Function string_keyed_entries 

pub fn string_keyed_entries(
    v: &Value,
) -> impl Iterator<Item = (&str, &Value)> + '_

Iterator over the string-keyed entries of a serde_yaml::Value that may or may not be a serde_yaml::Mapping — the canonical shape both per-Servico renderers reach for when splicing the upstream ComputeUnit YAML’s spec.* fields into their emitted output map.

Two identical-shape call sites collapse onto this helper — both per-Servico renderers previously carried a five-line if let Value::Mapping(_) = spec { for (k, v) in _ { if let Some(s) = k.as_str() { <dst>.insert(s, v.clone()) } } } block:

• caixa_flux’s programs_yaml_entry splices computeunit_yaml.spec.* into the emitted programs.yaml entry (serde_yaml::Mapping destination, via MappingExt::insert_str_key);
• caixa_helm’s build_values_yaml splices the same computeunit_yaml.spec.* into the values.yaml wrapped block (std::collections::BTreeMap<String, Value> destination, via BTreeMap::insert).

Both sites need the same walk (destructure as serde_yaml::Mapping, iterate its entries, keep only string-keyed pairs, hand the caller each (&str, &Value) pair) but drop the values into different destination map types, so the lift is at the iterator layer, not the insert layer. The caller keeps its own insert idiom ( MappingExt::insert_str_key on a serde_yaml::Mapping, BTreeMap::insert on the BTreeMap-shaped values block, a future renderer’s own destination) but reaches through one lifted walk with one contract on how non-string-keyed entries are handled: silently dropped, matching the behavior both renderers implemented inline via the if let Some(s) = k.as_str() filter.

Returns an empty iterator when v is not a serde_yaml::Value::Mapping — the shape the prior if let Value::Mapping(_) = v arm silently no-ops on (so a Null / String / Sequence / Number / Bool spec field, itself schema-invalid upstream but tolerated by the renderer, contributes zero entries to the destination map instead of raising a per-shape error). Non-string-keyed entries within a valid Mapping are silently dropped — the same behavior the prior if let Some(s) = k.as_str() arm carried, since serde_yaml permits arbitrary [Value] keys (numeric, boolean, sub-mapping) that don’t round-trip through the downstream K8s YAML-key surface (which requires string keys).

The next per-Servico renderer to land — the future per-Servico OCI packager whose emitted Dockerfile LABEL block spliced through the same computeunit_yaml.spec.* string-key set, the M4 per-Servico wasm.pleme.io/v1alpha1/ComputeUnit CR materializer whose emitted spec.* block splices the same set through onto the typed [kube::api::CustomResource] view, the future caixa-otel renderer’s per-Servico OpenTelemetry-Collector resource-attribute splice — gets the canonical string-key filter for free with one method call, instead of re-inlining the same five-line if let Value::Mapping(_) = _ walk.