Question 265682 in Json Question posted in
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Reorder values inside a JSON-embedded string based on a flag's value

I have two JSON files with different schema.
The sample data in the JSON files as

File1.json

{
  "ServiceSettings": {
    "ServiceName": "my-service",
    "RedisSettings": {
      "RedisHost": "HOST-A;HOST-B" 
    }
  }
}

File2.json:

{
  "RedisHost": "HOST-A;HOST-B"
}

I have a requirement as below and the conditions are passed through the pipelines, dynamically

I set a variable preset as

host_orderA="HOST-A;HOST-B"
&
host_orderB="HOST-B;HOST-A"

  1. if the condition is A, the RedisHost should be

    "RedisHost": "HOST-A;HOST-B"

  2. if the condition is B, the RedisHost should be

    "RedisHost": "HOST-B;HOST-A"

  3. Irrespective of the order of hosts list HOST-A & HOST-B in the actual JSON files, I want to order the hosts in the JSON and print or output data into a variable or use sponge to replace in the same JSON files, based on the conditions, 1 & 2 above.

I tried a few things using sed & JQ but was unable to attain proper output. I prefer to use JQ to replace it as it’s JSON-friendly.

Tags:

2

Answers


  1. 0

    It’s not a particularly clean solution, but the following works:

    condition=A # or condition=B
jq --arg condition "$condition" '
  def maybeReorderHost:
    ( if $condition == "A" then "HOST-A" else "HOST-B" end) as $priorityPattern |
    if type != "object" then . else (
      if .RedisHost? == null then . else (
        .RedisHost |= (split(";") as $hostArr |
        [[$hostArr[] | select(index($priorityPattern) != null)],
         [$hostArr[] | select(index($priorityPattern) == null)]]
        | add | join(";") )
    ) end
  ) end;

  walk(maybeReorderHost)
' <FileA.json

    We’re using split(";") to split your string into an array; filtering for the array elements that do match your desired pattern; filtering for the array elements that don’t match your pattern; and then concatenating those two sublists together.

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  2. 0

    If the format of .RedisHost is fixed, you can try :

    this=B
jq --arg this $this
    '(if $this == "A" then "B" else "A" end) as $that|
     (.. | select(type == "object" and has("RedisHost"))
           .RedisHost?) = "HOST-($this);HOST-($that)"' File1.json
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