lego/providers/dns/linode/linode.go
2016-08-29 12:37:19 -07:00

131 lines
3.6 KiB
Go

// Package linode implements a DNS provider for solving the DNS-01 challenge
// using Linode DNS.
package linode
import (
"errors"
"os"
"strings"
"time"
"github.com/timewasted/linode/dns"
"github.com/xenolf/lego/acme"
)
const (
dnsMinTTLSecs = 300
dnsUpdateFreqMins = 15
dnsUpdateFudgeSecs = 120
)
type hostedZoneInfo struct {
domainId int
resourceName string
}
// DNSProvider implements the acme.ChallengeProvider interface.
type DNSProvider struct {
linode *dns.DNS
}
// NewDNSProvider returns a DNSProvider instance configured for Linode.
// Credentials must be passed in the environment variable: LINODE_API_KEY.
func NewDNSProvider() (*DNSProvider, error) {
apiKey := os.Getenv("LINODE_API_KEY")
return NewDNSProviderCredentials(apiKey)
}
// NewDNSProviderCredentials uses the supplied credentials to return a
// DNSProvider instance configured for Linode.
func NewDNSProviderCredentials(apiKey string) (*DNSProvider, error) {
if len(apiKey) == 0 {
return nil, errors.New("Linode credentials missing")
}
return &DNSProvider{
linode: dns.New(apiKey),
}, nil
}
// Timeout returns the timeout and interval to use when checking for DNS
// propagation. Adjusting here to cope with spikes in propagation times.
func (p *DNSProvider) Timeout() (timeout, interval time.Duration) {
// Since Linode only updates their zone files every X minutes, we need
// to figure out how many minutes we have to wait until we hit the next
// interval of X. We then wait another couple of minutes, just to be
// safe. Hopefully at some point during all of this, the record will
// have propagated throughout Linode's network.
minsRemaining := dnsUpdateFreqMins - (time.Now().Minute() % dnsUpdateFreqMins)
timeout = (time.Duration(minsRemaining) * time.Minute) +
(dnsMinTTLSecs * time.Second) +
(dnsUpdateFudgeSecs * time.Second)
interval = 15 * time.Second
return
}
// Present creates a TXT record using the specified parameters.
func (p *DNSProvider) Present(domain, token, keyAuth string) error {
fqdn, value, _ := acme.DNS01Record(domain, keyAuth)
zone, err := p.getHostedZoneInfo(fqdn)
if err != nil {
return err
}
if _, err = p.linode.CreateDomainResourceTXT(zone.domainId, acme.UnFqdn(fqdn), value, 60); err != nil {
return err
}
return nil
}
// CleanUp removes the TXT record matching the specified parameters.
func (p *DNSProvider) CleanUp(domain, token, keyAuth string) error {
fqdn, value, _ := acme.DNS01Record(domain, keyAuth)
zone, err := p.getHostedZoneInfo(fqdn)
if err != nil {
return err
}
// Get all TXT records for the specified domain.
resources, err := p.linode.GetResourcesByType(zone.domainId, "TXT")
if err != nil {
return err
}
// Remove the specified resource, if it exists.
for _, resource := range resources {
if resource.Name == zone.resourceName && resource.Target == value {
resp, err := p.linode.DeleteDomainResource(resource.DomainID, resource.ResourceID)
if err != nil {
return err
}
if resp.ResourceID != resource.ResourceID {
return errors.New("Error deleting resource: resource IDs do not match!")
}
break
}
}
return nil
}
func (p *DNSProvider) getHostedZoneInfo(fqdn string) (*hostedZoneInfo, error) {
// Lookup the zone that handles the specified FQDN.
authZone, err := acme.FindZoneByFqdn(fqdn, acme.RecursiveNameservers)
if err != nil {
return nil, err
}
resourceName := strings.TrimSuffix(fqdn, "."+authZone)
// Query the authority zone.
domain, err := p.linode.GetDomain(acme.UnFqdn(authZone))
if err != nil {
return nil, err
}
return &hostedZoneInfo{
domainId: domain.DomainID,
resourceName: resourceName,
}, nil
}