# How to install a new Update Module

**URL:** <https://hub.mender.io/t/how-to-install-a-new-update-module/6630>\
**Category:** Update Modules\
**Created:** [March 15, 2024, 6:36am UTC](https://hub.mender.io/t/how-to-install-a-new-update-module/6630 "2024-03-15T06:36:58Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![lramirez](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/lramirez/32/1195_2.png) [@lramirez](https://hub.mender.io/u/lramirez)\
**Post date:** [March 15, 2024, 6:36am UTC](https://hub.mender.io/t/how-to-install-a-new-update-module/6630/1 "2024-03-15T06:36:58Z")

</div>

## Requirements

If you don’t have Remote Terminal Access to the device and you want to install the Update Module in runtime, you must have the `single-file` update module already as part of your rootfs, just check if the `/usr/share/mender/modules/v3/single-file` file exist. If not, then you must include it as part of a regular image OTA update, either for a [Yocto-based system](https://docs.mender.io/operating-system-updates-yocto-project) or a [Debian-based](https://docs.mender.io/operating-system-updates-debian-family) one.

## Context

What counts as an “application update” can vary greatly – a single file, a whole directory, even a container image. This makes it hard to have a single, rigid update method. Mender’s Update Module framework provides a flexible solution, allowing you to tailor application updates to your specific needs.

Update Modules are executable files residing in the `/usr/share/mender/modules/v3` directory (note: v3 represents the current protocol version). The Mender Client uses a defined parameter set to execute these modules, facilitating the update process.

The “Single File Update Module” installs a file of your choice into a specified directory on the device, and we are going to take advantage of it in this tutorial. You can read more about this Update Module in [here](https://hub.mender.io/t/single-file/486).

## Update Module creation

The structure of the Update Module require the definition of one or more states from the [Mender State Machine](https://docs.mender.io/artifact-creation/create-a-custom-update-module#the-state-machine-workflow).

For this example, we will take the simplest one described in [Mender’s docs](https://docs.mender.io/artifact-creation/create-a-custom-update-module#basic-example-file-copy-update-module):

```bash
cat << "EOF" > dummy-mender-module
#!/bin/bash

set -e

STATE="$1"
FILES="$2"

case "$STATE" in
    ArtifactInstall)
        cp "$FILES"/files/* /opt/
        ;;
esac
exit 0
EOF

```

This one will create a Mender Update Module named `dummy-mender-module`.

## Installation

### On run time

#### With Remote Terminal Access

If you already have Remote Terminal access, either by using the [Mender’s Troubleshooting add-on](https://docs.mender.io/add-ons/remote-terminal), SSH or any other protocol, you can just add the recently created file inside `/usr/share/mender/modules/v3`, just don’t forget to make it executable with `chmod +x my-module`.

And that’s it, any folder used in the Update Module like `/opt` must be created upfront.

#### Without Remote Terminal Access

For this one, we will create an `single-file` update module, following pretty similar steps as the ones in [this tutorial](https://hub.mender.io/t/single-file/486) with some tweaks:

Download single-file-artifact-gen, by running the following command:

```bash
wget https://raw.githubusercontent.com/mendersoftware/mender/master/support/modules-artifact-gen/single-file-artifact-gen

```

Make it executable:

```bash
chmod +x single-file-artifact-gen

```

And let’s create a file that will be used to set the executable permissions:

```bash
echo "+x" > permissions

```

Notice the `FILE` is the one we created above (`dummy-mender-module`) and the `DEST_DIR` the Update Modules path. Feel free to choose any `ARTIFACT_NAME`, `OUTPUT_PATH` and select a `DEVICE_TYPE` that matches with the `device_type` reported to the client as part of the device’s inventory. Notice the last `-f` to make sure it will be executable in the device side.

```bash

ARTIFACT_NAME="my-update-1.0"
DEVICE_TYPE="my-device-type"
OUTPUT_PATH="my-update-1.0.mender"
DEST_DIR="/usr/share/mender/modules/v3/"
FILE="dummy-mender-module"

./single-file-artifact-gen -n ${ARTIFACT_NAME} -t ${DEVICE_TYPE} -d ${DEST_DIR} -o ${OUTPUT_PATH} ${FILE} -- -f permissions

```

Now you can deploy this artifact by using Mender and your device will have installed the new Update Module.

### On build time

Just add the created Update Module by following:

- [Instructions for Yocto-based images](https://docs.mender.io/operating-system-updates-yocto-project/customize-mender#update-modules)

- [Instructions for Debian-based distros](https://docs.mender.io/operating-system-updates-debian-family/customize-mender#update-modules)