Tomcat 8.5/9 context reload on web app symlink change

Question

I have tomcat 8.5.72 where all applications are symlinks in the webapps

/usr/local/tomcat/webapps/app1 -> /data/app1.0.0.1

Everything works correctly on startup. I have autoDeploy and allowLinking configured.

Now I want to change symlink to point to /data/app1.0.0.2 and remove original /data/app1.0.0.1

And here i get an error SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.core.StandardContext.reload Exception starting Context with name [/app1]

Caused by: java.lang.IllegalArgumentException: The main resource set specified [/data/app1.0.0.1] is not valid

Was working good in tomcat 8.0.x. On 8.5.x I need to restart tomcat. I guess on 9 too

Maybe some security considerations lead to the change... but is there a way to restore old one? aka "re-read/re-resolve" symlinks?

Answer 1

Apparently it works fine if link is deleted and created. Issue happens if link target is changed with "ln -snf" - my case, where deployments are managed by puppet.

All the links now are resolved with getCanonicalPath or getAbsolutePath. So change it detected, but still for the old docBase points to old absolute dir.

I've ended up recompiling with patch in fixDocBase method in ContextConfig using getPath instead of getAbsolutePath/getCanonicalPath for directory based deployments