initial commit

.pre-commit-config.yaml

@@ -0,0 +1,18 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+#      - id: check-added-large-files
+      - id: check-yaml
+      - id: end-of-file-fixer
+      - id: trailing-whitespace
+  - repo: https://github.com/dnephin/pre-commit-golang.git
+    rev: v0.3.5
+    hooks:
+      - id: go-fmt
+      - id: go-imports
+# todo: hook does not support multiple binaries in one repo
+# https://github.com/dnephin/pre-commit-golang/issues/30
+#      - id: go-vet
+#      - id: go-lint
+      - id: go-cyclo

Makefile

@@ -0,0 +1,5 @@
+ARGS=
+
+.PHONY: run
+run:
+	go run ./cmd/ cover ${ARGS}

cmd/kubectl-pdb.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"os"
+
+	"github.com/dhenkel92/kubectl-pdb/pkg/cmd"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+)
+
+func main() {
+	flags := pflag.NewFlagSet("kubectl-pdb", pflag.ExitOnError)
+	pflag.CommandLine = flags
+
+	rootCmd := &cobra.Command{
+		Use:   "pdb",
+		Short: "Utility to work with pod disruption budgets",
+	}
+	rootCmd.AddCommand(cmd.NewCmdPdb(genericclioptions.IOStreams{In: os.Stdin, Out: os.Stdout, ErrOut: os.Stderr}))
+
+	if err := rootCmd.Execute(); err != nil {
+		os.Exit(1)
+	}
+}

go.mod

@@ -0,0 +1,68 @@
+module github.com/dhenkel92/kubectl-pdb
+
+go 1.18
+
+require (
+	github.com/spf13/cobra v1.6.0
+	github.com/spf13/pflag v1.0.5
+	k8s.io/apimachinery v0.23.13
+	k8s.io/cli-runtime v0.23.13
+	k8s.io/client-go v0.23.13
+)
+
+require (
+	github.com/PuerkitoBio/purell v1.1.1 // indirect
+	github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/evanphx/json-patch v4.12.0+incompatible // indirect
+	github.com/go-errors/errors v1.0.1 // indirect
+	github.com/go-logr/logr v1.2.3 // indirect
+	github.com/go-openapi/jsonpointer v0.19.5 // indirect
+	github.com/go-openapi/jsonreference v0.19.5 // indirect
+	github.com/go-openapi/swag v0.19.14 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/btree v1.0.1 // indirect
+	github.com/google/go-cmp v0.5.5 // indirect
+	github.com/google/gofuzz v1.1.0 // indirect
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
+	github.com/google/uuid v1.1.2 // indirect
+	github.com/googleapis/gnostic v0.5.5 // indirect
+	github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7 // indirect
+	github.com/imdario/mergo v0.3.5 // indirect
+	github.com/inconshreveable/mousetrap v1.0.1 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/liggitt/tabwriter v0.0.0-20181228230101-89fcab3d43de // indirect
+	github.com/mailru/easyjson v0.7.6 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/monochromegane/go-gitignore v0.0.0-20200626010858-205db1a8cc00 // indirect
+	github.com/peterbourgon/diskv v2.0.1+incompatible // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.0 // indirect
+	github.com/xlab/treeprint v0.0.0-20181112141820-a009c3971eca // indirect
+	go.starlark.net v0.0.0-20200306205701-8dd3e2ee1dd5 // indirect
+	golang.org/x/net v0.0.0-20220722155237-a158d28d115b // indirect
+	golang.org/x/oauth2 v0.0.0-20210819190943-2bc19b11175f // indirect
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/api v0.23.13 // indirect
+	k8s.io/klog/v2 v2.70.1 // indirect
+	// https://github.com/kubernetes/client-go/issues/1075
+	k8s.io/kube-openapi v0.0.0-20211115234752-e816edb12b65 // indirect
+	k8s.io/utils v0.0.0-20220728103510-ee6ede2d64ed // indirect
+	sigs.k8s.io/json v0.0.0-20220713155537-f223a00ba0e2 // indirect
+	sigs.k8s.io/kustomize/api v0.10.1 // indirect
+	sigs.k8s.io/kustomize/kyaml v0.13.0 // indirect
+	sigs.k8s.io/structured-merge-diff/v4 v4.2.3 // indirect
+	sigs.k8s.io/yaml v1.2.0 // indirect
+)

pkg/cmd/pdb.go

@@ -0,0 +1,181 @@
+package cmd
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/dhenkel92/kubectl-pdb/pkg/kube"
+	"github.com/liggitt/tabwriter"
+	"github.com/spf13/cobra"
+	corev1 "k8s.io/api/core/v1"
+	policyv1 "k8s.io/api/policy/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"k8s.io/cli-runtime/pkg/printers"
+)
+
+type PDBOptions struct {
+	genericclioptions.IOStreams
+
+	configFlags   *genericclioptions.ConfigFlags
+	AllNamespaces bool
+	Namespace     string
+	PodName       string
+	Output        string
+	Template      string
+}
+
+func NewPDBOptions(streams genericclioptions.IOStreams) *PDBOptions {
+	return &PDBOptions{
+		configFlags: genericclioptions.NewConfigFlags(true),
+		IOStreams:   streams,
+	}
+}
+
+func (o *PDBOptions) GetPrinter() (printers.ResourcePrinter, error) {
+	switch o.Output {
+	case "jsonpath":
+		return printers.NewJSONPathPrinter(o.Template)
+	case "json":
+		return &printers.JSONPrinter{}, nil
+	case "yaml":
+		return &printers.YAMLPrinter{}, nil
+	}
+	return printers.NewTablePrinter(printers.PrintOptions{
+		WithKind:      false,
+		NoHeaders:     false,
+		Wide:          false,
+		WithNamespace: o.AllNamespaces,
+		ShowLabels:    false,
+		ColumnLabels:  []string{},
+	}), nil
+}
+
+func (o *PDBOptions) GetNamespace() string {
+	if o.AllNamespaces {
+		return ""
+	}
+	return o.Namespace
+}
+
+func (o *PDBOptions) Complete(cmd *cobra.Command, args []string) error {
+	var err error
+
+	o.Namespace, _, err = o.configFlags.ToRawKubeConfigLoader().Namespace()
+	if err != nil {
+		return err
+	}
+
+	if len(args) > 0 && args[0] != "" {
+		o.PodName = args[0]
+	}
+
+	if strings.HasPrefix(o.Output, "jsonpath") {
+		split := strings.Split(o.Output, "=")
+		o.Output = split[0]
+		o.Template = split[1]
+	}
+	return nil
+}
+
+func (o *PDBOptions) Validate() error {
+	switch o.Output {
+	case "json", "yaml", "human", "jsonpath":
+	default:
+		return fmt.Errorf("invalid output '%s'", o.Output)
+	}
+	return nil
+}
+
+func (o *PDBOptions) getWriter() *tabwriter.Writer {
+	return printers.GetNewTabWriter(o.Out)
+}
+
+func (o *PDBOptions) Run() error {
+	printer, err := o.GetPrinter()
+	if err != nil {
+		return err
+	}
+
+	kubeClients, err := kube.New(o.configFlags)
+	if err != nil {
+		return err
+	}
+
+	pods, err := kubeClients.GetNamespacedPods(o.GetNamespace(), o.PodName)
+	if err != nil {
+		return err
+	}
+
+	pdbs, err := kubeClients.GetNamespacedPDBs(o.GetNamespace())
+	if err != nil {
+		return err
+	}
+
+	entries := make([]PodPDBEntry, 0, len(pods))
+	for ns, podLst := range pods {
+		podPDBs, ok := pdbs[ns]
+		if !ok {
+			continue
+		}
+
+		for _, pod := range podLst {
+			pdbs := getMatchingPDBs(&pod, podPDBs)
+			entries = append(entries, PodPDBEntry{
+				Pod:  pod,
+				Pdbs: pdbs,
+			})
+		}
+	}
+
+	lst := &PodPDBList{Items: entries}
+	w := o.getWriter()
+	if err := printer.PrintObj(lst.toMetaTable(), w); err != nil {
+		return err
+	}
+	return w.Flush()
+}
+
+func NewCmdPdb(streams genericclioptions.IOStreams) *cobra.Command {
+	o := NewPDBOptions(streams)
+
+	cmd := &cobra.Command{
+		Use:   "cover [pod name]",
+		Short: "Shows which PDBs are covering the given workload.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := o.Complete(cmd, args); err != nil {
+				return err
+			}
+			if err := o.Validate(); err != nil {
+				return err
+			}
+			if err := o.Run(); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+
+	flags := cmd.Flags()
+	flags.BoolVarP(&o.AllNamespaces, "all-namespaces", "a", false, "")
+	flags.StringVarP(&o.Output, "output", "o", "human", "[human, json, yaml, jsonpath]")
+	o.configFlags.AddFlags(flags)
+
+	return cmd
+}
+
+func getMatchingPDBs(pod *corev1.Pod, pdbs []policyv1.PodDisruptionBudget) []policyv1.PodDisruptionBudget {
+	ls := labels.Set(pod.Labels)
+
+	matchingPDBs := make([]policyv1.PodDisruptionBudget, 0)
+	for _, pdb := range pdbs {
+		// TODO catch error
+		selector, _ := metav1.LabelSelectorAsSelector(pdb.Spec.Selector)
+		if selector.Matches(ls) {
+			matchingPDBs = append(matchingPDBs, pdb)
+		}
+	}
+	return matchingPDBs
+}

pkg/cmd/pod_pdb_list.go

@@ -0,0 +1,62 @@
+package cmd
+
+import (
+	"strings"
+
+	corev1 "k8s.io/api/core/v1"
+	policyv1 "k8s.io/api/policy/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+type PodPDBEntry struct {
+	Pod  corev1.Pod
+	Pdbs []policyv1.PodDisruptionBudget
+}
+
+func (e *PodPDBEntry) getPDBList() string {
+	names := make([]string, 0, len(e.Pdbs))
+	for _, pdb := range e.Pdbs {
+		names = append(names, pdb.GetName())
+	}
+	return strings.Join(names, ", ")
+}
+
+func (e *PodPDBEntry) OwnerName() string {
+	for _, owner := range e.Pod.GetOwnerReferences() {
+		return owner.Kind
+	}
+	return ""
+}
+
+type PodPDBList struct {
+	Items []PodPDBEntry
+}
+
+func (lst *PodPDBList) toMetaTable() runtime.Object {
+	rows := make([]metav1.TableRow, 0, len(lst.Items))
+	for _, entry := range lst.Items {
+		rows = append(rows, metav1.TableRow{
+			Cells: []interface{}{
+				entry.OwnerName(),
+				entry.Pod.GetName(),
+				len(entry.Pdbs),
+				entry.getPDBList(),
+			},
+			Object: runtime.RawExtension{
+				Object: entry.Pod.DeepCopy(),
+			},
+		})
+	}
+
+	return &metav1.Table{
+		TypeMeta: metav1.TypeMeta{Kind: "pod", APIVersion: "v1"},
+		ColumnDefinitions: []metav1.TableColumnDefinition{
+			{Name: "owner", Type: "string", Format: "name", Description: "owner"},
+			{Name: "Name", Type: "string", Format: "name", Description: metav1.ObjectMeta{}.SwaggerDoc()["name"]},
+			{Name: "CNT", Type: "integer", Description: "Amount of pdbs"},
+			{Name: "PDBs", Type: "string", Description: "hello"},
+		},
+		Rows: rows,
+	}
+}