yannicklange / microdc-example

Example of docker-compose, consul in docker-compose, go-micro, and more.

Greeter

This repo exists to answer a few questions I'm frequently asked regarding usage of multi-step builds, docker-compose, consul, and go-micro. Configuration is as follows:

• api and srv have multi-step build files to compile in a container, and end with a minimal surface area (and size) container. Note: Generally I use a Makefile and arguments to dry up these files, but functionally it is the same process.
• Addition of dep for dependency resolution during container compilation. This is just an example for an approach that does not depend on committing the vendor directory, which I'm personally still on the fence about.
• compose file Root level docker-compose file for starting the full suite.
• compose file Integrates consul without the use of host mode networking or dev mode. This is one of the primary questions I field on a regular basis.
• compose file DNS resolution through consul for all apps. This allows a little inception of configuring the go-micro -registry_address to be consul.service.consul and knowing it will all Just Work™.

This example uses the api, srv, and cli components from the official micro greeter example. For details on each component, please review the original.

Contents

• srv - an RPC greeter service
• cli - an RPC client that calls the service once
• api - examples of RPC API and RESTful API

Run the suite

docker-compose up microapi

That's it. Seriously. The microapi block is configured with dependencies on all other components to provide a simple entry point.

Testing from the host

In the docker-compose file, microapi is bound to 8090 on the host. This allows for convenient curl based testing.

❯ curl "localhost:8090/greeter/say/hello?name=John"
{"message":"Hello John"}

Log samples for the above request:

microapi_1  | 172.20.0.1 - - [21/Sep/2017:17:28:33 +0000] "GET /greeter/say/hello?name=John HTTP/1.1" 200 24 "" "curl/7.54.0"

api_1       | 2017/09/21 17:28:33 Received Say.Hello API request

srv_1       | 2017/09/21 17:28:33 Received Say.Hello request

consul is also launched with a ui, and bound to the host at 8500. Navigate to http://localhost:8500/ui to view the current running services.