Not from an ENV variable per-se, but from the spring config. Hence anything in the application.yml can be pushed into a field in a REST service endpoint with the @Value annotation.
Simon > On 8 May 2017, at 14:59, Otto Fowler <ottobackwa...@gmail.com> wrote: > > So that stuff is read from the environment variable? > > > On May 8, 2017 at 09:27:48, Otto Fowler (ottobackwa...@gmail.com > <mailto:ottobackwa...@gmail.com>) wrote: > >> OK, that is great. My works has bridged the move of rest into ambari. >> Mentally, I obviously haven’t caught up :) >> I’ll look for an example where we are reading application configuration >> variables out in the rest service. >> >> Thanks! >> >> >> >> On May 8, 2017 at 09:08:46, Simon Elliston Ball (si...@simonellistonball.com >> <mailto:si...@simonellistonball.com>) wrote: >> >>> My proposal would be that the REST api use it’s application.yml for all the >>> parameters and have settings it needs included in that. E.g. the metron >>> directory you need is set as a property of that yml, which is then >>> accessible through the spring config auto-wiring - >>> @Value(“${metron.directory}”) private String path; in your service endpoint. >>> >>> The application.yml file is managed (generated) by Ambari on start of the >>> rest api service (also managed through ambari now). >>> >>> All the parameters are built from a combination of user specified settings >>> in Ambari, or service locations. "Where is storm?” is not something a user >>> should have to specify; Ambari already knows. However "where would you like >>> the metron directory?" is an input box somewhere in Ambari. Both are >>> exposed to the rest api through the application.yml file. >>> >>> It’s more Ambari pushes the config to the REST layer than pull from Ambari. >>> This way we’re using Ambari the way it is intended rather than trying to >>> make it be something it is not (e.g. etcd) >>> >>> Simon >>> >>> >>> >>>> On 8 May 2017, at 14:00, Otto Fowler <ottobackwa...@gmail.com >>>> <mailto:ottobackwa...@gmail.com>> wrote: >>>> >>>> I’m not sure I understand. Could you go on a bit? >>>> >>>> Right now, we have env parameters in ambari, that rest should honor. I >>>> don’t understand how moving rest config into ambari get’s my rest service >>>> access to those parameters >>>> >>>> >>>> >>>> On May 8, 2017 at 08:56:21, Simon Elliston Ball >>>> (si...@simonellistonball.com <mailto:si...@simonellistonball.com>) wrote: >>>> >>>>> Perhaps a better way of doing this would be to push the configuration of >>>>> the REST api (the application.yml) into ambari control and expose >>>>> parameters like that. That means the REST api doesn’t have to couple >>>>> directly to Ambari, and doesn’t have to reinvent the Ambari paradigm >>>>> (Ambari is not a configuration server, it’s a configuration file manager >>>>> at heart). If the relevant parameters changed in Ambari, a restart of the >>>>> REST service (and consequently re-write of it’s application.yml) would be >>>>> forced. The REST API itself would then just use a simple spring config >>>>> expression to pick up the value. >>>>> >>>>> Simon >>>>> >>>>> > On 8 May 2017, at 13:52, Otto Fowler <ottobackwa...@gmail.com >>>>> > <mailto:ottobackwa...@gmail.com>> wrote: >>>>> > >>>>> > The issue is that we have services that need to access the ambari rest >>>>> > api from >>>>> > inside the rest server. >>>>> > >>>>> > Technically, if someone changes the defaults for the metron directory >>>>> > etc, the >>>>> > rest won’t pick it up. >>>>> > >>>>> > I have a PR coming as a follow on to METRON-777 for installing >>>>> > extensions, >>>>> > and I write to hdfs, and hard coded to directory, but we allow the >>>>> > configuration. >>>>> > >>>>> > Other rest services write to hdfs as well. >>>>> > >>>>> > >>>>> > On May 8, 2017 at 08:45:32, Nick Allen (n...@nickallen.org >>>>> > <mailto:n...@nickallen.org>) wrote: >>>>> > >>>>> > As opposed to using the Ambari REST API to get this information? >>>>> > >>>>> > On Mon, May 8, 2017 at 8:06 AM, Otto Fowler <ottobackwa...@gmail.com >>>>> > <mailto:ottobackwa...@gmail.com>> wrote: >>>>> > >>>>> >> I was thinking about have an ambari ‘service’ in the rest api. >>>>> >> The initial purpose would be to be able to retrieve ambari >>>>> >> configuration >>>>> >> variables for the metron service and components. >>>>> >> >>>>> >> The api would be >>>>> >> >>>>> >> PUT: login to ambari -> ambari credentials for use with ambari, >>>>> >> session >>>>> >> variable >>>>> >> GET: /component | service if login provided, returns the configuration >>>>> >> >>>>> >> GET:/component | service | property name if login provided get the >>>>> >> property value for property name >>>>> >> >>>>> >> So, the caller would put the credentials, and after that point the >>>>> >> caller >>>>> >> or other services can use ambari service configurations, >>>>> >> for example to get the configured metron hdfs root directory. >>>>> >> >>>>> >> This is opposed to configuring credentials in the rest configuration. >>>>> >> >>>>> >> Thoughts? >>>>> >>
