feat(gcloud_iam): manage service account access

plugins/providers/gcloudiam/client.go

@@ -41,42 +41,55 @@ func newIamClient(credentialsJSON []byte, resourceName string) (*iamClient, erro
 	}, nil
 }
 
-func (c *iamClient) GetRoles() ([]*Role, error) {
-	var roles []*Role
+func (c *iamClient) ListServiceAccounts(ctx context.Context) ([]*iam.ServiceAccount, error) {
+	res, err := c.iamService.Projects.ServiceAccounts.List(c.resourceName).Context(ctx).Do()
+	if err != nil {
+		return nil, err
+	}
+	return res.Accounts, nil
+}
 
-	ctx := context.TODO()
-	req := c.iamService.Roles.List()
-	if err := req.Pages(ctx, func(page *iam.ListRolesResponse) error {
-		for _, role := range page.Roles {
-			roles = append(roles, c.fromIamRole(role))
+func (c *iamClient) GetGrantableRoles(ctx context.Context, resourceType string) ([]*iam.Role, error) {
+	var fullResourceName string
+	switch resourceType {
+	case ResourceTypeOrganization:
+		orgID := strings.Replace(c.resourceName, ResourceNameOrganizationPrefix, "", 1)
+		fullResourceName = fmt.Sprintf("//cloudresourcemanager.googleapis.com/organizations/%s", orgID)
+
+	case ResourceTypeProject:
+		projectID := strings.Replace(c.resourceName, ResourceNameProjectPrefix, "", 1)
+		fullResourceName = fmt.Sprintf("//cloudresourcemanager.googleapis.com/projects/%s", projectID)
+
+	case ResourceTypeServiceAccount:
+		projectID := strings.Replace(c.resourceName, ResourceNameProjectPrefix, "", 1)
+		res, err := c.iamService.Projects.ServiceAccounts.List(c.resourceName).PageSize(1).Context(ctx).Do()
+		if err != nil {
+			return nil, fmt.Errorf("getting a sample of service account: %w", err)
 		}
-		return nil
-	}); err != nil {
-		return nil, err
+		if res.Accounts == nil || len(res.Accounts) == 0 {
+			return nil, fmt.Errorf("no service accounts found in project %s", projectID)
+		}
+		fullResourceName = fmt.Sprintf("//iam.googleapis.com/%s", res.Accounts[0].Name)
+
+	default:
+		return nil, fmt.Errorf("unknown resource type %s", resourceType)
 	}
 
-	if strings.HasPrefix(c.resourceName, ResourceNameProjectPrefix) {
-		projectRolesReq := c.iamService.Projects.Roles.List(c.resourceName)
-		if err := projectRolesReq.Pages(ctx, func(page *iam.ListRolesResponse) error {
-			for _, role := range page.Roles {
-				roles = append(roles, c.fromIamRole(role))
-			}
-			return nil
-		}); err != nil {
-			return nil, err
+	roles := []*iam.Role{}
+	nextPageToken := ""
+	for {
+		req := &iam.QueryGrantableRolesRequest{
+			FullResourceName: fullResourceName,
+			PageToken:        nextPageToken,
 		}
-	} else if strings.HasPrefix(c.resourceName, ResourceNameOrganizationPrefix) {
-		orgRolesReq := c.iamService.Organizations.Roles.List(c.resourceName)
-		if err := orgRolesReq.Pages(ctx, func(page *iam.ListRolesResponse) error {
-			for _, role := range page.Roles {
-				roles = append(roles, c.fromIamRole(role))
-			}
-			return nil
-		}); err != nil {
+		res, err := c.iamService.Roles.QueryGrantableRoles(req).Context(ctx).Do()
+		if err != nil {
 			return nil, err
 		}
-	} else {
-		return nil, ErrInvalidResourceName
+		roles = append(roles, res.Roles...)
+		if nextPageToken = res.NextPageToken; nextPageToken == "" {
+			break
+		}
 	}
 
 	return roles, nil
@@ -138,6 +151,71 @@ func (c *iamClient) RevokeAccess(accountType, accountID, role string) error {
 	return err
 }
 
+func (c *iamClient) GrantServiceAccountAccess(ctx context.Context, sa, accountType, accountID, role string) error {
+	policy, err := c.iamService.Projects.ServiceAccounts.
+		GetIamPolicy(sa).Context(ctx).Do()
+	if err != nil {
+		return fmt.Errorf("getting IAM policy of service account %q: %w", sa, err)
+	}
+
+	member := fmt.Sprintf("%s:%s", accountType, accountID)
+	roleExists := false
+	for _, b := range policy.Bindings {
+		if b.Role == role {
+			if containsString(b.Members, member) {
+				return ErrPermissionAlreadyExists
+			}
+			b.Members = append(b.Members, member)
+		}
+	}
+	if !roleExists {
+		policy.Bindings = append(policy.Bindings, &iam.Binding{
+			Role:    role,
+			Members: []string{member},
+		})
+	}
+
+	if _, err := c.iamService.Projects.ServiceAccounts.
+		SetIamPolicy(sa, &iam.SetIamPolicyRequest{Policy: policy}).
+		Context(ctx).Do(); err != nil {
+		return fmt.Errorf("setting IAM policy of service account %q: %w", sa, err)
+	}
+
+	return nil
+}
+
+func (c *iamClient) RevokeServiceAccountAccess(ctx context.Context, sa, accountType, accountID, role string) error {
+	policy, err := c.iamService.Projects.ServiceAccounts.
+		GetIamPolicy(sa).Context(ctx).Do()
+	if err != nil {
+		return fmt.Errorf("getting IAM policy of service account %q: %w", sa, err)
+	}
+
+	member := fmt.Sprintf("%s:%s", accountType, accountID)
+	for _, b := range policy.Bindings {
+		if b.Role == role {
+			removeIndex := -1
+			for i, m := range b.Members {
+				if m == member {
+					removeIndex = i
+				}
+			}
+			if removeIndex == -1 {
+				return ErrPermissionNotFound
+			}
+			b.Members = append(b.Members[:removeIndex], b.Members[removeIndex+1:]...)
+		}
+	}
+
+	if _, err := c.iamService.Projects.ServiceAccounts.
+		SetIamPolicy(sa, &iam.SetIamPolicyRequest{Policy: policy}).
+		Context(ctx).Do(); err != nil {
+		return fmt.Errorf("setting IAM policy of service account %q: %w", sa, err)
+	}
+
+	return nil
+}
+
 func (c *iamClient) ListAccess(ctx context.Context, resources []*domain.Resource) (domain.MapResourceAccess, error) {
 	policy, err := c.getIamPolicy(ctx)
 	if err != nil {
@@ -195,14 +273,6 @@ func (c *iamClient) setIamPolicy(ctx context.Context, policy *cloudresourcemanag
 	return nil, ErrInvalidResourceName
 }
 
-func (c *iamClient) fromIamRole(r *iam.Role) *Role {
-	return &Role{
-		Name:        r.Name,
-		Title:       r.Title,
-		Description: r.Description,
-	}
-}
-
 func containsString(arr []string, v string) bool {
 	for _, item := range arr {
 		if item == v {

plugins/providers/gcloudiam/config.go

@@ -1,13 +1,15 @@
 package gcloudiam
 
 import (
+	"context"
 	"encoding/base64"
 	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/go-playground/validator/v10"
 	"github.com/goto/guardian/domain"
+	"github.com/goto/guardian/utils"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -102,12 +104,29 @@ func (c *Config) parseAndValidate() error {
 		c.ProviderConfig.Credentials = credentials
 	}
 
-	if len(c.ProviderConfig.Resources) != 1 {
-		return ErrShouldHaveOneResource
+	if c.ProviderConfig.Resources == nil || len(c.ProviderConfig.Resources) == 0 {
+		return errors.New("empty resource config")
 	}
-	r := c.ProviderConfig.Resources[0]
-	if err := c.validateResourceConfig(r); err != nil {
-		validationErrors = append(validationErrors, err)
+	uniqueResourceTypes := make(map[string]bool)
+	for _, rc := range c.ProviderConfig.Resources {
+		if _, ok := uniqueResourceTypes[rc.Type]; ok {
+			validationErrors = append(validationErrors, fmt.Errorf("duplicate resource type: %q", rc.Type))
+		}
+		uniqueResourceTypes[rc.Type] = true
+
+		allowedResourceTypes := []string{}
+		if strings.HasPrefix(credentials.ResourceName, ResourceNameOrganizationPrefix) {
+			allowedResourceTypes = []string{ResourceTypeOrganization}
+		} else if strings.HasPrefix(credentials.ResourceName, ResourceNameProjectPrefix) {
+			allowedResourceTypes = []string{ResourceTypeProject, ResourceTypeServiceAccount}
+		}
+		if !utils.ContainsString(allowedResourceTypes, rc.Type) {
+			validationErrors = append(validationErrors, fmt.Errorf("invalid resource type: %q", rc.Type))
+		}
+
+		if len(rc.Roles) == 0 {
+			validationErrors = append(validationErrors, ErrRolesShouldNotBeEmpty)
+		}
 	}
 
 	if len(validationErrors) > 0 {
@@ -142,37 +161,14 @@ func (c *Config) validateCredentials(value interface{}) (*Credentials, error) {
 	return &credentials, nil
 }
 
-func (c *Config) validateResourceConfig(resource *domain.ResourceConfig) error {
-	resourceTypeValidation := fmt.Sprintf("oneof=%s %s", ResourceTypeProject, ResourceTypeOrganization)
-	if err := c.validator.Var(resource.Type, resourceTypeValidation); err != nil {
-		return err
-	}
-
-	if len(resource.Roles) == 0 {
-		return ErrRolesShouldNotBeEmpty
-	}
-
-	return nil
-}
-
 func (c *Config) validatePermissions(resource *domain.ResourceConfig, client GcloudIamClient) error {
-	iamRoles, err := client.GetRoles()
+	iamRoles, err := client.GetGrantableRoles(context.TODO(), resource.Type)
 	if err != nil {
 		return err
 	}
-
-	var roles []*domain.Role
-	for _, r := range iamRoles {
-		roles = append(roles, &domain.Role{
-			ID:          r.Name,
-			Name:        r.Title,
-			Description: r.Description,
-		})
-	}
-
-	rolesMap := make(map[string]*domain.Role)
-	for _, role := range roles {
-		rolesMap[role.ID] = role
+	rolesMap := make(map[string]bool)
+	for _, role := range iamRoles {
+		rolesMap[role.Name] = true
 	}
 
 	for _, ro := range resource.Roles {