I want to host node-red 24/7 on Raspberry Pi. Something was running it constantly, then, the power had gone out, then it came back. But, then, the data was not coming.
I want the node-red to run constantly (at least when the raspberry pi is running). I tried making an .SH file to make it constantly run, here is the code:
node-red
that is the command prompt line to run node-red.
That did not work, is there something that I can do about this?
What you're looking for is a process manager, there are many process managers available each with their own features.
Natively many linux distributions support this functionality via a system called systemd also called an init system.
Docker as a system is also an option but this may be excessive for your use-case.
Some popular process manager applications are:
supervisord
PM2
Additional reading:
A supervisord tutorial on Digital Ocean by Alex Garnett
A systemd tutorial on Digital Ocean by Justin Ellingwood
The node-red install instructions for raspberry pi cover the in the running as a service section
https://nodered.org/docs/getting-started/raspberrypi#running-as-a-service
It is most likely that you had used node-red-start to start Node-RED as a service, but you had not completed the latter step to enable the service to start on boot.
Autostart on boot
If you want Node-RED to run when the Pi is turned on, or re-booted,
you can enable the service to autostart by running the command:
sudo systemctl enable nodered.service
To disable the service, run the command:
sudo systemctl disable nodered.service
Related
I'm trying to stop the Mosquitto broker service on a centos 7 server.
I've stopped the service with
sudo systemctl stop mosquitto.service
then I've disabled it with
sudo systemctl disable mosquitto.service
with ps I still get
/usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf
if I kill it, it autorestarts automatically and even after a reboot It's still running.
The process is owned by an other user (admin).
How can I stop it definitively?
This has nothing to do with mosquitto but how systemd manages its services.
systemctl disable only affects the autostart of the service but a disabled service will still get started if another service depends on it.
Lets say you have got a service mqtt-client depending on mosquitto with e.g. Wants=mosquitto. Every time mqtt-client is started the mosquitto service gets started as well, even if it is disabled.
So one way is either to prevent mqtt-client from starting as well (and all other services which depend on mosquitto) or remove the dependency.
Another approach is to totally prevent the service from being loaded by masking it:
systemctl mask mosquitto - this way you can neither start it manually nor by another service.
I would recommend reworking your dependencies in the long run since masking will just create a symlink to dev/null so nothing happens if service gets loaded and you are not able to start it by yourself without unmasking it first.
I am building a mesos cluster from scratch (using Vagrant, which is not relevant for this issue).
OS: Ubuntu 16.04 (trusty)
Setup:
Master -> Runs ZooKeeper, Mesos-master, Marathon and Chronos
Slave -> Runs Mesos-slave
This is my provisioning script for the master node https://github.com/zeitgeist2018/infrastructure/blob/fix-marathon/provision/scripts/install-master.sh.
I have managed to register de slave into Mesos, install Marathon and Chronos frameworks, and run scheduled jobs in Chronos (both with docker and shell commands), but I can't get Marathon to work properly. The UI gets stuck in "Loading applications" as soon as I open it, and when I try to call the API, the request hangs forever with no response. In the API I tried to get simple marathon information and do deployments, both with the same hanging result.
I've been checking Marathon logs but I don't see anything error there. Just a couple of logs that may (or not) be a hint:
[2020-03-08 10:33:21,819] INFO Prompting Mesos for a heartbeat via explicit task reconciliation (mesosphere.marathon.core.heartbeat.MesosHeartbeatMonitor$$anon$1:marathon-akka.actor.default-dispatcher-6)
[2020-03-08 10:33:21,822] INFO Received fake heartbeat task-status update (mesosphere.marathon.core.heartbeat.MesosHeartbeatMonitor:Thread-87)
[2020-03-08 10:33:25,957] INFO Found no roles suitable for revive repetition. (mesosphere.marathon.core.launchqueue.impl.ReviveOffersStreamLogic$ReviveRepeaterLogic:marathon-akka.actor.default-dispatcher-7)
Installing jdk11 and choosing it as default fixed this issue for me without downgrading the Marathon to any other version.
in ubuntu 20.04:
sudo apt install openjdk-11-jre-headless
update-alternatives --config java
I increased the number of cpus, virtual machine in which the marathon was installed to 3 and the problem was solved.
I have managed to make it work. It was as simple as downgrading Marathon to v1.7.189. After that, it starts properly, and the API responds to requests.
I am new at programming Raspberry Pi, can you help me to find commands for "Exec" node?
vcgencmd measure_temp
For example this code gives the temperature of Raspberry Pi if you write it on "Exec" node in Node-Red.
There is no list of commands for the exec node.
This node can be used to run any application that can be executed on the platform running Node-RED, in this case linux.
(These applications should be things that run without requesting any further input after starting and provided output to stdout/stderr)
I have a Yocto based OS on which I have everything installed to start the network.
Nevertheless, at each boot I need to do systemctl start networking to start it. Initially the service was even masked. I found out how to unmask it but I can't find a way to start it automatically.
I don't know much about systemd but the networking.service is located in generator.late folder. From what I understood, it's generated afterward.
How can I enable it?
It depends if you want to enable the service only on one particular device. If yes, it is simple:
systemctl enable networking
Append the parameter --now if you also want to start the service just now.
If you want to enable the service on all your devices (i.e. it will be automatically enabled in all your images coming from build), the best way is to extend the recipe, but please see below for other ways how to handle the network. The process is describe at NXP support for example.
Some notes about networking.service itself: I assume that your networking.service comes from init-ifupdown recipe. If yes, is there any reason to handle network configuration using old SysV init script in system with systemd? The service is generated from SysV init script by systemd-sysv-generator. So I would suggest to try other networking services like systemd's native "systemd-networkd", "NetworkManager" or "connman". The best choice depends on type of your embedded systemd. These services are integrated with systemd much better.
Some more information on activating or enabling the services: https://unix.stackexchange.com/questions/302261/systemd-unit-activate-vs-enable
I am new to kuberenetes.
is it possible to turn every end user machine (PCs, Macs, RPi ... etc) who with full consent downloaded my electron research app that should turn their machines into nodes that ultimately comprise a k8s cluster which then i can run kubeflow.org on to do ML research?
Thanks
Kubernetes relies on some container engine. Usually that's docker, there are efforts to create a common container interface for kubernetes and that's where CRI-O comes in, an abstraction that would allow any container engine to run underneath it.
That being said, containers "don't exist" they are a native abstraction in the linux kernel comprised of cgroups and namespaces and what that means is that the abstraction and isolation doesn't live in the hypervisor (which usually talks to the kernel) as is the case with regular virtual machines, but rather in the actual linux kernel.
MacOS uses its own kernel which, to the extent of my knowledge, doesn't support any sort of containers.
Windows does support containers via Hyper-V and i believe that windows server has a more native built-in support for them. See this link for a better explanation https://learn.microsoft.com/en-us/virtualization/windowscontainers/about/ and also for kubernetes https://kubernetes.io/docs/getting-started-guides/windows/.
As far as Raspberry PI goes there is an ongoing effort that brought k8s to ARM see this link (https://github.com/luxas/kubernetes-on-arm). That being said, you need an entire cluster of raspberry pis to actually make that work, as it would require a lot of resources. One raspberry pi won't get you very far.
How to go about this?
You need linux to run kubernetes. Everywhere.
If you want to create a "giant" kubernetes cluster your best bet is to use a virtualization technology for the PC that is running windows or for the Mac and create virtual machines that you can use as kubernetes nodes.
In short, you create virtual machines where there's no Linux and install kubernetes natively where there is.
Parallels, Veertu or plain Xhyve is a good way of running virtualization on MacOs.
VmWare or VirtualBox are good virtualizations for both windows and mac.
Libvirt and virtualbox are good solutions for linux virtualisation.