kilo/cmd/kgctl/main.go
Lucas Servén Marín 61b52ce4ae
cmd/kgctl: improve default kubeconfig
This commit adds better handling of the default kubeconfig location in
the kgctl binary for cases where the `$KUBECONFIG` environment variable
is not set. In these cases, kgctl will default to
`$HOME/.kube/config`, putting it in line with tools like `kubectl` and
`kind`.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
2021-06-15 20:53:02 +02:00

133 lines
4.0 KiB
Go

// Copyright 2019 the Kilo 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 main
import (
"fmt"
"os"
"path/filepath"
"strings"
"github.com/spf13/cobra"
apiextensions "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
"github.com/squat/kilo/pkg/k8s"
kiloclient "github.com/squat/kilo/pkg/k8s/clientset/versioned"
"github.com/squat/kilo/pkg/mesh"
"github.com/squat/kilo/pkg/version"
)
const (
logLevelAll = "all"
logLevelDebug = "debug"
logLevelInfo = "info"
logLevelWarn = "warn"
logLevelError = "error"
logLevelNone = "none"
)
var (
availableBackends = strings.Join([]string{
k8s.Backend,
}, ", ")
availableGranularities = strings.Join([]string{
string(mesh.LogicalGranularity),
string(mesh.FullGranularity),
}, ", ")
availableLogLevels = strings.Join([]string{
logLevelAll,
logLevelDebug,
logLevelInfo,
logLevelWarn,
logLevelError,
logLevelNone,
}, ", ")
opts struct {
backend mesh.Backend
granularity mesh.Granularity
port uint32
}
backend string
granularity string
kubeconfig string
topologyLabel string
)
func runRoot(_ *cobra.Command, _ []string) error {
opts.granularity = mesh.Granularity(granularity)
switch opts.granularity {
case mesh.LogicalGranularity:
case mesh.FullGranularity:
default:
return fmt.Errorf("mesh granularity %v unknown; posible values are: %s", granularity, availableGranularities)
}
switch backend {
case k8s.Backend:
config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
if err != nil {
return fmt.Errorf("failed to create Kubernetes config: %v", err)
}
c := kubernetes.NewForConfigOrDie(config)
kc := kiloclient.NewForConfigOrDie(config)
ec := apiextensions.NewForConfigOrDie(config)
opts.backend = k8s.New(c, kc, ec, topologyLabel)
default:
return fmt.Errorf("backend %v unknown; posible values are: %s", backend, availableBackends)
}
if err := opts.backend.Nodes().Init(make(chan struct{})); err != nil {
return fmt.Errorf("failed to initialize node backend: %v", err)
}
if err := opts.backend.Peers().Init(make(chan struct{})); err != nil {
return fmt.Errorf("failed to initialize peer backend: %v", err)
}
return nil
}
func main() {
cmd := &cobra.Command{
Use: "kgctl",
Short: "Manage a Kilo network",
Long: "",
PersistentPreRunE: runRoot,
Version: version.Version,
}
cmd.PersistentFlags().StringVar(&backend, "backend", k8s.Backend, fmt.Sprintf("The backend for the mesh. Possible values: %s", availableBackends))
cmd.PersistentFlags().StringVar(&granularity, "mesh-granularity", string(mesh.LogicalGranularity), fmt.Sprintf("The granularity of the network mesh to create. Possible values: %s", availableGranularities))
defaultKubeconfig := os.Getenv("KUBECONFIG")
if _, err := os.Stat(defaultKubeconfig); os.IsNotExist(err) {
defaultKubeconfig = filepath.Join(os.Getenv("HOME"), ".kube/config")
}
cmd.PersistentFlags().StringVar(&kubeconfig, "kubeconfig", defaultKubeconfig, "Path to kubeconfig.")
cmd.PersistentFlags().Uint32Var(&opts.port, "port", mesh.DefaultKiloPort, "The WireGuard port over which the nodes communicate.")
cmd.PersistentFlags().StringVar(&topologyLabel, "topology-label", k8s.RegionLabelKey, "Kubernetes node label used to group nodes into logical locations.")
for _, subCmd := range []*cobra.Command{
graph(),
showConf(),
} {
cmd.AddCommand(subCmd)
}
if err := cmd.Execute(); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
}
}