Package 'azlogr' reference manual

Title:	Logging in 'R' and Post to 'Azure Log Analytics' Workspace
Description:	It extends the functionality of 'logger' package. Additional logging metadata can be configured to be collected. Logging messages are displayed on console and optionally they are sent to 'Azure Log Analytics' workspace in real-time.
Authors:	Vivek Atal [aut, cre] (ORCID: <https://orcid.org/0000-0002-9948-7458>)
Maintainer:	Vivek Atal <[email protected]>
License:	MIT + file LICENSE
Version:	0.0.6
Built:	2026-05-18 08:31:07 UTC
Source:	https://github.com/atalv/azlogr

Add additional meta variable

Description

Add additional meta variables in the logging context on top of the ones that are readily collected in get_logger_meta_variables function. It might be needed to add some other metadata specific to the logging usage - that goal is served by this function.

Usage

.add_meta_variables(
  additional_fields = NULL,
  log_level = NULL,
  namespace = NA_character_,
  .logcall = sys.call(),
  .topcall = sys.call(-1),
  .topenv = parent.frame()
)
.add_meta_variables(
  additional_fields = NULL,
  log_level = NULL,
  namespace = NA_character_,
  .logcall = sys.call(),
  .topcall = sys.call(-1),
  .topenv = parent.frame()
)

Arguments

additional_fields

A named vector of type list with key-value pairs of additional meta data which needs to be added in logging context on top of log_fields. The respective value of each key is expected to be of length 1. It is NULL by default.

log_level

log level as per log_levels

namespace

string referring to the logger environment / config to be used to override the target of the message record to be used instead of the default namespace, which is defined by the R package name from which the logger was called, and falls back to a common, global namespace.

.logcall

the logging call being evaluated (useful in formatters and layouts when you want to have access to the raw, unevaluated R expression)

.topcall

R expression from which the logging function was called (useful in formatters and layouts to extract the calling function's name or arguments)

.topenv

original frame of the .topcall calling function where the formatter function will be evaluated and that is used to look up the namespace as well via logger:::top_env_name

Value

Returns a vector of collected meta-data. It is used in defining the log_layout function.

Build API signature for logging to 'Azure Log Analytics'

Description

'Azure Log Analytics' HTTP REST API documentation for 'Python' is followed to create the 'R' version of it. 'Python' version of this function is described at https://learn.microsoft.com/en-us/azure/azure-monitor/logs/data-collector-api?tabs=python#sample-requests/

Usage

.build_signature(
  customer_id,
  shared_key,
  date,
  content_length,
  method,
  content_type,
  resource
)
.build_signature(
  customer_id,
  shared_key,
  date,
  content_length,
  method,
  content_type,
  resource
)

Arguments

customer_id

customer_id of the 'Azure Log Analytics' workspace

shared_key

shared_key of the 'Azure Log Analytics' workspace

date

date-time of logging event

content_length

Content length of the body

method

Only one value is expected - POST

content_type

Only one value is expected - application/json

resource

Only one value is expected - /api/logs

Value

Returns part of the header of HTTP POST request to be sent to 'Azure Log Analytics' workspace

Customized logging layout

Description

This is an extended function of layout_json function from 'logger' package. Objective is to add additional component in the logging layout in JSON format so that they can also be reported while logging along with the components collected by .add_meta_variables.

Usage

.layout_json_custom(
  log_fields = c("time", "level", "ns", "ans", "topenv", "fn", "node", "arch", "os_name",
    "os_release", "os_version", "pid", "user", "msg"),
  additional_fields = NULL,
  enforce_ascii_msg = TRUE,
  enforce_tz_utc = TRUE
)
.layout_json_custom(
  log_fields = c("time", "level", "ns", "ans", "topenv", "fn", "node", "arch", "os_name",
    "os_release", "os_version", "pid", "user", "msg"),
  additional_fields = NULL,
  enforce_ascii_msg = TRUE,
  enforce_tz_utc = TRUE
)

Arguments

log_fields

Vector of components which are collected in get_logger_meta_variables function. Converting time component to UTC additionally.

additional_fields

enforce_ascii_msg

If TRUE (default), the logging message is guaranteed to have all non-ASCII characters escaped. If FALSE, the characters will be logged as-is. Please note, it is better to ensure ASCII, otherwise there might be error while sending the HTTP POST request to 'Azure Log Analytics' workspace.

enforce_tz_utc

If TRUE (default), the logging time field is converted to UTC timezone while sending the logging dump to 'Azure Log Analytics' workspace. If FALSE, then the local time captured by Sys.time is recorded in the time field.

Value

Returns a generator function typically to be used by log_layout function.

Build and send a request to the POST API of 'Azure Log Analytics'

Description

Build and send a request to the POST API of 'Azure Log Analytics'

Usage

.post_data(customer_id, shared_key, body, log_type)
.post_data(customer_id, shared_key, body, log_type)

Arguments

customer_id

customer_id of the 'Azure Log Analytics' workspace

shared_key

shared_key of the 'Azure Log Analytics' workspace

body

Content or message to be logged in JSON format

log_type

Log-Type as defined in 'Azure Log Analytics' document, for custom logging

Value

Returns the HTTP response object

Get configuration value

Description

Get the configuration value of a specific key which was set (or not set) using set_log_config function. If nothing was set, then it reuses the default value defined in the function signature of set_log_config function.

Usage

get_log_config(key = NULL)
get_log_config(key = NULL)

Arguments

key

Specify the key whose value needs to be extracted. NULL implies no specific key, rather all of them to be extracted at once.

Value

Returns the respective configuration value of the given key. If key is NULL, then all the configuration values will be returned together as a list.

Examples

  # Get configuration value without setting anything
  get_log_config("log_to_azure")
  # Set some configuration first and then get the respective values
  set_log_config(enforce_tz_utc = FALSE, log_to_azure = FALSE)
  get_log_config("enforce_tz_utc")
  get_log_config("log_to_azure")
  # Reset the values
  set_log_config()
  get_log_config("log_to_azure")

  # Extract list of all configurations
  get_log_config()

# Get configuration value without setting anything
  get_log_config("log_to_azure")
  # Set some configuration first and then get the respective values
  set_log_config(enforce_tz_utc = FALSE, log_to_azure = FALSE)
  get_log_config("enforce_tz_utc")
  get_log_config("log_to_azure")
  # Reset the values
  set_log_config()
  get_log_config("log_to_azure")

  # Extract list of all configurations
  get_log_config()

Logging related functions

Description

Logger function defined which are created on top of log_level and layout_json - these are part of another package 'logger'. Additional capabilities have been added to those functions which enables this function to be able to send logs directly to the 'Azure Log Analytics' workspace, and also have control to post log outputs into the console - as per user input. Note that, logging threshold can be directly set (if needed) using log_threshold function from 'logger' package.

Usage

logger_level(
  ...,
  log_fields = get_log_config("log_fields"),
  additional_fields = get_log_config("additional_fields"),
  enforce_ascii_msg = get_log_config("enforce_ascii_msg"),
  enforce_tz_utc = get_log_config("enforce_tz_utc"),
  log_to_azure = get_log_config("log_to_azure"),
  log_type = get_log_config("log_type"),
  log_customer_id = Sys.getenv(get_log_config("customer_id_env"), "abcd"),
  log_shared_key = Sys.getenv(get_log_config("shared_key_env"), "abcd")
)

logger_info(...)

logger_error(...)

logger_warn(...)

logger_debug(...)

logger_fatal(...)

logger_success(...)

logger_trace(...)
logger_level(
  ...,
  log_fields = get_log_config("log_fields"),
  additional_fields = get_log_config("additional_fields"),
  enforce_ascii_msg = get_log_config("enforce_ascii_msg"),
  enforce_tz_utc = get_log_config("enforce_tz_utc"),
  log_to_azure = get_log_config("log_to_azure"),
  log_type = get_log_config("log_type"),
  log_customer_id = Sys.getenv(get_log_config("customer_id_env"), "abcd"),
  log_shared_key = Sys.getenv(get_log_config("shared_key_env"), "abcd")
)

logger_info(...)

logger_error(...)

logger_warn(...)

logger_debug(...)

logger_fatal(...)

logger_success(...)

logger_trace(...)

Arguments

...

Content(s) of this argument is directly passed on to log_level function of the 'logger' package.

log_fields

Character vector of field names to be included in the JSON. These field names are automatically collected by get_logger_meta_variables function, please refer to that function's documentation to see which fields are collected.

additional_fields

enforce_ascii_msg

enforce_tz_utc

log_to_azure

If TRUE (default), then logs will be sent to 'Azure Log Analytics' workspace and console. Else if FALSE then logs will not be sent to 'Azure Log Analytics' workspace, it will only be displayed on console, which is the default layout of 'logger' package.

log_type

Single element character vector is expected. Logs will be posted to this event on 'Azure Log Analytics'. For details, check this: https://learn.microsoft.com/en-us/azure/azure-monitor/logs/data-collector-api?tabs=python/ . Default value is "log_from_r".

log_customer_id

Workspace ID of 'Azure Log Analytics' workspace. By default it fetches from the environment variable named AZ_LOG_ID. If the environment variable is not set, then a dummy value "abcd" is used. The environment variable's name can be modified by set_log_config

log_shared_key

Shared key of 'Azure Log Analytics' workspace. By default it fetches from the environment variable named AZ_LOG_KEY. If the environment variable is not set, then a dummy value "abcd" is used. The environment variable's name can be modified by set_log_config

Details

Most of the arguments of this function have a default value which is read from the output of get_log_config. The idea is to run the set_log_config function once to define the default arguments; and use them automatically while logging anything without the need of specifying them every time it is triggered.
'Azure Log Analytics' workspace id and shared key are intentionally fetched from environment variables for security purpose. It is not a good practice to specify them explicitly. Using environment variable is one easy approach to potentially hide it from unintentional user.
It may take ~5–10 minutes to see the logging messages on the 'Azure Log Analytics' portal after the first time a message is posted to a new custom log table.

Value

If log_to_azure is FALSE then log output is shown on console. Else, if TRUE, then log output is shown on console, as well as posted to 'Azure Log Analytics' workspace under the custom table name as specified by log_type argument. If POST request is unsuccessful, then additional warning message is thrown with POST request response. If POST request is successful, then it invisibly returns the POST object.

Note

Logging layout is set in JSON format, required to send to 'Azure Log Analytics'. Note that this layout modifies the global namespace of 'logger' package by default - that is not important for this use case.

logger_info is a wrapper function around logger_level - logging level is set as INFO by default.

logger_error is a wrapper function around logger_level - logging level is set as ERROR by default.

logger_warn is a wrapper function around logger_level - logging level is set as WARN by default.

logger_debug is a wrapper function around logger_level - logging level is set as DEBUG by default.

logger_fatal is a wrapper function around logger_level - logging level is set as FATAL by default.

logger_success is a wrapper function around logger_level - logging level is set as SUCCESS by default.

logger_trace is a wrapper function around logger_level - logging level is set as TRACE by default.

Examples

# Define logging config and then use logger_* functions to log
set_log_config(log_to_azure = FALSE)
logger_level(logger::INFO, "logging message")
# Specify other arguments explicitly inside the logger_level function
logger_level(logger::INFO, "logging message", log_to_azure = FALSE)

# For ease, use wrapper functions instead of using `logger_level` function as
# below
logger_info("logging message info", log_to_azure = FALSE)

# Also, instead of writing `log_to_azure = FALSE` every time, set the
# configuration in one step using `set_log_config`, and continue to use
# wrapper functions as usual.
set_log_config(log_to_azure = FALSE)
logger_info("logging message info")

# Wrapper function for log level 'error'
logger_error("logging message error")

# Wrapper function for log level 'warn'
logger_warn("logging message warn")

# Change log threshold to debug
logger::log_threshold(logger::DEBUG)
# Wrapper function for log level 'debug'
logger_debug("logging message debug")

# Wrapper function for log level 'fatal'
logger_fatal("logging message fatal")

# Wrapper function for log level 'success'
logger_success("logging message success")

# Change logging threshold
logger::log_threshold(logger::TRACE)
# Wrapper function for log level 'trace'
logger_trace("logging message trace")

# Define logging config and then use logger_* functions to log
set_log_config(log_to_azure = FALSE)
logger_level(logger::INFO, "logging message")
# Specify other arguments explicitly inside the logger_level function
logger_level(logger::INFO, "logging message", log_to_azure = FALSE)

# For ease, use wrapper functions instead of using `logger_level` function as
# below
logger_info("logging message info", log_to_azure = FALSE)

# Also, instead of writing `log_to_azure = FALSE` every time, set the
# configuration in one step using `set_log_config`, and continue to use
# wrapper functions as usual.
set_log_config(log_to_azure = FALSE)
logger_info("logging message info")

# Wrapper function for log level 'error'
logger_error("logging message error")

# Wrapper function for log level 'warn'
logger_warn("logging message warn")

# Change log threshold to debug
logger::log_threshold(logger::DEBUG)
# Wrapper function for log level 'debug'
logger_debug("logging message debug")

# Wrapper function for log level 'fatal'
logger_fatal("logging message fatal")

# Wrapper function for log level 'success'
logger_success("logging message success")

# Change logging threshold
logger::log_threshold(logger::TRACE)
# Wrapper function for log level 'trace'
logger_trace("logging message trace")

Set logging configuration

Description

Set the logging configuration once by executing this function. There won't be any need to set them every time while logging something via logger_level or any wrapper of that, e.g. logger_info function(s).

Usage

set_log_config(
  log_fields = c("level", "time", "msg"),
  additional_fields = NULL,
  enforce_ascii_msg = TRUE,
  enforce_tz_utc = TRUE,
  log_to_azure = TRUE,
  log_type = "log_from_r",
  customer_id_env = "AZ_LOG_ID",
  shared_key_env = "AZ_LOG_KEY"
)
set_log_config(
  log_fields = c("level", "time", "msg"),
  additional_fields = NULL,
  enforce_ascii_msg = TRUE,
  enforce_tz_utc = TRUE,
  log_to_azure = TRUE,
  log_type = "log_from_r",
  customer_id_env = "AZ_LOG_ID",
  shared_key_env = "AZ_LOG_KEY"
)

Arguments

log_fields

additional_fields

enforce_ascii_msg

enforce_tz_utc

log_to_azure

log_type

customer_id_env

The name of the environment variable (default is AZ_LOG_ID) which stores the workspace ID of the 'Azure Log Analytics' workspace. Please refer https://learn.microsoft.com/en-us/azure/azure-monitor/logs/data-collector-api?tabs=powershell#sample-requests/ to see how you may get the required workspace ID.

shared_key_env

The name of the environment variable (default is AZ_LOG_KEY) which stores the shared key of the 'Azure Log Analytics' workspace. Please refer https://learn.microsoft.com/en-us/azure/azure-monitor/logs/data-collector-api?tabs=powershell#sample-requests/ to see how you may get the required shared key.

Value

It saves the configuration in an environment enclosed within this package. Returns nothing explicitly.

Examples

  set_log_config(log_fields = c("level", "time", "msg", "user", "pid"))
  set_log_config(enforce_tz_utc = FALSE, log_to_azure = FALSE)

set_log_config(log_fields = c("level", "time", "msg", "user", "pid"))
  set_log_config(enforce_tz_utc = FALSE, log_to_azure = FALSE)

Package 'azlogr'

Help Index

Add additional meta variable

Description

Usage

Arguments

Value

Build API signature for logging to 'Azure Log Analytics'

Description

Usage

Arguments

Value

Customized logging layout

Description

Usage

Arguments

Value

Build and send a request to the POST API of 'Azure Log Analytics'

Description

Usage

Arguments

Value

Get configuration value

Description

Usage

Arguments

Value

Examples

Logging related functions

Description

Usage

Arguments

Details

Value

Note

Examples

Set logging configuration

Description

Usage

Arguments

Value

Examples