How to undo setting Elasticsearch Index to readonly?

So I just set one of my indices to readonly, and now want to delete it.

To set it to readonly:

PUT my_index/_settings
{ "index": { "index.blocks.read_only" : true } }

When I tried to delete it I got this response:

ClusterBlockException[blocked by: [FORBIDDEN/5/index read-only (api)];]

Then I tried to set the index to readonly false:

PUT my_index/_settings
{ "index": { "index.blocks.read_only" : false } }

But that gives the same error message as above. So how to set readonly back to false?

The correct way to make es index read-only is

PUT your_index/_settings
{
  "index": {
    "blocks.read_only": true
  }
}

change true to false to undo it.

You set non dynamic setting with

   {
      "index": {
        "blocks.read_only": false
      }
    }

which I think was not your intention. Also I think you should have seen an error during first operation itself as non dynamic settings can be updated only on close indices.

run

POST your_index/_close

and then try changing it.