About the prefix part I think it should not matter. Just put your prefix instead of ' None .<ADDRESS>'

No. It is actually string concatenation. What you actually get is that an original string is broken into several parts. That are concatenated as following:
-d'{....' + ' + '....}'

@<1526734383564722176:profile|BoredBat47> Please try running the following command

curl -XPOST -H 'Content-Type: application/json' 'localhost:9200/events-training_debug_image-*/_update_by_query?conflicts=proceed' -d'{
    "script": {
        "source": "ctx._source.url = ctx._source.url.replace('

.<OLD_ADDRESS>', '

.<NEW_ADDRESS>')",
        "lang": "painless"
    },
    "query": {"prefix": {"url": {"value": "

.<OLD_ADDRESS>", "case_insensitive": true}}}
}'

@<1722061389024989184:profile|ResponsiveKoala38> Hello. What if my old fileserver address was not matching the None scheme? It was http and didn't have a domain, only ip address. Should I put my old address as it was in the replace method?

Hi @<1526734383564722176:profile|BoredBat47> , did the last update urls command work for you? I want to update our documentation

A bit confusing. But this is what linux shell wants if you have single quotes inside double quotes inside outer single quotes

Ah, I see. I forgot to escape the single quotes inside script. Please replace the current script source:
"ctx._source.url = ctx._source.url.replace('http://<MY_OLD_ADDRESS>', ' None .<NEW_ADDRESS>')"
With the escaped one:
"ctx._source.url = ctx._source.url.replace('''http://<MY_OLD_ADDRESS>''', ''' None .<NEW_ADDRESS>''')"

@<1722061389024989184:profile|ResponsiveKoala38> Got following error. Sorry for a screenshot, I can't copy text from web terminal I am using right now.

Hi @<1526734383564722176:profile|BoredBat47> , do you mean new debug samples or old ones? Please note that older debug samples were registered to the previous URL

It's the same request you provided just without "case_sensitive" option and with my endpoints @<1722061389024989184:profile|ResponsiveKoala38>

@<1526734383564722176:profile|BoredBat47> Can you please share the exact command that you are running?

@<1722061389024989184:profile|ResponsiveKoala38> Sure, I'll get back to you as it finishes

I'll get back to you in a minute

@<1722061389024989184:profile|ResponsiveKoala38> Shouldn't the escape slash be before the quote?

@<1523701070390366208:profile|CostlyOstrich36> Yes, I know. Above I posted a link where there's a solution. DB request to elastic to change those URLs. My question is: where to send this DB request? What endpoint? Request provided in FAQ in incomplete. It lacks URL where to send the request to.

curl --header "Content-Type: application/json" \
--request POST \
--data '{
    "script": {
        "source": "ctx._source.url = ctx._source.url.replace('

.<OLD_ADDRESS>', '

.<NEW_ADDRESS>')",
        "lang": "painless"
    },
    "query": {
        "match_all": {}
    }
}' \

@<1722061389024989184:profile|ResponsiveKoala38> My bad, I was indeed using double quotes. I fixed it and now script is working. I'll wait for results

I figured it was something with syntax but I thought single ticks inside double quotes should work without escaping 😀

Please let me know if it fixes the UI. I will ask to update our documentation then

Yeah, they should:) The problem is that they are inside outer single quotes -d'{...}'

You'd have to change the URLs in elastic itself

Please share you command

curl -XPOST -H 'Content-Type: application/json' 'localhost:9200/events-training_debug_image-*/_update_by_query?conflicts=proceed' -d'{
    "script": {
        "source": "ctx._source.url = ctx._source.url.replace('http://<MY_OLD_ADDRESS>', '

.<NEW_ADDRESS>')",
        "lang": "painless"
    },
    "query": {"prefix": {"url": {"value": "http://<MY_OLD_ADDRESS>"}}}
}'

@<1722061389024989184:profile|ResponsiveKoala38> Now I can see the images where previously it was placeholders with text "Unable to upload the images"

@<1722061389024989184:profile|ResponsiveKoala38> It fixed the issue!

Should I remove "case-sensitive" option from a query?

Great! Thanks:)

@<1523701070390366208:profile|CostlyOstrich36> My question basically is what host do I need to send POST request to change paths? curl to localhost:9200 (where elastic is running) is not working

@<1523701070390366208:profile|CostlyOstrich36> Old debug samples. My URL for files server has changed, and old debug sampled are not shown.

Can you please share it as a text
It is indistinguishable visually but I want to make sure that each single quote is replaced with single quote slash single quote single quote
and not single quote slash double quote