The application is written in GO with purpose of having an easy way to run custom commands inside pods of k8s cluster and being notified about results via Slack. Supported golang version is currently 1.16.
Notifications are handled via Slack API library and kubernetes client-go is used for talking with kubernetes cluster.
The application can be configured via environmenal variables or by supplying app.env file into the root directory:
SLACK_TOKEN- slack access token.SLACK_CHANNEL_ID- slack channel ID.- opt.
KUBERNETES_MASTER_URL- k8s api url - opt.
KUBERNETES_BEARER_CONFIG- k8s secret token (seerbac.yaml) - opt.
KUBERNETES_NAMESPACE- k8s namespace where pod is running. KUBERNETES_POD_LABEL- k8s pod label to filter pods by.- opt.
KUBERNETES_CONTAINER- k8s pod container to exec commands into. KUBERNETES_POD_EXEC- command to be send to the pod.
The application will try to define whether it is running inside or ouside of the cluster and load / authenticate with appropriate kube config.
service account, role and rolebinding are usually needed for the application to work (see KUBERNETES_BEARER_CONFIG env. variable) - rbac.yaml already includes everything, just apply it on the cluster you are planning to work on and get service account token:
kubectl apply -f rbac.yaml
kubectl describe serviceaccount kube-go-exec -n kube-system | grep Tokens
kubectl describe secret <token> -n kube-system
GOOS=linux GOARCH=amd64 go build
This will cross-compile the application and create a binary kube_go_exec that you can run:
./kube_go_exec
kube-go-exec contains HELM chart available for deployment:
helm install kube-go-exec kube-go-exec
In such case RBAC resources mentioned above will be created automatically based on values.yaml settings and jobs will be executed as cronjob. In this case strict serviceAccount.namespace <-> KUBERNETES_NAMESPACE variable and role-scope mapping applies. You can also supply your custom RBAC settings. Variables passed to secrets create appropriate resources and secrets will be automatically attached to every cronjob.
Alternatively you can install the chart with helmfile:
helmfile -f example_helmfile.yaml apply