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https://issues.apache.org/jira/browse/CURATOR-457?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Zili Chen closed CURATOR-457.
-----------------------------
    Fix Version/s: 5.6.0
         Assignee: Zili Chen  (was: Jordan Zimmerman)
       Resolution: Fixed

master via d14cb464cbd4e8e0e1bb51daba76e84eb2e346db.

> Configuring service discovery paths
> -----------------------------------
>
>                 Key: CURATOR-457
>                 URL: https://issues.apache.org/jira/browse/CURATOR-457
>             Project: Apache Curator
>          Issue Type: Improvement
>            Reporter: Aleksander Melnichnikov
>            Assignee: Zili Chen
>            Priority: Minor
>             Fix For: 5.6.0
>
>
> Right now paths for services in service discovery hardcoded to pattern: 
> */\{basePath} /\{serviceName}/\{instanceId}.* And that's impossible to 
> configure paths this way:  */\{basePathPart1} 
> /\{serviceName}/\{basePathPart2}/\{instanceId}*
> For example:
>  If basePath = */base1/base2/base3*, serviceName = *serviceName*, instanceId 
> - *serviceId*
>  then path will be 
> */**base1**/**base2**/**base3**/**serviceName**/**serviceId*, that can't be 
> configured like this: 
> */**base1**/**base2/serviceName**/**base3**/**serviceId.*
> Because of strong encapsulation in ServiceDiscoveryImpl class (package 
> private method modifiers)
> {code:java}
> @VisibleForTesting
> String pathForName(String name) 
> { 
>     return ZKPaths.makePath(basePath, name); 
> }
> @VisibleForTesting 
> String pathForInstance(String name, String id)
> { 
>    return ZKPaths.makePath(pathForName(name), id);
> }
> {code}
> So, can we rethink visibility modifiers or add some extendable entity which 
> would be responsible for constructing paths? 
> For example:
> Create interface
> {code:java}
> /**
>  * A constructor which constructs path to services for service discovering
>  */
> public interface DiscoveryPathConstructor
> {
>     /**
>      * Return the path where all service names registered
>      * @return basePath
>      */
>     String getBasePath();
>     /**
>      * Return the path where all instances of service registered
>      * @param name service name
>      * @return path to service instances
>      */
>     String getPathForInstances(String name);
>     /**
>      * Return the path where concrete instance registered
>      * @param name service name
>      * @param id concrete instance id
>      * @return path to concrete instance
>      */
>     String getPathForInstance(String name, String id);
> }
> {code}
> Also make a constructor and field in ServiceDiscoveryImpl:
> {code:java}
>     private final DiscoveryPathConstructor pathConstructor;
>   /**
>      * @param client the client
>      * @param pathConstructor constructor for instances path
>      * @param serializer serializer for instances (e.g. {@link 
> JsonInstanceSerializer})
>      * @param thisInstance instance that represents the service that is 
> running. The instance will get auto-registered
>      * @param watchInstances if true, watches for changes to locally 
> registered instances
>      */
>     public ServiceDiscoveryImpl(CuratorFramework client, 
> DiscoveryPathConstructor pathConstructor, InstanceSerializer<T> serializer,
>                                 ServiceInstance<T> thisInstance, boolean 
> watchInstances)
>     {
>         this.watchInstances = watchInstances;
>         this.client = Preconditions.checkNotNull(client, "client cannot be 
> null");
>         this.serializer = Preconditions.checkNotNull(serializer, "serializer 
> cannot be null");
>         this.pathConstructor = Preconditions.checkNotNull(pathConstructor, 
> "pathConstructor cannot be null");
>         if ( thisInstance != null )
>         {
>             Entry<T> entry = new Entry<T>(thisInstance);
>             entry.cache = makeNodeCache(thisInstance);
>             services.put(thisInstance.getId(), entry);
>         }
>     }
> {code}
> You can view commit in my fork of framework, if that's ok - I can make a pull 
> request. 
> https://github.com/Me1kaa/curator/commit/6e6a34db7d71a84e3a53d284fc94e1fe2e3c10d8



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