Lazy-loading configuration for MantaClient (#357)

Resolves #311 by reading as many values directly from the config as possible in addition to introducing a new ConfigContext which will manage derived authentication objects: AuthAwareConfigContext. The new class also provides a reload() method for users to indicate that we should regenerate authentication objects. No guarantees are made about the thread-safety of AuthAwareConfigContext.

Author: tjcelaya

CHANGELOG.md

@@ -14,6 +14,9 @@ This project aims to adhere to [Semantic Versioning](http://semver.org/).
    `MantaConnectionFactoryConfigurator` containing their custom instance to the
    `MantaClient(ConfigContext, MantaConnectionFactoryConfigurator)` constructor. Constructor documentation
    explains the benefits and trade offs.
+ - `MantaClient` now allows for modification of authentication parameters by
+   [dynamically-reloading configuration state](https://github.com/joyent/java-manta/issues/311). `AuthAwareConfigContext` can
+   be used to wrap the desired configuration and provides a method to update derived objects atomically.
 ### Fixed
  - Clarify version history of `MantaInputStreamEntity`
  - MPU parts which were missing an ETag in their response were

USAGE.md

@@ -56,11 +56,6 @@ public class MantaDirectoryListingIterator implements Iterator<Map<String, Objec
      */
     private final int pagingSize;
 
-    /**
-     * Base Manta URL that all paths are appended to.
-     */
-    private final String url;
-
     /**
      * Path to directory in which we will iterate through its contents.
      */
@@ -111,20 +106,32 @@ public class MantaDirectoryListingIterator implements Iterator<Map<String, Objec
     /**
      * Create a new instance of a directory list iterator.
      *
-     * @param url base Manta URL that all paths are appended to
+     * @param url ignored
      * @param path path to directory in which we will iterate through its contents
      * @param httpHelper HTTP request helper class
      * @param pagingSize size of result set requested against the Manta API (2-1024).
      */
+    @Deprecated
     public MantaDirectoryListingIterator(final String url,
                                          final String path,
                                          final HttpHelper httpHelper,
                                          final int pagingSize) {
-        Validate.notNull(url, "URL must not be null");
+        this(path, httpHelper, pagingSize);
+    }
+
+    /**
+     * Create a new instance of a directory list iterator.
+     *
+     * @param path path to directory in which we will iterate through its contents
+     * @param httpHelper HTTP request helper class
+     * @param pagingSize size of result set requested against the Manta API (2-1024).
+     */
+    public MantaDirectoryListingIterator(final String path,
+                                         final HttpHelper httpHelper,
+                                         final int pagingSize) {
         Validate.notBlank(path, "Path must not be blank");
         Validate.notNull(httpHelper, "HTTP help must not be null");
 
-        this.url = url;
         this.path = path;
         this.httpHelper = httpHelper;
 
@@ -146,11 +153,10 @@ public MantaDirectoryListingIterator(final String url,
     private synchronized void selectReader() throws IOException {
         if (lastMarker == null) {
             String query = String.format("?limit=%d", pagingSize);
-            String uri = url + formatPath(path) + query;
-            HttpGet get = new HttpGet(uri);
+            final HttpGet request = httpHelper.getRequestFactory().get(formatPath(path) + query);
 
             IOUtils.closeQuietly(currentResponse);
-            currentResponse = httpHelper.executeRequest(get, null);
+            currentResponse = httpHelper.executeRequest(request, null);
             HttpEntity entity = currentResponse.getEntity();
             String contentType = entity.getContentType().getValue();
 
@@ -166,13 +172,12 @@ private synchronized void selectReader() throws IOException {
         } else {
             String query = String.format("?limit=%d&marker=%s",
                     pagingSize, URLEncoder.encode(lastMarker, "UTF-8"));
-            String uri = url + formatPath(path) + query;
-            HttpGet get = new HttpGet(uri);
+            final HttpGet request = httpHelper.getRequestFactory().get(formatPath(path) + query);
 
             IOUtils.closeQuietly(br);
             IOUtils.closeQuietly(currentResponse);
 
-            currentResponse = httpHelper.executeRequest(get, null);
+            currentResponse = httpHelper.executeRequest(request, null);
             HttpEntity entity = currentResponse.getEntity();
             Reader streamReader = new InputStreamReader(entity.getContent(),
                     StandardCharsets.UTF_8.name());

java-manta-client-unshaded/src/main/java/com/joyent/manta/client/MantaClient.java

@@ -9,6 +9,7 @@
 
 import com.joyent.http.signature.KeyFingerprinter;
 import com.joyent.http.signature.ThreadLocalSigner;
+import com.joyent.manta.config.AuthAwareConfigContext;
 import com.joyent.manta.config.ConfigContext;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.Validate;
@@ -28,32 +29,31 @@
  * @since 3.0.0
  */
 public class UriSigner {
-    /**
-     * Manta configuration object.
-     */
-    private final ConfigContext config;
 
     /**
-     * HTTP signature generator instance.
+     * Authentication Helper which provides objects needed for signing.
      */
-    private final ThreadLocalSigner signer;
+    private final AuthAwareConfigContext authConfig;
 
     /**
-     * Cryptographic key pair used to sign URIs.
-     */
-    private final KeyPair keyPair;
-
-    /**
-     * Creates a new instance.
+     * DEPRECATED: Creates an instance based on a new authentication context.
      *
      * @param config Manta configuration context
      * @param keyPair cryptographic key pair used to sign URIs
      * @param signer Signer configured to work with the the given keyPair
      */
+    @Deprecated
     public UriSigner(final ConfigContext config, final KeyPair keyPair, final ThreadLocalSigner signer) {
-        this.config = config;
-        this.keyPair = keyPair;
-        this.signer = signer;
+        this(new AuthAwareConfigContext(config));
+    }
+
+    /**
+     * Creates a new instance. This constructor is package-private because this class is being made package private.
+     *
+     * @param authConfig Manta authentication context
+     */
+    UriSigner(final AuthAwareConfigContext authConfig) {
+        this.authConfig = authConfig;
     }
 
     /**
@@ -77,11 +77,14 @@ public URI signURI(final URI uri, final String method, final long expires)
                     "Query must be null or empty. URI: %s", uri);
         }
 
+        final ThreadLocalSigner signer = authConfig.getSigner();
+
         final String charset = "UTF-8";
         final String algorithm = signer.get().getHttpHeaderAlgorithm().toUpperCase();
-        final String keyId = String.format("/%s/keys/%s",
-                                           config.getMantaUser(),
-                                           KeyFingerprinter.md5Fingerprint(keyPair));
+        final String keyId = String.format(
+                "/%s/keys/%s",
+                authConfig.getMantaUser(),
+                KeyFingerprinter.md5Fingerprint(authConfig.getKeyPair()));
 
         final String keyIdEncoded = URLEncoder.encode(keyId, charset);
 
@@ -95,10 +98,11 @@ public URI signURI(final URI uri, final String method, final long expires)
 
 
         StringBuilder request = new StringBuilder();
-        final byte[] sigBytes = sigText.toString().getBytes(
-                StandardCharsets.UTF_8);
-        final byte[] signed = signer.get().sign(config.getMantaUser(),
-                                                keyPair, sigBytes);
+        final byte[] sigBytes = sigText.toString().getBytes(StandardCharsets.UTF_8);
+
+        // first parameter isn't actually used for anything, just checked for nullness
+        final byte[] signed = signer.get().sign("", authConfig.getKeyPair(), sigBytes);
+
         final String encoded = new String(Base64.encode(signed), charset);
         final String urlEncoded = URLEncoder.encode(encoded, charset);