Migrate from the deprecated mitchellh/mapstructure to go-viper/mapstructure - #83
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The [mitchellh/mapstructure](https://github.com/mitchellh/mapstructure) package is archived and no longer receives updates (see mitchellh/mapstructure#349). The blessed fork (see https://gist.github.com/mitchellh/90029601268e59a29e64e55bab1c5bdc) is [go-viper/mapstructure](https://github.com/go-viper/mapstructure), which viper itself has used since v1.20. This migration was attempted before in #49 and reverted in #53 because it broke Cilium's `TestNodeAddressWhitelist`. The API is almost the same, but go-viper/mapstructure#6 changed `StringToSliceHookFunc` so it only fires when the target type is exactly `[]string`. The mitchellh version fired for any slice kind. As a result, a comma-separated string coming from the environment or a configmap is no longer split before being decoded into slices of other element types, such as `[]netip.Prefix`. Each element then gets the whole unsplit string. Swapping only the import path, as #49 did, silently changes this behavior. Use `StringToWeakSliceHookFunc` instead. go-viper/mapstructure provides it to bring back the pre-v2 behavior, and its implementation matches the mitchellh `StringToSliceHookFunc`. Hook ordering is unchanged: `TextUnmarshallerHookFunc` still runs before the slice split, so types like `net.IP` (`[]byte`) are not split on commas. `TestHiveTextUnmarshaler` (added in #79, after the revert) covers the case that broke Cilium: it decodes "10.0.0.0/8,192.168.0.0/16" from the configmap into a `[]netip.Prefix`. It fails with a plain import swap and passes with this change. Signed-off-by: Hadrien Patte <hadrien.patte@datadoghq.com>
Since v1.20, viper uses github.com/go-viper/mapstructure/v2 instead of the archived github.com/mitchellh/mapstructure. The previous commit moved hive's direct usage to go-viper/mapstructure/v2, and viper v1.18.2 was the last thing still pulling in mitchellh/mapstructure. With this bump, it is gone from the module graph entirely, for hive and for its dependents. Signed-off-by: Hadrien Patte <hadrien.patte@datadoghq.com>
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@HadrienPatte Tx for this update!
Do you feel we have adequate test coverage to make sure this does not break anything else?
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See cilium/hive#83 Signed-off-by: Hadrien Patte <hadrien.patte@datadoghq.com>
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I tested updating hive to this PR's version in cilium/cilium and ran tests there and all passed so yeah I'm fairly confident that this will work this time: cilium/cilium@fa0750e |
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The mitchellh/mapstructure package is archived and no longer receives updates (see mitchellh/mapstructure#349). The blessed fork (see https://gist.github.com/mitchellh/90029601268e59a29e64e55bab1c5bdc) is go-viper/mapstructure, which viper itself has used since v1.20.
This migration was attempted before in #49 and reverted in #53 because it broke Cilium's
TestNodeAddressWhitelist.The API is almost the same, but go-viper/mapstructure#6 changed
StringToSliceHookFuncso it only fires when the target type is exactly[]string. The mitchellh version fired for any slice kind. As a result, a comma-separated string coming from the environment or a configmap is no longer split before being decoded into slices of other element types, such as[]netip.Prefix. Each element then gets the whole unsplit string. Swapping only the import path, as #49 did, silently changes this behavior.Use
StringToWeakSliceHookFuncinstead. go-viper/mapstructure provides it to bring back the pre-v2 behavior, and its implementation matches the mitchellhStringToSliceHookFunc. Hook ordering is unchanged:TextUnmarshallerHookFuncstill runs before the slice split, so types likenet.IP([]byte) are not split on commas.TestHiveTextUnmarshaler(added in #79, after the revert) covers the case that broke Cilium: it decodes "10.0.0.0/8,192.168.0.0/16" from the configmap into a[]netip.Prefix. It fails with a plain import swap and passes with this change.