[jira] [Created] (CASSANDRA-13211) cassandra shell script uses bad approach to write "Unable to find java" error to stderr, causing real issue to be masked by a permission error if user has changed user since logging in

["Max Bowsher (JIRA)" <ji...@apache.org>]

Max Bowsher created CASSANDRA-13211:
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             Summary: cassandra shell script uses bad approach to write "Unable to find java" error to stderr, causing real issue to be masked by a permission error if user has changed user since logging in
                 Key: CASSANDRA-13211
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13211
             Project: Cassandra
          Issue Type: Bug
            Reporter: Max Bowsher


The cassandra startup shell script contains this line:

    echo Unable to find java executable. Check JAVA_HOME and PATH environment variables. > /dev/stderr

The problem here is the construct "> /dev/stderr". If the user invoking Cassandra has changed user (for example, by SSHing in as a personal user, and then sudo-ing to an application user responsible for executing the Cassandra daemon), then the attempt to open /dev/stderr will fail, because it will point to a PTY node under /dev/pts/ owned by the original user.

Ultimately this leads to the real problem being masked by the confusing error message "bash: /dev/stderr: Permission denied".

The correct technique is to replace "> /dev/stderr" with ">&2" which will write to the already open stderr file descriptor, instead of resolving the chain of symlinks starting at /dev/stderr, and attempting to reopen the target by name.



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