This page explains how Kubernetes objects are represented in the Kubernetes API, and how you can express them in .yaml format.
Kubernetes objects are persistent entities in the Kubernetes system. Kubernetes uses these entities to represent the state of your cluster. Specifically, they can describe:
A Kubernetes object is a -once you create the object, the Kubernetes system will constantly work to ensure that object exists. By creating an object, yous desired state.
To work with Kubernetes objects?-whether to create, modify, or delete them-you`ll need to use the Kubernetes API. When you use the kubectl command-line interface, for example, the CLI makes the necessary Kubernetes API calls for you. You can also use the Kubernetes API directly in your own programs using one of the Client Libraries.
Almost every Kubernetes object includes two nested object fields that govern the object`s configuration: the object spec and the object status. For objects that have a spec, you have to set this when you create the object, providing a description of the characteristics you want the resource to have: its desired state.
The status describes the current state of the object, supplied and updated by the Kubernetes system and its components. The Kubernetes control plane continually and actively manages every object`s actual state to match the desired state you supplied.
For example: in Kubernetes, a Deployment is an object that can represent an application running on your cluster. When you create the Deployment, you might set the Deployment spec to specify that you want three replicas of the application to be running. The Kubernetes system reads the Deployment spec and starts three instances of your desired application-updating the status to match your spec. If any of those instances should fail (a status change), the Kubernetes system responds to the difference between spec and status by making a correction-in this case, starting a replacement instance.
For more information on the object spec, status, and metadata, see the Kubernetes API Conventions.
When you create an object in Kubernetes, you must provide the object spec that describes its desired state, as well as some basic information about the object (such as a name). When you use the Kubernetes API to create the object (either directly or via kubectl), that API request must include that information as JSON in the request body. Most often, you provide the information to kubectl in a .yaml file. kubectl converts the information to JSON when making the API request.
Here`s an example .yaml file that shows the required fields and object spec for a Kubernetes Deployment:
In the .yaml file for the Kubernetes object you want to create, you`ll need to set values for the following fields:
The precise format of the object spec is different for every Kubernetes object, and contains nested fields specific to that object. The Kubernetes API Reference can help you find the spec format for all of the objects you can create using Kubernetes. For example, the spec format for a Pod can be found in PodSpec v1 core, and the spec format for a Deployment can be found in DeploymentSpec v1 apps.
There may be the need to record some actions on objects that do not result in changes to the object content. For example, copying the object to new storage or validating fixity and finding nothing amiss. The log directory is the location in an OCFL object where such events can be recorded. The OCFL does not make any assumptions about the contents of this directory but, if it exists, then its contents will not be subject any validation processes.
Forward delta differencing is a key, though optional, feature of the OCFL that means that parts of an OCFL object version that are unchanged from a previous version are not stored again. This has the potential to significantly improve storage efficiency when objects have multiple versions, whether through ongoing curatorial action or the accessioning of updated material.
When a new version of an OCFL Object is created from an earlier version and a client wishes to implement forward delta differencing, then the possible file operations are handled in the following manner (with reference to the state and manifest blocks of the OCFL object`s inventory file):
The OCFL is designed to be a specification that covers objects at rest and consequently does not specify in detail update and file locking mechanisms since these are implementation dependent features. Nevertheless, this section includes a simple example of a way to update OCFL Objects in a manner that tries to ensure that updates are as transactional as possible, and that failures are detectable and recoverable. Objects that are being updated are, of course, not expected to be valid OCFL objects until the update operation is completed. Creating a new OCFL Object only differs from updating in that it involves creating a version directory before version update logic takes over.
Starting with this version, you can review the query that represents your changes in the data editor. There is now a DML button that is active if there are pending changes:
If you change the name of an object in the code, this tiny button on the toolbar will let you do a refactoring! For example, this is how it works for aliases:
Sometimes you have unresolved objects in your script. When you do, DataGrip doesn’t understand where these objects are located and suspects that they don’t exist at all. While in many cases this is true, sometimes the objects are unresolved because you just need to tweak the context you are working on.
We’ve added the Refresh database quick-fix, which will help you if an object has been added to the database from somewhere else since the last time you refreshed your database.
Previously, the SQL formatter had three options for modifying object names in your code: to upper case, to lower case or don`t change. But it turned out that this was not enough – some people need the object names to be changed according to the casing which was used in the declaration. Now we provide that option.
SYNOPSIS use version; $version version?new(); must be quoted for Perl 5.8.1 print $version; 12.2.1 print $version-numify; if ( $version gt ) true $alphaver version?new(); must be quoted! print $alphaver; 1.02_030 print $alphaver-is_alpha(); true $ver qv(1.2); 1.2.0 $ver qv(); 1.2.0 $perlver version?new(5.005_03); must not be quoted! print $perlver;
Overloaded version objects for all versions of Perl. This module implements all of the features of version objects which will be part of Perl 5.10.0 except automatic version object creation.
For the purposes of this module, a version ``number that is discussed in the various editions of the Camel book.
The concept template Property Sets for Objects describes how an object occurrence can be related to a single or multiple property sets. A property set contains a single or multiple properties. The data types of an individual property are single value, enumerated value, bounded value, table value, reference value, list value, and combination of property occurrences.
Property sets can also be related to an object type, see concept Property Sets for Types. They then define the common properties for all occurrences of the same type. If the same property (by name) is provided by the same property set (by name), then the properties directly assigned to the object occurrence override the properties assigned to the object type.
You may also read through the annotated source code. There is a modular version with clickable import references as well.
Note: Collection functions work on arrays, objects, and array-like objects such as arguments, NodeList and similar. But it works by duck-typing, so avoid passing objects with a numeric length property. It`s also good to note that an each loop cannot be broken out of — to break, use _.find instead.
pluck_.pluck(list, propertyName) A convenient version of what is perhaps the most common use-case for map: extracting a list of property values.
indexBy_.indexBy(list, iteratee, [context]) Given a list, and an iteratee function that returns a key for each element in the list (or a property name), returns an object with an index of each item. Just like groupBy, but for when you know your keys are unique.
countBy_.countBy(list, iteratee, [context]) Sorts a list into groups and returns a count for the number of objects in each group. Similar to groupBy, but instead of returning a list of values, returns a count for the number of values in that group.
shuffle_.shuffle(list) Returns a shuffled copy of the list, using a version of the Fisher-Yates shuffle.
toArray_.toArray(list) Creates a real Array from the list (anything that can be iterated over). Useful for transmuting the arguments object.
result_.result(object, property, [defaultValue]) If the value of the named property is a function then invoke it with the object as context; otherwise, return it. If a default value is provided and the property doesn`t exist or is undefined then the default will be returned. If defaultValue is a function its result will be returned.
We offer objects version
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