Web349 Logging Library

This .NET Core 6 library contains the logging functionality used throughout Web349's internal and external projects. Contains a powerful Datadog logger.

ENV variable configuration

Required	Name	Type	Default	Notes
	WEB349_LOGGING_LOGLEVEL	string	Verbose	The log level. Must be any of the following values: Silent, Fatal, Error, Warning, Information, Debug, Verbose
	WEB349_LOGGING_CENSORSHIP_ENABLED	bool	true	Toggles censorship of potentially sensitive information in the enriched fields of log events. The function looks for keywords configured in the WEB349_LOGGING_CENSORSHIP_KEYWORDS env var.
	WEB349_LOGGING_CENSORSHIP_KEYWORDS	string	api;key;secret;credential;auth;cookie;login	A semi-colon (;) delimited list of keywords to look for in the enriched fields of log events. Setting this ENV var to a custom value will replace the default values, unless explicitely specified.
✅	WEB349_LOGGING_DATADOG_APIKEY	string		Your Datadog API key
✅	WEB349_LOGGING_DATADOG_SITE	string		The Datadog site to send logs to. Must be any of the following values: US1, US3, US5, EU, AP1, US1_GOV
	WEB349_LOGGING_DATADOG_SOURCE	string		Fills the Source field in Datadog
	WEB349_LOGGING_DATADOG_SERVICE	string		Fills the Service field in Datadog
	WEB349_LOGGING_DATADOG_HOST	string		Fills the Host field in Datadog
	WEB349_LOGGING_DATADOG_COMPRESSLOGS	bool	true	Set to true to enable gzip compression
	WEB349_LOGGING_DATADOG_BATCH_SIZE	int	10	The maximum size of a single log event batch.
	WEB349_LOGGING_DATADOG_BATCH_AGE	int	5	The maximum age, in seconds, of a single log event batch that has not reached its maximum batch size
	WEB349_LOGGING_DATADOG_HTTPCLIENT_TIMEOUT	int	10	Underlying HttpClient timeout in seconds
	WEB349_LOGGING_SLACK_HTTPCLIENT_TIMEOUT	int	10	Underlying HttpClient timeout in seconds for calling the registered Webhook URL
	WEB349_LOGGING_SLACK_WEBHOOKURL_<NAME>	string		A SlackLogger needs a name argument in its constructor that should match up with this ENV var
	WEB349_LOGGING_DISPATCHER_DELAY_IDLE	int	1000	The delay, in miliseconds, for the log batch dispatcher to wait in between polls while idling.
	WEB349_LOGGING_DISPATCHER_DELAY_ACTIVE	int	100	The delay, in miliseconds, for the log batch dispatcher to wait in between polls while processing log events.

Requirements

• .NET Core 6 Download at dot.net
• System.Text.Json for JSON serialization

Notes

• Each instance of a Logger class creates its own context logger.Context for identification purposes. If not specified during Logger implementation creation, the Context is a new GUID.
• While technically possible, multiple threads should not share the same Logger instance.
• Each Logger context keeps track of an int64 Event ID field allowing for easier identification and log tracing.
• At the moment of writing SlackLogger only supports sending of unenriched, text-only messages. Use Markdown to apply formatting in Slack.
• The SlackLogger name has the follow regular expression limitation: ^[a-zA-Z0-9_]+$.
• The Dispatcher settings only apply to Logger implementations that use a producer/consumer dispatching service to send off the logs (e.g., SlackLogger and DatadogLogger).

Datadog logger usage examples

Logging regular information

Logger logger = new DatadogLogger();
logger.LogInformation("This is the message that will appear in Datadog");

Logging enriched information

Logger logger = new DatadogLogger();
logger
    .Enrich("fieldName", 123)
    .Enrich("anotherFieldName", "some string value")
    .Enrich("foo", serializableBarObject)
.LogInformation("This is the message that will appear in Datadog, with the three fields enriched above");

Logging an Exception

Logger logger = new DatadogLogger();
try
{
	throw new Exception("oops");
}
catch(Exception ex)
{
	logger.LogError(ex.Message, ex);
}

Slack logger usage examples

Logging regular information

// the Slack webhook URL will match to the value set to WEB349_LOGGING_SLACK_WEBHOOKURL_SERVICENAME
// dashes (-) will be replace with an underscore (_) and spaces are removed.
Logger serviceNameLogger = new SlackLogger("serviceName");
serviceNameLogger.LogInformation("a message");

Information censorship usage example

The library has the ability to censor potentially sensitive information from enriched fields. See WEB349_LOGGING_CENSORSHIP_KEYWORDS for more information. The following is an example of information censorship:

Logger logger = new DatadogLogger();
logger
    .Enrich("myFieldNotCensored", obj)
    .Enrich("apiKeyBeingCensored", apiKeyStr) // this field contains 'api' and its value will be censored to '***'
.LogDebug("Hello friend, this is a DEBUG log event with one censored and one uncensored field");

Contribution

Want to help? Comments? Love? Hate? Open up an Issueo or Pull Request on Github: https://github.com/web349/logging

Disclaimer

This software is provided for free, AS IS, without any guarantees whatsoever, because I felt there were no easy-to-use Datadog loggers for .NET Core.