forked from openshift/origin
-
Notifications
You must be signed in to change notification settings - Fork 0
/
ovs.go
181 lines (159 loc) · 5.24 KB
/
ovs.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
// Package ovs provides a wrapper around ovs-vsctl and ovs-ofctl
package ovs
import (
"fmt"
"strconv"
"strings"
"github.com/golang/glog"
"k8s.io/kubernetes/pkg/util/exec"
)
const (
OVS_OFCTL = "ovs-ofctl"
OVS_VSCTL = "ovs-vsctl"
)
type Interface struct {
execer exec.Interface
bridge string
}
// New returns a new ovs.Interface
func New(execer exec.Interface, bridge string) (*Interface, error) {
if _, err := execer.LookPath(OVS_OFCTL); err != nil {
return nil, fmt.Errorf("OVS is not installed")
}
if _, err := execer.LookPath(OVS_VSCTL); err != nil {
return nil, fmt.Errorf("OVS is not installed")
}
return &Interface{execer: execer, bridge: bridge}, nil
}
func (ovsif *Interface) exec(cmd string, args ...string) (string, error) {
if cmd == OVS_OFCTL {
args = append([]string{"-O", "OpenFlow13"}, args...)
}
glog.V(5).Infof("Executing: %s %s", cmd, strings.Join(args, " "))
output, err := ovsif.execer.Command(cmd, args...).CombinedOutput()
if err != nil {
glog.V(5).Infof("Error executing %s: %s", cmd, string(output))
return "", err
}
outStr := string(output)
if outStr != "" {
// If output is a single line, strip the trailing newline
nl := strings.Index(outStr, "\n")
if nl == len(outStr)-1 {
outStr = outStr[:nl]
}
}
return outStr, nil
}
// AddBridge creates the bridge associated with the interface, optionally setting
// properties on it (as with "ovs-vsctl set Bridge ..."). If the bridge already
// existed, it will be destroyed and recreated.
func (ovsif *Interface) AddBridge(properties ...string) error {
args := []string{"--if-exists", "del-br", ovsif.bridge, "--", "add-br", ovsif.bridge}
if len(properties) > 0 {
args = append(args, "--", "set", "Bridge", ovsif.bridge)
args = append(args, properties...)
}
_, err := ovsif.exec(OVS_VSCTL, args...)
return err
}
// DeleteBridge deletes the bridge associated with the interface. (It is an
// error if the bridge does not exist.)
func (ovsif *Interface) DeleteBridge() error {
_, err := ovsif.exec(OVS_VSCTL, "del-br", ovsif.bridge)
return err
}
// AddPort adds an interface to the bridge, requesting the indicated port
// number, and optionally setting properties on it (as with "ovs-vsctl set
// Interface ..."). Returns the allocated port number (or an error).
func (ovsif *Interface) AddPort(port string, ofportRequest int, properties ...string) (int, error) {
args := []string{"--may-exist", "add-port", ovsif.bridge, port}
if ofportRequest > 0 || len(properties) > 0 {
args = append(args, "--", "set", "Interface", port)
if ofportRequest > 0 {
args = append(args, fmt.Sprintf("ofport_request=%d", ofportRequest))
}
if len(properties) > 0 {
args = append(args, properties...)
}
}
_, err := ovsif.exec(OVS_VSCTL, args...)
if err != nil {
return -1, err
}
ofportStr, err := ovsif.exec(OVS_VSCTL, "get", "Interface", port, "ofport")
if err != nil {
return -1, err
}
ofport, err := strconv.Atoi(ofportStr)
if err != nil {
return -1, fmt.Errorf("Could not parse allocated ofport %q: %v", ofportStr, err)
}
if ofportRequest > 0 && ofportRequest != ofport {
return -1, fmt.Errorf("Allocated ofport (%d) did not match request (%d)", ofport, ofportRequest)
}
return ofport, nil
}
// DeletePort removes an interface from the bridge. (It is not an
// error if the interface is not currently a bridge port.)
func (ovsif *Interface) DeletePort(port string) error {
_, err := ovsif.exec(OVS_VSCTL, "--if-exists", "del-port", ovsif.bridge, port)
return err
}
type Transaction struct {
ovsif *Interface
err error
}
func (tx *Transaction) exec(cmd string, args ...string) (string, error) {
out := ""
if tx.err == nil {
out, tx.err = tx.ovsif.exec(cmd, args...)
}
return out, tx.err
}
// NewTransaction begins a new OVS transaction. If an error occurs at
// any step in the transaction, it will be recorded until
// EndTransaction(), and any further calls on the transaction will be
// ignored.
func (ovsif *Interface) NewTransaction() *Transaction {
return &Transaction{ovsif: ovsif}
}
// AddFlow adds a flow to the bridge. The arguments are passed to fmt.Sprintf().
func (tx *Transaction) AddFlow(flow string, args ...interface{}) {
if len(args) > 0 {
flow = fmt.Sprintf(flow, args...)
}
tx.exec(OVS_OFCTL, "add-flow", tx.ovsif.bridge, flow)
}
// DeleteFlows deletes all matching flows from the bridge. The arguments are
// passed to fmt.Sprintf().
func (tx *Transaction) DeleteFlows(flow string, args ...interface{}) {
if len(args) > 0 {
flow = fmt.Sprintf(flow, args...)
}
tx.exec(OVS_OFCTL, "del-flows", tx.ovsif.bridge, flow)
}
// EndTransaction ends an OVS transaction and returns any error that occurred
// during the transaction. You should not use the transaction again after
// calling this function.
func (tx *Transaction) EndTransaction() error {
err := tx.err
tx.err = nil
return err
}
// DumpFlows dumps the flow table for the bridge and returns it as an array of
// strings, one per flow.
func (ovsif *Interface) DumpFlows() ([]string, error) {
out, err := ovsif.exec(OVS_OFCTL, "dump-flows", ovsif.bridge)
if err != nil {
return nil, err
}
lines := strings.Split(out, "\n")
flows := make([]string, 0, len(lines))
for _, line := range lines {
if strings.Contains(line, "cookie=") {
flows = append(flows, line)
}
}
return flows, nil
}