k9s/internal/watch/meta.go

120 lines
2.8 KiB
Go

package watch
import (
"errors"
"fmt"
"github.com/derailed/k9s/internal/k8s"
"github.com/rs/zerolog/log"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/client-go/tools/cache"
)
type (
// Row represents a collection of string fields.
Row []string
// RowEvent represents a call for action after a resource reconciliation.
// Tracks whether a resource got added, deleted or updated.
RowEvent struct {
Action watch.EventType
Fields Row
Deltas Row
}
// RowEvents tracks resource update events.
RowEvents map[string]*RowEvent
// TableData tracks a K8s resource for tabular display.
TableData struct {
Header Row
Rows RowEvents
Namespace string
}
)
// TableListenerFn represents a table data listener.
type TableListenerFn func(TableData)
// CallbackInformer an informer that allows listeners registration.
type CallbackInformer interface {
cache.SharedIndexInformer
Get(fqn string) (interface{}, error)
List(ns string) (k8s.Collection, error)
SetListener(ns string, cb TableListenerFn)
UnsetListener(ns string)
}
// Meta represents a collection of cluster wide watchers.
type Meta struct {
informers map[string]CallbackInformer
client k8s.Connection
podInformer *Pod
listenerFn TableListenerFn
}
// NewMeta creates a new cluster resource informer
func NewMeta(client k8s.Connection, ns string) *Meta {
m := Meta{client: client, informers: map[string]CallbackInformer{}}
m.init(ns)
return &m
}
func (m *Meta) init(ns string) {
po := NewPod(m.client, ns)
m.informers = map[string]CallbackInformer{
NodeIndex: NewNode(m.client),
NodeMXIndex: NewNodeMetrics(m.client),
PodIndex: po,
PodMXIndex: NewPodMetrics(m.client, ns),
ContainerIndex: NewContainer(po),
}
}
// List items from store.
func (m *Meta) List(res, ns string) (k8s.Collection, error) {
if m == nil {
return nil, fmt.Errorf("No meta exists")
}
if i, ok := m.informers[res]; ok {
return i.List(ns)
}
return nil, fmt.Errorf("No informer found for resource %s", res)
}
// RegisterListener register table data listeners.
func (m *Meta) RegisterListener(res, ns string, cb TableListenerFn) {
if informer, ok := m.informers[res]; ok {
informer.SetListener(ns, cb)
} else {
log.Error().Msgf("No informer for %q:%s", ns, res)
}
}
// UnregisterListener register table data listeners.
func (m *Meta) UnregisterListener(ns string) {
for _, i := range m.informers {
i.UnsetListener(ns)
}
}
// Get a resource by name.
func (m Meta) Get(res, fqn string) (interface{}, error) {
if informer, ok := m.informers[res]; ok {
return informer.Get(fqn)
}
return nil, errors.New("Unable to local resource")
}
// Run starts watching cluster resources.
func (m *Meta) Run(closeCh <-chan struct{}) {
for i := range m.informers {
go func(informer CallbackInformer, c <-chan struct{}) {
informer.Run(c)
}(m.informers[i], closeCh)
}
}