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Split descriptors

This guide shows the different ways to feed Kubernetes YAML to kubesplit and where the resulting files are written.

Unlike a formatter, kubesplit always writes to a directory (one file per resource), never to STDOUT. Check the available options with kubesplit --help (or see the CLI options reference).

Split a file

Use -i/--input for the source file and -o/--output for the target directory. The directory is created if it does not exist:

kubesplit --input all-in-one.yml --output out

--output-dir is an accepted alias of --output:

kubesplit --input all-in-one.yml --output-dir out

Read from STDIN

If you omit -i/--input, or pass - as its value, kubesplit reads from STDIN. This is what makes it composable with kustomize, helm, kubectl, cat, etc.

# implicit STDIN
cat all-in-one.yml | kubesplit --output out

# explicit STDIN
cat all-in-one.yml | kubesplit --input - --output out

Note

-o/--output is mandatory. There is no STDOUT mode because kubesplit produces many files, not a single stream. If you only want to reformat a single YAML document, use yamkix instead.

Reuse or clean the output directory

By default, kubesplit writes into the output directory without removing anything that is already there. Re-running on a changed input therefore leaves behind files for resources that no longer exist.

Use -c/--clean-output-dir to wipe the output directory (a full rmtree) before writing:

kubesplit --input all-in-one.yml --output out --clean-output-dir

Warning

--clean-output-dir recursively deletes the target directory before regenerating it. Point it only at a directory you own and that contains nothing but generated output.

Understand the console summary

While processing, kubesplit prints its resolved configuration and a resource count to stderr:

[kubesplit(0.5.0)] Processing: input=all-in-one.yml, output_dir=out, clean_output_dir=True, prefix_resource_files=True, typ=rt, explicit_start=True, ...
Found [16] valid / [0] lists / [1] invalid / [2] empty resources

The counts tell you what kubesplit did with each document in the stream:

  • valid — recognized single resources, one file each.
  • lists — *List resources (e.g. ConfigMapList), written as a single file each (see File naming and layout).
  • invalid — documents that don't look like Kubernetes resources; ignored.
  • empty — empty documents (e.g. a trailing ---); ignored.

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