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Showing posts with the label Kubernetes

Dockers.. Basic commandlets

In this article we will go through some of the basic commands used in dockers. So lets get started. 1) docker ps This command is used to list all the running containers ie: $ docker ps CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                                        NAMES 4ba5baace270        couchbase           "/entrypoint.sh couc…"   8 seconds ago       Up 5 seconds        8091-8096/tcp, 11207/tcp, 11210-11211/tcp, 18091-18096/tcp   naughty_hopper 6c1773f25479        nginx               "nginx -g 'daemon of…"   5 minutes ago       Up 5 minutes        80/tcp                                                       compassionate_dijkstra 2) docker ps -a This command list all the container into the docker, whether its in running, stopped or exited. $ docker ps -a CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS     

Secret in Kubernetes

Secret in Kubernetes Secrets in Kubernetes are sensitive information like Shh keys, tokens, credentials etc. As in general its must require to store such kind of secret object in encrypted way rather than plantext to reduce the risk of exposing such kind of information to unauthorised species. A secret is not encrypted, only base64-encoded by default. Its require to create an EncryptionConfiguraton with a key and proper identity. All secret data and configuration are stored onto etcd which is accessible via API server. Secret data on nodes are stored on tmpfs volumes. Individual secret size is limited to 1MB in size. The larger size limit is discouraged as it may exhausted apiserver and kubelet memory.  To use secret its require that pod needs to reference with secret. A secret can be used in 2 ways with pod: as file in a volume mounted on one or more containers, or use by kubelets while pulling images from the pod. There are two steps involved in setting up secret

Rolling Updates and Rollbacks in Kubernetes

Rolling Updates and Rollbacks in K8s In our environment everyone has several application deployed and running successfully. Each application comes with a version and time by time application vendor releases new version of it where new version consist of new features and previous bug fixes. Now, its become must task to update our applications to leverage new features. So, how will be make the strategy to upgrade our applications into production environment. Its quite difficult to update all the application at once as it would hamper the stability of the environment. In Kubernetes there is default strategy of deployment called Rolling updates where we do not destroy all the application at one, instead we bring down the application older version and bring back the new version of the application one by one. By doing this application never goes down and upgrade is seamless. It's require to specify the upgrade strategy into the deployment. If there is no suc

Monitoring & Logging in Kubernetes

Monitoring cluster components  of Kubernetes (K8s) There are various type of monitoring we can perform at the cluster, node level and pod level. At cluster level we can monitor like number nodes running, how many are healthy, performance status, network usage etc.   At the POD level we can monitor disk and cpu, memory utilisation, Performance metrics of each POD about its resources. To utilise the experience of monitoring on kubernetes cluster we can use “ Metrics server ”  We can have 1 metrics server per cluster. It's retrieves the information about Nodes , PODS aggregate them and store them into memory.  Matrics server is IN-MEMORY solution where the data or information which it fatch from nodes and pod will be in memory and does not store it in disk.  As Metrics server is " IN-MEMORY " where it's not possible to retrieve the historical data about the kubernetes resources. To get the historical data its require to use advance to

What Is Kubernetes.....

What Is Kubernetes..... Running a container on a laptop is relatively simple. But, connecting containers across multiple hosts, scaling them, deploying applications without downtime, and service discovery among several aspects, can be difficult.                                             Kubernetes is the one which addresses those challenges from the start with a set of primitives and a powerful open and extensible API. The ability to add new objects and controllers allows easy customization for various production needs.  According to the  kubernetes.io  website, Kubernetes is:  "an open-source system for automating deployment, scaling, and management of containerized applications".  Kubernetes is that it builds on 15 years of experience at Google in a project called borg.   Kubernetes is inspired by Borg - the internal system used by Google to manage its applications (e.g. Gmail, Apps, GCE). Methodology of Kubernetes Deploying c