dockerpc enables JSON-RPC over Docker plugins.
This project was inspired by the pie plugin architecture.
Like pie, it enables you to create an JSON-RPC plugin communication over standard in/standard out,
however, it uses Docker containers as pie plugin providers.
stdin/out/error is still used for RPC; however, all of the communication occurs over
the Docker API (via the /attach API).
Currently, only plugin providers are supported (not consumers) and you must run Docker on a
non-unix socket port.
go get github.com/jandre/dockerpc
- Put your
pieplugin provider in a Docker container as the entrypoint.
Example plugin.go:
// Command example_plugin is an example of a very simple plugin.
//
// example_plugin provides two APIs that communicate via JSON-RPC. It is
// expected to be started by example_master.
package main
import (
"log"
"net/rpc/jsonrpc"
"github.com/natefinch/pie"
)
func main() {
log.SetPrefix("[plugin log] ")
p := pie.NewProvider()
if err := p.RegisterName("Plugin", api{}); err != nil {
log.Fatalf("failed to register Plugin: %s", err)
}
if err := p.RegisterName("Plugin2", api2{}); err != nil {
log.Fatalf("failed to register Plugin2: %s", err)
}
p.ServeCodec(jsonrpc.NewServerCodec)
}
type api struct{}
func (api) SayHi(name string, response *string) error {
log.Printf("got call for SayHi with name %q", name)
*response = "Hi " + name
return nil
}
type api2 struct{}
func (api2) SayBye(name string, response *string) error {
log.Printf("got call for SayBye with name %q", name)
*response = ""
for i := 0; i < 500; i++ {
*response += "asdf asdf adsf a dsf adsf asdf asdf sdaffasdf adsf asdf asdf asdf asd fas df adfs asdf asdf asdf asd fas df asdf sad fjdaskfjldaksjfklajsdflkdjsalkfjlkdasjfdlaj Bye " + name
}
return nil
}Example Dockerfile:
from golang:1.5
RUN mkdir -p /tmp
COPY ./plugin.go /tmp/plugin.go
WORKDIR /tmp
RUN go get -d -v
RUN go build -o bin/plugin plugin.go
RUN cp bin/plugin /bin
ENTRYPOINT ["/bin/plugin"]
- Build the docker image.
docker build -t docker-plugin:latest --no-cache .- In your plugin caller, use
dockerpc.NewClientto start thedocker-plugincontainer and connect to the RPC service via Docker's API.
The example below will execute the 'Plugin.SayHi' method in the container!
image := "docker-plugin:latest"
host := "tcp://127.0.0.1:4500"
name := "my-container-name"
client := dockerpc.NewClient(name, image, host)
...
var result string
err := client.Call("Plugin.SayHi", "Jen", &result)See the ./example directory for an example of a plugin, and a caller that launches the plugin via Docker.
$ cd $GOPATH/src/github.com/jandre/dockerpc/example
$ cd ./plugin && make # may need `sudo make` if you aren't in the docker user group.
$ cd ../caller && make
$ ./caller
2015/10/12 08:15:01 [plugin log] 2015/10/12 12:09:23 got call for SayHi with name "jen"
2015/10/12 08:15:01 Plugin.SayHi jen Returned: Hi jen
2015/10/12 08:15:01 [plugin log] 2015/10/12 12:09:23 got call for SayHi with name "bob"
2015/10/12 08:15:01 Plugin.SayHi bob Returned: Hi bob
2015/10/12 08:15:01
2015/10/12 08:15:01 Error: rpc: can't find method Plugin.SayHi2- Tests
- Implement consumer plugin
- Support unix socket connection to Docker.
- github.com/natefinch/pie
- github.com/fsouza/go-dockerclient (for queryString function)