Application Case Study: Nextcloud

Table of Contents


In this ThreeFold guide, we explore how to create an application on the Dashboard. To do so, we will use the Nextcloud application as a case study. This application is ideal to study since it uses many of the ThreeFold Grid functionalities, such as gateways and gateway domains.

By reading this guide, you should have a proper understanding of the general process of building a new application on the ThreeFold Grid. This might give you inspiration to build your own application and contribute to the ThreeFold Dashboard.

Process Overview and Preparation Steps

The bulk of the files needed for the Nextcloud application can be found in the ThreeFold tfgrid-sdk-ts repository on GitHub. More specifically, we are interested in the subdirectory called playground.

While there are many ways to proceed in the development of a ThreeFold application for the Dashboard, we present here a general method that works efficiently and is well organized.

The information provided here is specific to the Nextcloud workload, but it can be applied to other types of workload.

Before building the Nextcloud application, we first deployed a Nextcloud instance on the ThreeFold Grid with a full virtual machine. Once this deployment was working well, we built a Nextcloud flist. You can consult the Nextcloud flist code in the ThreeFold Tech tf-images repository. We note that the flist uses a micro VM. There are some differences between a full VM and a micro VM. We propose users to first start deploying with a full VM and then adjust their work when they want to publish a flist with a micro VM, since full VM are easier to work with. You can of course start directly with a micro VM if you want.

In sum, once we were comfortable launching Nextcloud on a full VM and also using an flist, we were ready to tackle the building of an application. These steps should be taken into account when building your own application. We proceed this way to ensure that the workload is properly configured. Once we know the flist is working properly, we can focus on the application aspect of the deployment, knowing the deployment itself is working properly.

Building an Application

In the subsections that follow, we cover all the different files that either need to be updated or created when building an application on the Dashboard.

For the most part, the work consists of updating existing files to add the Nextcloud information. As you will see, the bulk of the work is happening with the file named tf_nextcloud.vue, where we set the main application page seen on the Dashboard.

Add an Icon

We added a Nextcloud icon to be featured on the Dashboard by adding a png file at the following directory packages/playground/public/images/icons/nextcloud.png.

Add a Description

We added a description to the Nextcloud application by adding a markdown file at the following directory packages/playground/public/info/ This file contains a short description of Nextcloud for users to quickly understand what the application does.

Update deployment_list.ts

In the file deployment_list.ts, we set parameters to be shared with the Nextcloud application during deployment. The file is available in the following directory packages/playground/src/constants/deployment_list.ts.

In our case, the Nextcloud content is the following:

  nextcloud: {
    SSH_KEY: _ssh,
    NEXTCLOUD_AIO_LINK: "Nextcloud Setup",
    NEXTCLOUD_DOMAIN: "Nextcloud Domain",

We can see here that the application will receive the SSH public key, the Nextcloud setup, and domain links. The SSH public key will allow users to connect to the VM via SSH. The Nextcloud setup link is linked to the Nextcloud domain is used to set the domain name to the Nextcloud instance. The Nextcloud setup and domain links will be linked to the Actions buttons once the workload is deployed.

Update /types/index.ts

In the file index.ts, located in the directory packages/playground/src/types/, we set the ProjectName, SolutionCode, and solutionType for the Nextcloud application.

We added the line Nextcloud = "Nextcloud", in the array export enum ProjectName. This will provide a name for the Nextcloud application, which will be used in the Deployment table shown on the Dashboard.

We added the line nextcloud = "nc" in the array export enum SolutionCode. This will be used notably as a prefix for the randomly generated deployment name. For example, when the user deploys a Nextcloud application, the name of the VM could be ncxwbt2.

We also added the line nextcloud: "Nextcloud", in the array export const solutionType: { [key: string]: string } =. This will be used when setting a contract with the TFGrid.

Update /router/index.ts

In the file index.ts, located at the directory packages/playground/src/router/, we add the following lines in the function createApplicationsRoutes():

      path: DashboardRoutes.Applications.Nextcloud,
      component: () => import("../views/nextcloud_view.vue"),
      meta: {
        title: "Nextcloud",
        info: { page: "info/" },
        navbarConfig: {
          back: true,
          path: [
            { title: "Deploy" },
              title: "Applications",
              disabled: false,
              to: DashboardRoutes.Deploy.Applications,
              title: "Nextcloud",

We can see that this section makes use of the Nextcloud description seen in the section Add a Description. It also sets the path to the nextcloud_view.vue file.

Update vm_deployment_table.vue

In the file vm_deployment_table.vue, located in the directory packages/playground/src/components/, we added the line ProjectName.Nextcloud in the constant section named IPV4Solutions.

The Nextcloud IPv4 address will thus be shown in the deployment table after the user has deployed the Nextcloud application.

If, for example, we wanted to display the WireGuard address in the deployment table, we would add ProjectName.Nextcloud in the array named WireguardSolutions.

Update delete_deployment.ts

In the file delete_deployment.ts, located in the directory packages/playground/src/utils, we added the line ProjectName.Nextcloud, in the function solutionHasGateway(projectName: ProjectName).

Update tf_deployment_list.vue

In the file tf_deployment_list.vue, located at the directory packages/playground/src/weblets, we added the following code to set Actions buttons that are clickable once the workload is deployed:

        <template #Nextcloud-actions="{ item }">
            tooltip="Show Details"
            @click="openDialog(tabs[activeTab].value, item)"
            tooltip="Open Nextcloud"
            :href="'https://' + item.value[0].env.NEXTCLOUD_DOMAIN"
            tooltip="Nextcloud Setup"
            :href="'https://' + item.value[0].env.NEXTCLOUD_AIO_LINK"

We note that this section makes use of the NEXTCLOUD_DOMAIN and NEXTCLOUD_AIO_LINK environment variables shown in the section Update deployment_list.ts.

At the end of the file, at the section const tabs: Tab[], we also added the line { title: "Nextcloud", value: "Nextcloud", imgPath: "images/icons/nextcloud.png" },. We note that this line makes use of the Nextcloud icon we set in the icons directory.

Create nextcloud_view.vue

We created a file named nextcloud_view.vue. Instead of starting from scratch, we took a file template from an already existing file, in our case it was owncloud_view.vue. We only needed to change a few lines to make it work with the Nextcloud application.

    <TfNextcloud />

    <template #list>
      <TfDeploymentList title="Nextcloud Instances" :project-name="name" />

<script lang="ts">
import { ProjectName } from "../types";
import TfDeploymentList from "../applications/tf_deployment_list.vue";
import TfNextcloud from "../applications/tf_nextcloud.vue";

export default {
  name: "NextcloudView",
  components: {
  setup() {
    return { name: ProjectName.Nextcloud };

The line containing TfDeploymentList title sets the strings used to present the different Nextcloud instances in the deployment table, populated once we deploy a Nextcloud workload on the Dashboard.

We also note that this file imports the variables TfDeploymentList and TfNextcloud from the files tf_deployment_list.vue and tf_nextcloud.vue respectively. These variables are then exported in the section export default. We recall that in tf_deployment_list.vue, we set the Actions button, as well as set the application name and icon. The file tf_nextcloud.vue is covered in the next section.

Create tf_nextcloud.vue

Still in the directory packages/playground/src/weblets, we created a file named tf_nextcloud.vue. Instead of starting from scratch, it can be recommended to start from a template of an application that is close to the current application you are building. In our case, we started with the file owncloud.vue. That being said, since the Nextcloud application uses the gateway as well as gateway domains, some major updates were necessary. This file constitutes the bulk of the work when building an application for the Dashboard. For this reason, we dedicate more attention to this file and explore it section by section.

This file is mainly composed of three sections. The first section, template will be used to configure and set the proper deployment configurations. The second section, the first script section will import the necessary modules and variables, set the constants, and set the asynchronous function that will query the TFGrid to deploy the application instance. The third section, the second script section, imports modules and variables and exports them.

Template Section

We first start to explore the template main section.

The section weblet-layout defines the basic layout of the application. This section sets the variable names for the different deployment configurations, such as the CPU, the memory and the disk. These variables will then be set to specific quantities when the users set the application on the Dashboard.

The section template #title sets the main title displayed on the Dashboard application page.

The section form-validator contains many subsections that will serve to configure the application deployment.

The first subsection of form-validator is input-validator. This subsection is used to give a name to the application instance. This subsection provides strict requirements for the Name of the application instance. While the name is automatically generated randomly by the Dashboard, users can also set their own name, to the extent that they follow the name requirements.

The following subsection is called SelectSolutionFlavor. In this subsection, we provide templates for the users to choose the deployment parameters. The parameters are CPU, memory and disk. As stated before, the names of those parameters have been set in the section application-layout.

The subsection Networks is where we set the TFGrid parameter options. In our case, the user can decide to enable ipv4 and mycelium.

The subsections called input-tooltip are used to generated information for the users. The developer can decide to either simply display a message as string, and also to set a clickable hyperlink.

The first input-tooltip of the Nextcloud instance provides a hyperlink leading to the TF Manual dedicated nodes documentation. This tooltip also contains a v-switch. This gives a toggle button that can be enabled or disabled. In this case, the user can either enable the option Dedicated or not. The name given to this option is dedicated. We can see further in the document, at line 122, that this option is set as a constant and is false by default (ref(false)).

The second input-tooltip is about certified node. As with the previous tool-tip, it is accompanied by a v-switch named certified. Also further in the document, we can see at line 123 that this option is set as a constant and set to false by default (set(false)).

The subsection template #footer-actions configures the Deploy button. As we can see here, we set validateBeforeDeploy to ensure that the user selects a proper node and deployment configurations before being able to query the TFGrid to deploy the application instance.

By the end of this subsection, we arrive at the end of the weblet-layout subsection and of the template section.

First Script Section (Setup)

The first part of this section consists of importing modules from the src directory as well as GridClient from @threefold/grid_client and computed, type Ref, and ref from vue. Then we set constants based on the template section.

One constant to notice is flist. This constant is given the URL to the Nextcloud flist that we created for the application deployment. For more information on how to create this flist, read the Nextcloud flist case study available on the ThreeFold Manual.

In the function finalize, we set the output displayed when the deployment has been successful. It's important to add relevant information for the user here. In the case of Nextcloud, we add the following text to provide guidance to the user:

Successfully deployed a Nextcloud instance. Under Actions, click on the button Nextcloud Setup to set up Nextcloud. After installation, you can access the Nextcloud instance by clicking on the Open Nextcloud button or navigating to your Nextcloud domain.

A big part of the first script section is the asynchronous function deploy. As the constant projectName, we set the following:

ProjectName.Nextcloud.toLowerCase() + "/" + name.value

For our Nextcloud instance, the user can decide to use a gateway or not as well as a custom or gateway domain. The constant domain sets this. 148 consists of setting the proper domain whether the user chose a custom or a gateway domain:

const domain = selectionDetails.value!.domain!.enabledCustomDomain ? selectionDetails.value!.domain!.customDomain : subdomain + "." + selectionDetails.value!.domain!.selectedDomain?.publicConfig.domain;

The constant has_gateway is set to true only if both customDomain and ipv4.value are set to false:

const has_gateway = !(selectionDetails.value!.domain!.enabledCustomDomain && ipv4.value);

The constant aio_link is composed of the domain variable set earlier followed by /aio. This will ensure that the Action button to open the Nextcloud AIO page is properly set.

const aio_link = domain + "/aio";

Once the above-mentioned constants are set, the asynchronous function deploy will deploy the application instance on the TFGrid. This can be seen in the section try.

This section references to all the necessary parameters to deploy the application instance as defined by the user on the TFGrid. For example, the subsection envs contains all the necessary environment variables for the deployment, such as the SSH public key (SSH_KEY), as well as the domain and Nextcloudt setup URLs (NEXTCLOUD_DOMAIN, NEXTCLOUD_AIO_LINK). We also pass a boolean telling the deployer if there is a gateway within the deployment (GATEWAY) as well as the IPv4 address (IPV4).

If this try function fails, we catch the error and display Failed to deploy a Nextcloud instance. as shown in the section catch (e).

The next section is an if statement that will be triggered if the deployment consists of a custom domain and an IPv4 connection. In this case, we call the function finalize to deploy the application instance by passing the vm as a parameter.

If this is not the case, we trigger the second try function where we set the gateway. Once this is done, we finally trigger the function finalize to deploy the application instance with the gateway set.

Second Script Section

The second script section imports different modules necessary to run the application and then exports many of them as a package for the application, in our case TFNextcloud.

The import section of this script section should be common for all applications using a gateway.

The export section (export default) is set with TFNextcloud as its name.

Testing an application

You can test this application or the application you are creating by deploying the Dashboard locally. For more information on this, feel free to read the documentation Deploy the Dashboard of the ThreeFold Manual.

This is very useful, if not necessary when testing and building your own application.

Contributing to the Dashboard

If you've created a new application and you wish to share it to the ThreeFold community, feel free to fork the ThreeFold tfgrid-sdk-ts repository to your own GitHub account, add the new application to the Dashboard and then create a pull request. The ThreeFold development team will be happy to review your code and propose changes if needed.


We now went through the Nextcloud application code and explored how to create a new application for the ThreeFold Dashboard. This case study should have given you the necessary tools and knowledge to understand the general steps when it comes to creating a new application. Of course, each application will be different and you will most certainly need to adjust the files presented here when you build your own application.

Should you have any questions or feedback, you can ask the ThreeFold community for help on the ThreeFold Forum or on the ThreeFold Grid Tester Community chat on Telegram.

Last change: 2024-05-27