You can also use Konvoy to deploy Kubernetes on a single laptop using Docker to simulate cluster nodes and networking topology. This is very useful for development and end-to-end testing with Konvoy.
Before starting the development machine installation, you should verify the following:
- Docker version 18.09.2 or later
- kubectl v1.17.17 or later (for interacting with the running cluster)
- Docker is configured with the following minimum requirements for CPU, memory, and disk:
- 4 CPUs
- 8 GB memory
- 40 GB of free disk space
- The disk used by Docker should be less than 85% full.
After verifying your prerequisites, you can create a Kubernetes cluster on your development machine using the following command:
konvoy up --provisioner=docker [--cluster-name <YOUR_SPECIFIED_NAME>]
This command creates Docker containers, each of which simulates a cluster host. And then it installs the Kubernetes cluster in those Docker containers, and installs default addons to support the Kubernetes cluster.
konvoy up --provisioner=docker command does the following:
- Provisions one Docker container as the Kubernetes control plane node
- Provisions one Docker container as the Kubernetes worker node
- Deploy Kubernetes in the above Docker containers
- Deploys all of the following default addons:
- Static local volume provisioner
- Kubernetes dashboard
- Operations portal
- Dex identity service
- Dex Kubernetes client authenticator
- Traefik forward authorization proxy
The following addons are not installed by default.
However, you could enable those addons by editing
cluster.yaml and run
konvoy up again.
- Elasticsearch (including Elasticsearch Exporter)
- Fluent Bit
- Prometheus operator (including Grafana, AlertManager and Prometheus Adapter)
Viewing installation operations
As noted above, you start the cluster installation by running the
konvoy up --provisioner=docker command.
konvoy up --provisioner=docker command runs, you will see output about the operations performed.
The first set of messages you see is the output generated by Terraform as it provisions your nodes using Terraform Docker provider.
After the nodes are provisioned, Ansible connects to the hosts (Docker containers) and installs Kubernetes in steps called tasks and playbooks. Near the end of the output, addons are installed.
Viewing cluster operations
You can access user interfaces to monitor your cluster through the Operations Portal.
After you run the
konvoy up --provisioner=docker command, if the installation is successful, the command output displays the information you need to access the Operations Portal.
You should see information similar to this:
Kubernetes cluster and addons deployed successfully! Run `konvoy apply kubeconfig` to update kubectl credentials. Navigate to the URL below to access various services running in the cluster. https://172.17.1.200/ops/landing And login using the credentials below. Username: AUTO_GENERATED_USERNAME Password: SOME_AUTO_GENERATED_PASSWORD_12345 The dashboard and services may take a few minutes to be accessible.
Using a virtual private network for Docker on MacOS
If you use Docker on a MacOS computer, the host does not have direct access to the Docker network. Because of this limitation, you cannot directly access the services running in Docker containers using their IP addresses (including the operations portal).
To access the services in Docker containers when using a MacOS computer, you can create a virtual private network (VPN) between the host and the Docker network.
Create a VPN for Docker on MacOS
Create the virtual private network (VPN) by running the following command:
curl -sL https://raw.githubusercontent.com/mesosphere/docker-mac-network/master/mac-network.sh | bash -s create
Destroy the VPN on MacOS
Destroy the virtual private network (VPN) when it is no longer needed by running the following command:
curl -sL https://raw.githubusercontent.com/mesosphere/docker-mac-network/master/mac-network.sh | bash -s destroy
Differences from deploying on AWS
By deploying Konvoy using Docker, you should note the following differences from deploying on a public cloud infrastructure. The Docker based install essentially simulates an on-premises environment.
- MetalLB is used for creating Service (type
- Keepalived is used to provide high availablility for Kubernetes API servers.
- Static local volume provisioner is used to create local Persistent Volumes.
Accessing cluster nodes
As mentioned above, cluster nodes are simulated using Docker containers.
Use the command
docker exec to access the nodes in the corresponding container.
First, list the containers running:
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 45fecdd2008b 7845b297b4ed "/usr/local/bin/entr…" 37 minutes ago Up 37 minutes 0.0.0.0:22000->22/tcp, 0.0.0.0:46000->6443/tcp konvoy-control-plane-0 a95ede5b272a 7845b297b4ed "/usr/local/bin/entr…" 37 minutes ago Up 37 minutes 0.0.0.0:22010->22/tcp konvoy-worker-pool0-0
The containers for the cluster nodes are named using the following convention:
- Control plane nodes:
- Worker nodes:
Once you identify the node you want to access,
docker exec into the container:
docker exec -ti konvoy-control-plane-0 /bin/bash