bb

Building Blocks or bb is a tool that can simulate many of the typical scenarios of a cloud-native Service-Oriented Architecture based on microservices.

Using bb

bb publishes a single container, buoyantio/bb. Instances of this container receive and return a simple message, described by the protobuf schema in this repository. This known interface allows for bb containers to be arranged in many different ways, like building a structure using LEGO blocks.

The best way to find out about bb features is by using the --help command and checking out the self-contained documentation.

Running locally

If you want to run bb locally, outside a Kubernetes cluster or Docker, you need to build a binary for your environment. The usual way to go about this is using Go's standard build tools. From this repository's root, run:

$ mkdir -p target && go build -o target/bb .

This will create a bb binary in the target directory. You can run this on your computer but, unless you use Linux, you won't be able to use this same binary on Docker or Kubernetes.

As an example of how to use bb on your computer, let's create a simple two-service setup. Open a terminal and type in the following:

$  target/bb terminus --grpc-server-port 9090 --response-text BANANA

Then, on a second terminal window, type this:

$ target/bb point-to-point-channel --grpc-downstream-server localhost:9090 --h1-server-port 8080

Now, on a third terminal, type this and you should see a similar response:

$ curl localhost:8080
{"requestUid":"in:http-sid:point-to-point-channel-grpc:-1-h1:8080-387107000","payload":"BANANA"}

The first command you typed created a gRPC server on port 9090 following the terminus strategy, which will return the payload defined as the --response-text argument for any valid request.

The second command creates an HTTP 1.1 server on port 8080 following the point-to-point channel strategy, and has the gRPC server previously defined as its downstream. It will receive any HTTP 1.1 request, convert it to gRPC, and forward it to the downstream server. It will also get the gRPC response from the server, convert it to JSON-over-HTTP, and return to its client.

Running on Kubernetes

Although bb can be useful to test things locally as described above, its main use case is to create complicated environments inside Kubernetes clusters.

To use bb with Kubernetes, the first step you need to take is to publish its Docker image to your Kubernetes cluster. Here we will be using a local kind cluster to demonstrate its use.

First, start your cluster:

$ kind create cluster

You should then build a Docker image for bb:

$ docker build -t buoyantio/bb:latest .

A test run using the Docker CLI should return usage information and confirm that everything is ok:

$ docker run buoyantio/bb:latest
Building Blocks or `bb` is a tool that can simulate many of the typical scenarios of a cloud-native Service-Oriented Architecture based on microservices.

Usage:
  bb [command]

Available Commands:
  broadcast-channel      Forwards the request to all downstream services.
  completion             Generate the autocompletion script for the specified shell
  help                   Help about any command
  http-egress            Receives a request, makes a HTTP(S) call to a specified URL and return the body of the response
  point-to-point-channel Forwards the request to one and only one downstream service.
  terminus               Receives the request and returns a pre-defined response

Flags:
      --downstream-timeout duration      timeout to use when making downstream connections and requests. (default 1m0s)
      --fire-and-forget                  do not wait for a response when contacting downstream services.
      --grpc-downstream-server strings   list of servers (hostname:port) to send messages to using gRPC, can be repeated
      --grpc-proxy string                optional proxy to route gRPC requests
      --grpc-server-port int             port to bind a gRPC server to (default -1)
      --h1-downstream-server strings     list of servers (protocol://hostname:port) to send messages to using HTTP 1.1, can be repeated
      --h1-server-port int               port to bind a HTTP 1.1 server to (default -1)
  -h, --help                             help for bb
      --id string                        identifier for this container
      --log-level string                 log level, must be one of: panic, fatal, error, warn, info, debug (default "info")
      --percent-failure int              percentage of requests that this service will automatically fail
      --sleep-in-millis int              amount of milliseconds to wait before actually start processing a request
      --terminate-after int              terminate the process after this many requests

Use "bb [command] --help" for more information about a command.

Next load the image into your kind cluster, with:

$ kind load docker-image buoyantio/bb:latest

To build the exact same scenario we had above, but for Kubernetes, you can deploy a YAML configuration like the one in our examples directory. You can deploy it to your Kubernetes cluster by running:

$ kubectl apply -f examples/bb-readme/application.yaml

You can then port-forward and use curl to query the service:

$ kubectl -n bb-readme port-forward svc/bb-readme-gateway-svc 8080 &
Forwarding from [::1]:8080 -> 8080

$ curl http://localhost:8080
Handling connection for 8080
{"requestUID":"in:http-sid:point-to-point-channel-grpc:-1-h1:8080-395520418","payload":"BANANA"}