Yamltypes

Tools for loading and validating yaml config files.

package is shipped with 2 entry points scripts:

• yamlconfig: This tool can validate a yaml file against its spec.

  The spec file can be either automatically found given the filename or given as parameter with --meta

• yaml2rst: This tool automatically creates a rst documentation of the types defined in a directory.

Yamltypes module

A common problem for the complex CI system developer is to separate its configuration logic from its configuration data.

• Logic is the configuration of the builder, what does it build, what are the buildsteps, etc
• Data is the parameter you want to easily change in the day to day maintainance work. What are the slaves, and their capabilities? What branches are needed to be tracked? under what conditions? etc

YamlConfig helps to resolve this problem by providing tools to create and describe a set of yaml files that are used as input for your master.cfg

Originally made for buildbot configuration, the spec format it defines can be used to describe any kind of json compatible data.

Each parsed yaml file can be given a .meta.yaml file that acts as a schema file describing what is allowed in the file, and potencially how to present it in an edition UI.

.meta.yaml file Format

the meta yaml file is a yaml file made of nested dicts, describing the type of data the type checker is waiting for.

Root Node

the meta yaml file must describe the root type, which will snowball all the nested type checks

root:
  type: dict
  kids:
     param1:
     type: int
     param2:
     type: string

will match:

param1: 1
param2: stringvalue

imports Node

The meta yaml file can use types described in another file. For that, it will import a list of .types.yaml files.

A .types.yaml is a yaml file defining a map of named types. ex:

foo:
    type: string
    values: [bar]

can be used in a myconfig.meta.yaml:

imports:
    - foo.type.yaml
root:
    type: dict
    kids:
        foo:
            type: listoffoos

Base types

base types are:

int

an integer

string

a string

boolean

a true/false boolean

float

a floating point number

Compound types

A value of compound type is composed of several subtypes values or key/value:

dict

an associative array that has a defined list of childrens key

map

an associative array that has an arbitrary list childrens keys

list

a list of arbitrary values

set

a list that ensure member unicity (you cannot have several time the same value)

Specifying types of values

For map, list, set, it is possible to specify what type is expected as the values. The syntax is:

type: <compound_type>of<type>s

for example, following types are valid

type: mapofstrings
type: listofints
type: listofsetsofints

User defined types

You can specify a meta.yaml file defining the map of types, you can reuse inside your main meta.yaml file. e.g:

location:
    type: string
    values: [l1,l2,l3,l4,l5,l6]

This defines a location type, which is a string with 6 possible values.

types modifers

Each type can be associated with a number of modifiers, that will extend the number of specification you describe for it:

values:

a set of possible values that the attribute can take

name:

the name of the attribute as displayed in the UI

default:

The value the attribute takes if it is not defined explicitly

forbidden:

a python expression checking whether this attribute should not be defined in a particular configuration

required:

a python expression checking whether this attribute must be defined in a particular configuration

maybenull:

a python expression checking whether this attribute must be defined in a particular configuration

More complex example

The meta.yaml:

root:
  type: dict
  kids:
     slaves:
        type: listofdicts
        name: Build Slaves
        kids:
          caps:
            type: dict
            name: Capabilities
            kids:
                builder:
                    name: Used by builder
                    type: setofstrings
                    values: [ autolint, build ]
                    required: true
                location:
                    type: location
                    required: true
                speed:
                    type: string
                    default: fast
                    values: [fast,slow]
          slaves:
            type: setofstrings

matches a yaml file like:

slaves:
-       caps:
                builder: [build]
                location: l4
        slaves: [buildbot1build]
-       caps:
                builder: [autolint, build]
                location: l1
                speed: fast
        slaves: [build3build, build4build, build5build]