A developer updates an HTTP service to incorporate a circuit breaker pattern using Opossum. The tutorial demonstrates wiring the circuit breaker into the Axios instance, updating request configurations to support opting out, and configuring the module to handle service resilience within a NestJS application.
Length 5:40
Captions English (Generated), Spanish (Auto-translated), French (Auto-translated), Korean (Auto-translated), Portuguese (Auto-translated), Vietnamese (Auto-translated) #typescript #nestjs #axios #circuit breaker #programming #software development #coding #backend
0:00 Now to actually wire this circuit breaker in, we are gonna go back to our 0:03 HTTP service. 0:05 Remember, in the constructor here, this is where we're actually creating the 0:09 underlying Axios instance that is used application-wide, 0:13 and we're already wrapping it in create Axios instance from our 0:17 factory, where, as you remember, we apply our 0:21 HTTP keep alive as well as Axios retry functionality. 0:25 Now, this is great that we have this because at this point, 0:28 we have the underlying 0:29 instance. That's what we need for this next stage of 0:32 composition, 0:33 where we're going to wrap the breaker inside of 0:37 the circuit breaker using almost like a decorator pattern. 0:41 So at this point in the constructor, we have the instance. 0:44 Now what we wanna do is 0:46 create the HTTP breaker that's gonna be another member variable 0:50 of the class. So we have the instance. 0:52 We'll also now declare the 0:55 breaker, 0:56 which will be of type HTTP breaker from the factory that we've just set up. 1:00 And now what we wanna do is set this.breaker equal to 1:04 createHttpCircuitBreaker. Here we pass in the underlying 1:08 Axios instance that we've already configured, 1:11 and then the underlying dynamic 1:12 options which come from... Well, in this case, we need this 1:16 defined on the HTTP options. So let's head back 1:20 into HTTP module options where we have our circuit breaker 1:24 options, but now we need to add them to our 1:27 HTTP module options. So for this, I'll simply add a 1:31 new circuit breaker parameter, 1:35 which will be the optional circuit breaker options here 1:38 that allow us to configure it dynamically at module runtime. 1:41 And so now 1:43 we can pass through back in the HTTP service, the underlying circuit 1:47 breaker options, which allows us to configure it. 1:50 And this is wonderful. We have the breaker now available.
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