Now determining the list of blobstores based on the available identity/credential property pairs, with optional override via the 'jclouds.tweetstore.blobstores' system property

demos/tweetstore/runatcloud-tweetstore/src/main/java/org/jclouds/demo/tweetstore/config/GuiceServletConfig.java

@@ -19,7 +19,12 @@
 package org.jclouds.demo.tweetstore.config;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.base.Predicates.in;
+import static com.google.common.collect.ImmutableSet.copyOf;
+import static com.google.common.collect.Sets.filter;
 import static java.util.concurrent.TimeUnit.MINUTES;
+import static org.jclouds.demo.tweetstore.reference.TweetStoreConstants.PROPERTY_TWEETSTORE_BLOBSTORES;
 import static org.jclouds.demo.tweetstore.reference.TweetStoreConstants.PROPERTY_TWEETSTORE_CONTAINER;
 import static org.jclouds.demo.tweetstore.reference.TwitterConstants.PROPERTY_TWITTER_ACCESSTOKEN;
 import static org.jclouds.demo.tweetstore.reference.TwitterConstants.PROPERTY_TWITTER_ACCESSTOKEN_SECRET;
@@ -38,9 +43,10 @@ import javax.servlet.ServletContextEvent;
 
 import org.jclouds.blobstore.BlobStoreContext;
 import org.jclouds.blobstore.BlobStoreContextFactory;
+import org.jclouds.demo.tweetstore.config.util.CredentialsCollector;
 import org.jclouds.demo.tweetstore.config.util.HttpRequestTask;
-import org.jclouds.demo.tweetstore.config.util.TaskQueue;
 import org.jclouds.demo.tweetstore.config.util.HttpRequestTask.Factory;
+import org.jclouds.demo.tweetstore.config.util.TaskQueue;
 import org.jclouds.demo.tweetstore.controller.AddTweetsController;
 import org.jclouds.demo.tweetstore.controller.StoreTweetsController;
 import org.jclouds.http.HttpRequest;
@@ -69,8 +75,6 @@ import com.google.inject.servlet.ServletModule;
  * @author Adrian Cole
  */
 public class GuiceServletConfig extends GuiceServletContextListener {
-    public static final String PROPERTY_BLOBSTORE_CONTEXTS = "blobstore.contexts";
-
     private Map<String, BlobStoreContext> providerTypeToBlobStoreMap;
     private Twitter twitterClient;
     private String container;
@@ -100,7 +104,7 @@ public class GuiceServletConfig extends GuiceServletContextListener {
 
         // instantiate and store references to all blobstores by provider name
         providerTypeToBlobStoreMap = Maps.newHashMap();
-        for (String hint : Splitter.on(',').split(checkNotNull(props.getProperty(PROPERTY_BLOBSTORE_CONTEXTS), PROPERTY_BLOBSTORE_CONTEXTS))) {
+        for (String hint : getBlobstoreContexts(props)) {
             providerTypeToBlobStoreMap.put(hint, blobStoreContextFactory.createContext(hint, modules, props));
         }
 
@@ -118,6 +122,16 @@ public class GuiceServletConfig extends GuiceServletContextListener {
         super.contextInitialized(servletContextEvent);
     }
 
+    private static Iterable<String> getBlobstoreContexts(Properties props) {
+        Set<String> contexts = new CredentialsCollector().apply(props).keySet();
+        String explicitContexts = props.getProperty(PROPERTY_TWEETSTORE_BLOBSTORES);
+        if (explicitContexts != null) {
+            contexts = filter(contexts, in(copyOf(Splitter.on(',').split(explicitContexts))));
+        }
+        checkState(!contexts.isEmpty(), "no credentials available for any requested  context");
+        return contexts;
+    }
+
     private static URI withUrl(ServletContext servletContext, String url) {
         return URI.create("http://" + checkNotNull(servletContext.getInitParameter("application.host"), "application.host")
                 + servletContext.getContextPath() + url);

demos/tweetstore/runatcloud-tweetstore/src/main/java/org/jclouds/demo/tweetstore/config/util/CredentialsCollector.java

@@ -0,0 +1,153 @@
+/**
+ *
+ * Copyright (C) 2011 Cloud Conscious, LLC. <info@cloudconscious.com>
+ *
+ * ====================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ====================================================================
+ */
+package org.jclouds.demo.tweetstore.config.util;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.base.Predicates.notNull;
+import static com.google.common.collect.Collections2.filter;
+import static com.google.common.collect.Collections2.transform;
+import static com.google.common.collect.ImmutableSet.copyOf;
+import static com.google.common.collect.Maps.filterValues;
+import static org.jclouds.util.Maps2.fromKeys;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Properties;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.jclouds.demo.tweetstore.config.util.CredentialsCollector.Credential;
+
+import com.google.common.annotations.GwtIncompatible;
+import com.google.common.base.Function;
+import com.google.common.base.Predicate;
+
+/**
+ * Reads provider credentials from a {@link Properties} bag.
+ * 
+ * @author Andrew Phillips
+ *
+ */
+public class CredentialsCollector implements Function<Properties, Map<String, Credential>> {
+    private static final String IDENTITY_PROPERTY_SUFFIX = ".identity";
+    private static final String CREDENTIAL_PROPERTY_SUFFIX = ".credential";
+    
+    // using the identity for provider name extraction
+    private static final Pattern IDENTITY_PROPERTY_PATTERN =
+        Pattern.compile("([a-zA-Z0-9-]+)" + Pattern.quote(IDENTITY_PROPERTY_SUFFIX));
+    
+    @Override
+    public Map<String, Credential> apply(final Properties properties) {
+        Collection<String> providerNames = transform(
+                filter(properties.stringPropertyNames(), MatchesPattern.matches(IDENTITY_PROPERTY_PATTERN)), 
+                new Function<String, String>() {
+                    @Override
+                    public String apply(String input) {
+                        Matcher matcher = IDENTITY_PROPERTY_PATTERN.matcher(input);
+                        // as a side-effect, sets the matching group!
+                        checkState(matcher.matches(), "'%s' should match '%s'", input, IDENTITY_PROPERTY_PATTERN);
+                        return matcher.group(1);
+                    }
+                });
+        /*
+         * Providers without a credential property result in null values, which are
+         * removed from the returned map.
+         */
+        return filterValues(fromKeys(copyOf(providerNames), new Function<String, Credential>() {
+            @Override
+            public Credential apply(String providerName) {
+                String identity = properties.getProperty(providerName + IDENTITY_PROPERTY_SUFFIX);
+                String credential = properties.getProperty(providerName + CREDENTIAL_PROPERTY_SUFFIX);
+                return (((identity != null) && (credential != null)) 
+                        ? new Credential(identity, credential) 
+                        : null);
+            }
+        }), notNull());
+    }
+    
+    public static class Credential {
+        private final String identity;
+        private final String credential;
+        
+        public Credential(String identity, String credential) {
+            this.identity = checkNotNull(identity, "identity");
+            this.credential = checkNotNull(credential, "credential");
+        }
+        
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result
+                    + ((credential == null) ? 0 : credential.hashCode());
+            result = prime * result
+                    + ((identity == null) ? 0 : identity.hashCode());
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj)
+                return true;
+            if (obj == null)
+                return false;
+            if (getClass() != obj.getClass())
+                return false;
+            Credential other = (Credential) obj;
+            if (credential == null) {
+                if (other.credential != null)
+                    return false;
+            } else if (!credential.equals(other.credential))
+                return false;
+            if (identity == null) {
+                if (other.identity != null)
+                    return false;
+            } else if (!identity.equals(other.identity))
+                return false;
+            return true;
+        }
+
+        public String getIdentity() {
+            return identity;
+        }
+
+        public String getCredential() {
+            return credential;
+        }
+    }
+    
+    @GwtIncompatible(value = "java.util.regex.Pattern")
+    private static class MatchesPattern implements Predicate<String> {
+        private final Pattern pattern;
+        
+        private MatchesPattern(Pattern pattern) {
+            this.pattern = pattern;
+        }
+
+        @Override
+        public boolean apply(String input) {
+            return pattern.matcher(input).matches();
+        }
+        
+        private static MatchesPattern matches(Pattern pattern) {
+            return new MatchesPattern(pattern);
+        }
+    }
+}

demos/tweetstore/runatcloud-tweetstore/src/test/java/org/jclouds/demo/tweetstore/config/util/CredentialsCollectorTest.java

@@ -0,0 +1,82 @@
+/**
+ *
+ * Copyright (C) 2011 Cloud Conscious, LLC. <info@cloudconscious.com>
+ *
+ * ====================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ====================================================================
+ */
+package org.jclouds.demo.tweetstore.config.util;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+import java.util.Map;
+import java.util.Properties;
+
+import org.jclouds.demo.tweetstore.config.util.CredentialsCollector;
+import org.jclouds.demo.tweetstore.config.util.CredentialsCollector.Credential;
+import org.testng.annotations.Test;
+
+import com.google.common.collect.ImmutableMap;
+
+/**
+ * Tests behavior of {@code CredentialsCollector}
+ * 
+ * @author Andrew Phillips
+ */
+@Test(groups = "unit")
+public class CredentialsCollectorTest {
+    private CredentialsCollector collector = new CredentialsCollector();
+    
+    public void testEmptyProperties() {
+        assertTrue(collector.apply(new Properties()).isEmpty(), 
+                "Expected returned map to be empty");
+    }
+
+    public void testNoCredentials() {
+        Properties properties = propertiesOf(ImmutableMap.of("not-an-identity", 
+                "v1", "not-a-credential", "v2"));
+        assertTrue(collector.apply(properties).isEmpty(), 
+                "Expected returned map to be empty");
+    }
+    
+    private static Properties propertiesOf(Map<String, String> entries) {
+        Properties properties = new Properties();
+        properties.putAll(entries);
+        return properties;
+    }
+    
+    public void testNonMatchingCredentials() {
+        Properties properties = propertiesOf(ImmutableMap.of("non_matching.identity", "v1",
+                "non_matching.credential", "v2"));
+        assertTrue(collector.apply(properties).isEmpty(), 
+                "Expected returned map to be empty");
+    }
+    
+    public void testIncompleteCredentials() {
+        Properties properties = propertiesOf(ImmutableMap.of("acme.identity", "v1",
+                "acme-2.credential", "v2"));
+        assertTrue(collector.apply(properties).isEmpty(), 
+                "Expected returned map to be empty");
+    }
+    
+    public void testCredentials() {
+        Properties properties = propertiesOf(ImmutableMap.of("acme.identity", "v1",
+                "acme.credential", "v2", "acme-2.identity", "v3",
+                "acme-2.credential", "v4"));
+        assertEquals(collector.apply(properties), 
+                ImmutableMap.of("acme", new Credential("v1", "v2"),
+                        "acme-2", new Credential("v3", "v4")));        
+    }
+}

demos/tweetstore/runatcloud-tweetstore/src/test/java/org/jclouds/demo/tweetstore/integration/TweetStoreLiveTest.java

@@ -40,7 +40,6 @@ import java.util.concurrent.TimeoutException;
 
 import org.jclouds.blobstore.BlobStoreContext;
 import org.jclouds.blobstore.BlobStoreContextFactory;
-import org.jclouds.demo.tweetstore.config.GuiceServletConfig;
 import org.jclouds.demo.tweetstore.controller.StoreTweetsController;
 import org.jclouds.logging.log4j.config.Log4JLoggingModule;
 import org.jclouds.rest.AuthorizationException;
@@ -57,7 +56,6 @@ import twitter4j.TwitterFactory;
 import twitter4j.conf.Configuration;
 import twitter4j.conf.ConfigurationBuilder;
 
-import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Maps;
@@ -86,7 +84,6 @@ public class TweetStoreLiveTest {
        container = getRequiredSystemProperty(PROPERTY_TWEETSTORE_CONTAINER);
 
       props.setProperty(PROPERTY_TWEETSTORE_CONTAINER, container);
-      props.setProperty(GuiceServletConfig.PROPERTY_BLOBSTORE_CONTEXTS, Joiner.on(',').join(blobstores));
 
       // put all identity/credential pairs into the client
       addCredentialsForBlobStores(props);