resource_kubernetes_auth_backend_config.go

package vault

import (
	"fmt"
	"log"
	"regexp"
	"strings"

	"github.com/hashicorp/terraform/helper/schema"
	"github.com/hashicorp/vault/api"
)

var (
	kubernetesAuthBackendConfigFromPathRegex = regexp.MustCompile("^auth/(.+)/config$")
)

func kubernetesAuthBackendConfigResource() *schema.Resource {
	return &schema.Resource{
		Create: kubernetesAuthBackendConfigCreate,
		Read:   kubernetesAuthBackendConfigRead,
		Update: kubernetesAuthBackendConfigUpdate,
		Delete: kubernetesAuthBackendConfigDelete,
		Exists: kubernetesAuthBackendConfigExists,
		Importer: &schema.ResourceImporter{
			State: schema.ImportStatePassthrough,
		},

		Schema: map[string]*schema.Schema{
			"kubernetes_host": {
				Type:        schema.TypeString,
				Required:    true,
				Description: "Host must be a host string, a host:port pair, or a URL to the base of the Kubernetes API server.",
			},
			"kubernetes_ca_cert": {
				Type:        schema.TypeString,
				Description: "PEM encoded CA cert for use by the TLS client used to talk with the Kubernetes API.",
				Optional:    true,
				Default:     "",
			},
			"token_reviewer_jwt": {
				Type:        schema.TypeString,
				Description: "A service account JWT used to access the TokenReview API to validate other JWTs during login. If not set the JWT used for login will be used to access the API.",
				Default:     "",
				Optional:    true,
				Sensitive:   true,
			},
			"pem_keys": {
				Type:        schema.TypeList,
				Elem:        &schema.Schema{Type: schema.TypeString},
				Description: "Optional list of PEM-formatted public keys or certificates used to verify the signatures of Kubernetes service account JWTs. If a certificate is given, its public key will be extracted. Not every installation of Kubernetes exposes these keys.",
				Optional:    true,
			},
			"backend": {
				Type:        schema.TypeString,
				Optional:    true,
				Description: "Unique name of the kubernetes backend to configure.",
				ForceNew:    true,
				Default:     "kubernetes",
				// standardise on no beginning or trailing slashes
				StateFunc: func(v interface{}) string {
					return strings.Trim(v.(string), "/")
				},
			},
		},
	}
}

func kubernetesAuthBackendConfigPath(backend string) string {
	return "auth/" + strings.Trim(backend, "/") + "/config"
}

func kubernetesAuthBackendConfigCreate(d *schema.ResourceData, meta interface{}) error {
	client := meta.(*api.Client)

	backend := d.Get("backend").(string)

	path := kubernetesAuthBackendConfigPath(backend)
	log.Printf("[DEBUG] Writing Kubernetes auth backend config %q", path)

	data := map[string]interface{}{}

	if v, ok := d.GetOk("kubernetes_ca_cert"); ok {
		data["kubernetes_ca_cert"] = v.(string)
	}

	if v, ok := d.GetOk("token_reviewer_jwt"); ok {
		data["token_reviewer_jwt"] = v.(string)
	}

	if v, ok := d.GetOkExists("pem_keys"); ok {
		var pemKeys []string
		for _, pemKey := range v.([]interface{}) {
			pemKeys = append(pemKeys, pemKey.(string))
		}
		data["pem_keys"] = strings.Join(pemKeys, ",")
	}
	data["kubernetes_host"] = d.Get("kubernetes_host").(string)

	_, err := client.Logical().Write(path, data)
	if err != nil {
		return fmt.Errorf("error writing Kubernetes auth backend config %q: %s", path, err)
	}

	d.SetId(path)
	// NOTE: Since reading the auth/<backend>/config does
	// not return the `token_reviewer_jwt`,
	// set it from data after successfully storing it in Vault.
	d.Set("token_reviewer_jwt", data["token_reviewer_jwt"])
	log.Printf("[DEBUG] Wrote Kubernetes auth backend config %q", path)

	return kubernetesAuthBackendConfigRead(d, meta)
}

func kubernetesAuthBackendConfigBackendFromPath(path string) (string, error) {
	if !kubernetesAuthBackendConfigFromPathRegex.MatchString(path) {
		return "", fmt.Errorf("no backend found")
	}
	res := kubernetesAuthBackendConfigFromPathRegex.FindStringSubmatch(path)
	if len(res) != 2 {
		return "", fmt.Errorf("unexpected number of matches (%d) for backend", len(res))
	}
	return res[1], nil
}

func kubernetesAuthBackendConfigRead(d *schema.ResourceData, meta interface{}) error {
	client := meta.(*api.Client)
	path := d.Id()

	backend, err := kubernetesAuthBackendConfigBackendFromPath(path)
	if err != nil {
		return fmt.Errorf("invalid path %q for Kubernetes auth backend config: %s", path, err)
	}

	log.Printf("[DEBUG] Reading Kubernetes auth backend config %q", path)
	resp, err := client.Logical().Read(path)
	if err != nil {
		return fmt.Errorf("error reading Kubernetes auth backend config %q: %s", path, err)
	}
	log.Printf("[DEBUG] Read Kubernetes auth backend config %q", path)
	if resp == nil {
		log.Printf("[WARN] Kubernetes auth backend config %q not found, removing from state", path)
		d.SetId("")
		return nil
	}

	d.Set("backend", backend)
	d.Set("kubernetes_host", resp.Data["kubernetes_host"])
	d.Set("kubernetes_ca_cert", resp.Data["kubernetes_ca_cert"])

	iPemKeys := resp.Data["pem_keys"].([]interface{})
	pemKeys := make([]string, 0, len(iPemKeys))

	for _, iPemKey := range iPemKeys {
		pemKeys = append(pemKeys, iPemKey.(string))
	}

	d.Set("pem_keys", pemKeys)

	return nil
}

func kubernetesAuthBackendConfigUpdate(d *schema.ResourceData, meta interface{}) error {
	client := meta.(*api.Client)
	path := d.Id()

	log.Printf("[DEBUG] Updating Kubernetes auth backend config %q", path)

	data := map[string]interface{}{}

	if v, ok := d.GetOk("kubernetes_ca_cert"); ok {
		data["kubernetes_ca_cert"] = v.(string)
	}

	if v, ok := d.GetOk("token_reviewer_jwt"); ok {
		data["token_reviewer_jwt"] = v.(string)
	}

	if v, ok := d.GetOkExists("pem_keys"); ok {
		var pemKeys []string
		for _, pemKey := range v.([]interface{}) {
			pemKeys = append(pemKeys, pemKey.(string))
		}
		data["pem_keys"] = strings.Join(pemKeys, ",")
	}
	data["kubernetes_host"] = d.Get("kubernetes_host").(string)

	_, err := client.Logical().Write(path, data)
	if err != nil {
		return fmt.Errorf("error updating Kubernetes auth backend config %q: %s", path, err)
	}

	// NOTE: Only `SetId` after it's successfully written in Vault
	d.SetId(path)

	log.Printf("[DEBUG] Updated Kubernetes auth backend config %q", path)

	return kubernetesAuthBackendConfigRead(d, meta)
}

func kubernetesAuthBackendConfigDelete(d *schema.ResourceData, meta interface{}) error {
	path := d.Id()
	log.Printf("[DEBUG] Deleted Kubernetes auth backend config %q", path)
	d.SetId("")
	return nil
}

func kubernetesAuthBackendConfigExists(d *schema.ResourceData, meta interface{}) (bool, error) {
	client := meta.(*api.Client)

	path := d.Id()
	log.Printf("[DEBUG] Checking if Kubernetes auth backend config %q exists", path)

	resp, err := client.Logical().Read(path)
	if err != nil {
		return true, fmt.Errorf("error checking if Kubernetes auth backend config %q exists: %s", path, err)
	}
	log.Printf("[DEBUG] Checked if Kubernetes auth backend config %q exists", path)

	return resp != nil, nil
}