Tree kill not killing spawned docker processes

[maja5627]

Is tree kill meant to kill all child processes? Even if they are docker processes? I am trying to kill a child process that runs docker commands but kill tree only kills the node process. I will attach some code snippets but kill(childID) is not killing the sub processes.

const kill = require('tree-kill'); / npm install tree-kill --save

I create a bash script and spawn a child process to run it.
`let buildScript = "docker build -t " + image_name + " . \n";

buildScript += "docker run -v /var/run/docker.sock:/var/run/docker.sock " + image_name + " \n";

buildScript += "docker rmi " + image_name + " \n";

const dockerBuild = spawn('bash', ['-c', buildScript]);

console.log(dockerBuild.pid);

childPID = dockerBuild.pid;`

then to try to kill it I run
`console.log('child piid ======', childPID);

kill(childPID, 'SIGKILL', function(err) {
    console.log('error here ------', err);
});` 

The childPID comes in correctly and the node process does get killed I believe but docker run and build continue to run even after I have called the tree kill with the childPID. Any help or suggestions would be great thank you!