-
Notifications
You must be signed in to change notification settings - Fork 1
/
graph.go
303 lines (263 loc) · 9.78 KB
/
graph.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
/*
Copyright 2017 The Kubernetes 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 node
import (
"sync"
pvutil "k8s.io/kubernetes/pkg/api/persistentvolume"
podutil "k8s.io/kubernetes/pkg/api/pod"
api "k8s.io/kubernetes/pkg/apis/core"
"k8s.io/kubernetes/third_party/forked/gonum/graph"
"k8s.io/kubernetes/third_party/forked/gonum/graph/simple"
)
// namedVertex implements graph.Node and remembers the type, namespace, and name of its related API object
type namedVertex struct {
name string
namespace string
id int
vertexType vertexType
}
func newNamedVertex(vertexType vertexType, namespace, name string, id int) *namedVertex {
return &namedVertex{
vertexType: vertexType,
name: name,
namespace: namespace,
id: id,
}
}
func (n *namedVertex) ID() int {
return n.id
}
func (n *namedVertex) String() string {
if len(n.namespace) == 0 {
return vertexTypes[n.vertexType] + ":" + n.name
}
return vertexTypes[n.vertexType] + ":" + n.namespace + "/" + n.name
}
// destinationEdge is a graph edge that includes a denormalized reference to the final destination vertex.
// This should only be used when there is a single leaf vertex reachable from T.
type destinationEdge struct {
F graph.Node
T graph.Node
Destination graph.Node
}
func newDestinationEdge(from, to, destination graph.Node) graph.Edge {
return &destinationEdge{F: from, T: to, Destination: destination}
}
func (e *destinationEdge) From() graph.Node { return e.F }
func (e *destinationEdge) To() graph.Node { return e.T }
func (e *destinationEdge) Weight() float64 { return 0 }
func (e *destinationEdge) DestinationID() int { return e.Destination.ID() }
// Graph holds graph vertices and a way to look up a vertex for a particular API type/namespace/name.
// All edges point toward the vertices representing Kubernetes nodes:
//
// node <- pod
// pod <- secret,configmap,pvc
// pvc <- pv
// pv <- secret
type Graph struct {
lock sync.RWMutex
graph *simple.DirectedAcyclicGraph
// vertices is a map of type -> namespace -> name -> vertex
vertices map[vertexType]namespaceVertexMapping
}
// namespaceVertexMapping is a map of namespace -> name -> vertex
type namespaceVertexMapping map[string]nameVertexMapping
// nameVertexMapping is a map of name -> vertex
type nameVertexMapping map[string]*namedVertex
func NewGraph() *Graph {
return &Graph{
vertices: map[vertexType]namespaceVertexMapping{},
graph: simple.NewDirectedAcyclicGraph(0, 0),
}
}
// vertexType indicates the type of the API object the vertex represents.
// represented as a byte to minimize space used in the vertices.
type vertexType byte
const (
configMapVertexType vertexType = iota
nodeVertexType
podVertexType
pvcVertexType
pvVertexType
secretVertexType
vaVertexType
serviceAccountVertexType
)
var vertexTypes = map[vertexType]string{
configMapVertexType: "configmap",
nodeVertexType: "node",
podVertexType: "pod",
pvcVertexType: "pvc",
pvVertexType: "pv",
secretVertexType: "secret",
vaVertexType: "volumeattachment",
serviceAccountVertexType: "serviceAccount",
}
// must be called under a write lock
func (g *Graph) getOrCreateVertex_locked(vertexType vertexType, namespace, name string) *namedVertex {
if vertex, exists := g.getVertex_rlocked(vertexType, namespace, name); exists {
return vertex
}
return g.createVertex_locked(vertexType, namespace, name)
}
// must be called under a read lock
func (g *Graph) getVertex_rlocked(vertexType vertexType, namespace, name string) (*namedVertex, bool) {
vertex, exists := g.vertices[vertexType][namespace][name]
return vertex, exists
}
// must be called under a write lock
func (g *Graph) createVertex_locked(vertexType vertexType, namespace, name string) *namedVertex {
typedVertices, exists := g.vertices[vertexType]
if !exists {
typedVertices = namespaceVertexMapping{}
g.vertices[vertexType] = typedVertices
}
namespacedVertices, exists := typedVertices[namespace]
if !exists {
namespacedVertices = map[string]*namedVertex{}
typedVertices[namespace] = namespacedVertices
}
vertex := newNamedVertex(vertexType, namespace, name, g.graph.NewNodeID())
namespacedVertices[name] = vertex
g.graph.AddNode(vertex)
return vertex
}
// must be called under write lock
func (g *Graph) deleteVertex_locked(vertexType vertexType, namespace, name string) {
vertex, exists := g.getVertex_rlocked(vertexType, namespace, name)
if !exists {
return
}
// find existing neighbors with a single edge (meaning we are their only neighbor)
neighborsToRemove := []graph.Node{}
g.graph.VisitFrom(vertex, func(neighbor graph.Node) bool {
// this downstream neighbor has only one edge (which must be from us), so remove them as well
if g.graph.Degree(neighbor) == 1 {
neighborsToRemove = append(neighborsToRemove, neighbor)
}
return true
})
g.graph.VisitTo(vertex, func(neighbor graph.Node) bool {
// this upstream neighbor has only one edge (which must be to us), so remove them as well
if g.graph.Degree(neighbor) == 1 {
neighborsToRemove = append(neighborsToRemove, neighbor)
}
return true
})
// remove the vertex
g.graph.RemoveNode(vertex)
delete(g.vertices[vertexType][namespace], name)
if len(g.vertices[vertexType][namespace]) == 0 {
delete(g.vertices[vertexType], namespace)
}
// remove neighbors that are now edgeless
for _, neighbor := range neighborsToRemove {
g.graph.RemoveNode(neighbor)
n := neighbor.(*namedVertex)
delete(g.vertices[n.vertexType][n.namespace], n.name)
if len(g.vertices[n.vertexType][n.namespace]) == 0 {
delete(g.vertices[n.vertexType], n.namespace)
}
}
}
// AddPod should only be called once spec.NodeName is populated.
// It sets up edges for the following relationships (which are immutable for a pod once bound to a node):
//
// pod -> node
//
// secret -> pod
// configmap -> pod
// pvc -> pod
// svcacct -> pod
func (g *Graph) AddPod(pod *api.Pod) {
g.lock.Lock()
defer g.lock.Unlock()
g.deleteVertex_locked(podVertexType, pod.Namespace, pod.Name)
podVertex := g.getOrCreateVertex_locked(podVertexType, pod.Namespace, pod.Name)
nodeVertex := g.getOrCreateVertex_locked(nodeVertexType, "", pod.Spec.NodeName)
g.graph.SetEdge(newDestinationEdge(podVertex, nodeVertex, nodeVertex))
// TODO(mikedanese): If the pod doesn't mount the service account secrets,
// should the node still get access to the service account?
//
// ref https://github.com/kubernetes/kubernetes/issues/58790
if len(pod.Spec.ServiceAccountName) > 0 {
g.graph.SetEdge(newDestinationEdge(g.getOrCreateVertex_locked(serviceAccountVertexType, pod.Namespace, pod.Spec.ServiceAccountName), podVertex, nodeVertex))
}
podutil.VisitPodSecretNames(pod, func(secret string) bool {
g.graph.SetEdge(newDestinationEdge(g.getOrCreateVertex_locked(secretVertexType, pod.Namespace, secret), podVertex, nodeVertex))
return true
})
podutil.VisitPodConfigmapNames(pod, func(configmap string) bool {
g.graph.SetEdge(newDestinationEdge(g.getOrCreateVertex_locked(configMapVertexType, pod.Namespace, configmap), podVertex, nodeVertex))
return true
})
for _, v := range pod.Spec.Volumes {
if v.PersistentVolumeClaim != nil {
g.graph.SetEdge(newDestinationEdge(g.getOrCreateVertex_locked(pvcVertexType, pod.Namespace, v.PersistentVolumeClaim.ClaimName), podVertex, nodeVertex))
}
}
}
func (g *Graph) DeletePod(name, namespace string) {
g.lock.Lock()
defer g.lock.Unlock()
g.deleteVertex_locked(podVertexType, namespace, name)
}
// AddPV sets up edges for the following relationships:
//
// secret -> pv
//
// pv -> pvc
func (g *Graph) AddPV(pv *api.PersistentVolume) {
g.lock.Lock()
defer g.lock.Unlock()
// clear existing edges
g.deleteVertex_locked(pvVertexType, "", pv.Name)
// if we have a pvc, establish new edges
if pv.Spec.ClaimRef != nil {
pvVertex := g.getOrCreateVertex_locked(pvVertexType, "", pv.Name)
// since we don't know the other end of the pvc -> pod -> node chain (or it may not even exist yet), we can't decorate these edges with kubernetes node info
g.graph.SetEdge(simple.Edge{F: pvVertex, T: g.getOrCreateVertex_locked(pvcVertexType, pv.Spec.ClaimRef.Namespace, pv.Spec.ClaimRef.Name)})
pvutil.VisitPVSecretNames(pv, func(namespace, secret string, kubeletVisible bool) bool {
// This grants access to the named secret in the same namespace as the bound PVC
if kubeletVisible {
g.graph.SetEdge(simple.Edge{F: g.getOrCreateVertex_locked(secretVertexType, namespace, secret), T: pvVertex})
}
return true
})
}
}
func (g *Graph) DeletePV(name string) {
g.lock.Lock()
defer g.lock.Unlock()
g.deleteVertex_locked(pvVertexType, "", name)
}
// AddVolumeAttachment sets up edges for the following relationships:
//
// volume attachment -> node
func (g *Graph) AddVolumeAttachment(attachmentName, nodeName string) {
g.lock.Lock()
defer g.lock.Unlock()
// clear existing edges
g.deleteVertex_locked(vaVertexType, "", attachmentName)
// if we have a node, establish new edges
if len(nodeName) > 0 {
vaVertex := g.getOrCreateVertex_locked(vaVertexType, "", attachmentName)
nodeVertex := g.getOrCreateVertex_locked(nodeVertexType, "", nodeName)
g.graph.SetEdge(newDestinationEdge(vaVertex, nodeVertex, nodeVertex))
}
}
func (g *Graph) DeleteVolumeAttachment(name string) {
g.lock.Lock()
defer g.lock.Unlock()
g.deleteVertex_locked(vaVertexType, "", name)
}