doker is a CLI tool that enables the use of common docker-cli commands but on the context of a kubernetes cluster. It allows users to manage and operate both containers and images mainly by connecting to the docker daemons running on each node in the kubernetes cluster. This is done by running a daemonset which acts like an agent that talks to the docker daemon on the node, and performs tasks.
This would require the dockerd to be present on the node, whose sock is mounted to the daemonset allowing it to interact.
The inital focus of this tool is to help you manage images in your cluster as there is no concrete kubernetes primitive for images. But all the commands from the docker-cli will be replicated here.
First, The Daemonset can be installed on the cluster by running
kubectl apply -f https://raw.githubusercontent.com/Pothulapati/doker/master/deploy/manifests.yamlNow, doker (this project's cli tool) can be installed by running
curl -sL https://raw.githubusercontent.com/Pothulapati/doker/master/bin/install.sh | shThis requires the kubeConfig file to be present and set to the current cluster.
Now that you have installed, you can list the images in your cluster by runnning
tarun@tarun-Inspiron-5559:work/doker ‹master*›$ doker images
gke-images-default-pool-aafc8b9e-lqkd
REPOSITORY TAG IMAGE ID CREATED SIZE
tarunpothulapati/dokerd latest 5f96e6ae49f2 4 hours ago 1.65GB
k8s.gcr.io/kube-proxy v1.13.11-gke.23 f2cfe256a767 2 weeks ago 83.7MB
k8s.gcr.io/prometheus-to-sd v0.8.2 3df88c7a6ea8 3 months ago 37.9MB
k8s.gcr.io/k8s-dns-sidecar-amd64 1.15.4 928a271628ea 8 months ago 79.3MB
k8s.gcr.io/k8s-dns-kube-dns-amd64 1.15.4 305ac63fd465 8 months ago 87MB
k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64 1.15.4 d16f387fc6c5 8 months ago 77.8MB
gcr.io/stackdriver-agents/stackdriver-logging-agent 1.6.8 4270b0a6eeb1 9 months ago 265MB
k8s.gcr.io/prometheus-to-sd v0.5.0 42e4387da83f 11 months ago 41.9MB
k8s.gcr.io/prometheus-to-sd v0.4.2 626698890281 11 months ago 41.9MB
k8s.gcr.io/addon-resizer 1.8.4 5ec630648120 15 months ago 38.3MB
k8s.gcr.io/metrics-server-amd64 v0.3.1 61a0c90da56e 16 months ago 40.8MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 2 years ago 742kB
gke-images-default-pool-aafc8b9e-tj3m
REPOSITORY TAG IMAGE ID CREATED SIZE
tarunpothulapati/dokerd latest 5f96e6ae49f2 4 hours ago 1.65GB
k8s.gcr.io/kube-proxy v1.13.11-gke.23 f2cfe256a767 2 weeks ago 83.7MB
k8s.gcr.io/prometheus-to-sd v0.8.2 3df88c7a6ea8 3 months ago 37.9MB
k8s.gcr.io/k8s-dns-sidecar-amd64 1.15.4 928a271628ea 8 months ago 79.3MB
k8s.gcr.io/k8s-dns-kube-dns-amd64 1.15.4 305ac63fd465 8 months ago 87MB
k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64 1.15.4 d16f387fc6c5 8 months ago 77.8MB
gcr.io/stackdriver-agents/stackdriver-logging-agent 1.6.8 4270b0a6eeb1 9 months ago 265MB
k8s.gcr.io/prometheus-to-sd v0.5.0 42e4387da83f 11 months ago 41.9MB
k8s.gcr.io/event-exporter v0.2.4 e7c317b95d73 11 months ago 47.3MB
k8s.gcr.io/prometheus-to-sd v0.4.2 626698890281 11 months ago 41.9MB
k8s.gcr.io/defaultbackend-amd64 1.5 b5af743e5984 16 months ago 5.13MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 2 years ago 742kB
gke-images-default-pool-aafc8b9e-3xhn
REPOSITORY TAG IMAGE ID CREATED SIZE
tarunpothulapati/dokerd latest 5f96e6ae49f2 4 hours ago 1.65GB
k8s.gcr.io/kube-proxy v1.13.11-gke.23 f2cfe256a767 2 weeks ago 83.7MB
k8s.gcr.io/prometheus-to-sd v0.8.2 3df88c7a6ea8 3 months ago 37.9MB
gke.gcr.io/heapster v1.7.0 c153bcbe94af 5 months ago 84MB
gcr.io/stackdriver-agents/stackdriver-logging-agent 1.6.8 4270b0a6eeb1 9 months ago 265MB
k8s.gcr.io/fluentd-gcp-scaler 0.5.2 3dfc22ad2d25 9 months ago 90.5MB
k8s.gcr.io/prometheus-to-sd v0.5.0 42e4387da83f 11 months ago 41.9MB
k8s.gcr.io/cluster-proportional-autoscaler-amd64 1.3.0 33813c948942 16 months ago 45.8MB
k8s.gcr.io/addon-resizer 1.8.3 b57c00a12f6c 18 months ago 33.1MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 2 years ago 742kBAs you can see all the images categorized by the node name are printed out.
Now, Let's try loading hello-world docker image into your kubernetes nodes.
tarun@tarun-Inspiron-5559:work/doker ‹master*›$ doker load hello-world
Loading images to gke-images-default-pool-aafc8b9e-lqkd
Loading images to gke-images-default-pool-aafc8b9e-tj3m
Loading images to gke-images-default-pool-aafc8b9e-3xhnNow,
You should be able to see the hello-world image in your kubernetes nodes.
tarun@tarun-Inspiron-5559:work/doker ‹master*›$ doker images | grep hello-world
hello-world latest fce289e99eb9 13 months ago 1.84kB
hello-world latest fce289e99eb9 13 months ago 1.84kB
hello-world latest fce289e99eb9 13 months ago 1.84kB- Dokerd: This is the daemon that is deployed as a web-server and listens for HTTP requests from the cli.
- doker: This is the docker like cli, which talks to the dokerd agents through the kubenetes proxy sub-resources and passes commands.
- Add more container management commands.
- Support Labeling of Nodes.
- Write tests for dokerd client.
- Support for more larger files.