feat(stacks): add the ability to migrate stacks to another endpoint (#1976)

* feat(stacks): add the ability to migrate stacks to another endpoint

* feat(stack-details): do not redirect to alternate endpoint after migration

* fix(api): fix merge conflicts

* feat(stack-details): add a modal to confirm stack migration

api/http/handler/stacks/stack_migrate.go

@@ -0,0 +1,132 @@
+package stacks
+
+import (
+	"net/http"
+
+	"github.com/portainer/portainer"
+	httperror "github.com/portainer/portainer/http/error"
+	"github.com/portainer/portainer/http/proxy"
+	"github.com/portainer/portainer/http/request"
+	"github.com/portainer/portainer/http/response"
+	"github.com/portainer/portainer/http/security"
+)
+
+type stackMigratePayload struct {
+	EndpointID int
+	SwarmID    string
+}
+
+func (payload *stackMigratePayload) Validate(r *http.Request) error {
+	if payload.EndpointID == 0 {
+		return portainer.Error("Invalid endpoint identifier. Must be a positive number")
+	}
+	return nil
+}
+
+// POST request on /api/stacks/:id/migrate
+func (handler *Handler) stackMigrate(w http.ResponseWriter, r *http.Request) *httperror.HandlerError {
+	stackID, err := request.RetrieveNumericRouteVariableValue(r, "id")
+	if err != nil {
+		return &httperror.HandlerError{http.StatusBadRequest, "Invalid stack identifier route variable", err}
+	}
+
+	var payload stackMigratePayload
+	err = request.DecodeAndValidateJSONPayload(r, &payload)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusBadRequest, "Invalid request payload", err}
+	}
+
+	stack, err := handler.StackService.Stack(portainer.StackID(stackID))
+	if err == portainer.ErrObjectNotFound {
+		return &httperror.HandlerError{http.StatusNotFound, "Unable to find a stack with the specified identifier inside the database", err}
+	} else if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to find a stack with the specified identifier inside the database", err}
+	}
+
+	resourceControl, err := handler.ResourceControlService.ResourceControlByResourceID(stack.Name)
+	if err != nil && err != portainer.ErrObjectNotFound {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to retrieve a resource control associated to the stack", err}
+	}
+
+	securityContext, err := security.RetrieveRestrictedRequestContext(r)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to retrieve info from request context", err}
+	}
+
+	if resourceControl != nil {
+		if !securityContext.IsAdmin && !proxy.CanAccessStack(stack, resourceControl, securityContext.UserID, securityContext.UserMemberships) {
+			return &httperror.HandlerError{http.StatusForbidden, "Access denied to resource", portainer.ErrResourceAccessDenied}
+		}
+	}
+
+	endpoint, err := handler.EndpointService.Endpoint(stack.EndpointID)
+	if err == portainer.ErrObjectNotFound {
+		return &httperror.HandlerError{http.StatusNotFound, "Unable to find the endpoint associated to the stack inside the database", err}
+	} else if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to find the endpoint associated to the stack inside the database", err}
+	}
+
+	targetEndpoint, err := handler.EndpointService.Endpoint(portainer.EndpointID(payload.EndpointID))
+	if err == portainer.ErrObjectNotFound {
+		return &httperror.HandlerError{http.StatusNotFound, "Unable to find an endpoint with the specified identifier inside the database", err}
+	} else if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to find an endpoint with the specified identifier inside the database", err}
+	}
+
+	stack.EndpointID = portainer.EndpointID(payload.EndpointID)
+	if payload.SwarmID != "" {
+		stack.SwarmID = payload.SwarmID
+	}
+
+	migrationError := handler.migrateStack(r, stack, targetEndpoint)
+	if migrationError != nil {
+		return migrationError
+	}
+
+	err = handler.deleteStack(stack, endpoint)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, err.Error(), err}
+	}
+
+	err = handler.StackService.UpdateStack(stack.ID, stack)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to persist the stack changes inside the database", err}
+	}
+
+	return response.JSON(w, stack)
+}
+
+func (handler *Handler) migrateStack(r *http.Request, stack *portainer.Stack, next *portainer.Endpoint) *httperror.HandlerError {
+	if stack.Type == portainer.DockerSwarmStack {
+		return handler.migrateSwarmStack(r, stack, next)
+	}
+	return handler.migrateComposeStack(r, stack, next)
+}
+
+func (handler *Handler) migrateComposeStack(r *http.Request, stack *portainer.Stack, next *portainer.Endpoint) *httperror.HandlerError {
+	config, configErr := handler.createComposeDeployConfig(r, stack, next)
+	if configErr != nil {
+		return configErr
+	}
+
+	err := handler.deployComposeStack(config)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, err.Error(), err}
+	}
+
+	return nil
+}
+
+func (handler *Handler) migrateSwarmStack(r *http.Request, stack *portainer.Stack, next *portainer.Endpoint) *httperror.HandlerError {
+	config, configErr := handler.createSwarmDeployConfig(r, stack, next, true)
+	if configErr != nil {
+		return configErr
+	}
+
+	err := handler.deploySwarmStack(config)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, err.Error(), err}
+	}
+
+	return nil
+}