public class DownloadProducerFromProperties
extends java.lang.Object
implements com.google.common.base.Function<DownloadResolverManager.DownloadRequirement,DownloadResolverManager.DownloadTargets>

Based on the contents of brooklyn properties, sets up rules for resolving where to download artifacts from, for installing entities. By default, these rules override the DOWNLOAD_URL defined on the entities in code. Global properties can be specified that apply to all entities. Entity-specific properties can also be specified (which override the global properties for that entity type). Below is an example of realistic configuration for an enterprise who have an in-house repository that must be used for everything, rather than going out to the public internet.

 // FIXME Check format for including addonname- only if addonname is non-null?
 // FIXME Use this in a testng test case
 brooklyn.downloads.all.url=http://downloads.acme.com/brookyn/repository/${simpletype}/${simpletype}-${addon?? addon-}${version}.${fileSuffix!.tar.gz}
 
 

To illustrate the features and variations one can use, below is an example of global properties that can be specified. The semicolon-separated list of URLs will be tried in-order until one succeeds. The fallback url says to use that if all other URLs fail (or no others are specified).

 brooklyn.downloads.all.url=http://myurl1/${simpletype}-${version}.tar.gz; http://myurl2/${simpletype}-${version}.tar.gz
 brooklyn.downloads.all.fallbackurl=http://myurl3/${simpletype}-${version}.tar.gz
 
 

Similarly, entity-specific properties can be defined. All "global properties" will also apply to this entity type, unless explicitly overridden.

 brooklyn.downloads.entity.tomcatserver.url=http://mytomcaturl1/tomcat-${version}.tar.gz
 brooklyn.downloads.entity.tomcatserver.fallbackurl=http://myurl2/tomcat-${version}.tar.gz
 
 

Downloads for entity-specific add-ons can also be defined. All "global properties" will also apply to this entity type, unless explicitly overridden.

 brooklyn.downloads.entity.nginxcontroller.addon.stickymodule.url=http://myurl1/nginx-stickymodule-${version}.tar.gz
 brooklyn.downloads.entity.nginxcontroller.addon.stickymodule.fallbackurl=http://myurl2/nginx-stickymodule-${version}.tar.gz
 
 

If no explicit URLs are supplied, then by default it will use the DOWNLOAD_URL attribute of the entity (if supplied), followed by the fallbackurl if that fails. A URL can be a "template", where things of the form ${version} will be substituted for the value of "version" provided for that entity. The freemarker template engine is used to convert URLs (see http://freemarker.org). For example, one could use the URL:

 http://repo.acme.com/${simpletype}-${version}.${fileSuffix!tar.gz}
 
 

The following substitutions are available automatically for a template:

• entity: the Entity instance
• driver: the EntityDriver instance being used for the Entity
• simpletype: the unqualified name of the entity type
• type: the fully qualified name of the entity type
• addon: the name of the entity add-on, or null if it's the core entity artifact
• version: the version number of the entity to be installed (or of the add-on)