feat: support ndjson extension using json parser

Signed-off-by: Andreas Grub <grub@posteo.de>

Author: neiser

acceptance.bats

@@ -461,6 +461,12 @@ EOF"
   [ "$status" -eq 0 ]
 }
 
+@test "Can validate newline-delimited JSON log files" {
+  run ./conftest test -p examples/ndjson/policy/ examples/ndjson/sample.ndjson
+  [ "$status" -eq 1 ]
+  [[ "$output" =~ "2 tests, 1 passed, 0 warnings, 1 failure, 0 exceptions" ]]
+}
+
 @test "Should fail if strict is set and there are unused variables in the policy" {
   run ./conftest test -p examples/strict-rules/policy/ examples/kubernetes/deployment.yaml --strict
   [ "$status" -eq 1 ]

docs/examples.md

@@ -23,6 +23,7 @@ You can find examples using various other tools in the `examples` directory, inc
 * [Jsonnet](https://github.com/open-policy-agent/conftest/tree/master/examples/jsonnet)
 * [Kubernetes](https://github.com/open-policy-agent/conftest/tree/master/examples/kubernetes)
 * [Kustomize](https://github.com/open-policy-agent/conftest/tree/master/examples/kustomize)
+* [Newline-delimited JSON](https://github.com/open-policy-agent/conftest/tree/master/examples/ndjson)
 * [Properties](https://github.com/open-policy-agent/conftest/tree/master/examples/properties)
 * [Report](https://github.com/open-policy-agent/conftest/tree/master/examples/report)
 * [Serverless Framework](https://github.com/open-policy-agent/conftest/tree/master/examples/serverless)

examples/ndjson/policy/logs.rego

@@ -0,0 +1,7 @@
+package main
+import rego.v1
+
+deny contains msg if {
+	input.level == "ERROR"
+	msg = sprintf("error log found, message '%s'", [input.message])
+}

examples/ndjson/sample.ndjson

@@ -0,0 +1,2 @@
+{"level": "INFO", "message": "some message"}
+{"level": "ERROR", "message":  "some failure"}

parser/parser.go

@@ -180,6 +180,10 @@ func NewFromPath(path string) (Parser, error) {
 		return New(Dockerfile)
 	}
 
+	if fileExtension == "ndjson" {
+		return New(JSON)
+	}
+
 	if fileExtension == "yml" || fileExtension == "yaml" {
 		return New(YAML)
 	}

parser/parser_test.go

@@ -90,6 +90,11 @@ func TestNewFromPath(t *testing.T) {
 			&jsonc.Parser{},
 			false,
 		},
+		{
+			"jsonlines.ndjson",
+			&json.Parser{},
+			false,
+		},
 		{
 			"noextension",
 			&yaml.Parser{},