add requirements check

lib/msfdb_helpers/db_interface.rb

@@ -32,4 +32,8 @@ class DbInterface
     raise NotImplementedError
   end
 
+  def self.requirements
+    Array.new
+  end
+
 end

lib/msfdb_helpers/pg_ctl.rb

@@ -102,4 +102,8 @@ class PgCtl < DbInterface
       end
     end
   end
+
+  def self.requirements
+    %w(psql pg_ctl initdb createdb)
+  end
 end

lib/msfdb_helpers/pg_ctlcluster.rb

@@ -97,6 +97,10 @@ class PgCtlcluster < DbInterface
     end
   end
 
+  def self.requirements
+    %w(psql pg_ctlcluster pg_dropcluster pg_createcluster pg_config)
+  end
+
   private
 
   def get_postgres_version

msfdb

@@ -956,9 +956,8 @@ def installed?(cmd)
   !Msf::Util::Helper.which(cmd).nil?
 end
 
-def has_requirements
+def has_requirements(postgresql_cmds)
   ret_val = true
-  postgresql_cmds = %w(psql pg_ctl initdb createdb)
   other_cmds = %w(bundle thin)
   missing_msg = "Missing requirement: %<name>s does not appear to be installed or '%<prog>s' is not in the environment path"
 
@@ -1019,10 +1018,9 @@ if $PROGRAM_NAME == __FILE__
     abort
   end
 
-  if installed?("pg_ctl")
-    abort unless has_requirements
+  if installed?("pg_ctl") && has_requirements(PgCtl.requirements)
     @db_driver = PgCtl.new(db_path: @db, options: @options, localconf: @localconf, db_conf: @db_conf)
-  elsif installed?("pg_ctlcluster")
+  elsif installed?("pg_ctlcluster") && has_requirements(PgCtlcluster.requirements)
     @db_driver = PgCtlcluster.new(db_path: @db, options: @options, localconf: @localconf, db_conf: @db_conf)
   else
     abort