Variations on a 'k'

A docker image to do simple templating expansion of yaml-files (or any file for that matter!).

It's also a simple docker image with bash, kubectl, curl, yq and envsubst via gettext-base.

How do I run it

variations-on-a-k [--debug] [files/to/apply]

build your yaml with the --debug-flag to check debug statements.

`variation.yaml`

apiVersion: variation.config.k8s.io/v1beta1  #not sure this is allowed for legal reasons, so it may change
kind: ConfigVariation
variations:
- targetConfig: my-config.yaml  # relative path
  vary:
    csvSource: some.csv  # relative path
    literals:
      - JOHN: one
        INGRID: two
        MARIE: three
      - JOHN: five
        INGRID: six
        MARIE: '$JOHN and $INGRID is eleven'
- targetConfig: my-other-config.yaml
  vary:
    literals:
      - something: FOO
        other: BAR
        else: BAZ
      - something: foo
        other: bar
extraConfigs:
- some-config.yaml
- other-config.yaml

Notes

tip: use DOLLAR='$' for a value MY_VAR that persist all the way to the deployment: ${DOLLAR}{DOLLAR}{MY_VAR} or substituted at "global" scope ${DOLLAR}{MY_VAR} (for variations-on-a-k deploy -- [files]).
check what you can and can't do in envsubst
I have no idea how this works with many deployments (I also have no idea how kubernetes or kubectl handles a very very long deployment config) I am usually only using it for a small amount sub 20 deployments
the csv-handling is very plain, and very hacky: see hacky solution from terdon|stackoverflow which is used to escape commas inside '"' and then replace , with ¤ which is used as IFS='¤' list=($str_with_¤_in_it_in_stead_of_commas) (¤ is natively shift-4 on danish keyboards).
last but very important: escape " inside text with double backslash - \\" (e.g. in json MY_VAR: "\\"string\\":123" replaces $MY_VAR with "\"string\":123" which is required for your kubernetes config to be parsed properly).

Releaselog

0.4.0

changes to the Dockerfile solely. No longer inherits from bitnami/kubectl. ..uses ubuntu, and kubectl via lachlanevenson/k8s-kubectl shouldn't change anything from 0.3.0. ..This is the release candidate for 1.0.0. But I may just write this as a go-program in stead.

0.3.0

removed a dangling, wrongfully tagged docker image.
This is now a single entrance script.
simplified some code

0.2.2

fixed a bug where I used yq r - -j which sorted the array alphabetically. Breaking the feature added in 0.2.1.

0.2.1

fixed namespacing of apiVersion, from variation.configs... to variation.config (as used by other projects)
added feature "in-place parameter expansion" of literals and csv values to be able to handle local expansion at that context point.

0.2.0

changed from csv-only and kustomize-scanning to its own merits

0.1.2 and 0.1.1

bugfixes

0.1.0

first release

MikkelHJuul/variations-on-a-k