eco-goinfra

Overview

The eco-goinfra project contains a collection of generic packages that can be used across various test projects.

Project requirements

• golang v1.19.x

Usage

In order to re-use code from this project you need to import relevant package/packages in to your project code.

import "github.com/openshift-kni/eco-goinfra/pkg/NAME_OF_A_NEEDED_PACKAGE"

In addition, you need to add link to the project github.com/openshift-kni/eco-goinfra to your local go.mod file

require(
    github.com/openshift-kni/eco-goinfra latest
)

Clients package:

The clients package contains several api clients combined into a single struct. The New function of the clients package returns a ready connection to the cluster api. If the path to kubeconfig is not specified to the new function then the KUBECONFIG environment variable is used. In case of failure client.New("") returns nil.

import "github.com/openshift-kni/eco-goinfra/pkg/clients"

func main() {
    apiClients := clients.New("")
	
    if apiClients == nil {
        panic("Failed to load api client")
        }
    }
)

Client usage example

Cluster Objects

Every cluster object namespace, configmap, daemonset, deployment and other has its own package under packages directory. The structure of any object has common interface:

func NewBuilder() or New[ObjectName]Builder() // Initiates object struct. This function require minimum set of parameters that are required to create the object on a cluster.
func Pull() or Pull[ObjectName]() // Pulls existing object to struct.
func Create()  // Creates new object on cluster if it doesn't exist.
func Delete() // Removes object from cluster if it exists.
func Update() // Updates object based on new object's definition.
func Exist() // Returns bool if object exist.
func With***() // Set of mutiation functions that can mutate any part of the object. 

Please refer to namespace example for more info.

Validator Method

In order to ensure safe access to objects and members, each builder struct should include a validate method. This method should be invoked inside packages before accessing potentially uninitialized code to mitigate unintended errors. Example:

func (builder *Builder) WithMethod(someString string) *Builder {
    if valid, _ := builder.validate(); !valid {
        return builder
    }
    
    glog.V(100).Infof(
        "Updating builder %s in namespace %s with the string: %s",
        builder.Definition.Name, builder.Definition.Namespace, someString
    )
    
    builder.Definition.StringHolder = someString
    
    return builder
}

Typically, validate methods will check that pointers are not nil and that errorMsg has not been set. Here is an example of how the secret package validate method ensures that Builder.apiClient has properly been initalized before being called:

func main() {
	apiClient := clients.New("bad api client")

	_, err := secret.NewBuilder(
        apiClient, "mysecret", "mynamespace", v1SecretTypeDockerConfigJson).Create()
	if err != nil {
		log.Fatal(err)
	}
}

Instead of causing a panic, the method will return a proper error message:

2023/06/16 11:55:58 Loading kube client config from path "bad api client"
2023/06/16 11:55:58 Secret builder cannot have nil apiClient
exit status 1

Please refer to the secret pkg's use of the validate method for more information.

eco-goinfra - How to contribute

The project uses a development method - forking workflow

The following is a step-by-step example of forking workflow:

1. A developer forks the eco-goinfra project
2. A new local feature branch is created
3. A developer makes changes on the new branch.
4. New commits are created for the changes.
5. The branch gets pushed to developer's own server-side copy.
6. Changes are tested.
7. A developer opens a pull request(PR) from the new branch to the eco-goinfra.
8. The pull request gets approved from at least 2 reviewers for merge and is merged into the eco-goinfra .

Code conventions

Lint

Push requested are tested in a pipeline with golangci-lint. It is advised to add Golangci-lint integration to your development editor. It's recommended to run make lint before uploading a PR.

Functions format

If the function's arguments fit in a single line - use the following format:

func Function(argInt1, argInt2 int, argString1, argString2 string) {
    ...
}

If the function's arguments don't fit in a single line - use the following format:

func Function(
    argInt1 int,
    argInt2 int,
    argInt3 int,
    argInt4 int,
    argString1 string,
    argString2 string,
    argString3 string,
    argString4 string) {
    ...
}

One more acceptable format example:

func Function(
    argInt1, argInt2 int, argString1, argString2 string, argSlice1, argSlice2 []string) {
	
}