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Version: 1.11

Prometheus

Nauthilus has basic support for some Prometheus metrics.

local nauthilus_prometheus = require("nauthilus_prometheus")

Gauge vector​

You must create a gauge vector first before using it. This should be done in an init script.

nauthilus_prometheus.create_gauge_vec​

Creates a Prometheus gauge vector with specified name, help text, and labels.

Syntax​

nauthilus_prometheus.create_gauge_vec(name, help, labels)

Parameters​

  • name (string): The name of the gauge vector
  • help (string): Description text for the gauge vector
  • labels (table): A Lua table containing label names

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "http_client_concurrent_requests_total"
local help = "Measure the number of total concurrent HTTP client requests"
local labels = { "service" }

nauthilus_prometheus.create_gauge_vec(name, help, labels)

nauthilus_prometheus.add_gauge​

Adds a value to a gauge with specified labels.

Syntax​

nauthilus_prometheus.add_gauge(name, value, labels)

Parameters​

  • name (string): The name of the gauge vector
  • value (number): The value to add to the gauge
  • labels (table): A Lua table containing label values

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_gauge_name"
local value = 42
local labels = { "some label" }

nauthilus_prometheus.add_gauge(name, value, labels)

nauthilus_prometheus.sub_gauge​

Subtracts a value from a gauge with specified labels.

Syntax​

nauthilus_prometheus.sub_gauge(name, value, labels)

Parameters​

  • name (string): The name of the gauge vector
  • value (number): The value to subtract from the gauge
  • labels (table): A Lua table containing label values

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_gauge_name"
local value = 42
local labels = { "some label" }

nauthilus_prometheus.sub_gauge(name, value, labels)

nauthilus_prometheus.set_gauge​

Sets a gauge to a specific value with specified labels.

Syntax​

nauthilus_prometheus.set_gauge(name, value, labels)

Parameters​

  • name (string): The name of the gauge vector
  • value (number): The value to set the gauge to
  • labels (table): A Lua table containing label values

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_gauge_name"
local value = 42
local labels = { "some label" }

nauthilus_prometheus.set_gauge(name, value, labels)

nauthilus_prometheus.increment_gauge​

Increments a gauge counter by 1 with specified labels.

Syntax​

nauthilus_prometheus.increment_gauge(name, labels)

Parameters​

  • name (string): The name of the gauge vector
  • labels (table): A Lua table containing label key-value pairs

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "http_client_concurrent_requests_total"

nauthilus_prometheus.increment_gauge(name, { service = "some_service_name" })

nauthilus_prometheus.decrement_gauge​

Decrements a gauge counter by 1 with specified labels.

Syntax​

nauthilus_prometheus.decrement_gauge(name, labels)

Parameters​

  • name (string): The name of the gauge vector
  • labels (table): A Lua table containing label key-value pairs

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "http_client_concurrent_requests_total"

nauthilus_prometheus.decrement_gauge(name, { service = "some_service_name" })

Counter vector​

You must create a counter vector first before using it. This should be done in an init script.

nauthilus_prometheus.create_counter_vec​

Creates a Prometheus counter vector with specified name, help text, and labels.

Syntax​

nauthilus_prometheus.create_counter_vec(name, help, labels)

Parameters​

  • name (string): The name of the counter vector
  • help (string): Description text for the counter vector
  • labels (table): A Lua table containing label names

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_name"
local help = "Some description for this counter vector"
local labels = { "some_label"}

nauthilus_prometheus.create_counter_vec(name, help, labels)

nauthilus_prometheus.increment_counter​

Increments a counter by 1 with specified labels.

Syntax​

nauthilus_prometheus.increment_counter(name, labels)

Parameters​

  • name (string): The name of the counter vector
  • labels (table): A Lua table containing label values

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_counter_name"
local labels = { "some_label" }

nauthilus_prometheus.increment_counter(name, labels)

Summary vector​

You must create a summary vector first before using it. This should be done in an init script.

nauthilus_prometheus.create_summary_vec​

Creates a Prometheus summary vector with specified name, help text, and labels.

Syntax​

nauthilus_prometheus.create_summary_vec(name, help, labels)

Parameters​

  • name (string): The name of the summary vector
  • help (string): Description text for the summary vector
  • labels (table): A Lua table containing label names

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_name"
local help = "Some description for this summary vector"
local labels = { "some_label"}

nauthilus_prometheus.create_summary_vec(name, help, labels)

nauthilus_prometheus.start_summary_timer​

Starts a timer for a summary vector with specified labels.

Syntax​

local timer = nauthilus_prometheus.start_summary_timer(name, labels)

Parameters​

  • name (string): The name of the summary vector
  • labels (table): A Lua table containing label values

Returns​

  • timer (userdata): A timer object that can be passed to stop_timer

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_name"
local labels = { "some_label" }

local user_data_timer = nauthilus_prometheus.start_summary_timer(name, labels)

nauthilus_prometheus.stop_timer​

Stops a timer and records the elapsed time in the associated vector.

Syntax​

nauthilus_prometheus.stop_timer(timer)

Parameters​

  • timer (userdata): A timer object returned from start_summary_timer or start_histogram_timer

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

-- First start a timer
local name = "some_name"
local labels = { "some_label" }
local user_data_timer = nauthilus_prometheus.start_summary_timer(name, labels)

-- Do some work...

-- Then stop the timer
nauthilus_prometheus.stop_timer(user_data_timer)

Histogram vector​

You must create a histogram vector first before using it. This should be done in an init script.

nauthilus_prometheus.create_histogram_vec​

Creates a Prometheus histogram vector with specified name, help text, and labels.

Syntax​

nauthilus_prometheus.create_histogram_vec(name, help, labels)

Parameters​

  • name (string): The name of the histogram vector
  • help (string): Description text for the histogram vector
  • labels (table): A Lua table containing label names

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_name"
local help = "Some description for this histogram vector"
local labels = { "some_label"}

nauthilus_prometheus.create_histogram_vec(name, help, labels)

nauthilus_prometheus.start_histogram_timer​

Starts a timer for a histogram vector with specified labels.

Syntax​

local timer = nauthilus_prometheus.start_histogram_timer(name, labels)

Parameters​

  • name (string): The name of the histogram vector
  • labels (table): A Lua table containing label values

Returns​

  • timer (userdata): A timer object that can be passed to stop_timer

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

local name = "some_name"
local labels = { "some_label" }

local user_data_timer = nauthilus_prometheus.start_histogram_timer(name, labels)

nauthilus_prometheus.stop_timer​

Stops a histogram timer and records the elapsed time in the associated vector.

Syntax​

nauthilus_prometheus.stop_timer(timer)

Parameters​

  • timer (userdata): A timer object returned from start_histogram_timer

Returns​

None

Example​

local nauthilus_prometheus = require("nauthilus_prometheus")

-- First start a timer
local name = "some_name"
local labels = { "some_label" }
local user_data_timer = nauthilus_prometheus.start_histogram_timer(name, labels)

-- Do some work...

-- Then stop the timer
nauthilus_prometheus.stop_timer(user_data_timer)