Hi Tal,
Thanks for the explanation.
I tried having the custom type in a separate file and imported it to both
web.yaml and db.yaml.
Now in my web.yaml "database" node-template is still an abstract one. To have
the node-template "db-app" being substituted in place of "database" in web.yaml
I still need to import db.yaml.
This was my first question, Do we need to import db.yaml ( which provides the
substitutable node-templates ) to web.yaml ( which has the abstract node
template ) ?
I also tried the below without any custom node-type
1) Created a service-template "st-1" from db.yaml
2) Created a service-template "st-2" from web.yaml
3) Had an abstract node-template "database" ( node-type: tosca.nodes.Database)
as part of web.yaml "database"
4) Had an substation mapping of node-type "tosca.nodes.Database" with
capability as "database_endpoint"
5) I dint import db.yaml to web.yaml
I would expect the ARIA to go through the available service-templates (st-1)
which provides the substation capability when I try to create a service from
"st-2" ( web.yaml)
But it fails here, as it has no target node_template. So it looks like ARIA
wants the db.yaml to be imported to have the node-template ?
Please find below yaml files and results.
Node templates:
+----+------------+-------------+-----------------------+----------------------------+
| id | name | description | service_template_name | type_name
|
+----+------------+-------------+-----------------------+----------------------------+
| 1 | db_app | | st-1 |
tosca.nodes.Database |
| 2 | db_server | | st-1 | tosca.nodes.DBMS
|
| 3 | db_host | | st-1 |
tosca.nodes.Compute |
| 4 | web_server | | st-2 |
tosca.nodes.WebServer |
| 5 | web_host | | st-2 |
tosca.nodes.Compute |
| 6 | web_app | | st-2 |
tosca.nodes.WebApplication |
| 7 | database | | st-2 |
tosca.nodes.Database |
+----+------------+-------------+-----------------------+----------------------------+
[root@DJ-DEV substitution]#
[root@DJ-DEV substitution]#
[root@DJ-DEV substitution]# aria services create -t st-2 s1
Creating new service from service template st-2...
Validation issues:
5: requirement "host" of node "database_1" has no target node template
Web.yaml
tosca_definitions_version: tosca_simple_yaml_1_0
topology_template:
node_templates:
web_app:
type: tosca.nodes.WebApplication
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
requirements:
- host:
node: web_server
- dependency:
node: database
web_server:
type: tosca.nodes.WebServer
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
requirements:
- host:
node: web_host
web_host:
type: tosca.nodes.Compute
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
database:
type: tosca.nodes.Database
# type: my.nodes.database
properties:
name: web_db
db.yaml
tosca_definitions_version: tosca_simple_yaml_1_0
topology_template:
substitution_mappings:
node_type: tosca.nodes.Database
# node_type: my.nodes.database
capabilities:
database_endpoint: [ db_app, database_endpoint ]
node_templates:
db_app:
type: tosca.nodes.Database
properties:
name: sub_map_db
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
requirements:
- host:
node: db_server
db_server:
type: tosca.nodes.DBMS
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
requirements:
- host:
node: db_host
db_host:
type: tosca.nodes.Compute
interfaces:
Standard:
create:
implementation: sample.samplemethod
delete:
implementation: sample.samplemethod
Regards
DJ
-----Original Message-----
From: Tal Liron [mailto:[email protected]]
Sent: Friday, May 26, 2017 9:40 PM
To: [email protected]
Subject: Re: Query related to substitution mapping
Thanks, DJ. Much clearer now. Also it seems that the Apache mailing list throws
away attachments, so we will have to paste things in email.
I will clarify my meaning: I did not mean to say that you need to import types,
just that those types must be *available*. Indeed you'll see that the examples
given in the TOSCA spec don't use imports all. However, those examples use
standard simple profile types. In your example you are using a custom type.
How substitution mapping actually happens depends on the orchestrator, TOSCA
only specifies the grammar. So, how would the orchestrator know that types in
different services are compatible and can be chained/proxies/whatever in order
to implement service composition? All TOSCA provides us with here is names: the
type name and the mapped capability names.
That's fine, but ARIA is a validating parser. It doesn't just treat these names
at arbitrary strings, it checks to make sure that the type exists and that that
the mapped capabilities match those in the type. This is critical for making
sure the resulting service is valid and can indeed be composed by the
orchestrator.
So, how would you make sure that db.yaml knows about the "my.nodes.database"
type? My proposed solution is to always define types in separate files (think:
header files in C) which could then be imported by any other file that needs
them.
In this case I would "my.nodes.database" in its own file, let's say types.yaml.
Then db.yaml and web.yaml can both import types.yaml. The former is a
"provider" while the latter is a "consumer", but both work with the same basic
type.
Does this make sense?
On Fri, May 26, 2017 at 4:18 AM, D Jayachandran <[email protected]
> wrote:
> Hi Tal,
>
> Did you get the attachments ?
>
> If not . . please find below templates.
>
> db.yaml
>
> tosca_definitions_version: tosca_simple_yaml_1_0
>
> topology_template:
>
> substitution_mappings:
> # node_type: tosca.nodes.Database
> node_type: my.nodes.database
> capabilities:
> database_endpoint: [ db_app, database_endpoint ]
>
> node_templates:
>
> db_app:
> type: tosca.nodes.Database
> properties:
> name: sub_map_db
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
> requirements:
> - host:
> node: db_server
>
> db_server:
> type: tosca.nodes.DBMS
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
> requirements:
> - host:
> node: db_host
>
> db_host:
> type: tosca.nodes.Compute
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
>
>
> web.yaml
>
> tosca_definitions_version: tosca_simple_yaml_1_0
>
> imports:
> - ./db.yaml
>
> node_types:
> my.nodes.database:
> derived_from: tosca.nodes.Database
>
> topology_template:
>
> node_templates:
>
> web_app:
> type: tosca.nodes.WebApplication
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
> requirements:
> - host:
> node: web_server
> - dependency:
> node: database
>
> web_server:
> type: tosca.nodes.WebServer
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
> requirements:
> - host:
> node: web_host
>
> web_host:
> type: tosca.nodes.Compute
> interfaces:
> Standard:
> create:
> implementation: test_plugin.test_method
> delete:
> implementation: test_plugin.test_method
>
> database:
> # type: tosca.nodes.Database
> type: my.nodes.database
> properties:
> name: web_db
>
>
>
> Regards,
> DJ
> -----Original Message-----
> From: D Jayachandran
> Sent: Friday, May 26, 2017 2:30 PM
> To: [email protected]
> Cc: Vaishnavi K.R <[email protected]>; S Shenbaga Rajan <
> [email protected]>
> Subject: RE: Query related to substitution mapping
>
> Hi Tal,
>
> Please find the attachment for an example of substitution mapping.
> The db.yaml is the substituting template which is imported to web.yaml.
> The web.yaml has an abstract node template "database" which would be
> substituted with db.yaml.
>
> We want to understand is it mandatory to have templates imported for
> substitution to work ? Does TOSCA spec says this ?
> The use-case for us would be to have substitution mapping without
> importing the template but to find the template from the already
> available service-templates in the Database.
>
> You could refer Section 2.10 in TOSCA simple yaml 1.0 for more
> information on substitution mapping.
>
> Regards,
> DJ
>
> -----Original Message-----
> From: Tal Liron [mailto:[email protected]]
> Sent: Thursday, May 25, 2017 10:32 PM
> To: [email protected]
> Subject: Re: Query related to substitution mapping
>
> Hi DJ,
>
> I'm not sure what you mean by "the substituting template". Actually,
> ARIA does almost nothing with substitution templates right now, just
> parses, validates, and stores the info. Indeed, if you refer to a node
> type there, it should be expected that the current template would need
> to know of that type, possibly by importing.
>
> Could you provide a short example to clarify?
>
> On Thu, May 25, 2017 at 5:32 AM, D Jayachandran <
> [email protected]
> > wrote:
>
> > Hi,
> >
> > The substitution mapping works in the latest APACHE ARIA code only
> > if the substituting template is imported in the top-level template.
> >
> > This seems to be contradicting with the TOSCA specification where
> > the substitution is expected to happen without the import (though
> > not explicitly mentioned).
> >
> > We are looking at the possible ways to identify the appropriate node
> > template without importing the substituting template. ( Possibly by
> > going through already available service models for a substitutable
> > entity )
> >
> > Do you have any plans to have substitution mapping work without
> > having the template imported every time ?
> > Do you have any feedback on this and if our understanding is correct ?
> >
> >
> > Regards,
> > DJ
> >
> >
> >
> >
>
>
> --
> Tal Liron
> Senior Engineer
> [email protected] | +1 (773) 828-9339 Cloudify |
> http://getcloudify.org
> <http://getcloudify.org?utm_source=signaturesatori&utm_
> medium=email&utm_campaign=general_signature>
>
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>
--
Tal Liron
Senior Engineer
[email protected] | +1 (773) 828-9339
Cloudify | http://getcloudify.org
<http://getcloudify.org?utm_source=signaturesatori&utm_medium=email&utm_campaign=general_signature>
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