traefik/vendor/github.com/xenolf/lego/providers/dns/azure/azure.go
2018-04-09 18:28:03 +02:00

154 lines
5 KiB
Go

// Package azure implements a DNS provider for solving the DNS-01
// challenge using azure DNS.
// Azure doesn't like trailing dots on domain names, most of the acme code does.
package azure
import (
"context"
"fmt"
"os"
"strings"
"time"
"github.com/Azure/azure-sdk-for-go/services/dns/mgmt/2017-09-01/dns"
"github.com/Azure/go-autorest/autorest"
"github.com/Azure/go-autorest/autorest/adal"
"github.com/Azure/go-autorest/autorest/azure"
"github.com/Azure/go-autorest/autorest/to"
"github.com/xenolf/lego/acmev2"
)
// DNSProvider is an implementation of the acmev2.ChallengeProvider interface
type DNSProvider struct {
clientId string
clientSecret string
subscriptionId string
tenantId string
resourceGroup string
context context.Context
}
// NewDNSProvider returns a DNSProvider instance configured for azure.
// Credentials must be passed in the environment variables: AZURE_CLIENT_ID,
// AZURE_CLIENT_SECRET, AZURE_SUBSCRIPTION_ID, AZURE_TENANT_ID, AZURE_RESOURCE_GROUP
func NewDNSProvider() (*DNSProvider, error) {
clientId := os.Getenv("AZURE_CLIENT_ID")
clientSecret := os.Getenv("AZURE_CLIENT_SECRET")
subscriptionId := os.Getenv("AZURE_SUBSCRIPTION_ID")
tenantId := os.Getenv("AZURE_TENANT_ID")
resourceGroup := os.Getenv("AZURE_RESOURCE_GROUP")
return NewDNSProviderCredentials(clientId, clientSecret, subscriptionId, tenantId, resourceGroup)
}
// NewDNSProviderCredentials uses the supplied credentials to return a
// DNSProvider instance configured for azure.
func NewDNSProviderCredentials(clientId, clientSecret, subscriptionId, tenantId, resourceGroup string) (*DNSProvider, error) {
if clientId == "" || clientSecret == "" || subscriptionId == "" || tenantId == "" || resourceGroup == "" {
return nil, fmt.Errorf("Azure configuration missing")
}
return &DNSProvider{
clientId: clientId,
clientSecret: clientSecret,
subscriptionId: subscriptionId,
tenantId: tenantId,
resourceGroup: resourceGroup,
// TODO: A timeout can be added here for cancellation purposes.
context: context.Background(),
}, nil
}
// Timeout returns the timeout and interval to use when checking for DNS
// propagation. Adjusting here to cope with spikes in propagation times.
func (c *DNSProvider) Timeout() (timeout, interval time.Duration) {
return 120 * time.Second, 2 * time.Second
}
// Present creates a TXT record to fulfil the dns-01 challenge
func (c *DNSProvider) Present(domain, token, keyAuth string) error {
fqdn, value, _ := acmev2.DNS01Record(domain, keyAuth)
zone, err := c.getHostedZoneID(fqdn)
if err != nil {
return err
}
rsc := dns.NewRecordSetsClient(c.subscriptionId)
spt, err := c.newServicePrincipalTokenFromCredentials(azure.PublicCloud.ResourceManagerEndpoint)
rsc.Authorizer = autorest.NewBearerAuthorizer(spt)
relative := toRelativeRecord(fqdn, acmev2.ToFqdn(zone))
rec := dns.RecordSet{
Name: &relative,
RecordSetProperties: &dns.RecordSetProperties{
TTL: to.Int64Ptr(60),
TxtRecords: &[]dns.TxtRecord{dns.TxtRecord{Value: &[]string{value}}},
},
}
_, err = rsc.CreateOrUpdate(c.context, c.resourceGroup, zone, relative, dns.TXT, rec, "", "")
if err != nil {
return err
}
return nil
}
// Returns the relative record to the domain
func toRelativeRecord(domain, zone string) string {
return acmev2.UnFqdn(strings.TrimSuffix(domain, zone))
}
// CleanUp removes the TXT record matching the specified parameters
func (c *DNSProvider) CleanUp(domain, token, keyAuth string) error {
fqdn, _, _ := acmev2.DNS01Record(domain, keyAuth)
zone, err := c.getHostedZoneID(fqdn)
if err != nil {
return err
}
relative := toRelativeRecord(fqdn, acmev2.ToFqdn(zone))
rsc := dns.NewRecordSetsClient(c.subscriptionId)
spt, err := c.newServicePrincipalTokenFromCredentials(azure.PublicCloud.ResourceManagerEndpoint)
rsc.Authorizer = autorest.NewBearerAuthorizer(spt)
_, err = rsc.Delete(c.context, c.resourceGroup, zone, relative, dns.TXT, "")
if err != nil {
return err
}
return nil
}
// Checks that azure has a zone for this domain name.
func (c *DNSProvider) getHostedZoneID(fqdn string) (string, error) {
authZone, err := acmev2.FindZoneByFqdn(fqdn, acmev2.RecursiveNameservers)
if err != nil {
return "", err
}
// Now we want to to Azure and get the zone.
spt, err := c.newServicePrincipalTokenFromCredentials(azure.PublicCloud.ResourceManagerEndpoint)
dc := dns.NewZonesClient(c.subscriptionId)
dc.Authorizer = autorest.NewBearerAuthorizer(spt)
zone, err := dc.Get(c.context, c.resourceGroup, acmev2.UnFqdn(authZone))
if err != nil {
return "", err
}
// zone.Name shouldn't have a trailing dot(.)
return to.String(zone.Name), nil
}
// NewServicePrincipalTokenFromCredentials creates a new ServicePrincipalToken using values of the
// passed credentials map.
func (c *DNSProvider) newServicePrincipalTokenFromCredentials(scope string) (*adal.ServicePrincipalToken, error) {
oauthConfig, err := adal.NewOAuthConfig(azure.PublicCloud.ActiveDirectoryEndpoint, c.tenantId)
if err != nil {
panic(err)
}
return adal.NewServicePrincipalToken(*oauthConfig, c.clientId, c.clientSecret, scope)
}