designate.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.
*/

package main

import (
	"net"
	"net/http"
	"os"
	"strings"
	"time"

	"github.com/gophercloud/gophercloud"
	"github.com/gophercloud/gophercloud/openstack"

	"github.com/kubernetes-incubator/external-dns/pkg/tlsutils"
	log "github.com/sirupsen/logrus"
)

// copies environment variables to new names without overwriting existing values
func remapEnv(mapping map[string]string) {
	for k, v := range mapping {
		currentVal := os.Getenv(k)
		newVal := os.Getenv(v)
		if currentVal == "" && newVal != "" {
			os.Setenv(k, newVal)
		}
	}
}

// returns OpenStack Keystone authentication settings by obtaining values from standard environment variables.
// also fixes incompatibilities between gophercloud implementation and *-stackrc files that can be downloaded
// from OpenStack dashboard in latest versions
func getAuthSettings() (gophercloud.AuthOptions, error) {
	remapEnv(map[string]string{
		"OS_TENANT_NAME": "OS_PROJECT_NAME",
		"OS_TENANT_ID":   "OS_PROJECT_ID",
		"OS_DOMAIN_NAME": "OS_USER_DOMAIN_NAME",
		"OS_DOMAIN_ID":   "OS_USER_DOMAIN_ID",
	})

	opts, err := openstack.AuthOptionsFromEnv()
	if err != nil {
		return gophercloud.AuthOptions{}, err
	}
	opts.AllowReauth = true
	if !strings.HasSuffix(opts.IdentityEndpoint, "/") {
		opts.IdentityEndpoint += "/"
	}
	if !strings.HasSuffix(opts.IdentityEndpoint, "/v2.0/") && !strings.HasSuffix(opts.IdentityEndpoint, "/v3/") {
		opts.IdentityEndpoint += "v2.0/"
	}
	return opts, nil
}

// authenticate in OpenStack and obtain Designate service endpoint
func createDesignateServiceClient() (*gophercloud.ServiceClient, error) {
	opts, err := getAuthSettings()
	if err != nil {
		return nil, err
	}
	log.Infof("Using OpenStack Keystone at %s", opts.IdentityEndpoint)
	authProvider, err := openstack.NewClient(opts.IdentityEndpoint)
	if err != nil {
		return nil, err
	}

	tlsConfig, err := tlsutils.CreateTLSConfig("OPENSTACK")
	if err != nil {
		return nil, err
	}

	transport := &http.Transport{
		Proxy: http.ProxyFromEnvironment,
		DialContext: (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
		}).DialContext,
		MaxIdleConns:          100,
		IdleConnTimeout:       90 * time.Second,
		TLSHandshakeTimeout:   10 * time.Second,
		ExpectContinueTimeout: 1 * time.Second,
		TLSClientConfig:       tlsConfig,
	}
	authProvider.HTTPClient.Transport = transport

	if err = openstack.Authenticate(authProvider, opts); err != nil {
		return nil, err
	}

	eo := gophercloud.EndpointOpts{
		Region: os.Getenv("OS_REGION_NAME"),
	}

	client, err := openstack.NewDNSV2(authProvider, eo)
	if err != nil {
		return nil, err
	}
	log.Infof("Found OpenStack Designate service at %s", client.Endpoint)
	return client, nil
}