ILogLevelService

Reads and sets, at runtime, the log level of each category the host configures under Logging:LogLevel. The dashboard's server settings and the GraphQL API both call it, so the two read the same levels and change them the same way. Registered as a singleton by AddScheduler(...).

A level set here is applied to the host's LoggerFilterOptions as a post-configure step, and the options are signalled to change, so the logger factory re-reads its filters at once. The level sits over every configuration source and survives a reload of the host's configuration. Nothing is persisted: it lasts until the process restarts, and it changes the logging of the process that served the call only, not of the other processes of the deployment.

Signature

namespace Trax.Scheduler.Services.LogLevels;
 
public interface ILogLevelService
{
    IReadOnlyList<CategoryLogLevel> GetLogLevels();
    LogLevelUpdateResult SetLogLevels(IReadOnlyList<LogLevelChange> levels);
}
 
public record CategoryLogLevel(string Category, LogLevel Level, string? ConfiguredLevel, bool Overridden);
public record LogLevelChange(string Category, LogLevel Level);
public record LogLevelUpdateResult(bool Success, int Count, IReadOnlyList<string> NotApplied, string Message);

GetLogLevels

One CategoryLogLevel per category under Logging:LogLevel (and per category set here since), Default first and the rest by name.

Field	Meaning
`Category`	The category; `Default` is the level every other category falls back to
`Level`	The level the loggers filter the category at now: a level set here when there is one, otherwise the configured one, or `Information` when the configured value is not a level
`ConfiguredLevel`	The configured value as written; null for a category not configured
`Overridden`	Whether a level was set here, so `Level` is not the configured one

SetLogLevels

Sets each category's level, then reads back the level each is filtered at. Category names are matched ignoring case, and a category given twice takes the last level.

Only a category configured under Logging:LogLevel, or one set here before, can be set, so a call cannot turn on logging the host never configured. A list naming any other category, an undefined LogLevel value, or an empty list is refused whole: Success is false and nothing is set.

On success Count is the number of categories set. NotApplied lists any whose loggers still filter at another level, which happens when the host adds its own filter rule for the category after Trax; the message names them too.

Package

dotnet add package Trax.Scheduler