How to add new custom command to docker API? - docker

Question

I'm trying to add a new customized command to the docker API, along with all the commands found at docker/api/client
I added the following new mycomand.go file to the forked repository:
package client
import (
"fmt"
Cli "github.com/docker/docker/cli"
flag "github.com/docker/docker/pkg/mflag"
)
func (cli *DockerCli) CmdMycomnd(args ...string) error {
cmd := Cli.Subcmd("CmdMycomnd", []string{"CONTAINER"}, Cli.DockerCommands["CmdMycomnd"].Description, true)
cmd.Require(flag.Exact, 1)
cmd.ParseFlags(args, true)
fmt.Println("Hi!")
return nil
}
Also updated docker/cli/common DockerCommands data structure to contain my new command.
Then pushed the commit to the branch in github, following the instructions on docker doc page.
Now, build the docker using make and tried to execute the binary of the 'new' docker which is found in bundles/1.10.0-dev/binary/ by the command:
./docker-1.10.0-dev mycomnd [option]
The Problem: i get the error: docker: 'mycomnd' is not a docker command. Any idea how to get around this?

Answer 1

You need to add a .go file in the directory /api/client along with all the API commands.
The name of the file should be identical to the name of your command.
In that .go file you should include whatever your command does in a function named Cmd[YourCommandName]
Commit and push the changes to your forked github branch.
Make the binary file
Example:
Say you want to add the command ‘talk’, so you do the following:
Add a new source file named talk.go: $ touch talk.go
Add contents of the .go source file.
Update the project on git hub:
$ git add talk.go NOTE: your pwd should be /api/client
$ git commit -s -m "Making a dry run test."
$ git push --set-upstream origin dry-run-test
$ <add your github account name + password>
Now change directory to docker-master directory and make the project
Change directory to /bundles/1.10.0-dev/binary
Execute: ./docker-1-10-dev talk
DONE!
Contents of our new talk command:
package client
import (
"fmt"
Cli "github.com/docker/docker/cli"
flag "github.com/docker/docker/pkg/mflag"
)
func (cli *DockerCli) CmdTalk (args ...string) error {
cmd := Cli.Subcmd("talk", []string{"CONTAINER"}, Cli.DockerCommands["talk"].Description, true)
cmd.Require(flag.Exact, 0)
cmd.ParseFlags(args, true)
fmt.Println("Hi")
return nil
}
Screen Shot