| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package k8ssd |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "fmt" |
| 8 | "log/slog" |
| 9 | "os" |
| 10 | "strings" |
| 11 | "sync" |
| 12 | "time" |
| 13 | |
| 14 | "github.com/netdata/netdata/go/plugins/logger" |
| 15 | "github.com/netdata/netdata/go/plugins/plugin/agent/discovery/sd/model" |
| 16 | "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/k8sclient" |
| 17 | |
| 18 | corev1 "k8s.io/api/core/v1" |
| 19 | metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 20 | "k8s.io/apimachinery/pkg/runtime" |
| 21 | "k8s.io/apimachinery/pkg/watch" |
| 22 | "k8s.io/client-go/kubernetes" |
| 23 | "k8s.io/client-go/tools/cache" |
| 24 | "k8s.io/client-go/util/workqueue" |
| 25 | ) |
| 26 | |
| 27 | type role string |
| 28 | |
| 29 | const ( |
| 30 | rolePod role = "pod" |
| 31 | roleService role = "service" |
| 32 | ) |
| 33 | |
| 34 | const ( |
| 35 | envNodeName = "MY_NODE_NAME" |
| 36 | ) |
| 37 | |
| 38 | var log = logger.New().With( |
| 39 | slog.String("component", "service discovery"), |
| 40 | slog.String("discoverer", "kubernetes"), |
| 41 | ) |
| 42 | |
| 43 | func NewDiscoverer(cfg Config) (*KubeDiscoverer, error) { |
| 44 | if err := validateConfig(cfg); err != nil { |
| 45 | return nil, fmt.Errorf("config validation: %v", err) |
| 46 | } |
| 47 | |
| 48 | client, err := k8sclient.New("Netdata/service-td") |
| 49 | if err != nil { |
| 50 | return nil, fmt.Errorf("create clientset: %v", err) |
| 51 | } |
| 52 | |
| 53 | ns := cfg.Namespaces |
| 54 | if len(ns) == 0 { |
| 55 | ns = []string{corev1.NamespaceAll} |
| 56 | } |
| 57 | |
| 58 | selectorField := cfg.Selector.Field |
| 59 | if role(cfg.Role) == rolePod && cfg.Pod.LocalMode { |
| 60 | name := os.Getenv(envNodeName) |
| 61 | if name == "" { |
| 62 | return nil, fmt.Errorf("local_mode is enabled, but env '%s' not set", envNodeName) |
| 63 | } |
| 64 | selectorField = joinSelectors(selectorField, "spec.nodeName="+name) |
| 65 | } |
| 66 | |
| 67 | d := &KubeDiscoverer{ |
| 68 | Logger: log, |
| 69 | cfgSource: cfg.Source, |
| 70 | client: client, |
| 71 | role: role(cfg.Role), |
| 72 | namespaces: ns, |
| 73 | selectorLabel: cfg.Selector.Label, |
| 74 | selectorField: selectorField, |
| 75 | discoverers: make([]model.Discoverer, 0, len(ns)), |
| 76 | started: make(chan struct{}), |
| 77 | } |
| 78 | |
| 79 | return d, nil |
| 80 | } |
| 81 | |
| 82 | type KubeDiscoverer struct { |
| 83 | *logger.Logger |
| 84 | |
| 85 | cfgSource string |
| 86 | |
| 87 | client kubernetes.Interface |
| 88 | |
| 89 | role role |
| 90 | namespaces []string |
| 91 | selectorLabel string |
| 92 | selectorField string |
| 93 | discoverers []model.Discoverer |
| 94 | started chan struct{} |
| 95 | } |
| 96 | |
| 97 | func (d *KubeDiscoverer) String() string { |
| 98 | return "sd:k8s" |
| 99 | } |
| 100 | |
| 101 | const resyncPeriod = 10 * time.Minute |
| 102 | |
| 103 | func (d *KubeDiscoverer) Discover(ctx context.Context, in chan<- []model.TargetGroup) { |
| 104 | d.Info("instance is started") |
| 105 | defer d.Info("instance is stopped") |
| 106 | |
| 107 | for _, namespace := range d.namespaces { |
| 108 | var dd model.Discoverer |
| 109 | switch d.role { |
| 110 | case rolePod: |
| 111 | dd = d.setupPodDiscoverer(ctx, namespace) |
| 112 | case roleService: |
| 113 | dd = d.setupServiceDiscoverer(ctx, namespace) |
| 114 | default: |
| 115 | d.Errorf("unknown role: '%s'", d.role) |
| 116 | continue |
| 117 | } |
| 118 | d.discoverers = append(d.discoverers, dd) |
| 119 | } |
| 120 | |
| 121 | if len(d.discoverers) == 0 { |
| 122 | d.Error("no discoverers registered") |
| 123 | return |
| 124 | } |
| 125 | |
| 126 | d.Infof("registered: %v", d.discoverers) |
| 127 | |
| 128 | var wg sync.WaitGroup |
| 129 | updates := make(chan []model.TargetGroup) |
| 130 | |
| 131 | for _, disc := range d.discoverers { |
| 132 | wg.Add(1) |
| 133 | go func(disc model.Discoverer) { defer wg.Done(); disc.Discover(ctx, updates) }(disc) |
| 134 | } |
| 135 | |
| 136 | done := make(chan struct{}) |
| 137 | go func() { defer close(done); wg.Wait() }() |
| 138 | |
| 139 | close(d.started) |
| 140 | |
| 141 | for { |
| 142 | select { |
| 143 | case <-ctx.Done(): |
| 144 | select { |
| 145 | case <-done: |
| 146 | d.Info("all discoverers exited") |
| 147 | case <-time.After(time.Second * 5): |
| 148 | d.Warning("not all discoverers exited") |
| 149 | } |
| 150 | return |
| 151 | case <-done: |
| 152 | d.Info("all discoverers exited") |
| 153 | return |
| 154 | case tggs := <-updates: |
| 155 | if d.cfgSource != "" { |
| 156 | for _, tgg := range tggs { |
| 157 | if v, ok := tgg.(interface{ setSource(string) }); ok { |
| 158 | src := fmt.Sprintf("%s,%s", tgg.Source(), d.cfgSource) |
| 159 | v.setSource(src) |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | select { |
| 164 | case <-ctx.Done(): |
| 165 | case in <- tggs: |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | func (d *KubeDiscoverer) setupPodDiscoverer(ctx context.Context, ns string) *podDiscoverer { |
| 172 | pod := d.client.CoreV1().Pods(ns) |
| 173 | podLW := cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{ |
| 174 | ListWithContextFunc: func(_ context.Context, opts metav1.ListOptions) (runtime.Object, error) { |
| 175 | opts.FieldSelector = d.selectorField |
| 176 | opts.LabelSelector = d.selectorLabel |
| 177 | return pod.List(ctx, opts) |
| 178 | }, |
| 179 | WatchFuncWithContext: func(_ context.Context, opts metav1.ListOptions) (watch.Interface, error) { |
| 180 | opts.FieldSelector = d.selectorField |
| 181 | opts.LabelSelector = d.selectorLabel |
| 182 | return pod.Watch(ctx, opts) |
| 183 | }, |
| 184 | }, d.client) |
| 185 | |
| 186 | cmap := d.client.CoreV1().ConfigMaps(ns) |
| 187 | cmapLW := cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{ |
| 188 | ListWithContextFunc: func(_ context.Context, opts metav1.ListOptions) (runtime.Object, error) { |
| 189 | return cmap.List(ctx, opts) |
| 190 | }, |
| 191 | WatchFuncWithContext: func(_ context.Context, opts metav1.ListOptions) (watch.Interface, error) { |
| 192 | return cmap.Watch(ctx, opts) |
| 193 | }, |
| 194 | }, d.client) |
| 195 | |
| 196 | secret := d.client.CoreV1().Secrets(ns) |
| 197 | secretLW := cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{ |
| 198 | ListWithContextFunc: func(_ context.Context, opts metav1.ListOptions) (runtime.Object, error) { |
| 199 | return secret.List(ctx, opts) |
| 200 | }, |
| 201 | WatchFuncWithContext: func(_ context.Context, opts metav1.ListOptions) (watch.Interface, error) { |
| 202 | return secret.Watch(ctx, opts) |
| 203 | }, |
| 204 | }, d.client) |
| 205 | |
| 206 | td := newPodDiscoverer( |
| 207 | cache.NewSharedInformer(podLW, &corev1.Pod{}, resyncPeriod), |
| 208 | cache.NewSharedInformer(cmapLW, &corev1.ConfigMap{}, resyncPeriod), |
| 209 | cache.NewSharedInformer(secretLW, &corev1.Secret{}, resyncPeriod), |
| 210 | ) |
| 211 | |
| 212 | return td |
| 213 | } |
| 214 | |
| 215 | func (d *KubeDiscoverer) setupServiceDiscoverer(ctx context.Context, namespace string) *serviceDiscoverer { |
| 216 | svc := d.client.CoreV1().Services(namespace) |
| 217 | |
| 218 | svcLW := cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{ |
| 219 | ListWithContextFunc: func(_ context.Context, opts metav1.ListOptions) (runtime.Object, error) { |
| 220 | opts.FieldSelector = d.selectorField |
| 221 | opts.LabelSelector = d.selectorLabel |
| 222 | return svc.List(ctx, opts) |
| 223 | }, |
| 224 | WatchFuncWithContext: func(_ context.Context, opts metav1.ListOptions) (watch.Interface, error) { |
| 225 | opts.FieldSelector = d.selectorField |
| 226 | opts.LabelSelector = d.selectorLabel |
| 227 | return svc.Watch(ctx, opts) |
| 228 | }, |
| 229 | }, d.client) |
| 230 | |
| 231 | inf := cache.NewSharedInformer(svcLW, &corev1.Service{}, resyncPeriod) |
| 232 | |
| 233 | td := newServiceDiscoverer(inf) |
| 234 | |
| 235 | return td |
| 236 | } |
| 237 | |
| 238 | func enqueue(queue *workqueue.Typed[any], obj any) { |
| 239 | key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj) |
| 240 | if err != nil { |
| 241 | return |
| 242 | } |
| 243 | queue.Add(key) |
| 244 | } |
| 245 | |
| 246 | func joinSelectors(srs ...string) string { |
| 247 | var i int |
| 248 | for _, v := range srs { |
| 249 | if v != "" { |
| 250 | srs[i] = v |
| 251 | i++ |
| 252 | } |
| 253 | } |
| 254 | return strings.Join(srs[:i], ",") |
| 255 | } |