Debugging policies
When working on more complex queries (or when learning Rego), it's useful to see exactly how the policy is applied.
For this purpose you can use the --trace
flag.
This will output a large trace from Open Policy Agent like the following:
Tip
Only failed policies show traces. If you want to debug a passed policy, you need to make it fail on purpose.
$ trivy conf --trace configs/
2021-07-11T16:45:58.493+0300 INFO Detected config files: 1
Dockerfile (dockerfile)
=======================
Tests: 23 (SUCCESSES: 22, FAILURES: 1, EXCEPTIONS: 0)
Failures: 1 (UNKNOWN: 0, LOW: 0, MEDIUM: 0, HIGH: 1, CRITICAL: 0)
+---------------------------+------------+----------------------+----------+------------------------------------------+
| TYPE | MISCONF ID | CHECK | SEVERITY | MESSAGE |
+---------------------------+------------+----------------------+----------+------------------------------------------+
| Dockerfile Security Check | DS002 | Image user is 'root' | HIGH | Last USER command in |
| | | | | Dockerfile should not be 'root' |
| | | | | -->avd.aquasec.com/appshield/ds002 |
+---------------------------+------------+----------------------+----------+------------------------------------------+
ID: DS002
File: Dockerfile
Namespace: appshield.dockerfile.DS002
Query: data.appshield.dockerfile.DS002.deny
Message: Last USER command in Dockerfile should not be 'root'
TRACE Enter data.appshield.dockerfile.DS002.deny = _
TRACE | Eval data.appshield.dockerfile.DS002.deny = _
TRACE | Index data.appshield.dockerfile.DS002.deny matched 2 rules)
TRACE | Enter data.appshield.dockerfile.DS002.deny
TRACE | | Eval data.appshield.dockerfile.DS002.fail_user_count
TRACE | | Index data.appshield.dockerfile.DS002.fail_user_count (matched 1 rule)
TRACE | | Enter data.appshield.dockerfile.DS002.fail_user_count
TRACE | | | Eval __local559__ = data.appshield.dockerfile.DS002.get_user
TRACE | | | Index data.appshield.dockerfile.DS002.get_user (matched 1 rule)
TRACE | | | Enter data.appshield.dockerfile.DS002.get_user
TRACE | | | | Eval user = data.lib.docker.user[_]
TRACE | | | | Index data.lib.docker.user (matched 1 rule)
TRACE | | | | Enter data.lib.docker.user
TRACE | | | | | Eval instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | Eval count(__local559__, __local391__)
TRACE | | | Eval lt(__local391__, 1)
TRACE | | | Fail lt(__local391__, 1)
TRACE | | | Redo count(__local559__, __local391__)
TRACE | | | Redo __local559__ = data.appshield.dockerfile.DS002.get_user
TRACE | | Fail data.appshield.dockerfile.DS002.fail_user_count
TRACE | Enter data.appshield.dockerfile.DS002.deny
TRACE | | Eval data.appshield.dockerfile.DS002.fail_last_user_root
TRACE | | Index data.appshield.dockerfile.DS002.fail_last_user_root (matched 1 rule)
TRACE | | Enter data.appshield.dockerfile.DS002.fail_last_user_root
TRACE | | | Eval __local560__ = data.appshield.dockerfile.DS002.get_user
TRACE | | | Index data.appshield.dockerfile.DS002.get_user (matched 1 rule)
TRACE | | | Enter data.appshield.dockerfile.DS002.get_user
TRACE | | | | Eval user = data.lib.docker.user[_]
TRACE | | | | Index data.lib.docker.user (matched 1 rule)
TRACE | | | | Enter data.lib.docker.user
TRACE | | | | | Eval instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | Eval cast_array(__local560__, __local392__)
TRACE | | | Eval user = __local392__
TRACE | | | Eval __local561__ = data.appshield.dockerfile.DS002.get_user
TRACE | | | Index data.appshield.dockerfile.DS002.get_user (matched 1 rule)
TRACE | | | Enter data.appshield.dockerfile.DS002.get_user
TRACE | | | | Eval user = data.lib.docker.user[_]
TRACE | | | | Index data.lib.docker.user (matched 1 rule)
TRACE | | | | Enter data.lib.docker.user
TRACE | | | | | Eval instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Exit data.lib.docker.user
TRACE | | | | Eval username = user.Value[_]
TRACE | | | | Exit data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo data.appshield.dockerfile.DS002.get_user
TRACE | | | | Redo username = user.Value[_]
TRACE | | | | Redo user = data.lib.docker.user[_]
TRACE | | | | Redo data.lib.docker.user
TRACE | | | | | Redo instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | | | Eval instruction.Cmd = "user"
TRACE | | | | | Fail instruction.Cmd = "user"
TRACE | | | | | Redo instruction = input.stages[_][_]
TRACE | | | Eval count(__local561__, __local393__)
TRACE | | | Eval len = __local393__
TRACE | | | Eval minus(len, 1, __local394__)
TRACE | | | Eval user[__local394__] = "root"
TRACE | | | Exit data.appshield.dockerfile.DS002.fail_last_user_root
TRACE | | Eval res = "Last USER command in Dockerfile should not be 'root'"
TRACE | | Exit data.appshield.dockerfile.DS002.deny
TRACE | Redo data.appshield.dockerfile.DS002.deny
TRACE | | Redo res = "Last USER command in Dockerfile should not be 'root'"
TRACE | | Redo data.appshield.dockerfile.DS002.fail_last_user_root
TRACE | | Redo data.appshield.dockerfile.DS002.fail_last_user_root
TRACE | | | Redo user[__local394__] = "root"
TRACE | | | Redo minus(len, 1, __local394__)
TRACE | | | Redo len = __local393__
TRACE | | | Redo count(__local561__, __local393__)
TRACE | | | Redo __local561__ = data.appshield.dockerfile.DS002.get_user
TRACE | | | Redo user = __local392__
TRACE | | | Redo cast_array(__local560__, __local392__)
TRACE | | | Redo __local560__ = data.appshield.dockerfile.DS002.get_user
TRACE | Exit data.appshield.dockerfile.DS002.deny = _
TRACE Redo data.appshield.dockerfile.DS002.deny = _
TRACE | Redo data.appshield.dockerfile.DS002.deny = _