Creating Component: AppImage

This is part of the How-to: Create Components Guide.

This guide uses Cemu as an example. AppImages can have significantly different structures, so inspect each AppImage individually.

Note: This guide assumes you have read the Creating Component: Guide.

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Step 0: Create a Testing Directory

1. Ensure that a local copy of RetroDECK Cooker is installed.
2. Create the components directory: mkdir -p ~/retrodeck_dev/components

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Step 1: Download the AppImage

1. Download the AppImage from its official website, GitHub repository, or another trusted source.
2. Place the AppImage in:

~/retrodeck_dev/components/

1. Create a directory matching the component name:

~/retrodeck_dev/components/<component_name>

Example

Download Cemu:

wget "https://github.com/cemu-project/Cemu/releases/download/v2.6/Cemu-2.6-x86_64.AppImage"

The AppImage should be located at:

~/retrodeck_dev/components/Cemu-2.6-x86_64.AppImage

Create the component directory:

mkdir -p ~/retrodeck_dev/components/cemu

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Step 2: Set Permissions and Extract the AppImage

Open a terminal in:

~/retrodeck_dev/components/

Set Executable Permissions

chmod +x "<Application>.AppImage"

Extract the AppImage

./<Application>.AppImage --appimage-extract

Example

chmod +x "Cemu-2.6-x86_64.AppImage"

./Cemu-2.6-x86_64.AppImage --appimage-extract

This creates a directory named:

squashfs-root

That will contain:

    squashfs-root/
    ├── AppRun
    ├── apprun-hooks/
    ├── checkrt
    └── usr/
        ├── bin/       # Application binary
        ├── lib/
        └── share/

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Preparing Testing of the AppImage

During this stage, identify and document the files required by the application:

• Binary
• Dependencies
• Libraries
• Other important files

AppRun is present in AppImages and may be:

• A script that launches the application binary.
• A binary that launches the application.
• A symbolic link to the application binary.

Create the Component Directory

Create a directory for the component under the RetroDECK Flatpak's component directory.

For example, for Cemu:

~/.local/share/flatpak/app/net.retrodeck.retrodeck/current/active/files/retrodeck/components/cemu

In general:

~/.local/share/flatpak/app/net.retrodeck.retrodeck/current/active/files/retrodeck/components/<component_name>

Copy the Application Files

Copy the contents of the usr/ directory from the extracted AppImage into the RetroDECK component directory.

Do not copy the usr/ directory itself.

The structure varies between AppImages. For example, Cemu uses:

    squashfs-root/
    ├── AppRun
    ├── apprun-hooks/
    ├── checkrt
    └── usr/ <--- Copy under this
        ├── bin/
        ├── lib/
        ├── share/
        └── <other>/

Copy the required usr/ structure into:

~/.local/share/flatpak/app/net.retrodeck.retrodeck/current/active/files/retrodeck/components/<component_name>/

For example:

~/.local/share/flatpak/app/net.retrodeck.retrodeck/current/active/files/retrodeck/components/cemu/

The resulting structure should resemble:

    components/
    └── cemu/
        ├── bin/
        ├── lib/
        └── share/

Common AppImage Structures

AppImage V2

squashfs-root/
├── AppRun
└── usr/
    ├── bin/       # Application binary
    ├── lib/       # Libraries
    └── share/     # Application data and resources

AppImage V3

    squashfs-root/     # Links to AppDir
    └── AppDir/
        ├── bin/       # Application binary
        ├── lib/       # Libraries or symbolic link
        └── share/     # Application data and resources

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AppImage Structure Examples

Azahar

    squashfs-root/
    ├── AppRun
    ├── apprun-hooks/
    ├── checkrt
    └── usr/
        ├── bin/       # Application binary
        ├── lib/
        ├── share/
        ├── plugins/
        └── translations/

Mudlet

    squashfs-root/
    ├── AppRun
    ├── <translation files>
    ├── doc/           # Licenses and documentation
    ├── lcf/
    ├── lib/
    ├── mudlet         # Application binary
    ├── mudlet-lua
    ├── plugins/
    └── translations/

ES-DE

    squashfs-root/
    ├── AppRun
    └── usr/
        ├── bin/       # Application binary
        ├── lib/
        └── share/

OpenGOAL

    squashfs-root/
    ├── AppRun
    ├── apprun-hooks/
    ├── checkrt
    └── usr/
        ├── bin/       # Application binary
        ├── lib/
        └── share/

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Testing Guide

Start testing:

Read more: Component Testing Guide

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