carvel-dev
panic when using template.replace from within a module
Not sure if I'm attempting to do something that is not supposed to work but here goes:
With this:
#@ load('@ytt:template', t='template')
#@ load('job.lib.yml', 'job')
#@ load('fn/standard.star', 'std')
#@ def name_bundle(name):
#@ return std.suffix(name, 'config')
#@ end
#@
#@ def name_upload_job(name):
#@ return t.replace(job.config(std.suffix(name_bundle(name), 'upload')))
#@ end
- _: #@ name_upload_job(bundle.name)
where job.config is bound to default_config:
#@ def default_config(name):
name: #@ name
serial: true
build_log_retention:
builds: 20
days: 2
minimum_succeeded_builds: 1
#@ end
It works as expected.
However if I try to move the t.replace to the function in the job module:
#@ load('@ytt:template', t='template')
#@ load('job.lib.yml', 'job')
#@ load('fn/standard.star', 'std')
#@ def name_bundle(name):
#@ return std.suffix(name, 'config')
#@ end
#@
#@ def name_upload_job(name):
#@ return job.config(std.suffix(name_bundle(name), 'upload'))
#@ end
- _: #@ name_upload_job(bundle.name)
where job.config is bound to default_config:
#@ def _default_config(name):
name: #@ name
serial: true
build_log_retention:
builds: 20
days: 2
minimum_succeeded_builds: 1
#@ end
#@ def default_config(name):
#@ return t.replace(_default_config(name))
#@ end
then I get a panic:
ytt: Error:
- runtime error: index out of range [-1] (backtrace: goroutine 1 [running]:
in default_config
job.lib.yml:36 | #@ return t.replace(_default_config(name))
in name_upload_job
nexus-uploader.yml:22 | #@ return job.config(std.suffix(name_bundle(name), 'upload'))
in <toplevel>
nexus-uploader.yml:43 | - _: #@ name_upload_job(bundle.name)
reason:
runtime/debug.Stack(0x917400, 0x966da0, 0xc000318900)
runtime/debug/stack.go:24 +0x9d
github.com/k14s/ytt/pkg/template/core.ErrWrapper.func1.1(0xc0001ae3d8)
github.com/k14s/ytt@/pkg/template/core/errs.go:18 +0x9d
panic(0x966da0, 0xc000318900)
runtime/panic.go:679 +0x1b2
github.com/k14s/ytt/pkg/template.(*CompiledTemplate).TplReplaceNode(0xc0003da000, 0xc0001ce730, 0xc0001863f0, 0xc0004259f0, 0x1, 0x1, 0x0, 0x0, 0x0, 0x30, ...)
github.com/k14s/ytt@/pkg/template/compiled_template.go:285 +0xf4
github.com/k14s/ytt/pkg/template/core.ErrWrapper.func1(0xc0001ce730, 0xc0001863f0, 0xc0004259f0, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
github.com/k14s/ytt@/pkg/template/core/errs.go:25 +0xff
go.starlark.net/starlark.(*Builtin).CallInternal(0xc0001863f0, 0xc0001ce730, 0xc0004259f0, 0x1, 0x1, 0x0, 0x0, 0x0, 0xc000080000, 0x7f6b18146008, ...)
[email protected]/starlark/value.go:653 +0x8b
go.starlark.net/starlark.Call(0xc0001ce730, 0xae9160, 0xc0001863f0, 0xc0004259f0, 0x1, 0x1, 0x0, 0x0, 0x0, 0xae9120, ...)
[email protected]/starlark/eval.go:1028 +0x190
go.starlark.net/starlark.(*Function).CallInternal(0xc00038f0c0, 0xc0001ce730, 0xc000425700, 0x1, 0x1, 0x0, 0x0, 0x0, 0xc000080000, 0x7f6b18146008, ...)
[email protected]/starlark/interp.go:305 +0x3ed8
go.starlark.net/starlark.Call(0xc0001ce730, 0xae91e0, 0xc00038f0c0, 0xc000425700, 0x1, 0x1, 0x0, 0x0, 0x0, 0xae9b20, ...)
[email protected]/starlark/eval.go:1028 +0x190
go.starlark.net/starlark.(*Function).CallInternal(0xc0003e9540, 0xc0001ce730, 0xc000425680, 0x1, 0x1, 0x0, 0x0, 0x0, 0xc000080000, 0x7f6b18146008, ...)
[email protected]/starlark/interp.go:305 +0x3ed8
go.starlark.net/starlark.Call(0xc0001ce730, 0xae91e0, 0xc0003e9540, 0xc000425680, 0x1, 0x1, 0x0, 0x0, 0x0, 0xae9ae0, ...)
[email protected]/starlark/eval.go:1028 +0x190
go.starlark.net/starlark.(*Function).CallInternal(0xc000217a80, 0xc0001ce730, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x37, 0x38, ...)
[email protected]/starlark/interp.go:305 +0x3ed8
go.starlark.net/starlark.Call(0xc0001ce730, 0xae91e0, 0xc000217a80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x9, ...)
[email protected]/starlark/eval.go:1028 +0x190
go.starlark.net/starlark.(*Program).Init(0xc00000ead8, 0xc0001ce730, 0xc000187cb0, 0x0, 0x0, 0xc000217540)
[email protected]/starlark/eval.go:358 +0x96
github.com/k14s/ytt/pkg/template.(*CompiledTemplate).eval(0xc000034f60, 0xc0001ce730, 0xc000187cb0, 0x0, 0x0, 0x0, 0x0, 0x0)
github.com/k14s/ytt@/pkg/template/compiled_template.go:155 +0x247
github.com/k14s/ytt/pkg/template.(*CompiledTemplate).Eval(0xc000034f60, 0xc0001ce730, 0xae04e0, 0xc000186bd0, 0xc0000b4500, 0xc0001ce730, 0xc000187aa0, 0x7155ba, 0x7fffe411ff89)
github.com/k14s/ytt@/pkg/template/compiled_template.go:112 +0x6c8
github.com/k14s/ytt/pkg/workspace.(*TemplateLoader).EvalYAML(0xc000186bd0, 0xc0000b47d0, 0xc0000b47d0, 0xc0000b4500, 0xc00001ef00, 0x9, 0x10, 0x1)
github.com/k14s/ytt@/pkg/workspace/template_loader.go:169 +0x614
github.com/k14s/ytt/pkg/workspace.(*LibraryLoader).eval(0xc0001afad8, 0xc0001c6050, 0x0, 0xc00000e488, 0x1, 0x1, 0xc0001c6050, 0x0, 0x0, 0x1, ...)
github.com/k14s/ytt@/pkg/workspace/library_loader.go:139 +0xa6c
github.com/k14s/ytt/pkg/workspace.(*LibraryLoader).Eval(0xc0001afad8, 0xc0001c6050, 0x0, 0x0, 0xc0001c6050)
github.com/k14s/ytt@/pkg/workspace/library_loader.go:90 +0x50
github.com/k14s/ytt/pkg/cmd/template.(*TemplateOptions).RunWithFiles(0xc0000cf040, 0xc00001e580, 0x9, 0x10, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
github.com/k14s/ytt@/pkg/cmd/template/cmd.go:131 +0x3be
github.com/k14s/ytt/pkg/cmd/template.(*TemplateOptions).Run(0xc0000cf040, 0x0, 0x0)
github.com/k14s/ytt@/pkg/cmd/template/cmd.go:85 +0x288
github.com/k14s/ytt/pkg/cmd/template.NewCmd.func1(0xc00011a500, 0xc00011ea10, 0x0, 0x7, 0x0, 0x0)
github.com/k14s/ytt@/pkg/cmd/template/cmd.go:53 +0x2a
github.com/cppforlife/cobrautil.WrapRunEForCmd.func1.1(0xc00011a500, 0xc00011ea10, 0x0, 0x7, 0x0, 0x0)
github.com/cppforlife/[email protected]/misc.go:25 +0xaf
github.com/spf13/cobra.(*Command).execute(0xc00011a500, 0xc00001e090, 0x7, 0x7, 0xc00011a500, 0xc00001e090)
github.com/spf13/[email protected]/command.go:762 +0x460
github.com/spf13/cobra.(*Command).ExecuteC(0xc00011a500, 0xc00011a500, 0xe34340, 0x3)
github.com/spf13/[email protected]/command.go:852 +0x2ea
github.com/spf13/cobra.(*Command).Execute(...)
github.com/spf13/[email protected]/command.go:800
main.main()
github.com/k14s/ytt@/cmd/ytt/ytt.go:17 +0x103
)
Am I trying to do something that isn't supposed to work or is this a bug?
short repro scenario: https://get-ytt.io/#gist:https://gist.github.com/cppforlife/89108d13240490f604fc98e7ac04c236
ytt has several "special" functions that need to integrate deeper into structure building stack (vs regular functions that just return structures). template.replace is one of them. will dig in further to see whats going on.
...10 months later...
While we haven't seen others run into this issue, this falls under the category of "you're using the tool well, it's just a sufficiently advanced case that the current implementation didn't account for it."
This bug is relevant to ytt — we'd like for authors to be able to template.replace() from another module. If a contributor debugged this issue and fixed it, we would definitely accept that contribution.
That said, given the current set of priorities, the Carvel maintainers cannot commit to picking up this work, today.
As @cppforlife indicated above, this issue requires a more in-depth review to determine an approach.
That would likely result in a design discussion. It indicate that this is in a kind of "research" state, labeling this way and moving to "Carvel Accepted" pipeline.
We're going to move this to the Unprioritized Backlog for now. We're open to contributions but there will likely need to be some design discussions first. Please let us know if you'd be interested in contributing to this work.
