This repository was archived by the owner on Sep 3, 2024. It is now read-only.
This repository was archived by the owner on Sep 3, 2024. It is now read-only.
[BUG] panic: can't use ElementIterator on null value #389
Description
Describe the bug
When evaluating Terraform source code I am running into a panic panic: can't use ElementIterator on null value. Based on some testing I've done this seems to be caused when values in a locals block reference variables AND then another value in the locals block references the first value. You can see this in the IaC snippet I provided below. default_tags referencing variables is OK on it's own but when tags = concat(local.default_tags, ["test"]) is added then the panic occurs.
panic: can't use ElementIterator on null value
goroutine 1 [running]:
github.com/zclconf/go-cty/cty.Value.ElementIterator({{{0x13015a0?, 0xc00043de48?}}, {0x0?, 0x0?}})
/home/runner/go/pkg/mod/github.com/zclconf/go-cty@v1.10.0/cty/value_ops.go:1121 +0xc5
github.com/zclconf/go-cty/cty.Value.AsValueSlice({{{0x13015a0?, 0xc00043de48?}}, {0x0?, 0x0?}})
/home/runner/go/pkg/mod/github.com/zclconf/go-cty@v1.10.0/cty/value_ops.go:1303 +0xd3
github.com/snyk/policy-engine/pkg/hcl_interpreter.(*phantomAttrs).add.func1({0xc000090a90, 0x1, 0x1}, {0xc000158540, 0x12}, {{{0x13015a0?, 0xc00043de48?}}, {0x0?, 0x0?}})
/home/runner/go/pkg/mod/github.com/snyk/policy-engine@v0.15.0/pkg/hcl_interpreter/phantom_attrs.go:81 +0x16e
github.com/snyk/policy-engine/pkg/hcl_interpreter.(*phantomAttrs).add(0xc00040c218, {{0x1bb54b8, 0x0, 0x0}, {0xc00051e820, 0x2, 0x2}}, {{{0x13015a0, 0xc00043de48}}, {0x0, ...}})
/home/runner/go/pkg/mod/github.com/snyk/policy-engine@v0.15.0/pkg/hcl_interpreter/phantom_attrs.go:93 +0x296
github.com/snyk/policy-engine/pkg/hcl_interpreter.(*Evaluation).evaluate(0xc0000a8480)
/home/runner/go/pkg/mod/github.com/snyk/policy-engine@v0.15.0/pkg/hcl_interpreter/hcl_interpreter.go:267 +0x806
github.com/snyk/policy-engine/pkg/hcl_interpreter.EvaluateAnalysis(0xc000031f80)
/home/runner/go/pkg/mod/github.com/snyk/policy-engine@v0.15.0/pkg/hcl_interpreter/hcl_interpreter.go:192 +0x1cc
github.com/fugue/regula/v3/pkg/loader.newHclConfiguration(0xc00016a060)
/home/runner/work/regula/regula/pkg/loader/tf.go:105 +0x2a
github.com/fugue/regula/v3/pkg/loader.(*TfDetector).DetectDirectory(0x3?, {0x1302600, 0xc00012bd00}, {0x7?, 0x0?, {0x1bb54b8?, 0x3650c2207d6f068d?, 0x1?}})
/home/runner/work/regula/regula/pkg/loader/tf.go:95 +0x265
github.com/fugue/regula/v3/pkg/loader.(*directory).DetectType(0x1?, {0x12fbc38?, 0x1bb54b8?}, {0x39?, 0xae?, {0x1bb54b8?, 0xc0004aae20?, 0xc000414690?}})
/home/runner/work/regula/regula/pkg/loader/input.go:32 +0x39
github.com/fugue/regula/v3/pkg/loader.(*AutoDetector).DetectDirectory(0x7?, {0x1302600, 0xc00012bd00}, {0x30?, 0x75?, {0x1bb54b8?, 0x108abb0?, 0xc000326380?}})
/home/runner/work/regula/regula/pkg/loader/auto.go:26 +0xf8
github.com/fugue/regula/v3/pkg/loader.(*directory).DetectType(0x108abb0?, {0x12fbbc0?, 0xc00043cba0?}, {0x1?, 0x0?, {0x1bb54b8?, 0xc0004bde90?, 0x1b7ba40?}})
/home/runner/work/regula/regula/pkg/loader/input.go:32 +0x39
github.com/fugue/regula/v3/pkg/loader.LocalConfigurationLoader.func1()
/home/runner/work/regula/regula/pkg/loader/loadpaths.go:127 +0x5cd
github.com/fugue/regula/v3/cmd.NewRunCommand.func1(0xc000330f00, {0xc0004bc440, 0x0, 0x1})
/home/runner/work/regula/regula/cmd/run.go:145 +0x7f7
github.com/spf13/cobra.(*Command).execute(0xc000330f00, {0xc0004bc420, 0x1, 0x1})
/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:916 +0x862
github.com/spf13/cobra.(*Command).ExecuteC(0x1b4f8a0)
/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:1044 +0x3bc
github.com/spf13/cobra.(*Command).Execute(...)
/home/runner/go/pkg/mod/github.com/spf13/cobra@v1.6.1/command.go:968
github.com/fugue/regula/v3/cmd.Execute()
/home/runner/work/regula/regula/cmd/root.go:47 +0x25
main.main()
/home/runner/work/regula/regula/main.go:22 +0x17
How you're running Regula
- I'm using Regula v3.0.0 as a CLI tool and my Terraform source code as an input:
regula run -vOperating System
Ubuntu 22.04
IaC Configuration
variable "team" {
type = string
}
variable "service" {
type = string
}
variable "type" {
type = string
}
locals {
default_tags = [
"owner:tf",
"service:${var.service}",
"team:${var.team}",
"region:*",
"geo:*",
"env:*"
]
tags = concat(local.default_tags, ["test"])
}