This library supports transaction id handling. It provides methods for checking an http request for an 'X-Request-Id' header, and if present using the value of this as a transaction id.
If the header isn't present, the library will generate a transaction with a 'tid_' prefix and a random 10 character string.
Go provides support for passing around variables associated with a request lifecycle via the context package
Best practice for using this is to specify a context as the first argument to your function (see here for more information along with examples that this library draws on).
To extract a transactionID from a request, and create one if none found:
transactionID := transactionidutils.GetTransactionIDFromRequest(req)
To store that on a context:
transactionAwareContext := transactionidutils.TransactionAwareContext(context.Background(), transactionID)
NB: context.Background() is a non-nil, empty Context, typically used as the top-level context for incoming requests.
For extracting from a context:
transactionID, err := GetTransactionIDFromContext(ctx)
It's expected that the transaction ID will be used to output logs. An example using logrus:
log := log.WithFields(log.Fields{
transactionIdKey: ctx.Value(transactionIdKey),
})
NB: this will use the standard transaction id key("transaction_id") that is already used for Content programme log files.