Using the exec node to automate database backups

General
1

hi
I'm fairly new to node-red and am trying to automate execution of a command.

A bit of background. I am setting up a number of IOT sensors to collect data for a project I have. I am using a MING (Mosquitto, InfluxDB, Node-red, and Grafana) stack to collect the data points from the sensors, store them (influxdb) and display them. For now the server is running on a raspberry pi. I've used docker to set up the MING stack and it is running well.

I now would like to set up a backup for the InfluxDB database. I have mounted a shared folder back to my NAS at /home/dr/lab_data to hold it. Docker provides a command to export containers (eg Influxdb) into a .tar file.

sudo docker export -o /home/dr/lab_data/ influxdb

I can execute the command manually and it creates a .tar file in the location and now would like to automate this in code red.

I haven't been able to get the exec node to work.

simply inserting the above command returns error 127 with ...
Command failed: sudo docker export -o /home/dr/lab_data/test influxdb
/bin/bash: line 1: sudo: command not found

I have tried including the command in the injected message payload but this doesn't work.

any constructive suggestions would be welcome

2

You will not be able to execute sudo commands from node-red. You will need to add the user to the sudo group, or do it a 'more' node-red-way, use a node like dockerode to execute docker commands

3

This is how I backup the influx database from an Exec node.
Tar file is generate in the /home/nodered/dbs/backup_ex directory.

Capture
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Don't know if it will work in Docker.

4

This is not strictly true. You could edit sudoers to turn off the need for a password prompt for that command. Of course, this may be something of a security issue so should only be done after careful thought about possible consequences.

5

Is node red also running in Docker? If so, does that command run if you execute it from inside the node red docker container?