OpenTelemetry Functions

The following functions are intended to be used in implementations of the Telemetry Query Language that interact with otel data via the collector's internal data model, pdata. These functions may make assumptions about the types of the data returned by Paths.

Factory Functions

• SpanID
• TraceID
• Split

Functions

• delete_key
• delete_matching_keys
• keep_keys
• truncate_all
• limit
• replace_all_matches
• replace_all_patterns

SpanID

SpanID(bytes)

The SpanID factory function returns a pdata.SpanID struct from the given byte slice.

bytes is a byte slice of exactly 8 bytes.

Examples:

• SpanID(0x0000000000000000)

TraceID

TraceID(bytes)

The TraceID factory function returns a pdata.TraceID struct from the given byte slice.

bytes is a byte slice of exactly 16 bytes.

Examples:

• TraceID(0x00000000000000000000000000000000)

delete_key

delete_key(target, key)

The delete_key function removes a key from a pdata.Map

target is a path expression to a pdata.Map type field. key is a string that is a key in the map.

The key will be deleted from the map.

Examples:

• delete_key(attributes, "http.request.header.authorization")
• delete_key(resource.attributes, "http.request.header.authorization")

delete_matching_keys

delete_matching_keys(target, pattern)

The delete_matching_keys function removes all keys from a pdata.Map that match a regex pattern.

target is a path expression to a pdata.Map type field. pattern is a regex string.

All keys that match the pattern will be deleted from the map.

Examples:

• delete_key(attributes, "http.request.header.authorization")
• delete_key(resource.attributes, "http.request.header.authorization")

keep_keys

keep_keys(target, keys...)

The keep_keys function removes all keys from the pdata.Map that do not match one of the supplied keys.

target is a path expression to a pdata.Map type field. keys is a slice of one or more strings.

The map will be changed to only contain the keys specified by the list of strings.

Examples:

• keep_keys(attributes, "http.method")
• keep_keys(resource.attributes, "http.method", "http.route", "http.url")

truncate_all

truncate_all(target, limit)

The truncate_all function truncates all string values in a pdata.Map so that none are longer than the limit.

target is a path expression to a pdata.Map type field. limit is a non-negative integer.

The map will be mutated such that the number of characters in all string values is less than or equal to the limit. Non-string values are ignored.

Examples:

• truncate_all(attributes, 100)
• truncate_all(resource.attributes, 50)

limit

limit(target, limit, priority_keys)

The limit function reduces the number of elements in a pdata.Map to be no greater than the limit.

target is a path expression to a pdata.Map type field. limit is a non-negative integer. priority_keys is a list of strings of attribute keys that won't be dropped during limiting.

The number of priority keys must be less than the supplied limit.

The map will be mutated such that the number of items does not exceed the limit. The map is not copied or reallocated.

Which items are dropped is random, provide priority_keys to preserve required keys.

Examples:

• limit(attributes, 100)
• limit(resource.attributes, 50, "http.host", "http.method")

replace_all_matches

replace_all_matches(target, pattern, replacement)

The replace_all_matches function replaces any matching string value with the replacement string.

target is a path expression to a pdata.Map type field. pattern is a string following filepath.Match syntax. replacement is a string.

Each string value in target that matches pattern will get replaced with replacement. Non-string values are ignored.

Examples:

• replace_all_matches(attributes, "/user/*/list/*", "/user/{userId}/list/{listId}")

replace_all_patterns

replace_all_patterns(target, regex, replacement)

The replace_all_patterns function replaces any segments in a string value that match the regex pattern with the replacement string.

target is a path expression to a pdata.Map type field. regex is a regex string indicating a segment to replace. replacement is a string.

If one or more sections of target match regex they will get replaced with replacement.

Examples:

• replace_all_patterns(attributes, "/account/\\d{4}", "/account/{accountId}")

Split

Split(target, delimiter)

The Split factory function separates a string by the delimiter, and returns an array of substrings.

target is a string. delimiter is a string.

If the target is not a string or does not exist, the Split factory function will return nil.

Examples:

• Split("A|B|C", "|")