Order of operations/processing order
Processing overlays with a Yot instructions file
1a. Dynamic instructions (Templating)
Go templating was implemented in v0.4.0, and Sprig function support for Go templating was added in v0.5.0.
The -f or --values-file option may be used one or many times.
If you pass multiple values files, the first file passed in with -f or --values-file serves as the base set of values. Each additional values file passed is merged over the top of the base values sequentially in the order they were passed to yot producing a final set of values to be applied to the templated instructions. If a value is repeated in an additional values file, it will be overridden with the latest instance of that value winning.
1b. Static instructions (No templating) - v0.1.0 behavior
If no values files were passed, then the instructions file skips the templating mechanism and is loaded directly, as long as the document is valid YAML.
Consider the following example:
yot -i instructions.yaml -o ./output
yot will read the instructions.yaml file and any outputs will be placed directly in ./output/ .
2. Processing instructions
After the instructions have either been rendered or read, they are processed.
Yot provides three levels of specificity, being commonOverlays, yamlFiles[].overlays, and yamlFiles[]documents.overlays.
Processing begins at the instruction’s commonOverlays if they exist in the instruction set. yot processes the commonOverlays first if they exist by prepending them to each instance of yamlFiles[].overlays
If no commonOverlays have been defined, processing starts at the first path of the yamlFiles array and processes one YAML file path at a time sequentially. Within each YAML file path, overlays are processed first if set, followed by the items within the documents key, which applies overlays to specific documents within a multi-yaml document YAML file. A single YAML document in a YAML file could still be referred to by path: 0 from the documents key if desired.
3. Output
Output is sent to the output directory specified at runtime, or if it was not provided, the default path of ./output/, or to the location set within the yot.config or the YOT_OUTPUT_DIRECTORY environment variable.
Processing overlays with the CLI (no instructions file)
When performing one-off overlays via the CLI, Yot treats the -q or --query parameter as part of a commonOverlay. Based on the -a or --action, and -x or --value parameters a commonOverlay will be constructed within a in-memory instruction file, where -p or --path is loaded into the yamlFiles array.
Templating is not allowed in a CLI-only or one-off overlay operation. Processing occurs as described in Processing overlays with a Yot instructions file.
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