openstack: move credentials to instance user data

internal/cloud/openstack/imds.go

@@ -23,6 +23,7 @@ import (
 
 const (
 	imdsMetaDataURL = "http://169.254.169.254/openstack/2018-08-27/meta_data.json"
+	imdsUserDataURL = "http://169.254.169.254/openstack/2018-08-27/user_data"
 	ec2ImdsBaseURL  = "http://169.254.169.254/1.0/meta-data"
 	maxCacheAge     = 12 * time.Hour
 )
@@ -33,6 +34,7 @@ type imdsClient struct {
 	vpcIPCache     string
 	vpcIPCacheTime time.Time
 	cache          metadataResponse
+	userDataCache  userDataResponse
 	cacheTime      time.Time
 }
 
@@ -129,73 +131,73 @@ func (c *imdsClient) role(ctx context.Context) (role.Role, error) {
 }
 
 func (c *imdsClient) loadBalancerEndpoint(ctx context.Context) (string, error) {
-	if c.timeForUpdate(c.cacheTime) || c.cache.Tags.LoadBalancerEndpoint == "" {
+	if c.timeForUpdate(c.cacheTime) || c.userDataCache.LoadBalancerEndpoint == "" {
 		if err := c.update(ctx); err != nil {
 			return "", err
 		}
 	}
 
-	if c.cache.Tags.LoadBalancerEndpoint == "" {
+	if c.userDataCache.LoadBalancerEndpoint == "" {
 		return "", errors.New("unable to get load balancer endpoint")
 	}
 
-	return c.cache.Tags.LoadBalancerEndpoint, nil
+	return c.userDataCache.LoadBalancerEndpoint, nil
 }
 
 func (c *imdsClient) authURL(ctx context.Context) (string, error) {
-	if c.timeForUpdate(c.cacheTime) || c.cache.Tags.AuthURL == "" {
+	if c.timeForUpdate(c.cacheTime) || c.userDataCache.AuthURL == "" {
 		if err := c.update(ctx); err != nil {
 			return "", err
 		}
 	}
 
-	if c.cache.Tags.AuthURL == "" {
+	if c.userDataCache.AuthURL == "" {
 		return "", errors.New("unable to get auth url")
 	}
 
-	return c.cache.Tags.AuthURL, nil
+	return c.userDataCache.AuthURL, nil
 }
 
 func (c *imdsClient) userDomainName(ctx context.Context) (string, error) {
-	if c.timeForUpdate(c.cacheTime) || c.cache.Tags.UserDomainName == "" {
+	if c.timeForUpdate(c.cacheTime) || c.userDataCache.UserDomainName == "" {
 		if err := c.update(ctx); err != nil {
 			return "", err
 		}
 	}
 
-	if c.cache.Tags.UserDomainName == "" {
+	if c.userDataCache.UserDomainName == "" {
 		return "", errors.New("unable to get user domain name")
 	}
 
-	return c.cache.Tags.UserDomainName, nil
+	return c.userDataCache.UserDomainName, nil
 }
 
 func (c *imdsClient) username(ctx context.Context) (string, error) {
-	if c.timeForUpdate(c.cacheTime) || c.cache.Tags.Username == "" {
+	if c.timeForUpdate(c.cacheTime) || c.userDataCache.Username == "" {
 		if err := c.update(ctx); err != nil {
 			return "", err
 		}
 	}
 
-	if c.cache.Tags.Username == "" {
+	if c.userDataCache.Username == "" {
 		return "", errors.New("unable to get token name")
 	}
 
-	return c.cache.Tags.Username, nil
+	return c.userDataCache.Username, nil
 }
 
 func (c *imdsClient) password(ctx context.Context) (string, error) {
-	if c.timeForUpdate(c.cacheTime) || c.cache.Tags.Password == "" {
+	if c.timeForUpdate(c.cacheTime) || c.userDataCache.Password == "" {
 		if err := c.update(ctx); err != nil {
 			return "", err
 		}
 	}
 
-	if c.cache.Tags.Password == "" {
+	if c.userDataCache.Password == "" {
 		return "", errors.New("unable to get token password")
 	}
 
-	return c.cache.Tags.Password, nil
+	return c.userDataCache.Password, nil
 }
 
 // timeForUpdate checks whether an update is needed due to cache age.
@@ -203,18 +205,41 @@ func (c *imdsClient) timeForUpdate(t time.Time) bool {
 	return time.Since(t) > maxCacheAge
 }
 
-// update updates instance metadata from the azure imds API.
 func (c *imdsClient) update(ctx context.Context) error {
+	if err := c.updateInstanceMetadata(ctx); err != nil {
+		return fmt.Errorf("updating instance metadata: %w", err)
+	}
+	if err := c.updateUserData(ctx); err != nil {
+		return fmt.Errorf("updating user data: %w", err)
+	}
+	c.cacheTime = time.Now()
+	return nil
+}
+
+// update updates instance metadata from the azure imds API.
+func (c *imdsClient) updateInstanceMetadata(ctx context.Context) error {
 	resp, err := httpGet(ctx, c.client, imdsMetaDataURL)
 	if err != nil {
 		return err
 	}
 	var metadataResp metadataResponse
 	if err := json.Unmarshal(resp, &metadataResp); err != nil {
-		return fmt.Errorf("unmarshalling IMDS metadata response %q: %w", string(resp), err)
+		return fmt.Errorf("unmarshalling IMDS metadata response %q: %w", resp, err)
 	}
 	c.cache = metadataResp
-	c.cacheTime = time.Now()
+	return nil
+}
+
+func (c *imdsClient) updateUserData(ctx context.Context) error {
+	resp, err := httpGet(ctx, c.client, imdsUserDataURL)
+	if err != nil {
+		return err
+	}
+	var userdataResp userDataResponse
+	if err := json.Unmarshal(resp, &userdataResp); err != nil {
+		return fmt.Errorf("unmarshalling IMDS user_data response %q: %w", resp, err)
+	}
+	c.userDataCache = userdataResp
 	return nil
 }
 
@@ -265,6 +290,9 @@ type metadataTags struct {
 	InitSecretHash string `json:"constellation-init-secret-hash,omitempty"`
 	Role           string `json:"constellation-role,omitempty"`
 	UID            string `json:"constellation-uid,omitempty"`
+}
+
+type userDataResponse struct {
 	AuthURL              string `json:"openstack-auth-url,omitempty"`
 	UserDomainName       string `json:"openstack-user-domain-name,omitempty"`
 	Username             string `json:"openstack-username,omitempty"`

internal/cloud/openstack/imds_test.go

@@ -26,7 +26,7 @@ func TestProviderID(t *testing.T) {
 	someErr := errors.New("failed")
 
 	type testCase struct {
-		cache      metadataResponse
+		cache      any
 		cacheTime  time.Time
 		newClient  httpClientJSONCreateFunc
 		wantResult string
@@ -34,7 +34,7 @@ func TestProviderID(t *testing.T) {
 		wantErr    bool
 	}
 
-	newTestCases := func(mResp1, mResp2 metadataResponse, expect1, expect2 string) map[string]testCase {
+	newTestCases := func(mResp1, mResp2 any, expect1, expect2 string) map[string]testCase {
 		return map[string]testCase{
 			"cached": {
 				cache:      mResp1,
@@ -120,32 +120,32 @@ func TestProviderID(t *testing.T) {
 		"authURL": {
 			method: (*imdsClient).authURL,
 			testCases: newTestCases(
-				metadataResponse{Tags: metadataTags{AuthURL: "authURL1"}},
-				metadataResponse{Tags: metadataTags{AuthURL: "authURL2"}},
+				userDataResponse{AuthURL: "authURL1"},
+				userDataResponse{AuthURL: "authURL2"},
 				"authURL1", "authURL2",
 			),
 		},
 		"userDomainName": {
 			method: (*imdsClient).userDomainName,
 			testCases: newTestCases(
-				metadataResponse{Tags: metadataTags{UserDomainName: "userDomainName1"}},
-				metadataResponse{Tags: metadataTags{UserDomainName: "userDomainName2"}},
+				userDataResponse{UserDomainName: "userDomainName1"},
+				userDataResponse{UserDomainName: "userDomainName2"},
 				"userDomainName1", "userDomainName2",
 			),
 		},
 		"username": {
 			method: (*imdsClient).username,
 			testCases: newTestCases(
-				metadataResponse{Tags: metadataTags{Username: "username1"}},
-				metadataResponse{Tags: metadataTags{Username: "username2"}},
+				userDataResponse{Username: "username1"},
+				userDataResponse{Username: "username2"},
 				"username1", "username2",
 			),
 		},
 		"password": {
 			method: (*imdsClient).password,
 			testCases: newTestCases(
-				metadataResponse{Tags: metadataTags{Password: "password1"}},
-				metadataResponse{Tags: metadataTags{Password: "password2"}},
+				userDataResponse{Password: "password1"},
+				userDataResponse{Password: "password2"},
 				"password1", "password2",
 			),
 		},
@@ -162,9 +162,17 @@ func TestProviderID(t *testing.T) {
 					if tc.newClient != nil {
 						client = tc.newClient(require)
 					}
+					var cache metadataResponse
+					var userDataCache userDataResponse
+					if _, ok := tc.cache.(metadataResponse); ok {
+						cache = tc.cache.(metadataResponse)
+					} else if _, ok := tc.cache.(userDataResponse); ok {
+						userDataCache = tc.cache.(userDataResponse)
+					}
 					imds := &imdsClient{
 						client:        client,
-						cache:     tc.cache,
+						cache:         cache,
+						userDataCache: userDataCache,
 						cacheTime:     tc.cacheTime,
 					}
 
@@ -373,13 +381,13 @@ type httpClientJSONCreateFunc func(r *require.Assertions) *stubHTTPClientJSON
 
 type stubHTTPClientJSON struct {
 	require  *require.Assertions
-	response metadataResponse
+	response any
 	code     int
 	err      error
 	called   bool
 }
 
-func newStubHTTPClientJSONFunc(response metadataResponse, statusCode int, err error) httpClientJSONCreateFunc {
+func newStubHTTPClientJSONFunc(response any, statusCode int, err error) httpClientJSONCreateFunc {
 	return func(r *require.Assertions) *stubHTTPClientJSON {
 		return &stubHTTPClientJSON{
 			response: response,

terraform/infrastructure/openstack/modules/instance_group/main.tf

@@ -75,11 +75,13 @@ resource "openstack_compute_instance_v2" "instance_group_member" {
     constellation-role             = var.role
     constellation-uid              = var.uid
     constellation-init-secret-hash = var.init_secret_hash
+  }
+  user_data = jsonencode({
     openstack-auth-url               = var.identity_internal_url
     openstack-username               = var.openstack_username
     openstack-password               = var.openstack_password
     openstack-user-domain-name       = var.openstack_user_domain_name
     openstack-load-balancer-endpoint = var.openstack_load_balancer_endpoint
-  }
-  availability_zone_hints = var.availability_zone
+  })
+  availability_zone_hints = length(var.availability_zone) > 0 ? var.availability_zone : null
 }