Store output diskspace df -h JSON

Question

I am attempting to gather basic disk space information from a server using a bash script, and store the output in JSON format. I am looking to record the available & use

Answer 1

You can do:

$ df -Ph | awk '/^\// {print $1"\t"$2"\t"$4}' | python -c 'import json, fileinput; print json.dumps({"diskarray":[dict(zip(("mount", "spacetotal", "spaceavail"), l.split())) for l in fileinput.input()]}, indent=2)'
{
  "diskarray": [
    {
      "mount": "/dev/disk1", 
      "spacetotal": "931Gi", 
      "spaceavail": "623Gi"
    }, 
    {
      "mount": "/dev/disk2s2", 
      "spacetotal": "1.8Ti", 
      "spaceavail": "360Gi"
    }
  ]
}

Answer 2

Alternative Oneliner

$ df -hP | awk 'BEGIN {printf"{\"discarray\":["}{if($1=="Filesystem")next;if(a)printf",";printf"{\"mount\":\""$6"\",\"size\":\""$2"\",\"used\":\""$3"\",\"avail\":\""$4"\",\"use%\":\""$5"\"}";a++;}END{print"]}";}'

{
   "discarray":[
      {
         "mount":"/",
         "size":"3.9G",
         "used":"2.2G",
         "avail":"1.5G",
         "use%":"56%"
      },
      {
         "mount":"/dev",
         "size":"24G",
         "used":"0",
         "avail":"24G",
         "use%":"0%"
      }
   ]
}

Answer 3

The following does what you want, with the only requirement external to bash being a Python interpreter:

python_script=$(cat <<'EOF'
import sys, json

data = {'diskarray': []}
for line in sys.stdin.readlines():
    mount, avail, total = line.rstrip(';').split()
    data['diskarray'].append(dict(mount=mount, spacetotal=total, spaceavail=avail))
sys.stdout.write(json.dumps(data))
EOF
)

df -Ph | awk '/^\// { print $1" "$2" "$3";" }' | python -c "$python_script"

An alternate implementation using jq might look like this:

df -Ph | \
  jq -R -s '
    [
      split("\n") |
      .[] |
      if test("^/") then
        gsub(" +"; " ") | split(" ") | {mount: .[0], spacetotal: .[1], spaceavail: .[2]}
      else
        empty
      end
    ]'

Answer 4

Xidel, together with some XQuery magic can do what you want (I used your df -h output).

df -h | xidel -s - --xquery '
  {
    "diskarray":[
      for $x in x:lines($raw)[starts-with(.,"/")]
      let $a:=tokenize($x,"\s+")
      return {
        "mount":$a[1],
        "spacetotal":$a[2],
        "spaceavail":$a[4]
      }
    ]
  }
'
{
  "diskarray": [
    {
      "mount": "/dev/mapper/nodequery--vg-root",
      "spacetotal": "45G",
      "spaceavail": "41G"
    },
    {
      "mount": "/dev/sda2",
      "spacetotal": "237M",
      "spaceavail": "178M"
    },
    {
      "mount": "/dev/sda1",
      "spacetotal": "511M",
      "spaceavail": "508M"
    }
  ]
}