Editing inserting values in YAML based on criteria using a bash script - bash

Question

A YAML file as follows:
scrape_configs:
# The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
- job_name: 'prometheus'
static_configs:
- targets: ['localhost:9090']
- job_name: 'node-exporter'
relabel_configs:
- source_labels: [__address__]
target_label: instance
regex: '([^:]+)(:[0-9]+)?'
replacement: '${1}'
static_configs:
- labels:
type: 'YYY'
group: 'Bar'
targets:
- '192.168.1.134:80'
- '192.168.1.146:80'
- labels:
type: 'YYY'
group: 'Foo'
targets:
- '192.168.2.136:80'
- labels:
type: 'ZZZ'
group: 'Foo'
targets:
- '192.168.2.100:80'
I'd like to use a bash script to add the "targets" to the YAML based on "type" and "group". For example:
./add_host.sh 192.168.1.17:80 YYY Bar
Added bonus for deleting entries :)
Things I've tried (and failed):
Using jq;
Tried using sed to insert values, but I have trouble in finding the right section to insert it to (Block parsing).

Answer 1

You don't mean that you want to parse the YAML file with bash, do you? That would be tedious and error-prone, not to mention slow to execute. You must mean you want a command-line utility to manipulate the file.
What you want is something that parses the YAML into a data structure. If I were doing it, I'd try the Python PyYAML module. It represents the whole file as a nested data structure. Read it in, change the parts you want to change, and write it out.