terraform/backend/remote-state/kubernetes/backend.go

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package kubernetes
import (
"bytes"
"context"
"fmt"
"log"
"os"
"path/filepath"
"github.com/hashicorp/terraform/backend"
"github.com/hashicorp/terraform/internal/legacy/helper/schema"
"github.com/hashicorp/terraform/version"
"github.com/mitchellh/go-homedir"
k8sSchema "k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/client-go/dynamic"
"k8s.io/client-go/kubernetes"
coordinationv1 "k8s.io/client-go/kubernetes/typed/coordination/v1"
restclient "k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
)
// Modified from github.com/terraform-providers/terraform-provider-kubernetes
const (
noConfigError = `
[Kubernetes backend] Neither service_account nor load_config_file were set to true,
this could cause issues connecting to your Kubernetes cluster.
`
)
var (
secretResource = k8sSchema.GroupVersionResource{
Group: "",
Version: "v1",
Resource: "secrets",
}
)
// New creates a new backend for kubernetes remote state.
func New() backend.Backend {
s := &schema.Backend{
Schema: map[string]*schema.Schema{
"secret_suffix": {
Type: schema.TypeString,
Required: true,
Description: "Suffix used when creating the secret. The secret will be named in the format: `tfstate-{workspace}-{secret_suffix}`.",
},
"labels": {
Type: schema.TypeMap,
Optional: true,
Description: "Map of additional labels to be applied to the secret.",
Elem: &schema.Schema{Type: schema.TypeString},
},
"namespace": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_NAMESPACE", "default"),
Description: "Namespace to store the secret in.",
},
"in_cluster_config": {
Type: schema.TypeBool,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_IN_CLUSTER_CONFIG", false),
Description: "Used to authenticate to the cluster from inside a pod.",
},
"load_config_file": {
Type: schema.TypeBool,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_LOAD_CONFIG_FILE", true),
Description: "Load local kubeconfig.",
},
"host": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_HOST", ""),
Description: "The hostname (in form of URI) of Kubernetes master.",
},
"username": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_USER", ""),
Description: "The username to use for HTTP basic authentication when accessing the Kubernetes master endpoint.",
},
"password": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_PASSWORD", ""),
Description: "The password to use for HTTP basic authentication when accessing the Kubernetes master endpoint.",
},
"insecure": {
Type: schema.TypeBool,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_INSECURE", false),
Description: "Whether server should be accessed without verifying the TLS certificate.",
},
"client_certificate": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CLIENT_CERT_DATA", ""),
Description: "PEM-encoded client certificate for TLS authentication.",
},
"client_key": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CLIENT_KEY_DATA", ""),
Description: "PEM-encoded client certificate key for TLS authentication.",
},
"cluster_ca_certificate": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CLUSTER_CA_CERT_DATA", ""),
Description: "PEM-encoded root certificates bundle for TLS authentication.",
},
"config_paths": {
Type: schema.TypeList,
Elem: &schema.Schema{Type: schema.TypeString},
Optional: true,
Description: "A list of paths to kube config files. Can be set with KUBE_CONFIG_PATHS environment variable.",
},
"config_path": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CONFIG_PATH", ""),
Description: "Path to the kube config file. Can be set with KUBE_CONFIG_PATH environment variable.",
},
"config_context": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CTX", ""),
},
"config_context_auth_info": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CTX_AUTH_INFO", ""),
Description: "",
},
"config_context_cluster": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_CTX_CLUSTER", ""),
Description: "",
},
"token": {
Type: schema.TypeString,
Optional: true,
DefaultFunc: schema.EnvDefaultFunc("KUBE_TOKEN", ""),
Description: "Token to authentifcate a service account.",
},
"exec": {
Type: schema.TypeList,
Optional: true,
MaxItems: 1,
Elem: &schema.Resource{
Schema: map[string]*schema.Schema{
"api_version": {
Type: schema.TypeString,
Required: true,
},
"command": {
Type: schema.TypeString,
Required: true,
},
"env": {
Type: schema.TypeMap,
Optional: true,
Elem: &schema.Schema{Type: schema.TypeString},
},
"args": {
Type: schema.TypeList,
Optional: true,
Elem: &schema.Schema{Type: schema.TypeString},
},
},
},
Description: "Use a credential plugin to authenticate.",
},
},
}
result := &Backend{Backend: s}
result.Backend.ConfigureFunc = result.configure
return result
}
type Backend struct {
*schema.Backend
// The fields below are set from configure
kubernetesSecretClient dynamic.ResourceInterface
kubernetesLeaseClient coordinationv1.LeaseInterface
config *restclient.Config
namespace string
labels map[string]string
nameSuffix string
}
func (b Backend) KubernetesSecretClient() (dynamic.ResourceInterface, error) {
if b.kubernetesSecretClient != nil {
return b.kubernetesSecretClient, nil
}
client, err := dynamic.NewForConfig(b.config)
if err != nil {
return nil, fmt.Errorf("Failed to configure: %s", err)
}
b.kubernetesSecretClient = client.Resource(secretResource).Namespace(b.namespace)
return b.kubernetesSecretClient, nil
}
func (b Backend) KubernetesLeaseClient() (coordinationv1.LeaseInterface, error) {
if b.kubernetesLeaseClient != nil {
return b.kubernetesLeaseClient, nil
}
client, err := kubernetes.NewForConfig(b.config)
if err != nil {
return nil, err
}
b.kubernetesLeaseClient = client.CoordinationV1().Leases(b.namespace)
return b.kubernetesLeaseClient, nil
}
func (b *Backend) configure(ctx context.Context) error {
if b.config != nil {
return nil
}
// Grab the resource data
data := schema.FromContextBackendConfig(ctx)
cfg, err := getInitialConfig(data)
if err != nil {
return err
}
// Overriding with static configuration
cfg.UserAgent = fmt.Sprintf("HashiCorp/1.0 Terraform/%s", version.String())
if v, ok := data.GetOk("host"); ok {
cfg.Host = v.(string)
}
if v, ok := data.GetOk("username"); ok {
cfg.Username = v.(string)
}
if v, ok := data.GetOk("password"); ok {
cfg.Password = v.(string)
}
if v, ok := data.GetOk("insecure"); ok {
cfg.Insecure = v.(bool)
}
if v, ok := data.GetOk("cluster_ca_certificate"); ok {
cfg.CAData = bytes.NewBufferString(v.(string)).Bytes()
}
if v, ok := data.GetOk("client_certificate"); ok {
cfg.CertData = bytes.NewBufferString(v.(string)).Bytes()
}
if v, ok := data.GetOk("client_key"); ok {
cfg.KeyData = bytes.NewBufferString(v.(string)).Bytes()
}
if v, ok := data.GetOk("token"); ok {
cfg.BearerToken = v.(string)
}
if v, ok := data.GetOk("labels"); ok {
labels := map[string]string{}
for k, vv := range v.(map[string]interface{}) {
labels[k] = vv.(string)
}
b.labels = labels
}
ns := data.Get("namespace").(string)
b.namespace = ns
b.nameSuffix = data.Get("secret_suffix").(string)
b.config = cfg
return nil
}
func getInitialConfig(data *schema.ResourceData) (*restclient.Config, error) {
var cfg *restclient.Config
var err error
inCluster := data.Get("in_cluster_config").(bool)
if inCluster {
cfg, err = restclient.InClusterConfig()
if err != nil {
return nil, err
}
} else {
cfg, err = tryLoadingConfigFile(data)
if err != nil {
return nil, err
}
}
if cfg == nil {
cfg = &restclient.Config{}
}
return cfg, err
}
func tryLoadingConfigFile(d *schema.ResourceData) (*restclient.Config, error) {
loader := &clientcmd.ClientConfigLoadingRules{}
configPaths := []string{}
if v, ok := d.Get("config_path").(string); ok && v != "" {
configPaths = []string{v}
} else if v, ok := d.Get("config_paths").([]interface{}); ok && len(v) > 0 {
for _, p := range v {
configPaths = append(configPaths, p.(string))
}
} else if v := os.Getenv("KUBE_CONFIG_PATHS"); v != "" {
configPaths = filepath.SplitList(v)
}
expandedPaths := []string{}
for _, p := range configPaths {
path, err := homedir.Expand(p)
if err != nil {
log.Printf("[DEBUG] Could not expand path: %s", err)
return nil, err
}
log.Printf("[DEBUG] Using kubeconfig: %s", path)
expandedPaths = append(expandedPaths, path)
}
if len(expandedPaths) == 1 {
loader.ExplicitPath = expandedPaths[0]
} else {
loader.Precedence = expandedPaths
}
overrides := &clientcmd.ConfigOverrides{}
ctxSuffix := "; default context"
ctx, ctxOk := d.GetOk("config_context")
authInfo, authInfoOk := d.GetOk("config_context_auth_info")
cluster, clusterOk := d.GetOk("config_context_cluster")
if ctxOk || authInfoOk || clusterOk {
ctxSuffix = "; overriden context"
if ctxOk {
overrides.CurrentContext = ctx.(string)
ctxSuffix += fmt.Sprintf("; config ctx: %s", overrides.CurrentContext)
log.Printf("[DEBUG] Using custom current context: %q", overrides.CurrentContext)
}
overrides.Context = clientcmdapi.Context{}
if authInfoOk {
overrides.Context.AuthInfo = authInfo.(string)
ctxSuffix += fmt.Sprintf("; auth_info: %s", overrides.Context.AuthInfo)
}
if clusterOk {
overrides.Context.Cluster = cluster.(string)
ctxSuffix += fmt.Sprintf("; cluster: %s", overrides.Context.Cluster)
}
log.Printf("[DEBUG] Using overidden context: %#v", overrides.Context)
}
if v, ok := d.GetOk("exec"); ok {
exec := &clientcmdapi.ExecConfig{}
if spec, ok := v.([]interface{})[0].(map[string]interface{}); ok {
exec.APIVersion = spec["api_version"].(string)
exec.Command = spec["command"].(string)
exec.Args = expandStringSlice(spec["args"].([]interface{}))
for kk, vv := range spec["env"].(map[string]interface{}) {
exec.Env = append(exec.Env, clientcmdapi.ExecEnvVar{Name: kk, Value: vv.(string)})
}
} else {
return nil, fmt.Errorf("Failed to parse exec")
}
overrides.AuthInfo.Exec = exec
}
cc := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loader, overrides)
cfg, err := cc.ClientConfig()
if err != nil {
if pathErr, ok := err.(*os.PathError); ok && os.IsNotExist(pathErr.Err) {
log.Printf("[INFO] Unable to load config file as it doesn't exist at %q", pathErr.Path)
return nil, nil
}
return nil, fmt.Errorf("Failed to initialize kubernetes configuration: %s", err)
}
log.Printf("[INFO] Successfully initialized config")
return cfg, nil
}
func expandStringSlice(s []interface{}) []string {
result := make([]string, len(s), len(s))
for k, v := range s {
// Handle the Terraform parser bug which turns empty strings in lists to nil.
if v == nil {
result[k] = ""
} else {
result[k] = v.(string)
}
}
return result
}