Pipe MountPoint to audit logs

[clemon]

VAULT-15882
required for Vault Insights, this PR simply pipes the existing Request.MountPoint into audit logs

[hashicorp-cla]

All committers have signed the CLA.

[clemon]

• vault server in dev mode, audit logs enabled
• ./vault kv put -mount=secret chettest foo=bar
• audit log contains mount_point

{
  "time": "2023-04-27T21:13:03.726637Z",
  "type": "response",
  "auth": {
    [...]
  },
  "request": {
    "mount_point": "secret/",
    "mount_type": "kv",
    "mount_accessor": "kv_4f00a322",
    "mount_running_version": "v0.14.2+builtin",
    "mount_class": "secret",
    [...]
  },
  "response": {
    "mount_point": "secret/",
    "mount_type": "kv",
    "mount_accessor": "kv_4f00a322",
    "mount_running_plugin_version": "v0.14.2+builtin",
    "mount_class": "secret",
    [...]
    }
  }
}

[clemon]

via user-defined path

• ./vault secrets enable -path=chetkv kv
• ./vault kv put -mount=chetkv chettest foo=bar
• audit log contains mount_point chetkv

{
  "time": "2023-04-27T21:17:33.390072Z",
  "type": "response",
  "auth": {
    [...]
  },
  "request": {
    "mount_point": "chetkv/",
    "mount_type": "kv",
    "mount_accessor": "kv_f0cfb6c8",
    "mount_running_version": "v0.14.2+builtin",
    "mount_class": "secret",
    [...]
  },
  "response": {
    "mount_point": "chetkv/",
    "mount_type": "kv",
    "mount_accessor": "kv_f0cfb6c8",
    "mount_running_plugin_version": "v0.14.2+builtin",
    "mount_class": "secret"
  }
}

[clemon]

via user-generated subpath

• ./vault secrets enable -path=chetkv2/subpath kv
• ./vault kv put -mount=chetkv2/subpath chettest foo=bar
• audit log contains mount_point chetkv2/subpath

{
  "time": "2023-04-27T21:22:10.659441Z",
  "type": "response",
  "auth": {
    [...]
  },
  "request": {
    "mount_point": "chetkv2/subpath/",
    "mount_type": "kv",
    "mount_accessor": "kv_a9420101",
    "mount_running_version": "v0.14.2+builtin",
    "mount_class": "secret",
    [...]
  },
  "response": {
    "mount_point": "chetkv2/subpath/",
    "mount_type": "kv",
    "mount_accessor": "kv_a9420101",
    "mount_running_plugin_version": "v0.14.2+builtin",
    "mount_class": "secret"
  }
}

[swayne275]

Eyyyyy first Vault PR! Great work!

[swayne275]

would you mind backporting this to version 1.12.x also? i know I didn't specify that at the beginning, but it looks like clusters that currently have insights are running v1.12.x