Can I instruct p2 to use only the specified URL and no mirrors

[vogella]

A client of mine uses a proxy which blocks certain servers. Installing new / additional features from the release update sites as https://download.eclipse.org/releases/2023-03 via the Update manager from the Eclipse IDE is hard for him, as the p2 update UI also uses mirrors and these are blocked for him.

Can I somehow control that p2 does not use proxies for the installation?

cc @merks as Ed works a lot with p2.

[merks]

This static constant

p2/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java

Line 62 in aa4840f

public static final boolean MIRRORS_ENABLED = !"false".equals(Activator.getContext().getProperty("eclipse.p2.mirrors")); //$NON-NLS-1$//$NON-NLS-2$

is use here to guard fetching the mirror URL:

p2/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java

Lines 755 to 762 in aa4840f

	private synchronized URI getMirror(URI baseLocation, IProgressMonitor monitor) {
	monitor = IProgressMonitor.nullSafe(monitor);
	if (!MIRRORS_ENABLED || (!isForceThreading() && isLocal()))
	return baseLocation;
	if (mirrors == null)
	mirrors = new MirrorSelector(this, getTransport());
	return mirrors.getMirrorLocation(baseLocation, monitor);
	}

So -Declipse.p2.mirrors=false should do the trick.