BIND 10 #970: [kean] noisy traceback when piping into bindctl without login

[BIND 10 Development]

#970: [kean] noisy traceback when piping into bindctl without login
-------------------------------------+-------------------------------------
            Reporter:  jreed         |                        Owner:
                Type:  defect        |  UnAssigned
            Priority:  medium        |                       Status:
           Component:  bind-ctl      |  reviewing
            Keywords:                |                    Milestone:
           Sensitive:  0             |  Sprint-20131015
         Sub-Project:  DNS           |                   Resolution:
Estimated Difficulty:  0.0           |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:
                                     |  Medium
                                     |  Feature Depending on Ticket:
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
-------------------------------------+-------------------------------------
Changes (by kean):

 * owner:  kean => UnAssigned
 * status:  accepted => reviewing


Comment:

 This is another old bug that no longer seems to exist. I changed the
 ownership of my home directory .bind10 to root and ran bindctl:
 {{{
 ./bindctl
 Error reading saved username and password from
 /home/kean/.bind10/default_user.csv: [Errno 13] Permission denied:
 '/home/kean/.bind10/default_user.csv'

 No stored password file found.

 When the system is first set up you need to create at least one user
 account.
 For information on how to set up a BIND 10 system, please check see the
 BIND 10 Guide:

 http://bind10.isc.org/docs/bind10-guide.html#quick-start-auth-dns

 If a user account has been set up, please check the b10-cmdctl log for
 other
 information.

 Username: kean
 Password:
 ["login success"]
 Error saving user information: [Errno 13] Permission denied:
 '/home/kean/.bind10/default_user.csv'
 user info file name: /home/kean/.bind10/default_user.csv
 >
 }}}

 I then removed the {{{.bind10}}} directory, became root via {{{su}}} and
 re-ran bind10 and bindctl. The {{{.bind10}}} directory was correctly
 created in the root user's home directory, not in my directory.

 The code that decides where to put the directory looks like this:
 {{{
 self.csv_file_dir = pwd.getpwnam(getpass.getuser()).pw_dir + \
     os.sep + '.bind10' + os.sep
 }}}

 According to the Python docs for getpass.getuser: "This function checks
 the environment variables LOGNAME, USER, LNAME and USERNAME, in order, and
 returns the value of the first one which is set to a non-empty string. If
 none are set, the login name from the password database is returned on
 systems which support the pwd module, otherwise, an exception is raised."

 Certainly on Linux Fedora Core 19, after doing an {{{su}}} all of those
 variables except for USERNAME are all set to "root". Only USERNAME retians
 my original login. The bug did not specify which platform this was for but
 I suspect that on that platform LOGNAME or USER remained set to the
 original user name. The error is one of usage of {{{su}}}. It is
 considered good practice to do an "su -" so that the session acts as if it
 had just started up (and would therefore set the environment as if the
 real root user had logged in) rather than just changing the euid to 0, as
 happens with certain implementations of su.

 Regardless, the code above is correct (although perhaps overly complicated
 - it could probably just as easily use $HOME rather than bothering with
 parsing the passwd entries) and so my analysis of this bug is that it is
 simply no longer valid and requires no changes.

-- 
Ticket URL: <http://bind10.isc.org/ticket/970#comment:4>
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