vendor/k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/util.go

/*
Copyright 2018 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package phases

import (
	"github.com/spf13/cobra"

	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
	kubeadmapiv1beta1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta1"
	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/validation"
	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
	configutil "k8s.io/kubernetes/cmd/kubeadm/app/util/config"
	"k8s.io/kubernetes/pkg/version"
)

// runCmdPhase creates a cobra.Command Run function, by composing the call to the given cmdFunc with necessary additional steps (e.g preparation of input parameters)
func runCmdPhase(cmdFunc func(outDir string, cfg *kubeadmapi.InitConfiguration) error, outDir, cfgPath *string, cfg *kubeadmapiv1beta1.InitConfiguration, defaultKubernetesVersion string) func(cmd *cobra.Command, args []string) {

	// the following statement build a closure that wraps a call to a cmdFunc, binding
	// the function itself with the specific parameters of each sub command.
	// Please note that specific parameter should be passed as value, while other parameters - passed as reference -
	// are shared between sub commands and gets access to current value e.g. flags value.

	return func(cmd *cobra.Command, args []string) {
		if err := validation.ValidateMixedArguments(cmd.Flags()); err != nil {
			kubeadmutil.CheckErr(err)
		}

		// This is used for unit testing only...
		// If we wouldn't set this to something, the code would dynamically look up the version from the internet
		// By setting this explicitly for tests workarounds that
		if defaultKubernetesVersion != "" {
			cfg.KubernetesVersion = defaultKubernetesVersion
		} else {
			// KubernetesVersion is not used, but we set it explicitly to avoid the lookup
			// of the version from the internet when executing ConfigFileAndDefaultsToInternalConfig
			SetKubernetesVersion(cfg)
		}

		// This call returns the ready-to-use configuration based on the configuration file that might or might not exist and the default cfg populated by flags
		internalcfg, err := configutil.ConfigFileAndDefaultsToInternalConfig(*cfgPath, cfg)
		kubeadmutil.CheckErr(err)

		// Execute the cmdFunc
		err = cmdFunc(*outDir, internalcfg)
		kubeadmutil.CheckErr(err)
	}
}

// SetKubernetesVersion gets the current Kubeadm version and sets it as KubeadmVersion in the config,
// unless it's already set to a value different from the default.
func SetKubernetesVersion(cfg *kubeadmapiv1beta1.InitConfiguration) {

	if cfg.KubernetesVersion != kubeadmapiv1beta1.DefaultKubernetesVersion && cfg.KubernetesVersion != "" {
		return
	}
	cfg.KubernetesVersion = version.Get().String()
}