erocci is a new erlang frameowrk for building OCCI compliant REST APIs.

1. © 2014 Jean Parpaillon
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2. © 2014 Jean Parpaillon
LET'S GO CLOUD WATCHING
IS CLOUD VIRTUALIZATION ?
IS CLOUD STORAGE ?
IS CLOUD WEB++ ?
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3. © 2014 Jean Parpaillon
CLOUD IS REST...
int create_vm(char* name, int cores, int mem);
def get_bucket(size)
module:erase_stuff/3
GET http://example.com/bucket?size=12
PUT http://example.com/vm
{ "name": "myvm1",
"cores": 4,
"mem": 2.5 }
DELETE http://example.com/stuff/id1
object oriented
relational tables
relational tables
Resource oriented
factory pattern
builder iterator
observer
C(reate) R(ead) U(pdate) D(elete)
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4. © 2014 Jean Parpaillon
...SO IS EROCCI
PUT /myresource/id1
CREATE
POST /myresource/id1
UPDATE
GET /myresource/id1
READ
DELETE /myresource/id1
DELETE
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5. © 2014 Jean Parpaillon
"YET ANOTHER REST FRAMEWORK" ?
REST APIs looks similar, but are not interoperable
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6. © 2014 Jean Parpaillon
OCCI IS TYPED
Kind: a named list of attributes and actions
e.g.: http://schemas.ogf.org/occi/infrastructure#compute
Attribute: name, type (string, numeric, etc), mutability, occurrence, default value
Resource: an instance of a kind, identified with a URI
Action: an invocable operation applicable to a resource
e.g.: http://schemas.ogf.org/occi/infrastructure/compute/action#start
Kinds are inheritable
Inherits attributes and actions
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7. © 2014 Jean Parpaillon
OCCI IS EXTENSIBLE
Mixin: a named set of additional attributes and actions
e.g.: http://schemas.ogf.org/occi/infrastructure/networkinterface#ipnetworkinterface
Resource can be associated with one or several mixin
User Mixin: a user can create its own mixin, to tag resources
e.g.: http://example.com/occi/mixins#my_group1
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8. © 2014 Jean Parpaillon
OCCI IS RELATIONAL
Links are resources with specific attributes:
occi.core.source: resource URI
occi.core.target: resource URI
A collection is a list of resource URIs of the same kind/mixin
GET /collections/compute/
GET /collections/os_tpl/
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9. © 2014 Jean Parpaillon
OCCI IS SELF-DESCRIBED
GET /-/ (capabilities)
List of supported kinds + description
List of supported mixins + description
List of supported actions + description
Capabilities show collection's URL
http://schemas.ogf.org/occi/infrsatructure#compute -> /collections/compute
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10. © 2014 Jean Parpaillon
OCCI IS META-MODEL BASED
Category
scheme: URI
term: String
title: String [0..1]
Kind Mixin
Action
Entity
id: URI
Resource Link
Attribute
name: String
type: String [0..1]
mutable: Boolean [0..1]
required: Boolean [0..1]
default: String [0..1]
description: String [0..1]
0..1 *
actions 1*
actions
*
mixins
*
entities
1
kind
*
entities
1 target
1 source
*
links
0..1
parent
*
*
depends
*
1 *
attributes
* applies
Model consistency checking
Rendering independant
text/plain, application/json, etc.
Transport independant
HTTP, others...
Automatic model implementation
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11. © 2014 Jean Parpaillon
OCCI IMPLEMENTATIONS
rOCCI
occi4java
Frameworks
DoYouSpeakOCCI : test
Tools
CompatibleOne
pyOCNI
OpenStack, OpenNebula, etc
Specific implementations
Models are language extensions/libs
Hard to exchange models: what
about interoperability ?
Limits
See http://occi-wg.org/community/implementations/
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12. occi_store
occi_backend
supervisor
occi_backend_riak
backend
occi_backend_mnesia
backend
/
/path/to/resources
mount
create
load
update
delete
occi_hook
supervisor
call
on_save
on_load
on_update
on_delete
on_action
occi_hook_mgr
hook
notify
occi_renderer_json
occi_renderer
occi_renderer_occi
occi_renderer
occi_renderer_xml
occi_renderer
parse
render
parse
render
occi_listener_http
occi_listener
occi_listener_xmpp
occi_listener
based on cowboy based on exmpp
occi_category_mgr
supervisorcategories
description
<?xml >
<occi:extension>
<occi:kind>
...
</occi:kind>
</occi:extension>load
APPLICATION
MODEL
STANDARD OCCI API
STORAGE
occi_backend_XXX
backend
PROPRIETARY API
/other/path/to/resources
© 2014 Jean Parpaillon
EROCCI ARCHITECTURE
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13. © 2014 Jean Parpaillon
MULTIPLE REPRESENTATIONS
text/plain
Write your own rendering:
Implements: render, parse
text/occi
application/json (draft)
application/xml (experimental): see XSD: https://github.com/jeanparpaillon/occi-schemas
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14. /
/store/db1
/store/db2
/virt
occi_backend_mnesia
occi_backend_riak
occi_backend_odbc
occi_backend_libvirt
© 2014 Jean Parpaillon
MULTIPLE BACKENDS
Backends attached to mountpoints
Backends declare a schema
Storage backend: user-defined schema
API adapter: backend specific schema
Simple backend API
Implements CRUD operations
Shared kinds/mixins
Collection requests run in parallel
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15. © 2014 Jean Parpaillon
MULTIPLE TRANSPORTS
HTTP(S)
Natural REST transport
cowboy web server
100% erlang (easy to port)
Small, tested, scalable
(distributed)
XMPP
Ideal for M2M, IoT
Based on forked exmpp (erim)
<iq/> based
XML schema available
Extensible
Simple APIs for:
- dispatching requests (occi_store)
- parsing/rendering
Fault tolerant:
- erlang supervisor'ed
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16. © 2014 Jean Parpaillon
EXTENDING EROCCI
AS A REST "ORM"
Choose a storage backend
Load OCCI schema as XML
Choose a listener
Start it !
AS API ADAPTOR
Write your own backend
Implements CRUD operations
w/ calls to your favourite API
NEW TRANSPORT
Share your model
Just transport it differently
-> No erlang needed !
-> Need to write erlang (no harm)
-> Enjoy scalability, fault tolerance,
transports, etc.
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17. © 2014 Jean Parpaillon
ROADMAP
authn/authz
x509, HTTP basic etc, XMPP rosters,
oauth/openid, etc.
POSIX based with file-based backend ?
Contributions welcome !
Testing
Functional tests: migrate to Common Test
Unit tests: use eunit, add tests
POSIX based with file-based backend ?
Optimize occi_store
New storage backends
Riak (started...)
ODBC (SQL)
etc.
XMPP listener
XMPP component (API proxy)
Implements rosters, presence, etc
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18. © 2014 Jean Parpaillon
RESOURCES
Website:
Source code:
Continuous integration:
Mailing lists:
http://erocci.ow2.org
http://github.com/jeanparpaillon/erocci
https://travis-ci.org/jeanparpaillon/erocci
erocci-dev@ow2.org erocci-info@ow2.org
(ongoing work)
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19. © 2014 Jean Parpaillon
THANKS
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