OpenWRT 18.06 & Nodejs installing onoff node module [ solved ]

Jeff Seese

After upgrading to the latest OpenWRT per this blog post OpenWRT 18 available for omega2 & omega2+ I had some issues getting past working nodejs apps to work.

The root cause was the old onoff-node located at /usr/bin/onoff-node is no longer available via opkg install onoff-node. It is now possible to use the standard onoff module via npm.

However, to get there is a combination of several steps so I am going to explain the steps I went through to get it to work.

In short, make and gcc need to be installed so that npm can compile the onoff module. To be able to do that it's necessary to point opkg to the OpenWRT LEDE repos so they can be installed via opkg.

To compile onoff the omega will run out of ram so it's necessary to enable a swap file.

The Omega2S+ that I was working on didn't have enough room for python, nodejs and npm so I used an external SD card.

upgrade to the latest OS. OpenWRT 18 available for omega2 & omega2+

oupgrade --latest

After this finishes and you log back in you should see something like this.

Ω-ware: 0.3.2 b218

boot from the SD card. Booting from external storage

opkg update
opkg install kmod-usb-storage-extras e2fsprogs kmod-fs-ext4 block-mount

umount /tmp/mounts/SD-P1
echo -e "y" | (mkfs.ext4 /dev/mmcblk0p1)

mkdir /mnt/mmcblk0p1
mount /dev/mmcblk0p1 /mnt/mmcblk0p1
block detect > /etc/config/fstab
uci set fstab.@mount[0].target=/overlay
uci set fstab.@mount[0].enabled=1
uci commit
mount /dev/mmcblk0p1 /mnt/ ; tar -C /overlay -cvf - . | tar -C /mnt/ -xf - ; umount /mnt/

now reboot, and log back in. You should see a large overlay in your df -h output, something like this for an 8G SD carrd.

df -h
overlayfs:/overlay        7.2G    480.8M      6.4G   7% /

Create a swap file and activate it. Extending Omegas Available Memory

opkg update;
opkg install swap-utils

Make a swap file, I made min in my root directory since I now have additional space by mounting the SD card.

dd if=/dev/zero of=/root/swap.page bs=1M count=256

Turn on the swap file

swapon /tmp/mounts/USB-A1/swap.page

I didn't permanently mount mine I only need the swap file for this instance. To check the swap file sue the free command.

free
             total       used       free     shared    buffers     cached
Mem:        124920      71360      53560          8       6888      40624
-/+ buffers/cache:      23848     101072
Swap:       262140       2560     259580

You should see the Swap: line

Install python, nodejs, npm.

opkg install python nodejs node-npm

install node-gyp https://docs.onion.io/omega2-docs/node-red-article.html#

node --max_old_space_size=512 $(which npm) install -g node-gyp

Switch back to LEDE packages so that make and gcc can be installed. https://docs.onion.io/omega2-docs/using-opkg.html#using-opkg-switch-to-lede-repos

This is what my /etc/opkg/distfeeds.conf ended up looking like.

src/gz openwrt_core http://downloads.openwrt.org/releases/18.06-SNAPSHOT/targets/ramips/mt76x8/packages
src/gz openwrt_base http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/base
src/gz openwrt_luci http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/luci
src/gz openwrt_onion http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/onion
src/gz openwrt_packages http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/packages
src/gz openwrt_routing http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/routing
src/gz openwrt_telephony http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mipsel_24kc/telephony
src/gz omega2_core http://repo.onioniot.com/omega2/packages/core
src/gz omega2_base http://repo.onioniot.com/omega2/packages/base
src/gz omega2_packages http://repo.onioniot.com/omega2/packages/packages
src/gz omega2_routing http://repo.onioniot.com/omega2/packages/routing
src/gz omega2_onion http://repo.onioniot.com/omega2/packages/onion

basically I just uncommitted everything.

Install make and gcc https://docs.onion.io/omega2-docs/node-red-article.html#

opkg update
opkg install make gcc
ar -rc /usr/lib/libpthread.a

Go get a cup of coffee, this will take a few minutes.

Finally ready to install npm onoff This will take a few minutes.

node --max_old_space_size=512 $(which npm) install onoff

That's it. You should see onoff in your node_modules directory now.

I verified that it works with a quick test .js to toggle a GPIO.

Jeff Seese

Oh one thing I forgot to mention, after I got all this working I was able to tar the node_modules directory up and move it to an Omega2S+ with no SD card.

After updating it to OpenWRT18, the nodejs install is small enough no external boot is necessary and there is no need for NPM on the production boards since they will never install a package. So that is nice to be able to eliminate the SD card.