lupapiste-commons.gcp-json-logging — lupapiste/commons 5.3.14

combine-args-mw clj

(combine-args-mw {:keys [vargs msg-type] :as data})

Middleware for formatting log arguments as strings

The timbre-json-appender library eagerly considers logging arguments to be data. Logging calls like (timbre/warn :foo 42) would result in a) no message and b) {:args {:foo 42}}

See https://github.com/viesti/timbre-json-appender?tab=readme-ov-file#format-of-the-log-invocation

To work around this, we can use this middleware to produce the leading message string (and also include the arguments in a map).

string-stack-trace-mw clj

(string-stack-trace-mw {:keys [?err] :as data})

Adds stack_trace for logging errors for GCP and removes the ?err key containing the exception.

timbre-json-appender would create a nested map from the error with Throwable->map, but that is not useful for error reporting in GCP which does not recognize that format.

Additionally, timbre-json-appender can fail to log JSON if the Throwable data is not serializable or if the serialization causes an error in itself (e.g. with a component system map in the exception resulting in a stack overflow). It falls back to the basic text appender in that situation, polluting logs. To avoid this, the ?err key is removed completely from the log data.