Convert hiera-mysql-backend to use postgres

Gemfile

@@ -1,4 +1,4 @@
 source 'https://rubygems.org'
 
-# Specify your gem's dependencies in hiera-mysql-backend.gemspec
+# Specify your gem's dependencies in hiera-postgres-backend.gemspec
 gemspec

Gemfile.lock

@@ -1,22 +1,22 @@
 PATH
   remote: .
   specs:
-    hiera-mysql-backend (0.0.3)
+    hiera-postgres-backend (0.0.1)
       hiera
-      mysql2
+      pg
 
 GEM
   remote: https://rubygems.org/
   specs:
-    hiera (1.2.1)
+    hiera (1.3.0)
       json_pure
-    json_pure (1.8.0)
-    mysql2 (0.3.13)
-    rake (10.1.0)
+    json_pure (1.8.1)
+    pg (0.17.1)
+    rake (10.1.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  hiera-mysql-backend!
+  hiera-postgres-backend!
   rake

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2013 Roberto
+Copyright (c) 2013 Adrian Lopez
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in

README.md

@@ -1,24 +1,15 @@
-## hiera-mysql-backend
+## hiera-postgresql-backend
 
-Alternate MySQL backend for Hiera
+Alternate PostgreSQL backend for Hiera
 
-This is a MySQL backend for Hiera inspired by [hiera-mysql](https://github.com/crayfishx/hiera-mysql). Unfortunately no work has been done to that backend for the past 9 months and it was missing a couple of features I needed so I decided to pick up the torch and implement them myself.
+This is a PostgreSQL backend for Hiera inspired by [hiera-mysql-backend](https://github.com/Telmo/hiera-mysql-backend). 
 
-### What is different from hiera-mysql
-
-In [hiera-mysql](https://github.com/crayfishx/hiera-mysql) you define the queries in the hiera.yaml file. I felt this was too restricting so instead hiera-mysql-backend uses, poorly named, sql files. This sql files follow the Hiera hierarchy.
-
-[hiera-mysql](https://github.com/crayfishx/hiera-mysql) would also return the last matching query not the first one which I felt it was confusing.
-
-[hiera-mysql](https://github.com/crayfishx/hiera-mysql) used the mysql gem, I am partial to [mysql2](https://github.com/brianmario/mysql2)
-
-Exception handling. hiera-mysql would cause a puppet run to fail if one of the queries was incorrect. For example a fact that you are distributing with a module is needed for the query to return its data but that fact is not available outside the module having a `SELECT * from %{custom_fact}` would make puppet runs fail.
 
 ### What goes into the sql files.
 
 The poorly named sql files are really yaml files where the key is the lookup key and the value is the SQL statement (it accepts interpolation)
 
-Lets assume your _datadir_ is `/etc/puppet/hieradata/` and your hierarchy for hiera just have a common. hiera-mysql-backend would look for /etc/puppet/hieradata/common.sql the common.sql would look like:
+Lets assume your _datadir_ is `/etc/puppet/hieradata/` and your hierarchy for hiera just have a common. hiera-postgresql-backend would look for /etc/puppet/hieradata/common.sql the common.sql would look like:
 
 ```yaml
 ---
@@ -31,7 +22,7 @@ running `hiera applications` would run the query against the configured database
 
 ### Using
 
-`gem install hiera-mysql-backend`
+`gem install hiera-postgresql-backend`
 
 
 ### Configuring Hiera
@@ -42,12 +33,12 @@ Hiera configuration is pretty simple
 ---
 :backends:
   - yaml
-  - mysql2
+  - postgres
 
 :yaml:
   :datadir: /etc/puppet/hieradata
 
-:mysql2:
+:postgres:
   :datadir: /etc/puppet/hieradata
   :host: hostname
   :user: username

hiera-postgres-backend.gemspec

@@ -0,0 +1,19 @@
+# -*- encoding: utf-8 -*-
+
+Gem::Specification.new do |gem|
+  gem.name          = "hiera-postgres-backend"
+  gem.version       = "0.0.1"
+  gem.authors       = ["Adrian"]
+  gem.email         = ["[email protected]"]
+  gem.description   = %q{Alternative PostgreSQL backend for hiera}
+  gem.summary       = %q{Alternative PostgreSQL backend for hiera}
+  gem.homepage      = "https://github.com/adrianlzt/hiera-postgres-backend"
+
+  gem.files         = `git ls-files`.split($/)
+  gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
+  gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
+  gem.require_paths = ["lib"]
+  gem.add_dependency('pg')
+  gem.add_dependency('hiera')
+  gem.add_development_dependency('rake')
+end

lib/hiera/backend/mysql2_backend.rb → lib/hiera/backend/postgres_backend.rb

@@ -1,18 +1,18 @@
 class Hiera
   module Backend
-    class Mysql2_backend
+    class Postgres_backend
 
       def initialize(cache=nil)
         begin
-          require 'mysql2'
+          require 'pg'
         rescue LoadError
           require 'rubygems'
-          require 'mysql2'
+          require 'pg'
         end
 
         @cache = cache || Filecache.new
 
-        Hiera.debug("Hiera MySQL2 initialized")
+        Hiera.debug("Hiera PostgreSQL initialized")
       end
 
       def lookup(key, scope, order_override, resolution_type)
@@ -22,12 +22,12 @@ def lookup(key, scope, order_override, resolution_type)
         # so hiera('myvalue', 'test1') returns [nil,nil,nil,nil]
       	results = nil
 
-        Hiera.debug("looking up #{key} in MySQL2 Backend")
+        Hiera.debug("looking up #{key} in PostgreSQL Backend")
         Hiera.debug("resolution type is #{resolution_type}")
 
         Backend.datasources(scope, order_override) do |source|
           Hiera.debug("Looking for data source #{source}")
-          sqlfile = Backend.datafile(:mysql2, scope, source, "sql") || next
+          sqlfile = Backend.datafile(:postgres, scope, source, "sql") || next
 
           next unless File.exist?(sqlfile)
           data = @cache.read(sqlfile, Hash, {}) do |datafile|
@@ -52,18 +52,17 @@ def query(query)
         Hiera.debug("Executing SQL Query: #{query}")
 
         data=nil
-        mysql_host = Config[:mysql2][:host]
-        mysql_user = Config[:mysql2][:user]
-        mysql_pass = Config[:mysql2][:pass]
-        mysql_database = Config[:mysql2][:database]
-        client = Mysql2::Client.new(:host => mysql_host, 
-                                    :username => mysql_user, 
-                                    :password => mysql_pass, 
-                                    :database => mysql_database,
-                                    :reconnect => true)
+        pg_host = Config[:postgres][:host]
+        pg_user = Config[:postgres][:user]
+        pg_pass = Config[:postgres][:pass]
+        pg_database = Config[:postgres][:database]
+        client = PG::Connection.new(:host     => pg_host, 
+                                    :user     => pg_user, 
+                                    :password => pg_pass, 
+                                    :dbname   => pg_database)
         begin
-          data = client.query(query).to_a
-          Hiera.debug("Mysql Query returned #{data.size} rows")
+          data = client.exec(query).to_a
+          Hiera.debug("PostgreSQL Query returned #{data.size} rows")
         rescue => e
           Hiera.debug e.message
           data = nil