Small python script to compare fields in elasticsearch index template vs elasticsearch indices

compare.py

#! /usr/bin/python3
import json


# This is not a beutiful piece of code, however it works.
# If you have an elasticsearch index with defined fields in an index template but also dynamic mapping enabled
# you can run into not knowing what dynamic fields exist, which is not a good idea 
# so the idea here is to be able to list fields existing in templates and indices and compare them


# I recomend using:  "./compare.py  | column -t -s ','"
# Since this is not something I am publishing as a tool, just a snipped I decided not to spend any time adding pretty-print functions to it 

# Line 29-32 sets a few variables as True or False, those control what data is displayed


template = "/path/to/index/template.json" # GET _template/template_1
index    = "/path/to/mapping/info/from/index.json" # GET /my-index/_mapping





fList = []
iList = []



pil = False  # List all fields defined in the index 
pfl = False  # List all fields defined in the index template
umap = False # List all fields in the index template that are not defined in the index template
rep = True   # get some basic numeric info



with open(template) as json_file:
    template = json.load(json_file)


with open(index) as json_file:
    index = json.load(json_file)


tData = template["mappings"]["properties"]
iData = index["mapping"]["properties"]




# Recursion for nested fields 
def dig(data,name,liist):
    if "type" in data:
        type = data["type"]
        msg = name + "," + type
        liist.append(msg)
    else:
        if "properties" in data:
            d = data["properties"]
        else:
            d = data

        for x in d:
            dd = d[x]
            n = name + "." + x
            dig(dd,n,liist)





# what builds the data 
def makeList(fields,liist):
    for cat in fields:
        cdat = fields[cat]

        if "type" in cdat:
            type = cdat["type"]
            msg = cat + "," + type
            liist.append(msg)
        else:
            ddat = cdat["properties"]

            for d in ddat:
                cdat = ddat[d]
                name = cat + "." + d
                dig(cdat,name,liist)


# Make the data 
makeList(tData,fList)
makeList(iData,iList)


# Depending on what is selected in the beginning, here the actual output is generated

if pil:
    for entry in iList:
        print(entry)

if pfl:
    for entry in fList:
        print(entry)

if umap:
    for entry in iList:
        if entry in fList:
            pass
        else:
            print(entry)

if rep:
    ilen = len(iList)
    flen = len(fList)
    diff = abs(ilen - flen)

    m1 = "Number of fields defined in template:," + str(flen)
    m2 = "Number of fields defined in index:," + str(ilen)
    m3 = "Diffirence is:," + str(diff)

    print()
    print(m1)
    print(m2)
    print(m3)
    print()