Precision loss when handling large int64 numbers inside yaml config

[fishy]

This is a minimal example to demonstrate the bug:

$ helm version
version.BuildInfo{Version:"v3.9.0", GitCommit:"7ceeda6c585217a19a1131663d8cd1f7d641b2a7", GitTreeState:"clean", GoVersion:"go1.17.5"}
$ helm create example
Creating example
$ sed -i "s/replicaCount: 1/replicaCount: 9123456789012345678/" example/values.yaml
$ helm template example -f example/values.yaml | grep replicas
  replicas: 9.123456789012346e+18

the desired replicaCount is 9123456789012345678 in values.yaml, but it becomes 9.123456789012346e+18 (aka 9123456789012346000) in the final rendered yaml.

[github-actions]

This issue has been marked as stale because it has been open for 90 days with no activity. This thread will be automatically closed in 30 days if no further activity occurs.

[fishy]

this is still an issue.

[joejulian]

This has to do with the go templating float precision. You can solve this yourself using printf:

replicas: {{ printf "%32.0f" .Values.replicaCount | trim }}

[fishy]

This has to do with the go templating float precision. You can solve this yourself using printf:

replicas: {{ printf "%32.0f" .Values.replicaCount | trim }}

while that workaround works for some cases, it doesn't really work for other cases.

for example, we have a helm template to generate yaml config files to be mounted to our pods, and the value files could be some thing like this:

otherKey: otherValue

config:
  foo: bar
  idDenyList:
    - 9123456789012345678
    - <other really big int64 ids>

...

and when we use helm to generate the config.yaml file out of .Values.config, the precision loss will happen and we got ids in the config that will match the wrong ids.

[joejulian]

Please file an issue with golang at https://github.com/golang/go/issues. Prefix your issue with "x/text:" in the subject line, so it is easy to find.