NEST : Create Alias and set filter

Question

I am very new to ES. While exploring NEST client for .Net I came across a situation which am not able to figure out how to achieve using NEST.Net.

Configuration : .Net 4.6.1 NEST 7.2.0

What I am trying is to set an alias on an existing index. I was able to achieve it using following.

await _client.Indices.PutAliasAsync(indexName, aliasName);

This creates an alias on index though alias is empty.

Now I wanted to achieve below structure.

"MyIndexName" : {
    "aliases" : {
      "MyAliasName" : {
        "filter" : {
          "term" : {
            "MyFilterTerm" : "MyFilterTermValue"
          }
        }
      },
}

I used below snippet

await _client.Indices.PutAliasAsync(indexName, aliasName,
                                a => a.Filter<MyTestClass>(
                                    f => f.Term("MyFilterTerm", "MyFilterTermValue")));

public class MyTestClass {// not sure what this was supposed to be}

however this produces json as below.

"MyIndexName" : {
    "aliases" : {
      "MyAliasName" : {
        "filter" : {
          "term" : {
            "MyFilterTerm" : {
              "value" : "MyFilterTermValue"
            }
          }
        }
      },
}

How do I achieve the first JSON format?

Answer 1

The two JSON formats for the term query in the filter clause are the equivalent. NEST typically emits the longer form of queries, which for a term query is

"term" : {
    "<field>" : {
        "value" : "<value>"
    }
}

as opposed to the short form

"term" : {
    "<field>" : "<value>"
}