- In Nexus 3.12.1, create a proxy repository.
- Set "block outbound connections on the repository" to true.
- Fire a request to the repository.
You will see a warning like this in the log:
2018-06-26 14:30:18,863-0500 WARN [qtp335821775-220] admin org.sonatype.nexus.repository.maven.internal.proxy.MavenProxyFacet - Exception org.sonatype.nexus.repository.httpclient.RemoteBlockedIOException: Remote Manually Blocked checking remote for update, proxy repo maven-central failed to fetch foo/bar/maven-metadata.xml, content not in cache.
This will be repeated for every single request received by the proxy, filling the logs with useless messages.
This should be logged at DEBUG, if at all. Upon closer review moving the level to TRACE seems better since the blocked status of a repository can be easily determined from other INFO level log messages and the repository status is also visible when viewing the repositories list in the UI.