Missing servlet context in web lookup when using composite configuration

[apimentasoto]

Description

Web lookup doest not work when configuring a web application using a list of configuration files.

While using the log4j-web module and setting log4jConfiguration as a list of files the web initializer calls Configurator.initialize passing a Map.Entry<String, Object> as the last argument.

logging-log4j2/log4j-web/src/main/java/org/apache/logging/log4j/web/Log4jWebInitializerImpl.java

Lines 171 to 183 in 32075af

	if (location != null && location.contains(",")) {
	final List<URI> uris = getConfigURIs(location);
	this.loggerContext = Configurator.initialize(
	this.name,
	this.getClassLoader(),
	uris,
	WebLoggerContextUtils.createExternalEntry(this.servletContext));
	return;
	}
	final URI uri = getConfigURI(location);
	this.loggerContext = Configurator.initialize(
	this.name, this.getClassLoader(), uri, WebLoggerContextUtils.createExternalEntry(this.servletContext));

The configurator does not implement a method which accepts a list of locations and an entry (as it does for the case of a single location) and instead matches this method:

logging-log4j2/log4j-core/src/main/java/org/apache/logging/log4j/core/config/Configurator.java

Lines 184 to 188 in 32075af

	public static LoggerContext initialize(
	final String name,
	final ClassLoader loader,
	final List<URI> configLocations,
	final Object externalContext) {

Which in turn calls this which does not correctly set the context.

logging-log4j2/log4j-core/src/main/java/org/apache/logging/log4j/core/impl/Log4jContextFactory.java

Lines 290 to 301 in 32075af

	public LoggerContext getContext(
	final String fqcn,
	final ClassLoader loader,
	final Object externalContext,
	final boolean currentContext,
	final List<URI> configLocations,
	final String name) {
	final LoggerContext ctx =
	selector.getContext(fqcn, loader, currentContext, null /*this probably needs to change*/);
	if (externalContext != null && ctx.getExternalContext() == null) {
	ctx.setExternalContext(externalContext);
	}

Configuration

Version: 2.3.0

Operating system: windows 11

JDK: JDK 17

Reproduction

• Add log4j-web module to web applciation.
• Set the init param log4jConfiguration as a list of properties (<Parameter name="log4jConfiguration" value="log4j2-foo.properties,log4j2-bar.properties"/>)
• Lookup the servletContextName or any other ServletContxt variable in one of the properties files (${web:servletContextName})

[ppkarwasz]

@apimentasoto,

Thanks, we have quite a backlog, so I don't know when we will be able to implement this. Could you submit a PR?