NATS transport for go-kit #623
Conversation
| kitprometheus "github.com/go-kit/kit/metrics/prometheus" | ||
| httptransport "github.com/go-kit/kit/transport/http" | ||
| natstransport "github.com/go-kit/kit/transport/nats" | ||
| "fmt" |
There was a problem hiding this comment.
Stdlib packages should all be in the first block, see https://github.com/golang/go/wiki/CodeReviewComments#imports
|
|
||
| nc, err := nats.Connect(urls) | ||
|
|
||
| defer nc.Close() |
There was a problem hiding this comment.
err should be checked before deferring close, otherwise this could fail
|
|
||
| import ( | ||
| "context" | ||
| "github.com/nats-io/go-nats" |
There was a problem hiding this comment.
Stdlib imports should be in there own block, see https://github.com/golang/go/wiki/CodeReviewComments#imports
|
|
||
| "github.com/go-kit/kit/endpoint" | ||
| "github.com/nats-io/go-nats" | ||
| log "github.com/sirupsen/logrus" |
There was a problem hiding this comment.
Don't use external logger packages. go-kit has it's own logger package that should be used instead.
| // MsgHandler implements the MsgHandler type. | ||
| func (s Server) MsgHandler(msg *nats.Msg) { | ||
|
|
||
| urls := fmt.Sprint(os.Getenv("NATS_SERVER"), ", ", fmt.Sprintf("nats://%v:%v", os.Getenv("NATS_SERVICE_HOST"), os.Getenv("NATS_SERVICE_PORT"))) |
There was a problem hiding this comment.
This should get the original NATS connection instead of reading some environment variables and trying to connect to a NATS server.
Unfortunately there is currently no way to get the connection from the message. I think it would be best to just add a method in the go-nats package that allows replying directly on a *nats.Msg.
There was a problem hiding this comment.
I opened nats-io/go-nats#323 for this.
|
|
||
| // ServerAfter functions are executed on the HTTP response writer after the | ||
| // endpoint is invoked, but before anything is written to the client. | ||
| func ServerAfter(after ...ServerResponseFunc) ServerOption { |
There was a problem hiding this comment.
The appended functions are not used anywhere
| import ( | ||
| "context" | ||
|
|
||
| "fmt" |
There was a problem hiding this comment.
Stdlib imports should be a single block, not two
| // metadata headers to be transported to the server. ClientRequestFuncs are | ||
| // executed after creating the request but prior to sending the gRPC request to | ||
| // the server. | ||
| type ClientRequestFunc func(context.Context, *metadata.MD) context.Context |
There was a problem hiding this comment.
Why does this take a GRPC metadata map? NATS also has no way to send/receive metadata, so the you could do is pass the raw *nats.Msg.
This whole file currently makes not much sense, since it is written for a GRPC transport.
| return | ||
| } | ||
|
|
||
| payload, err := s.enc(ctx, response) |
There was a problem hiding this comment.
What if the message has no reply topic set? In this case there is no need for for encoding the response, since no one can receive it. This should probably just return before encoding the response, if there is no reply topic.
| defer nc.Close() | ||
|
|
||
| // Non-nil non empty context to take the place of the first context in th chain of handling. | ||
| ctx := context.TODO() |
There was a problem hiding this comment.
Since NATS doesn't provide us with a context or similiar this could probably be just context.Background().
|
Any updates on this one? Without some positive comment in the next couple days, I'll likely close. |
|
This is fixed now by #680 |
A implementation utilizing the NATS protocol
Description
NATS is a messaging protocol written in go similar to RabbitMQ, an encoder, decoder, and server has been adapted from the existing http and grpc examples.
Motivation and Context
We desired to use a light weight messaging protocol for microservice communication that was very light on the ceremony. We were very interested in NATS an adopted it to operate within the go-kit framework.
How Has This Been Tested?
Tests are coming
Screenshots (if appropriate):
Types of changes
Checklist: