Dropping privilege logging issue one VM (requires root)[BUG]

[vcrocher]

Description

CORC intentionally drop privileges to create log files even when run as root or sudoing. This is a problem when creating and writing to log requires these privileges: typically in VM with shared folder.

Actual Behavior

In VM, within a shared folder, requires specific user and group rights.
Works fine when run as user (not sudoing).
Fail with impossible log creation (spdlog exception) when run with sudo:

terminate called after throwing an instance of 'spdlog::spdlog_ex'
  what():  Failed opening file logs/CORC.log for writing: Permission denied
Aborted

Possible Fix

One idea would be to get actual user id and gid when sudoing but this is not sufficient and still fail:

/* Privileges management */

static uid_t uid, gid; //Saved uid and gid

void save_privileges() {

    uid = getuid();

    gid = getgid();

}

int drop_privileges() {

    if (uid == 0) {

        //If sudoing and not directly root (likely): use sudoer uid to create log files

        if(getenv("SUDO_UID")) {

            //Drop group privileges first

            if( setegid(atoi(getenv("SUDO_GID")))<0 || seteuid(atoi(getenv("SUDO_UID")))<0 ) {

                CO_errExit("Failed to drop privileges.");

                return -1;

            }

        }

        else {

            //Drop group privileges first

            if( setegid(1000)<0 || seteuid(1000)<0 ) {

                CO_errExit("Failed to drop privileges.");

                return -1;

            }

        }

    }

    return 0;

}

int restore_privileges() {

    if( setreuid(uid, gid)<0 ) {

        CO_errExit("Failed to restore privileges.");

        return -1;

    }

    return 0;

}
/* --------------------- */

=> This still produces the same error.
Workaround can be to not drop privileges in any cases and so create log files only accessible by root.