Github user nickwallen commented on a diff in the pull request:
https://github.com/apache/metron/pull/856#discussion_r158584449
--- Diff:
metron-stellar/stellar-common/src/main/java/org/apache/metron/stellar/common/utils/validation/StellarZookeeperBasedValidator.java
---
@@ -0,0 +1,106 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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
+ *
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+ * 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.apache.metron.stellar.common.utils.validation;
+
+import static
org.apache.metron.stellar.common.shell.StellarShell.ERROR_PROMPT;
+
+import java.lang.invoke.MethodHandles;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import org.apache.commons.lang.NullArgumentException;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.metron.stellar.common.StellarProcessor;
+import org.atteo.classindex.ClassIndex;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class StellarZookeeperBasedValidator implements StellarValidator {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+ private static final String FAILED_COMPILE = "Failed to compile";
+ private CuratorFramework client;
+
+ public StellarZookeeperBasedValidator(CuratorFramework client) throws
NullArgumentException {
+ if (client == null) {
+ throw new NullArgumentException("client");
+ }
+ this.client = client;
+ }
+
+
+ @Override
+ public Iterable<ValidationResult> validate(Optional<LineWriter> writer) {
+ // discover all the StellarConfigurationProvider
+ Set<StellarConfigurationProvider> providerSet = new HashSet<>();
+
+ for (Class<?> c :
ClassIndex.getSubclasses(StellarConfigurationProvider.class,
--- End diff --
If I understand this correctly, it seems that the
`StellarConfigurationProvider` interface allows us to extend where
configuration values get pulled in from. In your current default
implementation `ConfigurationProvider` you reach out to Zookeeper to pull in
the config.
If I wanted to validate configuration located on a file system, I would
just create a `FilesystemConfigurationProvider` implementation of this
interface.
The decision as to whether I want to validate the config in Zookeeper, on
the file system or both, needs to be user driven. A user should make that
decision based on how they call your new Stellar function.
Based on your discovery logic here, just having a
`FilesystemConfigurationProvider` on the classpath (or any other
implementation) will cause the configuration in the file system to get
validated. We don't want that to happen. We want the user to control that
behavior.
So I don't think we really need this discovery logic, which nicely
simplifies things. I think we could just alter the `StellarValidater`
interface to make this relationship simpler and more straight forward. The
`StellarConfigurationProvider` just gets passed in.
```
StellarValidator {
...
Iterable<ValidationResult> validate(StellarConfigurationProvider
provider);
...
}
```
---
