k8t 0.1.9

Kubernetes templating engine based on Jinja2

k8t

Pronounced katie [ˈkeɪti]

Simple cluster and environment specific aware templating for kubernetes manifests.

Table of Contents generated with DocToc

• installation
• usage
  • scaffolding
  • validate files
  • generate files
  • Overriding templates
  • Managing secrets
    • SSM
• TODO

installation

run this

$ pip install --user --upgrade k8t

usage

scaffolding

Create a new project folder with a cluster directory and an empty defaults file

$ k8t new project foobar

Create a new cluster

$ k8t new cluster A

Create a new environment

$ k8t new environment staging -c A
$ k8t new environment production

Generate a new deployment template for cluster A (currently only deployment and service are supported)

$ k8t new template deployment -c A

Specify prefixes for secrets

$ k8t edit config --cluster A --environment staging
secrets:
  prefix: "staging/application"```

Values can be easily added/modified in the same way

$ k8t edit values --cluster Ano creds to it anyway or dont know where to get

A typical setup should look something like this

.deploy/
├── clusters
│   ├── A
│   │   ├── config.yaml
│   │   ├── environments
│   │   │   ├── production
│   │   │   │   ├── config.yaml
│   │   │   │   ├── files
│   │   │   │   ├── templates
│   │   │   │   └── values.yaml
│   │   │   └── staging
│   │   │       ├── config.yaml
│   │   │       ├── files
│   │   │       ├── templates
│   │   │       └── values.yaml
│   │   ├── files
│   │   ├── templates
│   │   └── values.yaml
│   └── local
│       ├── environments
│       ├── files
│       ├── secret.yaml.j2
│       ├── templates
│       │   ├── database.yaml.j2
│       │   └── secret.yaml.j2
│       └── values.yaml
├── config.yaml
├── files
├── templates
│   ├── deployment.yaml.j2
│   └── secret.yaml.j2
└── values.yaml

validate files

While validation is done before generating, templates can be validated for environment files easily.

$ k8t validate

To validate for clusters/environments the usual options can be used

$ k8t validate -c A -e production

generate files

The --cluster flag will load variables from a directory. By default the file default.yaml in that directory will be loaded, however an environment can be specified with --environment.

$ k8t gen -c A -e staging

Additionally k8t will attempt to load a file defaults.yaml in the root directory. This way a set of default variables can be specified and selectively overriden via cluster and environment.

Additional values can be given via flag --value-file in the form of a file or --value KEY VALUE, both can be supplied multiple times.

Variables will be merged via deep merging. Default merge strategy is left-to-right. For the merge order see the output of

$ k8t --help

Overriding templates

Templates can be overriden on a cluster/environment level.

If a file application.yaml exists in the root templates folder, simply add a file with the same name to the cluster/environment template folder.

Managing secrets

SSM

Setup secrets on SSM

$ k8t edit config
secrets:
  provider: ssm
  prefix: "foobar"

TODO

• testing needs to be expanded
• add more templates for manifest scaffolding
• the ability to add additional template directories via the CLI
• validation functions for template values (e.g. memory/cpu values)