Partially fixing #2029 - failed caches doesn't throw an exception

If the main terminus fails you get an exception, but
not if a cache terminus fails.

Signed-off-by: Luke Kanies <luke@madstop.com>

2 files changed, 32 insertions, 7 deletions

diff --git a/lib/puppet/indirector/indirection.rb b/lib/puppet/indirector/indirection.rb
index 7ac214cd0..2a54ecc24 100644
--- a/lib/puppet/indirector/indirection.rb
+++ b/lib/puppet/indirector/indirection.rb
@@ -185,14 +185,12 @@ class Puppet::Indirector::Indirection
         request = request(:find, key, *args)
         terminus = prepare(request)
 
-        # See if our instance is in the cache and up to date.
-        if cache? and ! request.ignore_cache? and cached = cache.find(request)
-            if cached.expired?
-                Puppet.info "Not using expired %s for %s from cache; expired at %s" % [self.name, request.key, cached.expiration]
-            else
-                Puppet.debug "Using cached %s for %s" % [self.name, request.key]
-                return cached
+        begin
+            if result = find_in_cache(request)
+                return result
             end
+        rescue => detail
+            Puppet.err "Cached %s for %s failed: %s" % [self.name, request.key, detail]
         end
 
         # Otherwise, return the result from the terminus, caching if appropriate.
@@ -209,6 +207,18 @@ class Puppet::Indirector::Indirection
         return nil
     end
 
+    def find_in_cache(request)
+        # See if our instance is in the cache and up to date.
+        return nil unless cache? and ! request.ignore_cache? and cached = cache.find(request)
+        if cached.expired?
+            Puppet.info "Not using expired %s for %s from cache; expired at %s" % [self.name, request.key, cached.expiration]
+            return nil
+        end
+
+        Puppet.debug "Using cached %s for %s" % [self.name, request.key]
+        return cached
+    end
+
     # Remove something via the terminus.
     def destroy(key, *args)
         request = request(:destroy, key, *args)
diff --git a/spec/unit/indirector/indirection.rb b/spec/unit/indirector/indirection.rb
index dc4157fd2..a8bc8ba99 100755
--- a/spec/unit/indirector/indirection.rb
+++ b/spec/unit/indirector/indirection.rb
@@ -295,6 +295,21 @@ describe Puppet::Indirector::Indirection do
                     @indirection.find("/my/key").should equal(@instance)
                 end
 
+                it "should not fail if the cache fails" do
+                    @terminus.stubs(:find).returns @instance
+
+                    @cache.expects(:find).raises ArgumentError
+                    @cache.stubs(:save)
+                    lambda { @indirection.find("/my/key") }.should_not raise_error
+                end
+
+                it "should look in the main terminus if the cache fails" do
+                    @terminus.expects(:find).returns @instance
+                    @cache.expects(:find).raises ArgumentError
+                    @cache.stubs(:save)
+                    @indirection.find("/my/key").should equal(@instance)
+                end
+
                 it "should send a debug log if it is using the cached object" do
                     Puppet.expects(:debug)
                     @cache.stubs(:find).returns @instance