Remove dependency to sequel, sqlite3 and grit

Not every installation will use git + sql. Try to give helpful error
message on missing dependencies.

3 files changed, 17 insertions, 9 deletions

diff --git a/lib/oxidized/output/git.rb b/lib/oxidized/output/git.rb
index ff9237b..6f232cb 100644
--- a/lib/oxidized/output/git.rb
+++ b/lib/oxidized/output/git.rb
@@ -1,6 +1,10 @@
 module Oxidized
 class Git < Output
-  require 'grit'
+  begin
+    require 'grit'
+  rescue LoadError
+    raise LoadError, 'grit not found: sudo gem install grit'
+  end
   require 'oxidized/fix/grit' if RUBY_VERSION[0..1] == '2.'
   include Grit
 
diff --git a/lib/oxidized/source/sql.rb b/lib/oxidized/source/sql.rb
index f84a7a8..9f862e5 100644
--- a/lib/oxidized/source/sql.rb
+++ b/lib/oxidized/source/sql.rb
@@ -1,6 +1,10 @@
 module Oxidized
 class SQL < Source
-  require 'sequel'
+  begin
+    require 'sequel'
+  rescue LoadError
+    raise LoadError, 'sequel not found: sudo gem install sequel'
+  end
 
   def initialize
     super
@@ -23,7 +27,11 @@ class SQL < Source
     nodes = []
     db = case @cfg.adapter
     when 'sqlite'
-      require 'sqlite3'
+      begin
+        require 'sqlite3'
+      rescue LoadError
+        raise LoadError, 'sqlite3 not found: sudo apt install libsqlite3-dev; sudo gem install sqlite3'
+      end
       Sequel.sqlite @cfg.file
     end
     db[@cfg.table.to_sym].each do |node|
diff --git a/oxidized.gemspec b/oxidized.gemspec
index 6e132d4..e72e1ef 100644
--- a/oxidized.gemspec
+++ b/oxidized.gemspec
@@ -12,16 +12,12 @@ Gem::Specification.new do |s|
   s.executables       = %w( oxidized )
   s.require_path      = 'lib'
 
+  s.add_dependency 'asetus', '>= 0.0.7'
+  s.add_dependency 'slop'
   s.add_dependency 'net-ssh'
-  s.add_dependency 'sqlite3'
-  s.add_dependency 'grit'
-  s.add_dependency 'sequel'
   s.add_dependency 'sinatra'
   s.add_dependency 'sinatra-contrib'
   s.add_dependency 'puma'
   s.add_dependency 'haml'
   s.add_dependency 'sass'
-  s.add_dependency 'slop'
-  s.add_dependency 'asetus', '>= 0.0.7'
-
 end