6.3 KiB
| title | author | description | monikerRange | ms.author | ms.date | uid |
|---|---|---|---|---|---|---|
| W3CLogger in .NET Core and ASP.NET Core | wtgodbe | Learn how to create server logs in the W3C standard format. | >= aspnetcore-6.0 | wigodbe | 08/15/2022 | fundamentals/w3c-logger/index |
W3CLogger in ASP.NET Core
:::moniker range="= aspnetcore-6.0"
W3CLogger is a middleware that writes log files in the W3C standard format. The logs contain information about HTTP requests and HTTP responses. W3CLogger provides logs of:
- HTTP request information
- Common properties
- Headers
- HTTP response information
- Metadata about the request/response pair (date/time started, time taken)
W3CLogger is valuable in several scenarios to:
- Record information about incoming requests and responses.
- Filter which parts of the request and response are logged.
- Filter which headers to log.
W3CLogger can reduce the performance of an app. Consider the performance impact when selecting fields to log - the performance reduction will increase as you log more properties. Test the performance impact of the selected logging properties.
[!WARNING] W3CLogger can potentially log personally identifiable information (PII). Consider the risk and avoid logging sensitive information. By default, fields that could contain PII aren't logged.
Enable W3CLogger
Enable W3CLogger with xref:Microsoft.AspNetCore.Builder.HttpLoggingBuilderExtensions.UseW3CLogging%2A, which adds the W3CLogger middleware:
:::code language="csharp" source="samples/6.x/Program.cs" id="snippet_UseW3CLogging" highlight="3":::
By default, W3CLogger logs common properties such as path, status-code, date, time, and protocol. All information about a single request/response pair is written to the same line.
#Version: 1.0
#Start-Date: 2021-09-29 22:18:28
#Fields: date time c-ip s-computername s-ip s-port cs-method cs-uri-stem cs-uri-query sc-status time-taken cs-version cs-host cs(User-Agent) cs(Referer)
2021-09-29 22:18:28 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 59.9171 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
2021-09-29 22:18:28 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 0.1802 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
2021-09-29 22:18:30 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 0.0966 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
W3CLogger options
To configure the W3CLogger middleware, call xref:Microsoft.Extensions.DependencyInjection.HttpLoggingServicesExtensions.AddW3CLogging%2A in Program.cs:
:::code language="csharp" source="samples/6.x/Program.cs" id="snippet_AddW3CLogging" highlight="3":::
LoggingFields
xref:Microsoft.AspNetCore.HttpLogging.W3CLoggerOptions.LoggingFields%2A?displayProperty=nameWithType is a bit flag enumeration that configures specific parts of the request and response to log, and other information about the connection. LoggingFields defaults to include all possible fields except UserName and Cookie. For a complete list of available fields, see xref:Microsoft.AspNetCore.HttpLogging.W3CLoggingFields.
::: moniker-end
:::moniker range=">= aspnetcore-7.0"
W3CLogger is a middleware that writes log files in the W3C standard format. The logs contain information about HTTP requests and HTTP responses. W3CLogger provides logs of:
- HTTP request information
- Common properties
- Headers
- HTTP response information
- Metadata about the request/response pair (date/time started, time taken)
W3CLogger is valuable in several scenarios to:
- Record information about incoming requests and responses.
- Filter which parts of the request and response are logged.
- Filter which headers to log.
W3CLogger can reduce the performance of an app. Consider the performance impact when selecting fields to log - the performance reduction will increase as you log more properties. Test the performance impact of the selected logging properties.
[!WARNING] W3CLogger can potentially log personally identifiable information (PII). Consider the risk and avoid logging sensitive information. By default, fields that could contain PII aren't logged.
Enable W3CLogger
Enable W3CLogger with xref:Microsoft.AspNetCore.Builder.HttpLoggingBuilderExtensions.UseW3CLogging%2A, which adds the W3CLogger middleware:
:::code language="csharp" source="samples/6.x/Program.cs" id="snippet_UseW3CLogging" highlight="3":::
By default, W3CLogger logs common properties such as path, status-code, date, time, and protocol. All information about a single request/response pair is written to the same line.
#Version: 1.0
#Start-Date: 2021-09-29 22:18:28
#Fields: date time c-ip s-computername s-ip s-port cs-method cs-uri-stem cs-uri-query sc-status time-taken cs-version cs-host cs(User-Agent) cs(Referer)
2021-09-29 22:18:28 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 59.9171 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
2021-09-29 22:18:28 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 0.1802 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
2021-09-29 22:18:30 ::1 DESKTOP-LH3TLTA ::1 5000 GET / - 200 0.0966 HTTP/1.1 localhost:5000 Mozilla/5.0+(Windows+NT+10.0;+WOW64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/93.0.4577.82+Safari/537.36 -
W3CLogger options
To configure the W3CLogger middleware, call xref:Microsoft.Extensions.DependencyInjection.HttpLoggingServicesExtensions.AddW3CLogging%2A in Program.cs:
:::code language="csharp" source="samples/7.x/Program.cs" id="snippet_AddW3CLogging" highlight="3":::
LoggingFields
xref:Microsoft.AspNetCore.HttpLogging.W3CLoggerOptions.LoggingFields%2A?displayProperty=nameWithType is a bit flag enumeration that configures specific parts of the request and response to log, and other information about the connection. LoggingFields defaults to include all possible fields except UserName and Cookie. For a complete list of available fields, see xref:Microsoft.AspNetCore.HttpLogging.W3CLoggingFields.
::: moniker-end