v2.1.0
Go modules, resource ordering respected, generator and transformer plugins, eased loading restrictions, the notion of inventory, eased replica count modification. About ~90 issues closed since v2.0.3 in ~400 commits.
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Go modules
Kustomize now defines its dependencies in a top
level go.mod file. This is the first step
towards a package structure intentially exported
as one or more Go modules for use in other
programs (kubectl, kubebuilder, etc.) and in
kustomize plugins (see below).
Resource ordering
Kustomize now retains the depth-first order of resources as read, a frequently requested feature.
This means resource order can be controlled by editting kustomization files. This is also vital to applying user-defined transformations (plugins) in a particular order.
Nothing needs to be done to activate this; it happens automatically.
The build command now accepts a --reorder
flag with values legacy and none,
with a default value of legacy.
legacy means apply an ordering based on
GVK, that currently emits Namespace objects
first, and ValidatingWebhookConfiguration
objects last. This means that despite
automatic retention of load order, your
build output won’t change by default.
none means don’t reorder the resources before
output. Specify this to see output order
respect input order.
Generator and transformer plugins
Since the beginning (as kinflate back in Sep
2017), kustomize has read or generated resources,
applied a series of pipelined transformation to
them, and emitted the result to stdout.
At that time, the only way to change the behavior of a generator (e.g. a secret generator), or change the behavior of a transformer (e.g. a name changer, or json patcher), was to modify source code and put out a release.
v1.0.9 introduced generator options as a means to change the behavior of the only two generators available at the time - Secret and ConfigMap generators. It also introduced transformer configs as a way to fine tune the targets of transformations (e.g. to which fields selectors should be added). Most of the feature requests for kustomize revolve around changing the behavior of the builtin generators and transformers.
v2.1.0 adds an alpha plugin framework, that
encourages users to write their own generators or
transformers, declaring them as kubernetes
objects just like everything else, and apply them
as part of the kustomize build process.
To inform the API exposed to plugins, and to
confirm that the plugin framework can offer plugin
authors the same capabilities as builtin
operations, all the builtin generators and
tranformers have been converted to plugin form
(with one exceptions awaiting Go module
refinements). This means that adding, say, a
secretGenerator or commonAnnotations directive
to your kustomization will (in v2.1.0) trigger
execution of
code committed as a plugin.
For more information, see the kustomize plugin documentation.
Remove load restrictions
The following usage:
kustomize build --load_restrictor none $target
allows a kustomization.yaml file used in this
build to refer to files outside its own directory
(i.e. outside its root).
This is an opt-in to suppress a security feature that denies this precise behavior.
This feature should only be used to allow multiple
overlays (e.g. prod, staging and dev) to share a
patch file. To share resources, use a relative
path or URL to a kustomization directory in the
resources directive.
Inventory generation for pruning
Alpha
Users can add an inventory stanza to their
kustomization file, to add a special inventory
object to the build result.
This object applies to the cluster along with everything else in the build result and can be used by other clients to intelligently prune orphaned cluster resources.
For more information see the kustomize inventory object documentation.
Field changes / deprecations
resources expanded, bases deprecated
The resources field has been generalized; it now
accepts what formerly could only be specified in
the bases field.
This change was made to allow users fine control
over resource processing order. With a distinct
bases field, bases had to be loaded separately
from resources as a group. Now, base loading may
be interleaved as desired with the loading of
resource files from the current
directory. Resource ordering
had to be respected before this feature could be
introduced.
The bases field is now deprecated, and will be
deleted in some future major release. Manage the
deprecation simply moving the arguments of the
bases field to the resources field in the
desired order, e.g.
resources: - someResouceFile.yaml - someOtherResourceFile.yaml bases: - ../../someBaseDir
could become
resources: - someResouceFile.yaml - ../../someBaseDir - someOtherResourceFile.yaml
The kustomized edit fix command will do this for
you, though it will always put the bases at the
end.
As an aside, the resources, generators and
transformers fields now all accept the same
argument format.
Each field’s argument is a string list, where each entry is either a resource (a relative path to a YAML file) or a kustomization (a path or URL pointing to a directory with a kustomization file). A kustomization directory used in this context is called a base.
The fact that the generators and transformers
field accept bases and the fact that generator
and transformer configuration objects are just
normal k8s resources means that one can generate
or transform a generator or a transformer (see
TestTransformerTransformers).
replicas field
The common task of patching a deployment to edit the number of replicas is now made easier with the new replicas field.
envs field
An envs sub-field has been added to both
configMapGenerator and secretGenerator,
replacing the now deprecated (and singular)
env field. The new field accepts lists, just
like its sibling fields files and literals.
Optionally use kustomize edit fix to merge
singular env field into a plural field.