== Description This is a supplement to the dbi module, allowing you to avoid hard-coding passwords in your programs that make database connections. == Synopsis require 'dbi/dbrc' include DBI dbrc = DBRC.new("mydb") or dbrc = DBRC.new("mydb","someUser") puts dbrc.db puts dbrc.user puts dbrc.driver puts dbrc.timeout puts dbrc.max_reconn puts dbrc.interval puts dbrc.dsn dbh = DBI.connect(dbrc.dsn, dbrc.user, dbrc.password) == Requirements * Ruby 1.8.0 or later * sys-admin * win32-file (Win32 only) == Installation === Manual Installation * ruby test/ts_all.rb (optional) * ruby install.rb === Gem Installation * ruby dbi-dbrc.gemspec * gem install dbi-dbrc-.gem == Notes on the .dbrc file This module relies on a file in your home directory called ".dbrc", and it is meant to be analogous to the ".netrc" file used by programs such as telnet. The .dbrc file has several conditions that must be met by the module or it will fail: * Permissions must be set to 600 (Unix only). * Must be hidden (Win32 only). * Must be owned by the current user. * Must have database, user and password. Other fields are optional. * Must be in the following space-separated format (in the 'plain' version): database user password driver timeout maximum_reconnects interval e.g. mydb dan mypass oracle 10 2 30 You may include comments in the .dbrc file by starting the line with a "#" symbol A failure in any of the rules mentioned above will result in a DBRCError being raised. In addition, the file may also be encrypted on Win32 systems, in which case the file will automatically be (temporarily) decrypted. The format for XML (using the example above) is as follows: dan mypass oracle 30 10 2 The format for YAML is as follows: - mydb: user: dan password: mypass driver: oracle interval: 30 timeout: 10 max_reconn: 2 == Constants VERSION The current version of this packages, returned as a String. == Class Methods DBRC.new(db, user=nil, dir=nil) The constructor takes one to three arguments. The first argument is the database name. This *must* be provided. If only the database name is passed, the module will look for the first database entry in the .dbrc file that matches. The second argument, a user name, is optional. If it is passed, the module will look for the first entry in the .dbrc file where both the database *and* user name match. The third argument, also optional, specifies the directory where DBRC will look for the .dbrc file. By default, it looks in the pwuid (present working user id) home directory. The rules for a .dbrc file still apply. Win32 users should read the "Notes" section for how your home directory is determined. == Instance Methods DBRC#database The name of the database. Note that the same entry can appear more than once, presumably because you have multiple user id's for the same database. DBRC#db An alias for DBRC#database. DBRC#database=(database) Sets the database to +database+. This is generally discouraged because it does not automatically reset the dsn. DBRC#db=(database) An alias for DBRC#database=. DBRC#user A valid user name for that database. DBRC#user=(user) Sets the user name to +user+. DBRC#password The password for that user. DBRC#passwd An alias for DBRC#password. DBRC#password=(password) Sets the password to +password+. DBRC#passwd=(password) An alias for DBRC#password=. DBRC#driver The driver type for that database (Oracle, MySql, etc). DBRC#driver=(driver) Sets the driver to +driver+. This use is discouraged because it does not reset the dsn. DBRC#timeout The timeout period for a connection before the attempt is dropped. DBRC#time_out An alias for DBRC#timeout, provided purely for the sake of backwards compatability. DBRC#timeout=(int) Sets the timeout value to +int+. DBRC#maximum_reconnects The maximum number of reconnect attempts that should be made for the the database. Presumablly, you would use this with a "retry" within a rescue block. DBRC#max_reconn An alias for DBRC#maximum_reconnects. DBRC#maximum_reconnects=(max) Sets the maximum number of reconnect attempts to +max+. DBRC#max_reconn=(max) An alias for DBRC#maximum_reconnects. DBRC#interval The number of seconds to wait before attempting to reconnect to the database again should a network/database glitch occur. DBRC#interval=(int) Sets the interval seconds between connection attempts. DBRC#dsn Returns a string in "dbi::" format. DBRC#dsn=(dsn) Sets the dsn string to +dsn+. This method is discouraged because it does not automatically reset the driver or database. == Canonical Example This is a basic template for how I do things: require "dbi/dbrc" require "timeout" db = DBI::DBRC.new("somedb") n = db.max_reconn begin timeout(db.time_out){ DBI.connect(db.dsn,db.user,db.passwd) } rescue DBI::Error n -= 1 sleep db.interval if n > 0 retry if n > 0 raise rescue TimeoutError # handle timeout error end == Notes for Win32 Users The 'home' directory for Win32 users is determined by ENV['USERPROFILE']. If that is not set, ENV['HOME'] is used. If that is not set, then 'C:\Documents and Settings\' + Admin.get_user(Admin.get_login).home_dir is used. To make your file hidden, right click on the .dbrc file in your Explorer window, select "Properties" and check the "Hidden" checkbox. I was going to require that the .dbrc file be encrypted on Win32 systems, but that may require an official "certificate", assigned to you by a third party, which is a bit much to expect. However, if the file is encrypted, DBRC will attempt to decrypt it, parse it, and encrypt it again when done parsing. == Notes on running the test suite I cannot guarantee that the .dbrc files under the +examples+ subdirectories maintain the appropriate properties. This can cause failures for the test suite (which uses these files). The only solution is to perform a 'chmod 600 .dbrc' (on Unix) or set the properties to 'hidden' (on MS Windows) manually, for the file in question. == Summary These "methods" don't really do anything. They're simply meant as a convenience mechanism for you dbi connections, plus a little bit of obfuscation (for passwords). == Adding your own configuration If you want to add your own type of configuration file, you can still use the dbi-dbrc package. All you need to do is: * subclass DBRC * redefine the +parse_dbrc_config_file+ method Take a look at the XML and YML subclasses in dbrc.rb for two examples that you can work from. == Known Bugs I'm not positive about the dsn strings for databases other than Oracle. If it's not correct, please let me know. == Author Daniel J. Berger djberg96 at gmail dot com imperator on IRC (irc.freenode.net)