Examples

Basic rule usage

This first example show the simplest possible rule.

First we need to generate a rule:

$ echo "pattern nr = 18" > nr-rule.dog

And we also need have an input file:

$ echo 18 > input.txt

$ cargo r -q -- \
     eval \
     --policy nr-rule.dog \
     --input input.txt \
     --name nr-rule::nr
evaluate pattern: nr-rule::nr
Pattern: nr-rule::nr
Satisfied: true
Value:
  18
Rationale:
  primordial(true)

ok!

JSON input format

First we create our rule, and save it in a file named json-rule.dog:

$ echo "pattern nr = {
   nr: integer,
}" > json-rule.dog

And then we create an input file, and save it in a file named input.json:

$ echo "{
  "nr": 18
}" > input.json

And we can run the eval command:

$ cargo r -q -- \
     eval \
     --policy json-rule.dog \
     --input input.json \
     --name json-rule::nr

YAML input format

First we create our rule, and save it in a file named yaml-rule.dog:

$ echo "pattern nr = {
   nr: integer,
}" > yaml-rule.dog

And then we create an input file, and save it in a file named input.yaml:

$ echo "---
  nr: 18" > input.yaml

And then we specify the -t option to the eval command and specify the format as yaml:

$ cargo r -q -- \
     eval -t yaml \
     --policy yaml-rule.dog \
     --input input.yaml \
     --name yaml-rule::nr
evaluate pattern: yaml-rule::nr
Pattern: yaml-rule::nr
Satisfied: true
Value:
  nr: <<integer>>
Rationale:
  field: nr
    Pattern: <none>
    Satisfied: true
    Value:
      18
    Rationale:
      primordial(true)

ok!

Server

The swio command can also be used to run the policy server:

$ cargo r -q -- \
     serve \
     --policy json-rule.dog

You can then open http://localhost:8080 in your browser and navigate using the web UI.