_client",
     sha256 = "10d0c5af1a52a1d2da379e8e45b53978b9dedc90ff195bdff171ae17c1f1dd50",
     strip_prefix = "c-0.11.0",
     url = "https://github.com/kubernetes-client/c/archive/refs/tags/v0.11.0.zip",
)

http_archive(
      name = "rules_foreign_cc",
      sha256 = "a2e6fb56e649c1ee79703e99aa0c9d13c6cc53c8d7a0cbb8797ab2888bbc99a3",
      strip_prefix = "rules_foreign_cc-0.12.0",
      url = "https://github.com/bazelbuild/rules_foreign_cc/releases/download/0.12.0/rules_foreign_cc-0.12.0.tar.gz",
)

load("@rules_foreign_cc//foreign_cc:repositories.bzl", "rules_foreign_cc_dependencies")
rules_foreign_cc_dependencies()

load("@bazel_features//:deps.bzl", "bazel_features_deps")
bazel_features_deps()

BUILD file:

load("@rules_cc//cc:defs.bzl", "cc_binary")
load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")
load("@rules_foreign_cc//foreign_cc:defs.bzl", "make")
cmake(
    name = "kube_c",
    build_args = [
        "--verbose",
        "--",  # <- Pass remaining options to the native tool.
        "-j 1",
    ],
    lib_source = "@kubernetes_c_client//:kubernetes",
    out_shared_libs = ["libkubernetes.so"],
)

cc_binary(
    name = "create_pod",
    srcs = ["create_pod.c"],
    deps = [":kube_c"],
)

cc_binary(
    name = "list_pod",
    srcs = ["list_pod.c"],
    deps = [":kube_c"],
)

The added filegroup allows to import kubernetes C client (i.e. lib_source = "@kubernetes_c_client//:kubernetes"), use cmake or make bazel rule provided by rules_foreign_cc (https://github.com/bazel-contrib/rules_foreign_cc) to build and use.

Make sure you install the pre-requisites (libyaml,libwebsocket etc.) beforehand. A working example can be found here

[brendandburns]

nit: line break before the URL

[brendandburns]

Can you add a workflow to our Github Actions CI/CD that exercises this build file?

Otherwise, I worry that it will bit-rot if it isn't tested regularly.

Otherwise, small nit and then LGTM.

[brendandburns]

(oh, and thanks!)

[brendandburns]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: brendandburns, joyanta55

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