In this morning’s discussion, Matt suggested that the “proper” way to augment interfaces in Tosca types is to create a new type. I agree that this might be the
cleanest approach, but I’m afraid this might result in lots of unnecessary work for the template designer.
Let’s look at the logstash example below. All we want to do is to add one input (“elasticsearch_ip”) to the pre_configure_source operation on the Configure interface
on the ConnectTo relationship type. This would result in the following:
1.
First, we have to create a new Interface Type (e.g. MyConfigure), derived from tosca.interfaces.relationship.Configure, that adds the “elasticsearch_ip”
input to pre_configure_source). Note that if we had operation types as well, we would have had to first create a new operation type.
2.
Then, we have to create a new Relationship Type (e.g. MyConnectTo) derived from ConnectTo that uses the new MyConfigure interface.
3.
Then, we can create the Logstash node type with the “search_endpoint” requirement definition that uses the MyConnectTo relationship type
When the template designer creates the topology template that uses a Logstash node, they have to do the following:
1.
First, they have to create a relationship_template (e.g. search_endpoint_relationship) that assigns a value to the “elasticsearch_ip” input defined
in the MyConfigure interface of the MyConnectTo relationship type
2.
Then they have to specify the search_endpoint_relationship in the search_endpoint requirement assignment in the logstash node template
Most of these steps could be avoided if we simply allowed augmentation of interface operations in-line in requirement definitions and requirement assignments.
Chris
From: Sahdev P Zala [mailto:]
Sent: Tuesday, April 14, 2015 8:18 AM
To: Chris Lauwers
Cc:
Subject: Re: 2015-04-13 tosca_elk_DRAFT_CSAR: issues with requirements
Hi Chris,
Good catches. I will make updates per your suggestion for Logstash and any other node where it makes sense.
I have a question on node types grammar in spec for providing arguments to the 'relationship', interfaces in Logstash case. I will bring it up in today's YAML call.
Thanks!
Regards,
Sahdev Zala
____________________________ el
development, IBM Cloud
Durham, NC
(919)486-2915 T/L: 526-2915
From: Chris Lauwers <>
To: Sahdev P Zala/Durham/IBM@IBMUS
Cc: "" <>
Date: 04/13/2015 11:25 PM
Subject: 2015-04-13 tosca_elk_DRAFT_CSAR: issues with requirements
As promised, here are a number of comments on the latest CSAR file. Most of the issues with this file are with requirements definitions and assignments and are similar in nature.
I’ll use the logstash.yaml file to illustrate a couple of them.
The first set of issues has to do with requirement definitions in node types. logstash.yaml defines the following node type:
node_types:
tosca.nodes.SoftwareComponent.Logstash:
derived_from: tosca.nodes.SoftwareComponent
requirements:
search_endpoint:
capability: tosca.capabilities.Endpoint
node: tosca.nodes.SoftwareComponent.Elasticsearch
relationship:
type: tosca.relationships.ConnectsTo
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation:
type: string
inputs:
elasticsearch_ip:
type: string
This node type has invalid grammar for the search_endpoint requirement definition. According to the requirements definition grammar (section A.6.2.2) the ‘relationship’ keyname is
only allowed to take a relationship type name, not an extended grammar that overrides interfaces.
The second set of issues have to do with requirement assignments. The logstash node template in the tosca_elk.yaml file contains the following:
logstash:
type: tosca.nodes.SoftwareComponent.Logstash
requirements:
- host: logstash_server
- search_endpoint: elasticsearch
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation: Python/logstash/configure_elasticsearch.py
input:
elasticsearch_ip: { get_attribute: [elasticsearch_server, ip_address] }
There are 2 issues with this:
1. The syntax for ordered requirements assignment lists is invalid based on section A.7.2.2.2. The correct syntax is as follows:
logstash:
type: tosca.nodes.SoftwareComponent.Logstash
requirements:
- host: logstash_server
- search_endpoint:
node: elasticsearch
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation: Python/logstash/configure_elasticsearch.py
input:
elasticsearch_ip: { get_attribute: [elasticsearch_server, ip_address] }
2. More importantly, a requirement assignment does not take ‘interfaces’ as a top-level keyname. I imagine the intent here is to override interfaces for the relationship in
the requirement as follows:
logstash:
type: tosca.nodes.SoftwareComponent.Logstash
requirements:
- host: logstash_server
- search_endpoint:
node: elasticsearch
relationship:
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation: Python/logstash/configure_elasticsearch.py
input:
elasticsearch_ip: { get_attribute: [elasticsearch_server, ip_address] }
Unfortunately, the latest version of the grammar seems to have removed support for that as well so it is no longer possible to define interfaces directly in requirements. The only
option here is to introduce a relationship template with the appropriate interfaces.
Chris
From: Sahdev P Zala [mailto:]
Sent: Monday, April 13, 2015 4:42 PM
To: Chris Lauwers
Cc:
Subject: RE: [tosca] Groups - 2015-04-13 tosca_elk_DRAFT_CSAR.zip uploaded
Hi Chris, sounds great!
Thanks!!
Regards,
Sahdev Zala
From: Chris Lauwers <>
To: Sahdev P Zala/Durham/IBM@IBMUS
Cc: ""
<>
Date: 04/13/2015 07:17 PM
Subject: RE: [tosca] Groups - 2015-04-13 tosca_elk_DRAFT_CSAR.zip uploaded
Sent by: <>
Thanks Sahdev, I’ll start with an email, since a number of the issues will likely need some discussion. Based on the discussion, I can upload edited YAML files.
I’ll work on this later today and tomorrow.
Thanks,
Chris
From: Sahdev P Zala [mailto:]
Sent: Monday, April 13, 2015 4:15 PM
To: Chris Lauwers
Cc:
Subject: RE: [tosca] Groups - 2015-04-13 tosca_elk_DRAFT_CSAR.zip uploaded
Hi Chris,
Thank you so much for the review. I am looking forward to have your comments.
I think email probably is a good way or may be you can upload them as a doc at the same place we have CSAR? I will make changes per your comments unless I have questions or need to have a discussion.
Thanks again!
Regards,
Sahdev Zala
From: Chris Lauwers <>
To: Sahdev P Zala/Durham/IBM@IBMUS, ""
<>
Date: 04/13/2015 04:57 PM
Subject: RE: [tosca] Groups - 2015-04-13 tosca_elk_DRAFT_CSAR.zip uploaded
Sent by: <>
Hi Sahdev,
Thanks for the update. I finally managed to run this test case through my validator, and it turns out there are many issues with the YAML files in this package. In particular, many of the “requirements” sections (in Node Templates as well as in Node Types)
do not conform to the spec.
What is the best way for me to submit my comments so we can get this package updated?
Best regards,
Chris
From:
[mailto:]
On Behalf Of Sahdev Zala
Sent: Monday, April 13, 2015 7:10 AM
To:
Subject: [tosca] Groups - 2015-04-13 tosca_elk_DRAFT_CSAR.zip uploaded
Submitter's message
Document for InterOp. SC review.
Thanks to Matt and Christopher Kaufmann for their initial comments, update the draft with some minor changes. Thanks!
-- Sahdev Zala
Document Name:
2015-04-13 tosca_elk_DRAFT_CSAR.zip
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Submitter: Sahdev Zala
Group: OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) TC
Folder: Working Documents
Date submitted: 2015-04-13 07:09:19
