Skip to content

Debugging checks

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 checks show traces. If you want to debug a passed check, you need to make it fail on purpose.

$ trivy config --trace configs/
2022-05-16T13:47:58.853+0100    INFO    Detected config files: 1

Dockerfile (dockerfile)
=======================
Tests: 23 (SUCCESSES: 21, FAILURES: 2, EXCEPTIONS: 0)
Failures: 2 (UNKNOWN: 0, LOW: 0, MEDIUM: 1, HIGH: 1, CRITICAL: 0)

MEDIUM: Specify a tag in the 'FROM' statement for image 'alpine'
═══════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════
When using a 'FROM' statement you should use a specific tag to avoid uncontrolled behavior when the image is updated.

See https://avd.aquasec.com/misconfig/ds001
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
 Dockerfile:1
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1 [ FROM alpine:latest
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────


HIGH: Last USER command in Dockerfile should not be 'root'
═══════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════
Running containers with 'root' user can lead to a container escape situation. It is a best practice to run containers as non-root users, which can be done by adding a 'USER' statement to the Dockerfile.

See https://avd.aquasec.com/misconfig/ds002
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
 Dockerfile:3
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   3 [ USER root
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────



ID: DS001
File: Dockerfile
Namespace: builtin.dockerfile.DS001
Query: data.builtin.dockerfile.DS001.deny
Message: Specify a tag in the 'FROM' statement for image 'alpine'
TRACE  Enter data.builtin.dockerfile.DS001.deny = _
TRACE  | Eval data.builtin.dockerfile.DS001.deny = _
TRACE  | Index data.builtin.dockerfile.DS001.deny (matched 1 rule)
TRACE  | Enter data.builtin.dockerfile.DS001.deny
TRACE  | | Eval output = data.builtin.dockerfile.DS001.fail_latest[_]
TRACE  | | Index data.builtin.dockerfile.DS001.fail_latest (matched 1 rule)
TRACE  | | Enter data.builtin.dockerfile.DS001.fail_latest
TRACE  | | | Eval output = data.builtin.dockerfile.DS001.image_tags[_]
TRACE  | | | Index data.builtin.dockerfile.DS001.image_tags (matched 2 rules)
TRACE  | | | Enter data.builtin.dockerfile.DS001.image_tags
TRACE  | | | | Eval from = data.lib.docker.from[_]
TRACE  | | | | Index data.lib.docker.from (matched 1 rule)
TRACE  | | | | Enter data.lib.docker.from
TRACE  | | | | | Eval instruction = input.stages[_][_]
TRACE  | | | | | Eval instruction.Cmd = "from"
TRACE  | | | | | Exit data.lib.docker.from
TRACE  | | | | Redo data.lib.docker.from
TRACE  | | | | | Redo instruction.Cmd = "from"
TRACE  | | | | | Redo instruction = input.stages[_][_]
TRACE  | | | | | Eval instruction.Cmd = "from"
TRACE  | | | | | Fail instruction.Cmd = "from"
TRACE  | | | | | Redo instruction = input.stages[_][_]
TRACE  | | | | | Eval instruction.Cmd = "from"
TRACE  | | | | | Fail instruction.Cmd = "from"
TRACE  | | | | | Redo instruction = input.stages[_][_]
TRACE  | | | | Eval name = from.Value[0]
TRACE  | | | | Eval not startswith(name, "$")
TRACE  | | | | Enter startswith(name, "$")
TRACE  | | | | | Eval startswith(name, "$")
TRACE  | | | | | Fail startswith(name, "$")
TRACE  | | | | Eval data.builtin.dockerfile.DS001.parse_tag(name, __local505__)
TRACE  | | | | Index data.builtin.dockerfile.DS001.parse_tag (matched 2 rules)
TRACE  | | | | Enter data.builtin.dockerfile.DS001.parse_tag
TRACE  | | | | | Eval split(name, ":", __local504__)
TRACE  | | | | | Eval [img, tag] = __local504__
TRACE  | | | | | Exit data.builtin.dockerfile.DS001.parse_tag
TRACE  | | | | Eval [img, tag] = __local505__
TRACE  | | | | Eval output = {"cmd": from, "img": img, "tag": tag}
TRACE  | | | | Exit data.builtin.dockerfile.DS001.image_tags
TRACE  | | | Redo data.builtin.dockerfile.DS001.image_tags
TRACE  | | | | Redo output = {"cmd": from, "img": img, "tag": tag}
TRACE  | | | | Redo [img, tag] = __local505__
TRACE  | | | | Redo data.builtin.dockerfile.DS001.parse_tag(name, __local505__)
TRACE  | | | | Redo data.builtin.dockerfile.DS001.parse_tag
TRACE  | | | | | Redo [img, tag] = __local504__
TRACE  | | | | | Redo split(name, ":", __local504__)
TRACE  | | | | Enter data.builtin.dockerfile.DS001.parse_tag
TRACE  | | | | | Eval tag = "latest"
TRACE  | | | | | Eval not contains(img, ":")
TRACE  | | | | | Enter contains(img, ":")
TRACE  | | | | | | Eval contains(img, ":")
TRACE  | | | | | | Exit contains(img, ":")
TRACE  | | | | | Redo contains(img, ":")
TRACE  | | | | | | Redo contains(img, ":")
TRACE  | | | | | Fail not contains(img, ":")
TRACE  | | | | | Redo tag = "latest"
TRACE  | | | | Redo name = from.Value[0]
TRACE  | | | | Redo from = data.lib.docker.from[_]
TRACE  | | | Enter data.builtin.dockerfile.DS001.image_tags
TRACE  | | | | Eval from = data.lib.docker.from[i]
TRACE  | | | | Index data.lib.docker.from (matched 1 rule)
TRACE  | | | | Eval name = from.Value[0]
TRACE  | | | | Eval cmd_obj = input.stages[j][k]
TRACE  | | | | Eval possibilities = {"arg", "env"}
TRACE  | | | | Eval cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Fail cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Redo possibilities = {"arg", "env"}
TRACE  | | | | Redo cmd_obj = input.stages[j][k]
TRACE  | | | | Eval possibilities = {"arg", "env"}
TRACE  | | | | Eval cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Fail cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Redo possibilities = {"arg", "env"}
TRACE  | | | | Redo cmd_obj = input.stages[j][k]
TRACE  | | | | Eval possibilities = {"arg", "env"}
TRACE  | | | | Eval cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Fail cmd_obj.Cmd = possibilities[l]
TRACE  | | | | Redo possibilities = {"arg", "env"}
TRACE  | | | | Redo cmd_obj = input.stages[j][k]
TRACE  | | | | Redo name = from.Value[0]
TRACE  | | | | Redo from = data.lib.docker.from[i]
TRACE  | | | Eval __local752__ = output.img
TRACE  | | | Eval neq(__local752__, "scratch")
TRACE  | | | Eval __local753__ = output.img
TRACE  | | | Eval not data.builtin.dockerfile.DS001.is_alias(__local753__)
TRACE  | | | Enter data.builtin.dockerfile.DS001.is_alias(__local753__)
TRACE  | | | | Eval data.builtin.dockerfile.DS001.is_alias(__local753__)
TRACE  | | | | Index data.builtin.dockerfile.DS001.is_alias (matched 1 rule, early exit)
TRACE  | | | | Enter data.builtin.dockerfile.DS001.is_alias
TRACE  | | | | | Eval img = data.builtin.dockerfile.DS001.get_aliases[_]
TRACE  | | | | | Index data.builtin.dockerfile.DS001.get_aliases (matched 1 rule)
TRACE  | | | | | Enter data.builtin.dockerfile.DS001.get_aliases
TRACE  | | | | | | Eval from_cmd = data.lib.docker.from[_]
TRACE  | | | | | | Index data.lib.docker.from (matched 1 rule)
TRACE  | | | | | | Eval __local749__ = from_cmd.Value
TRACE  | | | | | | Eval data.builtin.dockerfile.DS001.get_alias(__local749__, __local503__)
TRACE  | | | | | | Index data.builtin.dockerfile.DS001.get_alias (matched 1 rule)
TRACE  | | | | | | Enter data.builtin.dockerfile.DS001.get_alias
TRACE  | | | | | | | Eval __local748__ = values[i]
TRACE  | | | | | | | Eval lower(__local748__, __local501__)
TRACE  | | | | | | | Eval "as" = __local501__
TRACE  | | | | | | | Fail "as" = __local501__
TRACE  | | | | | | | Redo lower(__local748__, __local501__)
TRACE  | | | | | | | Redo __local748__ = values[i]
TRACE  | | | | | | Fail data.builtin.dockerfile.DS001.get_alias(__local749__, __local503__)
TRACE  | | | | | | Redo __local749__ = from_cmd.Value
TRACE  | | | | | | Redo from_cmd = data.lib.docker.from[_]
TRACE  | | | | | Fail img = data.builtin.dockerfile.DS001.get_aliases[_]
TRACE  | | | | Fail data.builtin.dockerfile.DS001.is_alias(__local753__)
TRACE  | | | Eval output.tag = "latest"
TRACE  | | | Exit data.builtin.dockerfile.DS001.fail_latest
TRACE  | | Redo data.builtin.dockerfile.DS001.fail_latest
TRACE  | | | Redo output.tag = "latest"
TRACE  | | | Redo __local753__ = output.img
TRACE  | | | Redo neq(__local752__, "scratch")
TRACE  | | | Redo __local752__ = output.img
TRACE  | | | Redo output = data.builtin.dockerfile.DS001.image_tags[_]
TRACE  | | Eval __local754__ = output.img
TRACE  | | Eval sprintf("Specify a tag in the 'FROM' statement for image '%s'", [__local754__], __local509__)
TRACE  | | Eval msg = __local509__
TRACE  | | Eval __local755__ = output.cmd
TRACE  | | Eval data.lib.docker.result(msg, __local755__, __local510__)
TRACE  | | Index data.lib.docker.result (matched 1 rule)
TRACE  | | Enter data.lib.docker.result
TRACE  | | | Eval object.get(cmd, "EndLine", 0, __local470__)
TRACE  | | | Eval object.get(cmd, "Path", "", __local471__)
TRACE  | | | Eval object.get(cmd, "StartLine", 0, __local472__)
TRACE  | | | Eval result = {"endline": __local470__, "filepath": __local471__, "msg": msg, "startline": __local472__}
TRACE  | | | Exit data.lib.docker.result
TRACE  | | Eval res = __local510__
TRACE  | | Exit data.builtin.dockerfile.DS001.deny
TRACE  | Redo data.builtin.dockerfile.DS001.deny
TRACE  | | Redo res = __local510__
TRACE  | | Redo data.lib.docker.result(msg, __local755__, __local510__)
TRACE  | | Redo data.lib.docker.result
TRACE  | | | Redo result = {"endline": __local470__, "filepath": __local471__, "msg": msg, "startline": __local472__}
TRACE  | | | Redo object.get(cmd, "StartLine", 0, __local472__)
TRACE  | | | Redo object.get(cmd, "Path", "", __local471__)
TRACE  | | | Redo object.get(cmd, "EndLine", 0, __local470__)
TRACE  | | Redo __local755__ = output.cmd
TRACE  | | Redo msg = __local509__
TRACE  | | Redo sprintf("Specify a tag in the 'FROM' statement for image '%s'", [__local754__], __local509__)
TRACE  | | Redo __local754__ = output.img
TRACE  | | Redo output = data.builtin.dockerfile.DS001.fail_latest[_]
TRACE  | Exit data.builtin.dockerfile.DS001.deny = _
TRACE  Redo data.builtin.dockerfile.DS001.deny = _
TRACE  | Redo data.builtin.dockerfile.DS001.deny = _
TRACE


ID: DS002
File: Dockerfile
Namespace: builtin.dockerfile.DS002
Query: data.builtin.dockerfile.DS002.deny
Message: Last USER command in Dockerfile should not be 'root'
TRACE  Enter data.builtin.dockerfile.DS002.deny = _
TRACE  | Eval data.builtin.dockerfile.DS002.deny = _
TRACE  | Index data.builtin.dockerfile.DS002.deny (matched 2 rules)
TRACE  | Enter data.builtin.dockerfile.DS002.deny
TRACE  | | Eval data.builtin.dockerfile.DS002.fail_user_count
TRACE  | | Index data.builtin.dockerfile.DS002.fail_user_count (matched 1 rule, early exit)
TRACE  | | Enter data.builtin.dockerfile.DS002.fail_user_count
TRACE  | | | Eval __local771__ = data.builtin.dockerfile.DS002.get_user
TRACE  | | | Index data.builtin.dockerfile.DS002.get_user (matched 1 rule)
TRACE  | | | Enter data.builtin.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  | | | | | Exit 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 username = user.Value[_]
TRACE  | | | | Exit data.builtin.dockerfile.DS002.get_user
TRACE  | | | Redo data.builtin.dockerfile.DS002.get_user
TRACE  | | | | Redo username = user.Value[_]
TRACE  | | | | Redo user = data.lib.docker.user[_]
TRACE  | | | Eval count(__local771__, __local536__)
TRACE  | | | Eval lt(__local536__, 1)
TRACE  | | | Fail lt(__local536__, 1)
TRACE  | | | Redo count(__local771__, __local536__)
TRACE  | | | Redo __local771__ = data.builtin.dockerfile.DS002.get_user
TRACE  | | Fail data.builtin.dockerfile.DS002.fail_user_count
TRACE  | Enter data.builtin.dockerfile.DS002.deny
TRACE  | | Eval cmd = data.builtin.dockerfile.DS002.fail_last_user_root[_]
TRACE  | | Index data.builtin.dockerfile.DS002.fail_last_user_root (matched 1 rule)
TRACE  | | Enter data.builtin.dockerfile.DS002.fail_last_user_root
TRACE  | | | Eval stage_users = data.lib.docker.stage_user[_]
TRACE  | | | Index data.lib.docker.stage_user (matched 1 rule)
TRACE  | | | Enter data.lib.docker.stage_user
TRACE  | | | | Eval stage = input.stages[stage_name]
TRACE  | | | | Eval users = [cmd | cmd = stage[_]; cmd.Cmd = "user"]
TRACE  | | | | Enter cmd = stage[_]; cmd.Cmd = "user"
TRACE  | | | | | Eval cmd = stage[_]
TRACE  | | | | | Eval cmd.Cmd = "user"
TRACE  | | | | | Fail cmd.Cmd = "user"
TRACE  | | | | | Redo cmd = stage[_]
TRACE  | | | | | Eval cmd.Cmd = "user"
TRACE  | | | | | Exit cmd = stage[_]; cmd.Cmd = "user"
TRACE  | | | | Redo cmd = stage[_]; cmd.Cmd = "user"
TRACE  | | | | | Redo cmd.Cmd = "user"
TRACE  | | | | | Redo cmd = stage[_]
TRACE  | | | | | Eval cmd.Cmd = "user"
TRACE  | | | | | Fail cmd.Cmd = "user"
TRACE  | | | | | Redo cmd = stage[_]
TRACE  | | | | Exit data.lib.docker.stage_user
TRACE  | | | Redo data.lib.docker.stage_user
TRACE  | | | | Redo users = [cmd | cmd = stage[_]; cmd.Cmd = "user"]
TRACE  | | | | Redo stage = input.stages[stage_name]
TRACE  | | | Eval count(stage_users, __local537__)
TRACE  | | | Eval len = __local537__
TRACE  | | | Eval minus(len, 1, __local538__)
TRACE  | | | Eval last = stage_users[__local538__]
TRACE  | | | Eval user = last.Value[0]
TRACE  | | | Eval user = "root"
TRACE  | | | Exit data.builtin.dockerfile.DS002.fail_last_user_root
TRACE  | | Redo data.builtin.dockerfile.DS002.fail_last_user_root
TRACE  | | | Redo user = "root"
TRACE  | | | Redo user = last.Value[0]
TRACE  | | | Redo last = stage_users[__local538__]
TRACE  | | | Redo minus(len, 1, __local538__)
TRACE  | | | Redo len = __local537__
TRACE  | | | Redo count(stage_users, __local537__)
TRACE  | | | Redo stage_users = data.lib.docker.stage_user[_]
TRACE  | | Eval msg = "Last USER command in Dockerfile should not be 'root'"
TRACE  | | Eval data.lib.docker.result(msg, cmd, __local540__)
TRACE  | | Index data.lib.docker.result (matched 1 rule)
TRACE  | | Enter data.lib.docker.result
TRACE  | | | Eval object.get(cmd, "EndLine", 0, __local470__)
TRACE  | | | Eval object.get(cmd, "Path", "", __local471__)
TRACE  | | | Eval object.get(cmd, "StartLine", 0, __local472__)
TRACE  | | | Eval result = {"endline": __local470__, "filepath": __local471__, "msg": msg, "startline": __local472__}
TRACE  | | | Exit data.lib.docker.result
TRACE  | | Eval res = __local540__
TRACE  | | Exit data.builtin.dockerfile.DS002.deny
TRACE  | Redo data.builtin.dockerfile.DS002.deny
TRACE  | | Redo res = __local540__
TRACE  | | Redo data.lib.docker.result(msg, cmd, __local540__)
TRACE  | | Redo data.lib.docker.result
TRACE  | | | Redo result = {"endline": __local470__, "filepath": __local471__, "msg": msg, "startline": __local472__}
TRACE  | | | Redo object.get(cmd, "StartLine", 0, __local472__)
TRACE  | | | Redo object.get(cmd, "Path", "", __local471__)
TRACE  | | | Redo object.get(cmd, "EndLine", 0, __local470__)
TRACE  | | Redo msg = "Last USER command in Dockerfile should not be 'root'"
TRACE  | | Redo cmd = data.builtin.dockerfile.DS002.fail_last_user_root[_]
TRACE  | Exit data.builtin.dockerfile.DS002.deny = _
TRACE  Redo data.builtin.dockerfile.DS002.deny = _
TRACE  | Redo data.builtin.dockerfile.DS002.deny = _
TRACE