[SOLVED] JSON Help

I have a JSON that I am trying to edit. An array within the JSON has multiple elements with the same name and same sub-values. I want to edit only one of them in a bash script. Here is the JSON:

{
  "created": null,
  "category": "server-profiles",
  "serialNumberType": "Physical",
  "wwnType": "Physical",
  "macType": "Physical",
  "firmware": {
    "reapplyState": "NotApplying",
    "firmwareActivationType": "Scheduled",
    "firmwareScheduleDateTime": null,
    "firmwareInstallType": "FirmwareAndOSDrivers",
    "forceInstallFirmware": false,
    "manageFirmware": true,
    "firmwareBaselineUri": "/rest/firmware-drivers/spp-2019_03_0_85"
  },
  "hideUnusedFlexNics": null,
  "associatedServer": null,
  "affinity": null,
  "enclosureBay": null,
  "enclosureUri": null,
  "enclosureGroupUri": null,
  "serverHardwareTypeUri": "/rest/server-hardware-types/C309ABA9-3DFE-464E-9930-F4D61225C417",
  "serverHardwareUri": "/rest/server-hardware/30393137-3436-4536-34323939394C",
  "templateCompliance": "Unknown",
  "serverProfileTemplateUri": "/rest/server-profile-templates/28fa126e-bd5d-44ff-9b4c-1710555f8dcc",
  "bootMode": {
    "secureBoot": "Unmanaged",
    "pxeBootPolicy": "IPv4",
    "mode": "UEFIOptimized",
    "manageMode": true
  },
  "connectionSettings": {
    "connections": [],
    "reaplyState": "NotApplying"
  },
  "taskUri": null,
  "inProgress": false,
  "serverHardwareReapplyState": "NotApplying",
  "state": "Creating",
  "status": "OK",
  "modified": null,
  "refreshState": "NotRefreshing",
  "eTag": null,
  "osDeploymentSettings": null,
  "sanStorage": {
    "reaplyState": "NotApplying",
    "sanSystemCredentials": [],
    "volumeAttachments": [],
    "manageSanStorage": false
  },
  "localStorage": {
    "reaplyState": "NotApplying",
    "controllers": [],
    "sasLogicalJBODs": []
  },
  "managementProcessor": {
    "mpSettings": [
      {
        "args": {
          "password": null,
          "deleteAdministratorAccount": false
        },
        "settingType": "AdministratorAccount"
      },
      {
        "args": {
          "kerberosAuthentication": false,
          "directoryUserContext": [
            "dc=my,dc=com"
          ],
          "directoryServerPort": 636,
          "directoryServerAddress": "direct-serve.my.com",
          "password": null,
          "iloObjectDistinguishedName": "mysid",
          "directoryGenericLDAP": true,
          "directoryAuthentication": "defaultSchema"
        },
        "settingType": "Directory"
      },
      {
        "args": {
          "directoryGroupAccounts": [
            {
              "iLOConfigPriv": true,
              "virtualPowerAndResetPriv": true,
              "virtualMediaPriv": true,
              "remoteConsolePriv": true,
              "userConfigPriv": true,
              "groupSID": "S-1-5-22-2822724604-3899611472-1493707958-52883",
              "groupDN": "mygroup_OneView"
            },
            {
              "iLOConfigPriv": false,
              "virtualPowerAndResetPriv": true,
              "virtualMediaPriv": true,
              "remoteConsolePriv": true,
              "userConfigPriv": false,
              "groupSID": "S-1-5-22-2822724604-3899611472-1493707958-40755",
              "groupDN": "mygroup_OneView_RO"
            }
          ]
        },
        "settingType": "DirectoryGroups"
      }
    ],
    "manageMP": true,
    "reapplyState": "NotApplying"
  },
  "bios": {
    "reapplyState": "NotApplying",
    "overriddenSettings": [
      {
        "value": "NoState",
        "id": "MinProcIdlePkgState"
      },
      {
        "value": "MaxPerf",
        "id": "EnergyPerBios"
      }
    ],
    "manageBios": true
  },
  "boot": {
    "order": [],
    "manageBoot": false
  },
  "type": "ServerProfileV10",
  "uri": null,
  "name": "my-server",
  "description": "DL380 G9",
  "serialNumber": null,
  "uuid": null,
  "iscsiInitiatorName": null,
  "iscsiInitiatorNameType": "AutoGenerated"
}

I need to edit the password in the same section where kerberosAuthtication is. When I ran:

echo ${NEW_PROF} | jq -r '.managementProcessor.mpSettings[].args.password="mypassword"'

it says it cannot iterate over null. If I put in an index of 0, it just adds a new section. Does anyone know the correct method to edit this value?

Maybe PHP would be a better choice than bash for processing JSON data.

Better yet, just use JavaScript. It is JavaScript Object Notation after all.

It can be done with jq, but the solution is somewhat complex.

jq -r '.managementProcessor.mpSettings |= (map(if .args?.kerberosAuthentication? != null then .args.password="newPassword" else . end))'

Here we update .managementProcessor.mpSettings with the result of the operation on the right-hand side. In this case, we iterate over mpSettings and update the password to "newPassword" if the key kerberosAuthentication exists. Otherwise just print the current object.

Here is a test run. Notice that the only thing changed is the password.

jq -r '.managementProcessor.mpSettings |= (map(if .args?.kerberosAuthentication? != null then .args.password="newPassword" end))' < data.json | diff - data.json
73c73
<           "password": "newPassword",
---
>           "password": null,

PHP or Javascript might be better, but I don't know either of those. Individual, thanks for that! I'll give it a whirl!
Follow-up: My version of jq did not seem to like the '?' character. It flagged it as invalid each time. When I simply removed it, the update worked. My version of jq is 1.3. Thanks again!

Originally Posted by bradvan Follow-up: My version of jq did not seem to like the '?' character. It flagged it as invalid each time. When I simply removed it, the update worked. My version of jq is 1.3. Thanks again!

I should have asked what version you had installed. If you are going to be using jq a lot, I would recommend upgrading to the latest version.

I can't spell JSON, but I keep seeing references to jq here - looks like even I can get the general gist. Looks like a great tool.

Originally Posted by syg00 I can't spell JSON, but I keep seeing references to jq here - looks like even I can get the general gist. Looks like a great tool.

jq is fantastic. The syntax is a little intimidating, but once you get over it, it's truly great.