OTEL_RESOURCE_ATTRIBUTES values are not parsed as defined per spec

[pellared]

From the OTel spec:

The OTEL_RESOURCE_ATTRIBUTES environment variable will contain of a list of key value pairs, and these are expected to be represented in a format matching to the W3C Baggage, except that additional semi-colon delimited metadata is not supported, i.e.: key1=value1,key2=value2. All attribute values MUST be considered strings.

From the W3C spec:

A value contains a URL encoded UTF-8 string. Leading and trailing whitespaces (OWS) are allowed but MUST be trimmed when converting the header into a data structure.

Currently, the values defined in OTEL_RESOURCE_ATTRIBUTES (splitted by ,) are not parsed at all. Source code here.

Found thanks to: open-telemetry/opentelemetry-go#2963

[lgfa29]

open-telemetry/opentelemetry-specification#2670 updates the Resource spec to take percent-decode into account.

[martinjt]

Is this still the case @pellared ?

[pellared]

The OTEL_RESOURCE_ATTRIBUTES env var is still still not properly parsed.

It accepts keys that should not be allowed.

They values are not precent decoded as noted #3395 (comment)

Reference: https://www.w3.org/TR/baggage/#definition