Custom Application questions.

[Ajay K]

I was wondering if I can get some clarifications regarding custom application support that has been added since the new firmware of the conduit.

1) If I build an express based Rest based web service such as the one in the examples on the multitech site, the node modules that are required to support this application, where would that be installed?

2) Can I use any document based database such as Mongodb with the custom application and if so where should I be installing this?

3) This application is only going to be accessible via node-red and so basically accessible as a local host, is there any specific port numbers that I should be using within the conduit?

I am sure I will have some follow up questions, can you provide some guidance as to any limitations wrt to the custom applications that I need to be aware of.

Thanks,
Ajay.

[Jeff Hatch]

Ajay,

In the case of the expressHelloWorld example, all the node dependencies are right in the application, and are not installed outside of the application’s directory in /media/card/expressHelloWorld. That means that all the require statements are relative to the app.

The Mongodb server software can probably fit on the Conduit, but I would recommend that if you are going to have a significant amount of data (over 1 Meg) then you should probably have the actual data on the SD Card. There is maybe 7MB available of persistent flash available in /var/config that won’t get overwritten on upgrade.

As for localhost connections, you can pretty much use whatever ports you want. However, 53, 80, 443, and 1081 are used by DNS, the API, and Node-RED, respectively.

Hope that is helpful.

Jeff

[Ajay K]

Hi Jeff,

Thank you so much for your quick response.

What is the best way to install Mongodb on the conduit? I don’t think the data could exceed 1mb, but I could just to be sure ensure the actual data is on the SD card instead.

One other question I had as of today, my conduit is connected to the internet via the cellular connection i.e. via the sim card. I can’t get the conduit to use my in house internet connection. I didn’t see any steps on the multi-tech site how to configure internet connection when connected to my laptop.

Thanks,
Ajay.

[Ajay K]

Hi Jeff,

Sorry another follow up question, has the multitech team tested the conduit with a mongo db install? If so what version of mongo db should I be using as I see on the mongo db site there are various flavors depending on the OS, not sure which one to specifically pick?

Thanks,
Ajay.

[Jeff Hatch]

Ajay,

We have not tested installing Mongo on a Conduit. There have been customers that have installed Postgres DB, but not Mongo that I know of.

In order to install Mongo it will have to be compiled for ARM architecture. The AEP Conduit is based off of the Yocto OpenEmbedded project. There is a Mongo bitbake recipe for building it here:

https://layers.openembedded.org/layerindex/recipe/24093/

I would recommend using the mLinux distro to build Mongo and to generate the *.ipk files (packages) to install on the Conduit. There are instructions for getting started with that here:

Building Images

You can add your bitbake recipe to the meta-mlinux bitbake layer, and build Mongo. You will have a lot more questions, so don’t hesitate to ask.

Jeff

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