package observe
import (
"bytes"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/http/httptest"
"os"
"os/exec"
"sort"
"strconv"
"strings"
"sync"
"syscall"
"text/template"
"time"
"github.com/golang/glog"
"github.com/prometheus/client_golang/prometheus"
"github.com/spf13/cobra"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/api/meta"
"k8s.io/kubernetes/pkg/api/unversioned"
"k8s.io/kubernetes/pkg/client/cache"
"k8s.io/kubernetes/pkg/healthz"
cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
"k8s.io/kubernetes/pkg/kubectl/resource"
"k8s.io/kubernetes/pkg/runtime"
"k8s.io/kubernetes/pkg/util/jsonpath"
"k8s.io/kubernetes/pkg/watch"
"github.com/openshift/origin/pkg/cmd/templates"
"github.com/openshift/origin/pkg/cmd/util/clientcmd"
"github.com/openshift/origin/pkg/util/proc"
)
var (
observeCounts = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "observe_counts",
Help: "Number of changes observed to the underlying resource.",
},
[]string{"type"},
)
execDurations = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "observe_exec_durations_milliseconds",
Help: "Item execution latency distributions.",
},
[]string{"type", "exit_code"},
)
nameExecDurations = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "observe_name_exec_durations_milliseconds",
Help: "Name list execution latency distributions.",
},
[]string{"exit_code"},
)
)
var (
observeLong = templates.LongDesc(`
Observe changes to resources and take action on them
This command assists in building scripted reactions to changes that occur in
Kubernetes or OpenShift resources. This is frequently referred to as a
'controller' in Kubernetes and acts to ensure particular conditions are
maintained. On startup, observe will list all of the resources of a
particular type and execute the provided script on each one. Observe watches
the server for changes, and will reexecute the script for each update.
Observe works best for problems of the form "for every resource X, make sure
Y is true". Some examples of ways observe can be used include:
* Ensure every namespace has a quota or limit range object
* Ensure every service is registered in DNS by making calls to a DNS API
* Send an email alert whenever a node reports 'NotReady'
* Watch for the 'FailedScheduling' event and write an IRC message
* Dynamically provision persistent volumes when a new PVC is created
* Delete pods that have reached successful completion after a period of time.
The simplest pattern is maintaining an invariant on an object - for instance,
"every namespace should have an annotation that indicates its owner". If the
object is deleted no reaction is necessary. A variation on that pattern is
creating another object: "every namespace should have a quota object based
on the resources allowed for an owner".
$ cat set_owner.sh
#!/bin/sh
if [[ "$(%[1]s get namespace "$1" --template='{{ .metadata.annotations.owner }}')" == "" ]]; then
%[1]s annotate namespace "$1" owner=bob
fi
$ %[1]s observe namespaces -- ./set_owner.sh
The set_owner.sh script is invoked with a single argument (the namespace name)
for each namespace. This simple script ensures that any user without the
"owner" annotation gets one set, but preserves any existing value.
The next common of controller pattern is provisioning - making changes in an
external system to match the state of a Kubernetes resource. These scripts need
to account for deletions that may take place while the observe command is not
running. You can provide the list of known objects via the --names command,
which should return a newline-delimited list of names or namespace/name pairs.
Your command will be invoked whenever observe checks the latest state on the
server - any resources returned by --names that are not found on the server
will be passed to your --delete command.
For example, you may wish to ensure that every node that is added to Kubernetes
is added to your cluster inventory along with its IP:
$ cat add_to_inventory.sh
#!/bin/sh
echo "$1 $2" >> inventory
sort -u inventory -o inventory
$ cat remove_from_inventory.sh
#!/bin/sh
grep -vE "^$1 " inventory > /tmp/newinventory
mv -f /tmp/newinventory inventory
$ cat known_nodes.sh
#!/bin/sh
touch inventory
cut -f 1-1 -d ' ' inventory
$ %[1]s observe nodes -a '{ .status.addresses[0].address }' \
--names ./known_nodes.sh \
--delete ./remove_from_inventory.sh \
-- ./add_to_inventory.sh
If you stop the observe command and then delete a node, when you launch observe
again the contents of inventory will be compared to the list of nodes from the
server, and any node in the inventory file that no longer exists will trigger
a call to remove_from_inventory.sh with the name of the node.
Important: when handling deletes, the previous state of the object may not be
available and only the name/namespace of the object will be passed to your
--delete command as arguments (all custom arguments are omitted).
More complicated interactions build on the two examples above - your inventory
script could make a call to allocate storage on your infrastructure as a
service, or register node names in DNS, or set complex firewalls. The more
complex your integration, the more important it is to record enough data in the
remote system that you can identify when resources on either side are deleted.
Experimental: This command is under active development and may change without notice.`)
observeExample = templates.Examples(`
# Observe changes to services
%[1]s observe services
# Observe changes to services, including the clusterIP and invoke a script for each
%[1]s observe services -a '{ .spec.clusterIP }' -- register_dns.sh`)
)
// NewCmdObserve creates the observe command.
func NewCmdObserve(fullName string, f *clientcmd.Factory, out, errOut io.Writer) *cobra.Command {
options := &ObserveOptions{
baseCommandName: fullName,
retryCount: 2,
templateType: "jsonpath",
maximumErrors: 20,
listenAddr: ":11251",
}
cmd := &cobra.Command{
Use: "observe RESOURCE [-- COMMAND ...]",
Short: "Observe changes to resources and react to them (experimental)",
Long: fmt.Sprintf(observeLong, fullName),
Example: fmt.Sprintf(observeExample, fullName),
Run: func(cmd *cobra.Command, args []string) {
if err := options.Complete(f, cmd, args, out, errOut); err != nil {
cmdutil.CheckErr(err)
}
if err := options.Validate(args); err != nil {
cmdutil.CheckErr(cmdutil.UsageError(cmd, err.Error()))
}
if err := options.Run(); err != nil {
cmdutil.CheckErr(err)
}
},
}
// flags controlling what to select
cmd.Flags().BoolVar(&options.allNamespaces, "all-namespaces", false, "If present, list the requested object(s) across all projects. Project in current context is ignored.")
// to perform deletion synchronization
cmd.Flags().VarP(&options.deleteCommand, "delete", "d", "A command to run when resources are deleted. Specify mulitple times to add arguments.")
cmd.Flags().Var(&options.nameSyncCommand, "names", "A command that will list all of the currently known names, optional. Specify multiple times to add arguments. Use to get notifications when objects are deleted.")
// add additional arguments / info to the server
cmd.Flags().StringVar(&options.templateType, "output", options.templateType, "Controls the template type used for the --argument flags. Supported values are gotemplate and jsonpath.")
cmd.Flags().BoolVar(&options.strictTemplates, "strict-templates", false, "If true return an error on any field or map key that is not missing in a template.")
cmd.Flags().VarP(&options.templates, "argument", "a", "Template for the arguments to be passed to each command in the format defined by --output.")
cmd.Flags().StringVar(&options.typeEnvVar, "type-env-var", "", "The name of an env var to set with the type of event received ('Sync', 'Updated', 'Deleted', 'Added') to the reaction command or --delete.")
cmd.Flags().StringVar(&options.objectEnvVar, "object-env-var", "", "The name of an env var to serialize the object to when calling the command, optional.")
// control retries of individual commands
cmd.Flags().IntVar(&options.maximumErrors, "maximum-errors", options.maximumErrors, "Exit after this many errors have been detected with. May be set to -1 for no maximum.")
cmd.Flags().IntVar(&options.retryExitStatus, "retry-on-exit-code", 0, "If any command returns this exit code, retry up to --retry-count times.")
cmd.Flags().IntVar(&options.retryCount, "retry-count", options.retryCount, "The number of times to retry a failing command before continuing.")
// control observe program behavior
cmd.Flags().BoolVar(&options.once, "once", false, "Exit with a status code 0 after all current objects have been processed.")
cmd.Flags().DurationVar(&options.exitAfterPeriod, "exit-after", 0, "Exit with status code 0 after the provided duration, optional.")
cmd.Flags().DurationVar(&options.resyncPeriod, "resync-period", 0, "When non-zero, periodically reprocess every item from the server as a Sync event. Use to ensure external systems are kept up to date. Requires --names")
cmd.Flags().BoolVar(&options.printMetricsOnExit, "print-metrics-on-exit", false, "On exit write all metrics to stdout.")
cmd.Flags().StringVar(&options.listenAddr, "listen-addr", options.listenAddr, "The name of an interface to listen on to expose metrics and health checking.")
// additional debug output
cmd.Flags().BoolVar(&options.noHeaders, "no-headers", false, "Skip printing information about each event prior to executing the command.")
return cmd
}
type ObserveOptions struct {
out, errOut io.Writer
debugOut io.Writer
noHeaders bool
client resource.RESTClient
mapping *meta.RESTMapping
includeNamespace bool
// which resources to select
namespace string
allNamespaces bool
// additional debugging information
listenAddr string
// actions to take on each object
eachCommand []string
objectEnvVar string
typeEnvVar string
deleteCommand stringSliceFlag
// controls whether deletes are included
nameSyncCommand stringSliceFlag
// error handling logic
observedErrors int
maximumErrors int
retryCount int
retryExitStatus int
// when to exit or reprocess the list of items
once bool
exitAfterPeriod time.Duration
resyncPeriod time.Duration
printMetricsOnExit bool
// control the output of the command
templateType string
templates stringSliceFlag
printer ColumnPrinter
strictTemplates bool
argumentStore *objectArgumentsStore
// knownObjects is nil if we do not need to track deletions
knownObjects knownObjects
baseCommandName string
}
func (o *ObserveOptions) Complete(f *clientcmd.Factory, cmd *cobra.Command, args []string, out, errOut io.Writer) error {
var err error
var command []string
if i := cmd.ArgsLenAtDash(); i != -1 {
command = args[i:]
args = args[:i]
}
o.eachCommand = command
switch len(args) {
case 0:
return fmt.Errorf("you must specify at least one argument containing the resource to observe")
case 1:
default:
return fmt.Errorf("you may only specify one argument containing the resource to observe (use '--' to separate your resource and your command)")
}
gr := unversioned.ParseGroupResource(args[0])
if gr.Empty() {
return fmt.Errorf("unknown resource argument")
}
mapper, _ := f.Object(true)
version, err := mapper.KindFor(gr.WithVersion(""))
if err != nil {
return err
}
mapping, err := mapper.RESTMapping(version.GroupKind())
if err != nil {
return err
}
o.mapping = mapping
o.includeNamespace = mapping.Scope.Name() == meta.RESTScopeNamespace.Name()
client, err := f.ClientForMapping(mapping)
if err != nil {
return err
}
o.client = client
o.namespace, _, err = f.DefaultNamespace()
if err != nil {
return err
}
switch o.templateType {
case "jsonpath":
p, err := NewJSONPathArgumentPrinter(o.includeNamespace, o.strictTemplates, o.templates...)
if err != nil {
return err
}
o.printer = p
case "gotemplate":
p, err := NewGoTemplateArgumentPrinter(o.includeNamespace, o.strictTemplates, o.templates...)
if err != nil {
return err
}
o.printer = p
default:
return fmt.Errorf("template type %q not recognized - valid values are jsonpath and gotemplate", o.templateType)
}
o.printer = NewVersionedColumnPrinter(o.printer, o.mapping.ObjectConvertor, version.GroupVersion())
o.out, o.errOut = out, errOut
if o.noHeaders {
o.debugOut = ioutil.Discard
} else {
o.debugOut = out
}
o.argumentStore = &objectArgumentsStore{}
switch {
case len(o.nameSyncCommand) > 0:
o.argumentStore.keyFn = func() ([]string, error) {
var out []byte
err := retryCommandError(o.retryExitStatus, o.retryCount, func() error {
c := exec.Command(o.nameSyncCommand[0], o.nameSyncCommand[1:]...)
var err error
return measureCommandDuration(nameExecDurations, func() error {
out, err = c.Output()
return err
})
})
if err != nil {
if exit, ok := err.(*exec.ExitError); ok {
if len(exit.Stderr) > 0 {
err = fmt.Errorf("%v\n%s", err, string(exit.Stderr))
}
}
return nil, err
}
names := strings.Split(string(out), "\n")
sort.Sort(sort.StringSlice(names))
var outputNames []string
for i, s := range names {
if len(s) != 0 {
outputNames = names[i:]
break
}
}
glog.V(4).Infof("Found existing keys: %v", outputNames)
return outputNames, nil
}
o.knownObjects = o.argumentStore
case len(o.deleteCommand) > 0:
o.knownObjects = o.argumentStore
}
return nil
}
func (o *ObserveOptions) Validate(args []string) error {
if len(o.nameSyncCommand) > 0 && len(o.deleteCommand) == 0 {
return fmt.Errorf("--delete and --names must both be specified")
}
return nil
}
func (o *ObserveOptions) Run() error {
if len(o.deleteCommand) > 0 && len(o.nameSyncCommand) == 0 {
fmt.Fprintf(o.errOut, "warning: If you are modifying resources outside of %q, you should use the --names command to ensure you don't miss deletions that occur while the command is not running.\n", o.mapping.Resource)
}
// watch the given resource for changes
store := cache.NewDeltaFIFO(objectArgumentsKeyFunc, nil, o.knownObjects)
lw := restListWatcher{Helper: resource.NewHelper(o.client, o.mapping)}
if !o.allNamespaces {
lw.namespace = o.namespace
}
// ensure any child processes are reaped if we are running as PID 1
proc.StartReaper()
// listen on the provided address for metrics
if len(o.listenAddr) > 0 {
prometheus.MustRegister(observeCounts)
prometheus.MustRegister(execDurations)
prometheus.MustRegister(nameExecDurations)
errWaitingForSync := fmt.Errorf("waiting for initial sync")
healthz.InstallHandler(http.DefaultServeMux, healthz.NamedCheck("ready", func(r *http.Request) error {
if !store.HasSynced() {
return errWaitingForSync
}
return nil
}))
http.Handle("/metrics", prometheus.Handler())
go func() {
glog.Fatalf("Unable to listen on %q: %v", o.listenAddr, http.ListenAndServe(o.listenAddr, nil))
}()
glog.V(2).Infof("Listening on %s at /metrics and /healthz", o.listenAddr)
}
// exit cleanly after a certain period
// lock guards the loop to ensure no child processes are running
var lock sync.Mutex
if o.exitAfterPeriod > 0 {
go func() {
<-time.After(o.exitAfterPeriod)
lock.Lock()
o.dumpMetrics()
fmt.Fprintf(o.errOut, "Shutting down after %s ...\n", o.exitAfterPeriod)
os.Exit(0)
}()
}
defer o.dumpMetrics()
// start the reflector
reflector := cache.NewNamedReflector("observer", lw, nil, store, o.resyncPeriod)
reflector.Run()
if o.once {
// wait until the reflector reports it has completed the initial list and the
// fifo has been populated
for len(reflector.LastSyncResourceVersion()) == 0 {
time.Sleep(50 * time.Millisecond)
}
// if the store is empty, there is nothing to sync
if store.HasSynced() && len(store.ListKeys()) == 0 {
fmt.Fprintf(o.errOut, "Nothing to sync, exiting immediately\n")
return nil
}
}
// process all changes that occur in the resource
syncing := false
for {
_, err := store.Pop(func(obj interface{}) error {
// if we failed to retrieve the list of keys, exit
if err := o.argumentStore.ListKeysError(); err != nil {
return fmt.Errorf("unable to list known keys: %v", err)
}
deltas := obj.(cache.Deltas)
for _, delta := range deltas {
lock.Lock()
// handle before and after observe notification
switch {
case !syncing && delta.Type == cache.Sync:
if err := o.startSync(); err != nil {
return err
}
syncing = true
case syncing && delta.Type != cache.Sync:
if err := o.finishSync(); err != nil {
return err
}
syncing = false
}
// require the user to provide a name function in order to get events beyond added / updated
if !syncing && o.knownObjects == nil && !(delta.Type == cache.Added || delta.Type == cache.Updated) {
continue
}
observeCounts.WithLabelValues(string(delta.Type)).Inc()
// calculate the arguments for the delta and then invoke any command
object, arguments, output, err := o.calculateArguments(delta)
if err != nil {
return err
}
if err := o.next(delta.Type, object, output, arguments); err != nil {
return err
}
lock.Unlock()
}
return nil
})
if err != nil {
return err
}
// if we only want to run once, exit here
if o.once && store.HasSynced() {
if syncing {
if err := o.finishSync(); err != nil {
return err
}
}
return nil
}
}
}
// calculateArguments determines the arguments for a give delta and updates the argument store, or returns
// an error. If the object can be transformed into a full JSON object, that is also returned.
func (o *ObserveOptions) calculateArguments(delta cache.Delta) (runtime.Object, []string, []byte, error) {
var arguments []string
var object runtime.Object
var key string
var output []byte
switch t := delta.Object.(type) {
case cache.DeletedFinalStateUnknown:
key = t.Key
if obj, ok := t.Obj.(runtime.Object); ok {
object = obj
args, data, err := o.printer.Print(obj)
if err != nil {
return nil, nil, nil, fmt.Errorf("unable to write arguments: %v", err)
}
arguments = args
output = data
} else {
value, _, err := o.argumentStore.GetByKey(key)
if err != nil {
return nil, nil, nil, err
}
if value != nil {
args, ok := value.(objectArguments)
if !ok {
return nil, nil, nil, fmt.Errorf("unexpected cache value %T", value)
}
arguments = args.arguments
output = args.output
}
}
o.argumentStore.Remove(key)
case runtime.Object:
object = t
args, data, err := o.printer.Print(t)
if err != nil {
return nil, nil, nil, fmt.Errorf("unable to write arguments: %v", err)
}
arguments = args
output = data
key, _ = cache.MetaNamespaceKeyFunc(t)
if delta.Type == cache.Deleted {
o.argumentStore.Remove(key)
} else {
saved := objectArguments{key: key, arguments: arguments}
// only cache the object data if the commands will be using it.
if len(o.objectEnvVar) > 0 {
saved.output = output
}
o.argumentStore.Put(key, saved)
}
case objectArguments:
key = t.key
arguments = t.arguments
output = t.output
default:
return nil, nil, nil, fmt.Errorf("unrecognized object %T from cache store", delta.Object)
}
if object == nil {
namespace, name, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return nil, nil, nil, err
}
unstructured := &runtime.Unstructured{}
unstructured.SetNamespace(namespace)
unstructured.SetName(name)
object = unstructured
}
return object, arguments, output, nil
}
func (o *ObserveOptions) startSync() error {
fmt.Fprintf(o.debugOut, "# %s Sync started\n", time.Now().Format(time.RFC3339))
return nil
}
func (o *ObserveOptions) finishSync() error {
fmt.Fprintf(o.debugOut, "# %s Sync ended\n", time.Now().Format(time.RFC3339))
return nil
}
func (o *ObserveOptions) next(deltaType cache.DeltaType, obj runtime.Object, output []byte, arguments []string) error {
glog.V(4).Infof("Processing %s %v: %#v", deltaType, arguments, obj)
m, err := meta.Accessor(obj)
if err != nil {
return fmt.Errorf("unable to handle %T: %v", obj, err)
}
resourceVersion := m.GetResourceVersion()
outType := string(deltaType)
var args []string
if o.includeNamespace {
args = append(args, m.GetNamespace())
}
args = append(args, m.GetName())
var command string
switch {
case deltaType == cache.Deleted:
if len(o.deleteCommand) > 0 {
command = o.deleteCommand[0]
args = append(append([]string{}, o.deleteCommand[1:]...), args...)
}
case len(o.eachCommand) > 0:
command = o.eachCommand[0]
args = append(append([]string{}, o.eachCommand[1:]...), args...)
}
args = append(args, arguments...)
if len(command) == 0 {
fmt.Fprintf(o.debugOut, "# %s %s %s\t%s\n", time.Now().Format(time.RFC3339), outType, resourceVersion, printCommandLine(command, args...))
return nil
}
fmt.Fprintf(o.debugOut, "# %s %s %s\t%s\n", time.Now().Format(time.RFC3339), outType, resourceVersion, printCommandLine(command, args...))
out, errOut := &newlineTrailingWriter{w: o.out}, &newlineTrailingWriter{w: o.errOut}
err = retryCommandError(o.retryExitStatus, o.retryCount, func() error {
cmd := exec.Command(command, args...)
cmd.Stdout = out
cmd.Stderr = errOut
if len(o.objectEnvVar) > 0 {
cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", o.objectEnvVar, string(output)))
}
if len(o.typeEnvVar) > 0 {
cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", o.typeEnvVar, string(outType)))
}
err := measureCommandDuration(execDurations, cmd.Run, outType)
out.Flush()
errOut.Flush()
return err
})
if err != nil {
if code, ok := exitCodeForCommandError(err); ok && code != 0 {
err = fmt.Errorf("command %q exited with status code %d", command, code)
}
return o.handleCommandError(err)
}
return nil
}
func (o *ObserveOptions) handleCommandError(err error) error {
if err == nil {
return nil
}
o.observedErrors++
fmt.Fprintf(o.errOut, "error: %v\n", err)
if o.maximumErrors == -1 || o.observedErrors < o.maximumErrors {
return nil
}
return fmt.Errorf("reached maximum error limit of %d, exiting", o.maximumErrors)
}
func (o *ObserveOptions) dumpMetrics() {
if !o.printMetricsOnExit {
return
}
w := httptest.NewRecorder()
prometheus.UninstrumentedHandler().ServeHTTP(w, &http.Request{})
if w.Code == http.StatusOK {
fmt.Fprintf(o.out, w.Body.String())
}
}
func measureCommandDuration(m *prometheus.SummaryVec, fn func() error, labels ...string) error {
n := time.Now()
err := fn()
duration := time.Now().Sub(n)
statusCode, ok := exitCodeForCommandError(err)
if !ok {
statusCode = -1
}
m.WithLabelValues(append(labels, strconv.Itoa(statusCode))...).Observe(float64(duration / time.Millisecond))
return err
}
func exitCodeForCommandError(err error) (int, bool) {
if err == nil {
return 0, true
}
if exit, ok := err.(*exec.ExitError); ok {
if ws, ok := exit.ProcessState.Sys().(syscall.WaitStatus); ok {
return ws.ExitStatus(), true
}
}
return 0, false
}
func retryCommandError(onExitStatus, times int, fn func() error) error {
err := fn()
if err != nil && onExitStatus != 0 && times > 0 {
if status, ok := exitCodeForCommandError(err); ok {
if status == onExitStatus {
glog.V(4).Infof("retrying command: %v", err)
return retryCommandError(onExitStatus, times-1, fn)
}
}
}
return err
}
func printCommandLine(cmd string, args ...string) string {
outCmd := cmd
if strings.ContainsAny(outCmd, "\"\\ ") {
outCmd = strconv.Quote(outCmd)
}
if len(outCmd) == 0 {
outCmd = "\"\""
}
outArgs := make([]string, 0, len(args))
for _, s := range args {
if strings.ContainsAny(s, "\"\\ ") {
s = strconv.Quote(s)
}
if len(s) == 0 {
s = "\"\""
}
outArgs = append(outArgs, s)
}
if len(outArgs) == 0 {
return outCmd
}
return fmt.Sprintf("%s %s", outCmd, strings.Join(outArgs, " "))
}
type restListWatcher struct {
*resource.Helper
namespace string
}
func (lw restListWatcher) List(opt api.ListOptions) (runtime.Object, error) {
return lw.Helper.List(lw.namespace, "", opt.LabelSelector, false)
}
func (lw restListWatcher) Watch(opt api.ListOptions) (watch.Interface, error) {
return lw.Helper.Watch(lw.namespace, opt.ResourceVersion, "", opt.LabelSelector)
}
type JSONPathColumnPrinter struct {
includeNamespace bool
rawTemplates []string
templates []*jsonpath.JSONPath
buf *bytes.Buffer
}
func NewJSONPathArgumentPrinter(includeNamespace, strict bool, templates ...string) (*JSONPathColumnPrinter, error) {
p := &JSONPathColumnPrinter{
includeNamespace: includeNamespace,
rawTemplates: templates,
buf: &bytes.Buffer{},
}
for _, s := range templates {
t := jsonpath.New("template").AllowMissingKeys(!strict)
if err := t.Parse(s); err != nil {
return nil, err
}
p.templates = append(p.templates, t)
}
return p, nil
}
func (p *JSONPathColumnPrinter) Print(obj interface{}) ([]string, []byte, error) {
var columns []string
for i, t := range p.templates {
p.buf.Reset()
if err := t.Execute(p.buf, obj); err != nil {
return nil, nil, fmt.Errorf("error executing template '%v': '%v'\n----data----\n%+v\n", p.rawTemplates[i], err, obj)
}
columns = append(columns, p.buf.String())
}
return columns, nil, nil
}
type GoTemplateColumnPrinter struct {
includeNamespace bool
strict bool
rawTemplates []string
templates []*template.Template
buf *bytes.Buffer
}
func NewGoTemplateArgumentPrinter(includeNamespace, strict bool, templates ...string) (*GoTemplateColumnPrinter, error) {
p := &GoTemplateColumnPrinter{
includeNamespace: includeNamespace,
strict: strict,
rawTemplates: templates,
buf: &bytes.Buffer{},
}
for _, s := range templates {
t := template.New("template")
child, err := t.Parse(s)
if err != nil {
return nil, err
}
if !strict {
child.Option("missingkey=zero")
}
p.templates = append(p.templates, child)
}
return p, nil
}
func (p *GoTemplateColumnPrinter) Print(obj interface{}) ([]string, []byte, error) {
var columns []string
for i, t := range p.templates {
p.buf.Reset()
if err := t.Execute(p.buf, obj); err != nil {
return nil, nil, fmt.Errorf("error executing template '%v': '%v'\n----data----\n%+v\n", p.rawTemplates[i], err, obj)
}
// if the template resolves to the special <no value> result, return it as an empty string
// most arguments will prefer empty vs an arbitary constant, and we are making gotemplates consistent with
// jsonpath
if p.buf.String() == "<no value>" {
if p.strict {
return nil, nil, fmt.Errorf("error executing template '%v': <no value>", p.rawTemplates[i])
}
columns = append(columns, "")
} else {
columns = append(columns, p.buf.String())
}
}
return columns, nil, nil
}
type ColumnPrinter interface {
Print(obj interface{}) ([]string, []byte, error)
}
// VersionedPrinter takes runtime objects and ensures they are converted to a given API version
// prior to being passed to a nested printer.
type VersionedColumnPrinter struct {
printer ColumnPrinter
convertor runtime.ObjectConvertor
version runtime.GroupVersioner
}
// NewVersionedHumanReadablePrinter wraps a printer to convert objects to a known API version prior to printing.
func NewVersionedColumnPrinter(printer ColumnPrinter, convertor runtime.ObjectConvertor, version runtime.GroupVersioner) ColumnPrinter {
return &VersionedColumnPrinter{
printer: printer,
convertor: convertor,
version: version,
}
}
// Print converts the object to a map[string]interface{} in the target version before calling the nested printer.
func (p *VersionedColumnPrinter) Print(out interface{}) ([]string, []byte, error) {
var output []byte
if obj, ok := out.(runtime.Object); ok {
converted, err := p.convertor.ConvertToVersion(obj, p.version)
if err != nil {
if !runtime.IsNotRegisteredError(err) {
return nil, nil, err
}
converted = obj
}
data, err := json.Marshal(converted)
if err != nil {
return nil, nil, err
}
output = data
out = map[string]interface{}{}
if err := json.Unmarshal(data, &out); err != nil {
return nil, nil, err
}
}
args, _, err := p.printer.Print(out)
return args, output, err
}
type knownObjects interface {
cache.KeyListerGetter
ListKeysError() error
Put(key string, value interface{})
Remove(key string)
}
type objectArguments struct {
key string
arguments []string
output []byte
}
func objectArgumentsKeyFunc(obj interface{}) (string, error) {
if args, ok := obj.(objectArguments); ok {
return args.key, nil
}
return cache.MetaNamespaceKeyFunc(obj)
}
type objectArgumentsStore struct {
keyFn func() ([]string, error)
lock sync.Mutex
arguments map[string]interface{}
err error
}
func (r *objectArgumentsStore) ListKeysError() error {
r.lock.Lock()
defer r.lock.Unlock()
return r.err
}
func (r *objectArgumentsStore) ListKeys() []string {
r.lock.Lock()
defer r.lock.Unlock()
if r.keyFn != nil {
var keys []string
keys, r.err = r.keyFn()
return keys
}
keys := make([]string, 0, len(r.arguments))
for k := range r.arguments {
keys = append(keys, k)
}
return keys
}
func (r *objectArgumentsStore) GetByKey(key string) (interface{}, bool, error) {
r.lock.Lock()
defer r.lock.Unlock()
args := r.arguments[key]
return args, true, nil
}
func (r *objectArgumentsStore) Put(key string, arguments interface{}) {
r.lock.Lock()
defer r.lock.Unlock()
if r.arguments == nil {
r.arguments = make(map[string]interface{})
}
r.arguments[key] = arguments
}
func (r *objectArgumentsStore) Remove(key string) {
r.lock.Lock()
defer r.lock.Unlock()
delete(r.arguments, key)
}
type newlineTrailingWriter struct {
w io.Writer
openLine bool
}
func (w *newlineTrailingWriter) Write(data []byte) (int, error) {
if len(data) > 0 && data[len(data)-1] != '\n' {
w.openLine = true
}
return w.w.Write(data)
}
func (w *newlineTrailingWriter) Flush() error {
if w.openLine {
w.openLine = false
_, err := fmt.Fprintln(w.w)
return err
}
return nil
}
type stringSliceFlag []string
func (f *stringSliceFlag) Set(value string) error {
*f = append(*f, value)
return nil
}
func (f *stringSliceFlag) String() string { return strings.Join(*f, " ") }
func (f *stringSliceFlag) Type() string { return "string" }