App-service.md

Service App Guide

In this guide, we will show you how to write a hello world service app.

1. Create a service app

You can start developing a service app by using a service app template.

Copy the template, and start editing lib/index.js. The template contains code to print hello world.

2. Compile and run the service app on Linux

You can decide which lwnode executable to use when running a service app. For example, you can either use lwnode preinstalled on a Tizen platform, or use lwnode executable included when the service app is packaged. The latter approach allows you to use a lwnode executable specific for each service app.

First, add a lwnode executable to your app.

mkdir bin
cd bin

# Use the preinstalled lwnode on Tizen
ln -s /usr/bin/lwnode {lwnode path}/lwnode

# OR Include lwnode for this service
cp lwnode {lwnode path}/lwnode

Then, install Express.js module.

npx pnpm i express

While developing, you can run the service app on Linux as follows.

./bin/lwnode lib

3. Build Tizen RPMs

3.1 Create a RPM package

Build Tizen RPMs as follows.

gbs -c .github/gbs.conf build \
    -A armv7l \
    -P profile.t70std \
    -B ~/GBS-ROOT/helloworld \
    --include-all --incremental

In this example, we use ~/GBS-ROOT/helloworld as our output directory. Please note that gbs only works if the current directory is under a git repo, i.e., gbs searches for .git directory in your project root.

3.2 Install the RPM package

Install the rpm package on a target device. You can find the package in the following directory.

~/GBS-ROOT/helloworld/local/repos/t65std/armv7l/RPMS/helloworld-1.0.0-1.armv7l.rpm

Install the package on a target device

rpm -Uvh --nodeps --force helloworld-1.0.0-1.armv7l.rpm

4. Connect to the Web service

Open http://{target device IP}:3000 on a Web browser to see the service running. In this example, hello world should be printed on the browser.