external-dns/source/fake.go
Ian Smith f06fb65917 Fake source (#205)
* Expose inmemory provider to cli

So we can test `--source fake` without needing to touch AWS/Google.

* Add FakeSource

`external-dns --provider inmemory --source fake --dry-run --once`

OR

`external-dns --provider aws --source fake --fqdn-template <hostname suffix> --dry-run --once`

NB: `--fqdn-template` because otherwise we'll default to creating, e.g.,
`abcd.example.com`, which `--provider aws` filters out because you
likely don't have a Zone for `example.com.`  Could also be resolved by
removing the need to use a real provider; the inmemory provider,
perhaps, though it's not entirely hooked up.

Closes kubernetes-incubator/external-dns#22

* Style feedback from Travis CI

* Improve optionality of kubernetes client

* ref(sources): refactor source registration and lookup to be lazy.

* Revert "ref: refactor source registration/lookup to be lazily initialized"
2017-05-29 13:59:50 +02:00

103 lines
2.3 KiB
Go

/*
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.
*/
/*
Note: currently only supports IP targets (A records), not hostname targets
*/
package source
import (
"fmt"
"math/rand"
"net"
"time"
"github.com/kubernetes-incubator/external-dns/endpoint"
)
// fakeSource is an implementation of Source for that provides dummy endpoints
// for testing/dry-running of dns providers without needing an attached
// kubernetes cluster.
type fakeSource struct {
dnsName string
}
const (
defaultDNSName = "example.com"
)
func init() {
rand.Seed(time.Now().UnixNano())
}
// NewFakeSource creates a new fakeSource with the given client and namespace scope.
func NewFakeSource(dnsName string) (Source, error) {
if dnsName == "" {
dnsName = defaultDNSName
}
return &fakeSource{
dnsName: dnsName,
}, nil
}
// Endpoints returns endpoint objects
func (sc *fakeSource) Endpoints() ([]*endpoint.Endpoint, error) {
endpoints := make([]*endpoint.Endpoint, 10)
for i := 0; i < 10; i++ {
endpoints[i], _ = sc.generateEndpoint()
}
return endpoints, nil
}
func (sc *fakeSource) generateEndpoint() (*endpoint.Endpoint, error) {
endpoint := endpoint.NewEndpoint(
generateDNSName(4, sc.dnsName),
generateIPAddress(),
"A",
)
return endpoint, nil
}
func generateIPAddress() string {
// 192.0.2.[1-255] is reserved by RFC 5737 for documentation and examples
return net.IPv4(
byte(192),
byte(0),
byte(2),
byte(rand.Intn(253)+1),
).String()
}
var letterRunes = []rune("abcdefghijklmnopqrstuvwxyz")
func generateDNSName(prefixLength int, dnsName string) string {
prefixBytes := make([]rune, prefixLength)
for i := range prefixBytes {
prefixBytes[i] = letterRunes[rand.Intn(len(letterRunes))]
}
prefixStr := string(prefixBytes)
return fmt.Sprintf("%s.%s", prefixStr, dnsName)
}