Wrong behaviour deleting alias.

[myrfy001]

Elasticsearch version:
5.2.2
Plugins installed: []
head
JVM version:
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)
OS version:
Linux 3.10.0-229.el7.x86_64
Description of the problem including expected versus actual behavior:

With two index named foo_foo and bar_bar with the same alias foo like below:

index	alias
foo_foo	foo
bar_bar	foo

If use the following to remove the alias, only the alias of 'foo_foo' is removed, that's fine.

POST /_aliases 
{
  "actions": [
    {
      "remove": {
        "index": "foo_*",
        "alias": "foo"
      }
    }
  ]
}

BUT, if use the following to remove, both the alias of foo_foo and bar_bar will be removed, while I think only the foo_foo 's alias should be removed

POST /_aliases 
{
  "actions": [
    {
      "remove": {
        "index": "foo*",
        "alias": "foo"
      }
    }
  ]
}

Steps to reproduce:

1. Create Two Index using the following:

PUT /foo_foo
PUT /bar_bar

2. Add Alias for them using:

POST /_aliases
{
    "actions" : [
        { "add" : { "index" : "foo_foo", "alias" : "foo" } },
        { "add" : { "index" : "bar_bar", "alias" : "foo" } }
    ]
}

3. delete alias using:

POST /_aliases 
{
  "actions": [
    {
      "remove": {
        "index": "foo_*",
        "alias": "foo"
      }
    }
  ]
}

[olcbean]

This looks like a low hanging fruit. If so, I would like to have a look at it.

[jimczi]

@olcbean I just marked the issue as adopt me ;)

[bytetwin]

@jimczi I am a first timer and would like to work on this issue. Could you please share the file where I can start to look at ?

[kunal642]

@myrfy001 i cannot replicate the issue. I have followed the step and i am able to query bar_bar with the alias foo.

[jimczi]

@kunal642 the last step of the reproduction has a typo. I can reproduce the problem with the following request:

POST /_aliases 
{
  "actions": [
    {
      "remove": {
        "index": "foo*",
        "alias": "foo"
      }
    }
  ]
}

The problem here is that we resolve index: foo* to all indices and aliases that match the pattern.
@olcbean has a PR open that resolve the pattern on indices only.