[SOLVED] parsing and incrementing date in json file with jq

Issue

I would like to update multiple dates in a json file. My input json contains many properties but the following is the extracted part that matters: I want to parse the date in metadata, here 2022-07-27, replace it by today's date (e.g. 2022-08-05), and set the delta (here 9 days), and add that delta to all other date found in "data_1h" / "time"

edit: (first forgotten) I need also that metadata's date get eventually replaced by today's date.

I could wrote a small tool in any language, but I would like a linux script that can be run from a gitlab pipeline. It is about preparing mockdata for some tests.

So I started fighting with jq, awk or sed, but am a bit confused there. Maybe an experienced jq guy would find the solution immediately?

{
   "metadata": 
    {
        "modelrun_utc": "2022-07-27 00:00", 
        "modelrun_updatetime_utc": "2022-07-27 07:27"
    }, 
   "data_1h": 
   {
       "time": ["2022-07-27 00:00", "2022-07-27 01:00", "2022-08-03 11:00", "2022-08-03 12:00", "2022-08-03 13:00", "2022-08-03 14:00"]
   }
}

Any idea?

pseudo code would be:

base_date_str=$(jq .metadata.modelrun_utc $1)
echo $base_date_str
base_date=$(date -d $base_date_str)
today=$(date)
delta=$base_date-$today

input-data=$(jq .data_1h.time $1)

foreach (s in $input-data)
  # transform s to date d, add delta to d, replace s by d in output string
  
replace modelrun_utc modelrun_updatetime_utc by today's date only, keeping the time.

# write output json

How does this look like in real shell commands?

Expected output:

{
    "metadata": {
        "modelrun_utc": "2022-08-05 00:00",
        "modelrun_updatetime_utc": "2022-08-05 07:27"
    },
    "data_1h": {
        "time": [
            "2022-08-05 00:00",
            "2022-08-05 01:00",
            "2022-08-12 11:00",
            "2022-08-12 12:00",
            "2022-08-12 13:00",
            "2022-08-12 14:00"
        ]
    }
}

Solution

Here's one way using jq logic, not shell commands:

jq '(
  .metadata.modelrun_utc | strptime("%Y-%m-%d %H:%M")
  | (now - mktime) / (24 * 60 * 60)
) as $diffdays | .data_1h.time[] |= (
  strptime("%Y-%m-%d %H:%M") | .[2] += $diffdays
  | mktime | strftime("%Y-%m-%d %H:%M")
)'

{
  "metadata": {
    "modelrun_utc": "2022-07-27 00:00",
    "modelrun_updatetime_utc": "2022-07-27 07:27"
  },
  "data_1h": {
    "time": [
      "2022-08-05 00:00",
      "2022-08-05 01:00",
      "2022-08-12 11:00",
      "2022-08-12 12:00",
      "2022-08-12 13:00",
      "2022-08-12 14:00"
    ]
  }
}

Demo

Answered By - pmf

Answer Checked By - Cary Denson (WPSolving Admin)