This commit adds a Ruby script, `files/vmware_metrics`, that uses
`vmware-toolbox-cmd stat` to collect VM performance metrics from
an ESXi hypervisor.

This commit updates the `puppet_metrics_collector::sar_metric` type to
refer to `puppet_metrics_collector::sytem::scripts_dir` when configuring
metrics cleanup jobs.

This change allows the `puppet_metrics_collector::system` class to be
used without including the `puppet_metrics_collector` class --- which
enables spec testing of the system class.

This commit updates the `puppet_metrics_collector::system` class to
include collection of VMware metrics if the virtualization platform
is detected to be VMware.

The `Style/BracesAroundHashParameters` check gives bad advice that will
result in deprecation warnings with Ruby 2.7. This check has been
removed upstream starting with RuboCop 0.80.0.

(SUP-2054) Add VMware metrics collection

This commit updates the `pe_metric` and `sar_metric` types to use
`force => true` when ensuring to absent. This change allows non-empty
directories to be removed.

Fix ensure => absent for metrics

If the `puppet_metrics_collector::system` class is evaluated before the
`puppet_metrics_collector` class, a duplicate declaration error will
occur for output directories and scripts that are common to both classes.
The `system` class has guard logic to prevent this issue, this commit
copies the same logic to the top-level `puppet_metrics_collector` class
and updates the tests to ensure both orderings compile.

Co-authored-by: Jarret Lavallee <jarretlavallee@users.noreply.github.com>

This commit adds the skeleton of a `psql_metrics` script that will
collect performance metrics from the `pe-postgresql` service.
The skeleton currently checks the Postgres version number and
then exits without gathering any diagnostics.

This commit updates the `psql_metrics` script to gather data related
to Postgres checkpoint activity as reported by `pg_stat_bgwriter`.

This commit updates the psql_metrics script to gather information
on the oldest open transaction from the `pg_stat_activity` view.

This commit updates the psql_metrics script to collect
counts of connections grouped by their state (active, idle, etc.)
from `pg_stat_activity` along with the value of the `max_connections`
setting from `pg_settings`.

This commit updates the `psql_metrics` script to collect the
state, transaction horizons, and replication lag in bytes
from `pg_replication_slots`.

This commit updates the `psql_metrics` script to gather replication
status from the `pglogical.subscription` table. This status
is only reported for replica nodes as the `pg_replication_slots`
view has the most interesting data on the primary.

This commit updates the `psql_metrics` script to gather the
output of `pg_stat_database` for each database.

This commit updates the `psql_metrics` script to collect statistics
from regular and TOAST tables from the `pg_stat_all_tables` and
`pg_statio_all_tables` views along with `pg_relation_size()`.

To control the amount of data collected, statistics are only gathered
for tables that have allocated more than 2 pages of data (16 kB).

This commit updates the `psql_metrics` script to collect statistics
from the `pg_stat_all_indexes` and `pg_statio_all_indexes` views
along with `pg_relation_size()`.

To control the amount of data collected, statistics are only gathered
for indexes that have allocated more than 2 pages of data (16 kB).

This commit updates the `puppet_metrics_collector::system` class
to gather metrics from the local `pe-postgresql` instance if
`/opt/puppetlabs/server/bin/psql` is installed on a node.

This patch updates `psql_metrics` and `vmware_metrics` such that output
directories are created from the hostname without replacing `.` by `-`.
This change matches the behavior of the `system_metrics` script.

A missing `timestamp` key is also added to the output of `psql_metrics`.

(SUP-2058) Gather metrics from pe-postgresql

Prior to this commit, a warning would be presented when shipping metrics
using the json2timeseriesdb streaming. This commit adds a - to the the
command to stop the warning.

Prior to this commit, when an mbean was missing and error would be
logged. This commit changes the default for additional metrics to return
a null when the mbean returns a 404.

(GH-74) Return null when a mbean is missing

(gh-73) Append - to the metric command for json2timeseriesdb

This commit updates the changelog for the 6.2.0 release.

This commit releases 6.2.0 of the module.