Steps

# build operaotr-sdk
$ cd$GOPATH/src/github.com/operator-framework/operator-sdk
$ git checkout master
$ make dep
$ make install

# generate project
OPERATOR_NAME=echo-operator
GROUP=echo.redhat.com
VERSION=v1
KIND=EchoApp
$ cd$GOPATH/src/github.com/{user name}/
$ operator-sdk new ${OPERATOR_NAME} --api-version=${GROUP}/${VERSION} --kind=${KIND}
$ cd${OPERATOR_NAME}# build and push image
REGISTRY=docker.io
ORG=tohinkashem
TAG=v0.0.1
$ operator-sdk build ${REGISTRY}/${ORG}/${OPERATOR_NAME}:${TAG}
$ docker push ${REGISTRY}/${ORG}/${OPERATOR_NAME}:${TAG}

# addfieldstocustomtypestypeEchoAppstruct {
metav1.TypeMeta`json:",inline"`
metav1.ObjectMeta`json:"metadata"`SpecEchoAppSpec`json:"spec"`StatusEchoAppStatus`json:"status,omitempty"`
}
typeEchoAppSpecstruct {
Sizeint32`json:"size"`Imagestring`json:"image"`
}
typeEchoAppStatusstruct {
Nodes []string`json:"nodes"`
}

$ operator-sdk generate k8s