Introduction

Vault Telemetry provides you with a wealth of information regarding the operation of HashiCorp Vault.  You can configure Telemetry in Vault using the Telemetry configuration stanza. In this stanza, there are a few parameters that let you control the structure of the data. The two that we will discuss below let you control whether or not a hostname is prefixed to gauge values, and whether a metric should include a label denoting the host.

Explanation

disable_hostname

The disable_hostname value toggles whether or not gauge values should be prefixed with a local hostname. To see this in action, you have to view the raw data by sending the Vault process a USR1 signal - I've included an example of this command below.

kill -s USR1 <pid_of_vault>

Here are examples of this value disabled and enabled:

# disable_hostname set to false - note the appended hostname "0b5e82da6211"
[2022-05-09 15:15:30 +0000 UTC][G] 'vault.0b5e82da6211.runtime.alloc_bytes': 17073992.000

# disable_hostname set to true - note the lack of hostname
[2022-05-09 15:18:00 +0000 UTC][G] 'vault.runtime.alloc_bytes': 11546328.000

enable_hostname_label

The enable_hostname_label specifies if metrics should include a label denoting the 'host'. I can demonstrate by hitting the sys/metrics endpoint and specifying the format to be prometheus. An example of that command is below.

curl --header "X-Vault-Token: <insert_token_here>" 'http://127.0.0.1:8200/v1/sys/metrics?format=prometheus'

Here are examples of this value disabled and enabled:

# enable_hostname_label set to false - note the lack of a host label
vault_runtime_malloc_count 118103

# enable_hostname_label set to true - note the host label  "{host="0b5e82da6211"}"
vault_runtime_malloc_count{host="0b5e82da6211"} 187163