kube-inverter

• What This Tool Does
• Why
• Install
  • Run Executable
  • PIP + $PATH
• CLI Usage
  • Examples
    • Linux
      • In-place Update Against Multiple Files
      • Write to Separate File
• Points of Interest
  • Details About The New API Version's spec
    • Calculate diff Between Versions
    • v1beta1
    • v1
• Dev
  • Virtual Environment Setup

---

What This Tool Does

Converts Kubernetes Ingress YAML objects with apiVersion: networking.k8s.io/v1beta1 to apiVersion: networking.k8s.io/v1, modifying:

• Checks for apiVersion differences in the Points of Interest section.
• The keys/values for:
  • serviceName
  • ServicePort - either name (str) or port number (int)
• (Optional) Injects a configurable pathType into each Ingress object.
• YAML Comments/order/formatting are preserved... mostly. It depends on their scope, but hey, I'm tryin'!
• Skips over objects that do not fit the criteria to be converted.

Why

Kubernetes v1.22 is removing support for the v1beta1 apiVersion for Ingress objects, not just deprecating it. And kubectl convert was deprecated back in 1.17.

The Ingress syntax is changing a bit. Sure, you could update them by hand, which I do often, but that is lame. I have hundreds upon hundreds of Ingress objects to convert, and I bet others do as well, so this should help.

Install

Written in Python 3.6+

Run Executable

PyInstaller is used to create a single-file executable. Find them under Assets in Releases. Alternatively...

1. Get the code

git clone https://github.com/DaemonDude23/kube-inverter.git -b v0.3.0

2. Get into that directory

cd ./kube-inverter

3. Create symlink:

sudo ln -s ${PWD}/src/kube-inverter.py /usr/local/bin/kube-inverter

PIP + $PATH

1. Get the code

git clone https://github.com/DaemonDude23/kube-inverter.git -b v0.3.0

2. Get into that directory

cd ./kube-inverter

3. Create symlink:

sudo ln -s ${PWD}/src/kube-inverter.py /usr/local/bin/kube-inverter

4. Install dependencies:

pip3 install -U -r ./src/requirements.txt

CLI Usage

• By default, this will update your file in place. If that's not desired, write to a separate file with --output-file.
• Only one file is updated per run. Wrap this script in a loop (see examples further down) to operate against multiple files.

usage: kube-inverter [-h] [--debug] [--output-file OUTPUT_FILE] [--path-type PATH_TYPE] [--version] input_file

Converts Kubernetes Ingress objects from 'networking.k8s.io/v1beta1' to 'networking.k8s.io/v1'

optional arguments:
  -h, --help            show this help message and exit

  --debug               enable debug logging (default: False)
  --output-file OUTPUT_FILE, -o OUTPUT_FILE
                        Output file path. This disables an in-place update to the input file (default: None)
  --path-type PATH_TYPE, --pathType PATH_TYPE, -p PATH_TYPE
                        Path Type for Ingress rule. Options: 'Exact', 'ImplementationSpecific', 'Prefix' (default: None)
  --version, -v         show program's version number and exit
  input_file            input file

Examples

See examples folder.

The GIF below was generated with these commands:

cat ./examples/in-place-update/1.yaml && sleep 5s && \
kube-inverter --path-type Prefix ./examples/in-place-update/1.yaml && sleep 5s && \
cat ./examples/in-place-update/1.yaml && sleep 5s && \
kubectl apply --dry-run=server -f ./examples/in-place-update/1.yaml && sleep 5s

Linux

kube-inverter ./examples/in-place-update/1.yaml

In-place Update Against Multiple Files

find ./examples/in-place-update/ -type f -name '*.yaml' -exec kube-inverter '{}' \;

Write to Separate File

find ./examples/multiple-documents/ -type f -name '*.yaml' -exec kube-inverter --path-type Prefix '{}' -o '{}'-out \;

Points of Interest

Details About The New API Version's spec

Calculate diff Between Versions

diff <(kubectl explain ingresses --api-version=networking.k8s.io/v1beta1 --recursive) <(kubectl explain ingresses --api-version=networking.k8s.io/v1 --recursive)

Click to expand output

2c2
< VERSION:  networking.k8s.io/v1beta1
---
> VERSION:  networking.k8s.io/v1
43c43
<       backend <Object>
---
>       defaultBackend  <Object>
48,49c48,52
<          serviceName  <string>
<          servicePort  <string>
---
>          service      <Object>
>             name      <string>
>             port      <Object>
>                name   <string>
>                number <integer>
60,61c63,67
<                   serviceName <string>
<                   servicePort <string>
---
>                   service     <Object>
>                      name     <string>
>                      port     <Object>
>                         name  <string>
>                         number        <integer>

v1beta1

kubectl explain ingresses --api-version=networking.k8s.io/v1beta1 --recursive

Click to expand output

KIND:     Ingress
VERSION:  networking.k8s.io/v1beta1

DESCRIPTION:
     Ingress is a collection of rules that allow inbound connections to reach
     the endpoints defined by a backend. An Ingress can be configured to give
     services externally-reachable urls, load balance traffic, terminate SSL,
     offer name based virtual hosting etc.

FIELDS:
   apiVersion   <string>
   kind <string>
   metadata     <Object>
      annotations       <map[string]string>
      clusterName       <string>
      creationTimestamp <string>
      deletionGracePeriodSeconds        <integer>
      deletionTimestamp <string>
      finalizers        <[]string>
      generateName      <string>
      generation        <integer>
      labels    <map[string]string>
      managedFields     <[]Object>
         apiVersion     <string>
         fieldsType     <string>
         fieldsV1       <map[string]>
         manager        <string>
         operation      <string>
         time   <string>
      name      <string>
      namespace <string>
      ownerReferences   <[]Object>
         apiVersion     <string>
         blockOwnerDeletion     <boolean>
         controller     <boolean>
         kind   <string>
         name   <string>
         uid    <string>
      resourceVersion   <string>
      selfLink  <string>
      uid       <string>
   spec <Object>
      backend   <Object>
         resource       <Object>
            apiGroup    <string>
            kind        <string>
            name        <string>
         serviceName    <string>
         servicePort    <string>
      ingressClassName  <string>
      rules     <[]Object>
         host   <string>
         http   <Object>
            paths       <[]Object>
               backend  <Object>
                  resource      <Object>
                     apiGroup   <string>
                     kind       <string>
                     name       <string>
                  serviceName   <string>
                  servicePort   <string>
               path     <string>
               pathType <string>
      tls       <[]Object>
         hosts  <[]string>
         secretName     <string>
   status       <Object>
      loadBalancer      <Object>
         ingress        <[]Object>
            hostname    <string>
            ip  <string>
            ports       <[]Object>
               error    <string>
               port     <integer>
               protocol <string>

v1

kubectl explain ingresses --api-version=networking.k8s.io/v1 --recursive

Click to expand output

KIND:     Ingress
VERSION:  networking.k8s.io/v1

DESCRIPTION:
     Ingress is a collection of rules that allow inbound connections to reach
     the endpoints defined by a backend. An Ingress can be configured to give
     services externally-reachable urls, load balance traffic, terminate SSL,
     offer name based virtual hosting etc.

FIELDS:
   apiVersion   <string>
   kind <string>
   metadata     <Object>
      annotations       <map[string]string>
      clusterName       <string>
      creationTimestamp <string>
      deletionGracePeriodSeconds        <integer>
      deletionTimestamp <string>
      finalizers        <[]string>
      generateName      <string>
      generation        <integer>
      labels    <map[string]string>
      managedFields     <[]Object>
         apiVersion     <string>
         fieldsType     <string>
         fieldsV1       <map[string]>
         manager        <string>
         operation      <string>
         time   <string>
      name      <string>
      namespace <string>
      ownerReferences   <[]Object>
         apiVersion     <string>
         blockOwnerDeletion     <boolean>
         controller     <boolean>
         kind   <string>
         name   <string>
         uid    <string>
      resourceVersion   <string>
      selfLink  <string>
      uid       <string>
   spec <Object>
      defaultBackend    <Object>
         resource       <Object>
            apiGroup    <string>
            kind        <string>
            name        <string>
         service        <Object>
            name        <string>
            port        <Object>
               name     <string>
               number   <integer>
      ingressClassName  <string>
      rules     <[]Object>
         host   <string>
         http   <Object>
            paths       <[]Object>
               backend  <Object>
                  resource      <Object>
                     apiGroup   <string>
                     kind       <string>
                     name       <string>
                  service       <Object>
                     name       <string>
                     port       <Object>
                        name    <string>
                        number  <integer>
               path     <string>
               pathType <string>
      tls       <[]Object>
         hosts  <[]string>
         secretName     <string>
   status       <Object>
      loadBalancer      <Object>
         ingress        <[]Object>
            hostname    <string>
            ip  <string>
            ports       <[]Object>
               error    <string>
               port     <integer>
               protocol <string>

Dev

• Build Docs

Virtual Environment Setup

# assuming virtualenv is already installed...
virtualenv --python=python3.9 ./venv/
source ./venv/bin/activate
./venv/bin/python -m pip install --upgrade pip
pip3 install -U -r ./src/requirements.txt