Add Kustomize Support

[qclaogui]

Signed-off-by: Weifeng Wang qclaogui@gmail.com

Add Kustomize Support

Kustomize background

Kustomize is a CNCF project that is a part of Kubernetes. It's included in
the kubectl in order to allow users to customize their configurations without introducing templates.

Usage

kustomize encourages defining multiple variants - e.g. dev, staging and prod, as overlays on a common base.

It’s possible to create an additional overlay to compose these variants together - just declare the overlays as the bases of a new kustomization.

deploy/base provides a common base for kafka_exporter deploy to Kubernetes. People should Create variants using overlays to deploy in their own environment.

An overlay is just another kustomization, referring to the base, and referring to patches to apply to that base.
This arrangement makes it easy to manage your configuration with git. The base could have files from an upstream repository managed by someone else. The overlays could be in a repository you own. Arranging the repo clones as siblings on disk avoids the need for git submodules (though that works fine, if you are a submodule fan).

[oldthreefeng]

you should set the kafka server endpoint?

[qclaogui]

Hi @oldthreefeng, thanks for your reply.
We should try to keep the base simple, users could specify the configuration in the overlays environment. For example, I want to monitor a Kafka cluster in a dev environment:

1. Create development Environment:
   mkdir -p deploy/overlays/dev && cd deploy/overlays/dev

2. Create kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

namespace: kafka-exporter

resources:
- github.com/qclaogui/kafka_exporter/deploy/base?ref=add-kustomize-support

patchesStrategicMerge:
- patch_args.yaml

images:
- name: danielqsj/kafka-exporter
  newTag: v1.3.1

2. Create patch_args.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: kafka-exporter
spec:
  template:
    spec:
      containers:
      - name: kafka-exporter
        args:
        - --log.level=debug
        - --log.enable-sarama
        - --kafka.version=2.6.1
        #  - --sasl.enabled
        #  - --no-sasl.handshake
        #  - --sasl.username=xxx
        #  - --sasl.password=xxx
        #  - --sasl.mechanism=scram-sha512
        #  - --tls.enabled
        #  - --tls.insecure-skip-tls-verify
        - --kafka.server=xxx:9092
        - --kafka.server=xxx:9092

File structure:

└── deploy
   └── overlays
       └── dev
           ├── kustomization.yaml
           └── patch_args.yaml

3. Generate customized YAML with:

kustomize build deploy/overlays/dev > deploy/overlays/dev/deploy.yaml

or directly applied to a cluster:

kustomize build deploy/overlays/dev | kubectl apply -f -

[danielqsj]

/lgtm
thanks @qclaogui @oldthreefeng