+1
I agree that we need to maintain consistency in our YAML and BOM files, but
not just at the level of Brooklyn item and entity syntax. There should also
be a consistent structural format to the files. For example, when
specifying configuration, we allow items both inside the `brooklyn.config`
map, and outside it. For short examples, missing out `brooklyn.config` is
acceptable, but in general we should use it. There should also be
consistency in ordering the parts of an entity or catalog entry definition,
as well as the formatting of maps, lists and strings.
The following is a suggested style guide, for discussion.
- https://gist.github.com/grkvlt/62ee0ddeea2f4503f82ad25c2f9b31fd
The normative statements are listed here, and the document linked above
contains a conforming YAML fragment showing how they are interpreted.
1. Blueprints MUST place all configuration inside a `brooklyn.config` map,
and MUST use the fully qualified configuration key name
2. Lists MUST be indented properly, to allow IDE folding to work properly
3. Keywords MUST be formatted as `lowerCamel` tokens
4. Sensor, configuration key and section names MUST be formatted as
`lower-hyphen.dot-separated` tokens
5. The preamble for a catalog entry SHOULD contain the following keys,
which MUST appear in this order: version, id, name, description, iconUrl,
origin, license, licenseUrl, publish
6. Entities SHOULD contain the following sections, which MUST appear in
this order: brooklyn.parameters, brooklyn.config, brooklyn.initializers,
brooklyn.enrichers, brooklyn.policies, brooklyn.children
7. Catalog items SHOULD contain the following keys, which MUST appear in
this order: id, name, description, itemType, item
8. Entities and entity specifications SHOULD contain the following keys,
which MUST appear in this order: type, id, name, description, services
9. Names MUST be quoted strings
10. The description value MUST use the multi-line string syntax
11. Parameters SHOULD use the following keys, which MUST appear in this
order: name, label, description, type, default, constraints
Andrew.
On Mon, 20 Jun 2016 at 18:08 Aled Sage <[email protected]> wrote:
Thanks all,
Alex's suggestion makes a lot of sense. So we should:
1. agree short-term preferred syntax
2. update our docs and examples to *always* use that
3. discuss improvements for a more powerful syntax, and the longer term
bigger long-term overhaul.
It should be trivial to warn someone if they have not included the
"itemType", so I think we should do that short-term.
---
Any more opinions for the preferred syntax?
Aled
On 20/06/2016 14:44, Geoff Macartney wrote:
+1 for the proposal, and for staging it.
I actually quite like the suggestion of making items/item entirely
consistent (by requiring both). If I have
1 brooklyn.catalog:
2 version: "2.0.0-SNAPSHOT"
3
4 item:
5 type: server
6 id: testy
7 name: Testy McServer
and decide for some reason that I need a second item (maybe move one
here from another file), I can’t just add it below line 7. Instead I
have
to go editing lines 3-7 to add “items:” and change the indentation.
Sticking to items+item consistently will make this sort of refactoring
less
tedious. Just a thought.
Geoff
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Gnu PGP key - http://is.gd/TTTTuI
On 20 Jun 2016, at 14:17, Svetoslav Neykov <
[email protected]> wrote:
+1 for the proposal.
I find the current item-items functionality logical. "item" is used in
leaf items, "items" is used in non-leaf items. Forcing a non-leaf root
just
so we always have "items" is overhead.
Svet.
On 20.06.2016 г., at 15:47, Aled Sage <[email protected]> wrote:
Hi all,
The YAML format for adding catalog items accepts several different
ways of defining them. This has led to our examples being inconsistent,
our
code more complicated, and potential confusion for users when they see
different things that turn out to mean the same.
I think we should standardise on one approach, and deprecate the
other
ways.
---
_*Current Code*_
An example .bom file is shown below:
brooklyn.catalog:
items:
- id: entity1
version: "1.0.0"
itemType: entity
item:
type: org.apache.brooklyn.entity.machine.MachineEntity
Variants:
* If defining just a single item in the .bom file, you can optionally
miss out the "items".
* You can miss out the "itemType" - it will guess at it by trying to
treat it as an entity, a template, a location or a policy. The
default is "entity".
* You can include "services:" for entity or template types, or you
can
miss it out if there is just one entity in the item.
* Similar to "services:", you can include "brooklyn.policies:" or
"brooklyn.locations:".
If itemType is missing, this helps to infer the type. If it does
not
agree with itemType, then we add it as the item type and it will
fail later.
* You can define the item metadata at any level - it could be
directly
under "brooklyn.catalog" (in which case it applies to all items),
or
under a specific item (in which case it overrides any more general
metadata).
An example of a .bom for a single item is shown below:
brooklyn.catalog:
id: entity2
version: "1.0.0"
itemType: entity
item:
type: org.apache.brooklyn.entity.machine.MachineEntity
---
_*Proposal*_
I suggest we have the following stricter rules. Anything else is
deprecated, logging a warning.
* Always include "itemType".
* For entity, policy and location: do not include "services:",
"brooklyn.policies:" or "brooklyn.locations:" - i.e. it will expect
exactly one type in the item.
* For template, always expect "services:" (even if there is just one
thing). This is consistent with the YAML required when deploying an
application.
* Always include "items", even if there is just one item in it.
(reasoning: we do not support "service" versus "services", so why
support "item").
We should change the following (breaking backwards compatibility,
because it's really a bug):
* If the itemType differs from the actual type of the item, then
fail.
Aled
p.s. I'm in two minds about "item" versus "items": it is simpler with
the single item, and having "item" underneath "items" means it's not
quite
like the "services" analogy.
--
Andrew Kennedy ; Founder clocker.io project ; @grkvlt ; Cloudsoft
