Auth error for index template APIs doesn't include manage_index_templates cluster priv

[jrodewig]

Elasticsearch version (bin/elasticsearch --version): Latest elasticsearch-8.0.0-SNAPSHOT-darwin-x86_64.tar.gz

Plugins installed: []

JVM version (java -version):

openjdk version "15.0.1" 2020-10-20
OpenJDK Runtime Environment AdoptOpenJDK (build 15.0.1+9)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 15.0.1+9, mixed mode, sharing)

OS version (uname -a if on a Unix-like system):
Darwin 19.6.0 Darwin Kernel Version 19.6.0: Mon Aug 31 22:12:52 PDT 2020; root:xnu-6153.141.2~1/RELEASE_X86_64 x86_64

Description of the problem including expected versus actual behavior:

The manage_index_templates cluster privilege lets a user run the following APIs:

• Delete legacy index template
• Delete composable index template
• Get legacy index template
• Get composable index template
• Put legacy index template
• Put composable index template
• Simulate index
• Simulate template

However, the authorization error returned by these APIs does not list manage_index_templates as a privilege.

Steps to reproduce:

1. As the elastic user, create a mytest role with no cluster privileges:

POST _security/role/mytest
{
  "cluster": [
  ],
  "indices": [ ]
}

2. As the elastic user, create a test user with the mytest role:

POST _security/user/test
{
  "password" : "...",
  "roles" : [ "mytest" ]
}

3. Use one of the above APIs as the test user. For example, use the put composable index template API:

PUT _index_template/template_1
{
  "index_patterns" : ["te*"],
  "priority" : 1
}

The request returns the following error message. manage_index_templates should be in the list of privileges but is not included. Only manage,all are listed.

{
  "error" : {
    "root_cause" : [
      {
        "type" : "security_exception",
        "reason" : "action [indices:admin/index_template/put] is unauthorized for user [test], this action is granted by the privileges [manage,all]"
      }
    ],
    "type" : "security_exception",
    "reason" : "action [indices:admin/index_template/put] is unauthorized for user [test], this action is granted by the privileges [manage,all]"
  },
  "status" : 403
}

4. As the elastic user, add the manage_index_templates cluster privilege to the mytest role :

POST _security/role/mytest
{
  "cluster": [
    "manage_index_templates"
  ],
  "indices": [ ]
}

5. As the test user, use the above API again. This time, the attempt will succeed.

PUT _index_template/template_1
{
  "index_patterns" : ["te*"],
  "priority" : 1
}

[elasticmachine]

Pinging @elastic/es-security (Team:Security)

[elasticmachine]

Pinging @elastic/es-core-features (Team:Core/Features)

[tvernum]

Relates: #42166, #60357, #66900