The loop operator is used in order to execute an install script multiple times, it does so, and in process also sets and updates a variable with a count.
notes:
Please make sure to not set the incremental variable inside the target script as this will override the value set by the loop script.
- loopScript: <script to run>
count: <number of times>
var: <var to set>
onlyIf: <sub-command> #(Requires version 1.2.6 or higher)
notIf: <sub-command> #(Requires version 1.2.6 or higher)
loopScript: The script to run multiple times.count: The number of times to run the script.var: The variable to set and update.onlyIf: This sub command will run and if an output is received it will return true and thus allow executionnotIf: This sub command will run and if an output is received it will return false and thus prevent execution- loopScript: setup-kafka.yml
count: 3
var: NODE_ID
In the example above the script will be executed 3 times and the variable NODE_ID will be set to 0, 1, and 2, consecutively for each execution of the script. This makes it easy for installing clusters and managing them in a loop in a consistent way, and it ensures a more effective iterative approach to deploying and managing clusters, as the loop is not dependent on the script.
Setting the incremental variable inside the target script will override the value set by the loop script, for instance:
---
variables:
# note do not set Option here as it will be overwritten
NODE_ID: 0
steps:
- cmd: echo "Hello World = {{.NODE_ID}}" >> output.txt
And then using a loop script like this:
- loopScript: setup-kafka.yml
count: 3
var: NODE_ID
The above script will not set the NODE_ID value appropriately as it will be overwritten by the local variable.