Added shell commands. Refactored solvers.

This commit is contained in:
Chris Stuurman 2024-03-24 13:14:22 +02:00
parent 575340257e
commit e253f65029
8 changed files with 204 additions and 141 deletions

1
go.mod
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@ -10,6 +10,7 @@ require (
github.com/stretchr/testify v1.8.4
k8s.io/apiextensions-apiserver v0.29.0
k8s.io/client-go v0.29.0
github.com/sirupsen/logrus v1.9.3
)
require (

142
main.go
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@ -1,22 +1,10 @@
package main
import (
"encoding/json"
"fmt"
"os"
extapi "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
cmmetav1 "github.com/cert-manager/cert-manager/pkg/apis/meta/v1"
"github.com/cert-manager/cert-manager/pkg/acme/webhook/apis/acme/v1alpha1"
"github.com/cert-manager/cert-manager/pkg/acme/webhook/cmd"
"github.com/cert-manager/cert-manager/pkg/issuer/acme/dns/util"
)
const (
providerName = "sthome"
"github.com/stuurmcp/cert-manager-webhook-sthome/sthome"
)
var GroupName = os.Getenv("GROUP_NAME")
@ -26,132 +14,6 @@ func main() {
panic("GROUP_NAME must be specified")
}
cmd.RunWebhookServer(GroupName,
&sthomeDNSProviderSolver{},
&sthome.localDNSProviderSolver{},
)
}
// sthomeDNSProviderSolver implements the provider-specific logic needed to
// 'present' an ACME challenge TXT record for your own DNS provider.
// To do so, it must implement the `github.com/cert-manager/cert-manager/pkg/acme/webhook.Solver`
// interface.
type sthomeDNSProviderSolver struct {
// If a Kubernetes 'clientset' is needed, you must:
// 1. uncomment the additional `client` field in this structure below
// 2. uncomment the "k8s.io/client-go/kubernetes" import at the top of the file
// 3. uncomment the relevant code in the Initialize method below
// 4. ensure your webhook's service account has the required RBAC role
// assigned to it for interacting with the Kubernetes APIs you need.
client kubernetes.Clientset
}
// sthomeDNSProviderConfig is a structure that is used to decode into when
// solving a DNS01 challenge.
// This information is provided by cert-manager, and may be a reference to
// additional configuration that's needed to solve the challenge for this
// particular certificate or issuer.
// This typically includes references to Secret resources containing DNS
// provider credentials, in cases where a 'multi-tenant' DNS solver is being
// created.
// If you do *not* require per-issuer or per-certificate configuration to be
// provided to your webhook, you can skip decoding altogether in favour of
// using CLI flags or similar to provide configuration.
// You should not include sensitive information here. If credentials need to
// be used by your provider here, you should reference a Kubernetes Secret
// resource and fetch these credentials using a Kubernetes clientset.
type sthomeDNSProviderConfig struct {
// Change the two fields below according to the format of the configuration
// to be decoded.
// These fields will be set by users in the
// `issuer.spec.acme.dns01.providers.webhook.config` field.
Email string `json:"email"`
APIKeySecretRef cmmetav1.SecretKeySelector `json:"apiKeySecretRef"`
}
// Name is used as the name for this DNS solver when referencing it on the ACME
// Issuer resource.
// This should be unique **within the group name**, i.e. you can have two
// solvers configured with the same Name() **so long as they do not co-exist
// within a single webhook deployment**.
// For example, `cloudflare` may be used as the name of a solver.
func (c *sthomeDNSProviderSolver) Name() string {
return providerName
}
// Present is responsible for actually presenting the DNS record with the
// DNS provider.
// This method should tolerate being called multiple times with the same value.
// cert-manager itself will later perform a self check to ensure that the
// solver has correctly configured the DNS provider.
func (c *sthomeDNSProviderSolver) Present(ch *v1alpha1.ChallengeRequest) error {
domainName := extractDomainName(ch.ResolvedZone)
cfg, err := loadConfig(ch.Config)
if err != nil {
return err
}
// TODO: do something more useful with the decoded configuration
fmt.Printf("Decoded configuration %v", cfg)
fmt.Printf("presenting record for %s (%s)\n", ch.ResolvedFQDN, domainName)
// TODO: add code that sets a record in the DNS provider's console
return nil
}
// CleanUp should delete the relevant TXT record from the DNS provider console.
// If multiple TXT records exist with the same record name (e.g.
// _acme-challenge.example.com) then **only** the record with the same `key`
// value provided on the ChallengeRequest should be cleaned up.
// This is in order to facilitate multiple DNS validations for the same domain
// concurrently.
func (c *sthomeDNSProviderSolver) CleanUp(ch *v1alpha1.ChallengeRequest) error {
// TODO: add code that deletes a record from the DNS provider's console
return nil
}
// Initialize will be called when the webhook first starts.
// This method can be used to instantiate the webhook, i.e. initialising
// connections or warming up caches.
// Typically, the kubeClientConfig parameter is used to build a Kubernetes
// client that can be used to fetch resources from the Kubernetes API, e.g.
// Secret resources containing credentials used to authenticate with DNS
// provider accounts.
// The stopCh can be used to handle early termination of the webhook, in cases
// where a SIGTERM or similar signal is sent to the webhook process.
func (c *sthomeDNSProviderSolver) Initialize(kubeClientConfig *rest.Config, stopCh <-chan struct{}) error {
///// UNCOMMENT THE BELOW CODE TO MAKE A KUBERNETES CLIENTSET AVAILABLE TO
///// YOUR sthome DNS PROVIDER
cl, err := kubernetes.NewForConfig(kubeClientConfig)
if err != nil {
return err
}
c.client = *cl
///// END OF CODE TO MAKE KUBERNETES CLIENTSET AVAILABLE
return nil
}
// loadConfig is a small helper function that decodes JSON configuration into
// the typed config struct.
func loadConfig(cfgJSON *extapi.JSON) (sthomeDNSProviderConfig, error) {
cfg := sthomeDNSProviderConfig{}
// handle the 'base case' where no configuration has been provided
if cfgJSON == nil {
return cfg, nil
}
if err := json.Unmarshal(cfgJSON.Raw, &cfg); err != nil {
return cfg, fmt.Errorf("error decoding solver config: %v", err)
}
return cfg, nil
}
func extractDomainName(zone string) string {
authZone, err := util.FindZoneByFqdn(zone, util.RecursiveNameservers)
if err != nil {
fmt.Printf("could not get zone by fqdn %v", err)
return zone
}
return util.UnFqdn(authZone)
}

29
sthome/config.go Normal file
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@ -0,0 +1,29 @@
package sthome
import (
v1 "k8s.io/api/core/v1"
)
// localDNSProviderConfig is a structure that is used to decode into when
// solving a DNS01 challenge.
// This information is provided by cert-manager, and may be a reference to
// additional configuration that's needed to solve the challenge for this
// particular certificate or issuer.
// This typically includes references to Secret resources containing DNS
// provider credentials, in cases where a 'multi-tenant' DNS solver is being
// created.
// If you do *not* require per-issuer or per-certificate configuration to be
// provided to your webhook, you can skip decoding altogether in favour of
// using CLI flags or similar to provide configuration.
// You should not include sensitive information here. If credentials need to
// be used by your provider here, you should reference a Kubernetes Secret
// resource and fetch these credentials using a Kubernetes clientset.
type localDNSProviderConfig struct {
// Change the two fields below according to the format of the configuration
// to be decoded.
// These fields will be set by users in the
// `issuer.spec.acme.dns01.providers.webhook.config` field.
Email string `json:"email"`
APIKeySecretRef v1.SecretKeySelector `json:"apiKeySecretRef"`
}

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@ -1,3 +1,4 @@
// not implemented
package sthome
import (

28
sthome/shell.go Normal file
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@ -0,0 +1,28 @@
package sthome
import (
"os"
"os/exec"
)
func Execute(script string, command []string) (bool, error) {
cmd := &exec.Cmd{
Path: script,
Args: command,
Stdout: os.Stdout,
Stderr: os.Stderr,
}
err := cmd.Start()
if err != nil {
return false, err
}
err = cmd.Wait()
if err != nil {
return false, err
}
return true, nil
}

119
sthome/solver.local.go Normal file
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@ -0,0 +1,119 @@
package sthome
import (
"fmt"
//"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
//cmmetav1 "github.com/cert-manager/cert-manager/pkg/apis/meta/v1"
"github.com/cert-manager/cert-manager/pkg/acme/webhook/apis/acme/v1alpha1"
//"github.com/cert-manager/cert-manager/pkg/acme/webhook/cmd"
"github.com/cert-manager/cert-manager/pkg/issuer/acme/dns/util"
)
const (
providerName = "sthome"
dnsUpdaterScript = "/mnt/stpool1/scripts/acme/updatedns.sh"
)
// localDNSProviderSolver implements the provider-specific logic needed to
// 'present' an ACME challenge TXT record for your own DNS provider.
// To do so, it must implement the `github.com/cert-manager/cert-manager/pkg/acme/webhook.Solver`
// interface.
type localDNSProviderSolver struct {
client kubernetes.Clientset
//client kubernetes.Interface
}
// Name is used as the name for this DNS solver when referencing it on the ACME
// Issuer resource.
// This should be unique **within the group name**, i.e. you can have two
// solvers configured with the same Name() **so long as they do not co-exist
// within a single webhook deployment**.
// For example, `cloudflare` may be used as the name of a solver.
func (p *localDNSProviderSolver) Name() string {
return providerName
}
// Present is responsible for actually presenting the DNS record with the
// DNS provider.
// This method should tolerate being called multiple times with the same value.
// cert-manager itself will later perform a self check to ensure that the
// solver has correctly configured the DNS provider.
func (loc *localDNSProviderSolver) Present(ch *v1alpha1.ChallengeRequest) error {
domainName := extractDomainName(ch.ResolvedZone)
cfg, err := loadConfig(ch.Config)
if err != nil {
return err
}
// TODO: do something more useful with the decoded configuration
fmt.Printf("Decoded configuration %v", cfg)
fmt.Printf("presenting record for %s (%s)\n", ch.ResolvedFQDN, domainName)
// TODO: add code that sets a record in the DNS provider's console
// shell command
command := []string{
dnsUpdaterScript,
"arg1=-set",
"arg2=.net",
fmt.Sprintf("arg3=%s", ch.DNSName),
"arg4=TXT",
fmt.Sprintf("arg5=%s", ch.Key),
}
Execute(dnsUpdaterScript, command)
return nil
}
// CleanUp should delete the relevant TXT record from the DNS provider console.
// If multiple TXT records exist with the same record name (e.g.
// _acme-challenge.example.com) then **only** the record with the same `key`
// value provided on the ChallengeRequest should be cleaned up.
// This is in order to facilitate multiple DNS validations for the same domain
// concurrently.
func (s *localDNSProviderSolver) CleanUp(ch *v1alpha1.ChallengeRequest) error {
// TODO: add code that deletes a record from the DNS provider's console
// shell command
command := []string{
dnsUpdaterScript,
"arg1=-unset",
"arg2=.net",
fmt.Sprintf("arg3=%s", ch.DNSName),
"arg4=TXT",
fmt.Sprintf("arg5=%s", ch.Key),
}
Execute(dnsUpdaterScript, command)
return nil
}
// Initialize will be called when the webhook first starts.
// This method can be used to instantiate the webhook, i.e. initialising
// connections or warming up caches.
// Typically, the kubeClientConfig parameter is used to build a Kubernetes
// client that can be used to fetch resources from the Kubernetes API, e.g.
// Secret resources containing credentials used to authenticate with DNS
// provider accounts.
// The stopCh can be used to handle early termination of the webhook, in cases
// where a SIGTERM or similar signal is sent to the webhook process.
func (c *localDNSProviderSolver) Initialize(kubeClientConfig *rest.Config, stopCh <-chan struct{}) error {
cl, err := kubernetes.NewForConfig(kubeClientConfig)
if err != nil {
return fmt.Errorf("failed to get kubernetes client: %w", err)
}
c.client = *cl
return nil
}
func extractDomainName(zone string) string {
authZone, err := util.FindZoneByFqdn(zone, util.RecursiveNameservers)
if err != nil {
fmt.Printf("could not get zone by fqdn %v", err)
return zone
}
return util.UnFqdn(authZone)
}

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@ -1,4 +1,4 @@
// must pass cert-manager DNS conformance tests
// not implemented
package sthome
import (

23
sthome/utils.go Normal file
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@ -0,0 +1,23 @@
package sthome
import (
"encoding/json"
"fmt"
extapi "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
)
// loadConfig is a small helper function that decodes JSON configuration into
// the typed config struct.
func loadConfig(cfgJSON *extapi.JSON) (localDNSProviderConfig, error) {
cfg := localDNSProviderConfig{}
// handle the 'base case' where no configuration has been provided
if cfgJSON == nil {
return cfg, nil
}
if err := json.Unmarshal(cfgJSON.Raw, &cfg); err != nil {
return cfg, fmt.Errorf("error decoding solver config: %v", err)
}
return cfg, nil
}