A Passionate Techie

Kubernetes is a  cluster  and  orchestration  engine for docker containers. In other words Kubernetes is  an open source software or tool which is used to orchestrate and manage docker containers in cluster environment. Kubernetes is also known as k8s and it was developed by Google and donated to “Cloud Native Computing foundation” In Kubernetes setup we have one master node and multiple nodes. Cluster nodes is known as worker node or Minion. From the master node we manage the cluster and its nodes using ‘ kubeadm ‘ and ‘ kubectl ‘  command. Kubernetes can be installed and deployed using following methods: Minikube ( It is a single node kubernetes cluster) Kops ( Multi node kubernetes setup into AWS ) Kubeadm ( Multi Node Cluster in our own premises) In this article we will install latest version of Kubernetes 1.7 on CentOS 7 / RHEL 7 with kubeadm utility. In my setup I am taking three CentOS 7 servers with minimal installation. One server will acts master node and rest two serve...

Personally I think if you are looking for a container management solution in today’s world, you have to invest your time in  Kubernetes  (k8s). There is no doubt about that because of multiple factors. To the best of my undestanding, these points include: Kubernetes is  Open Source Great momentum in terms of activities & contribution at its  Open Source Project Decades of experience running its  predecessor  at Google Support of multiple OS and infrastructure software vendors Rate at which features are being released Production readiness (Damn it,  Pokemon Go  met its scale due to Kubernetes) Number of features available. Check out the list of features at the  home page . The general perception about a management solution like Kubernetes is that it would require quite a bit of setup for you to try it out locally. What this means is that it would take some time to set it up but more than setting it up, you might probably get access to it only during staging phase or so...

Now login to your chef-node/chef-client and type ohai.  Ohai is automatically bootstraped when we install chef. You will get an output similar to below: ...... "OPEN_MAX": 1024, "PAGESIZE": 4096, "PAGE_SIZE": 4096, "PASS_MAX": 8192, "PTHREAD_DESTRUCTOR_ITERATIONS": 4, "PTHREAD_KEYS_MAX": 1024, "PTHREAD_STACK_MIN": 16384, "PTHREAD_THREADS_MAX": null, "SCHAR_MAX": 127, "SCHAR_MIN": -128, "SHRT_MAX": 32767, "SHRT_MIN": -32768, "SSIZE_MAX": 32767, "TTY_NAME_MAX": 32, "TZNAME_MAX": 6, "UCHAR_MAX": 255, "UINT_MAX": 4294967295, "UIO_MAXIOV": 1024, "ULONG_MAX": 18446744073709551615, "USHRT_MAX": 65535, "WORD_BIT": 32, "_AVPHYS_PAGES": 768366, "_NPROCESSORS_CONF": 2, "_NPROCESSORS_ONLN": 2, "_PHYS_PAGES": 970577, "_POSIX_ARG_MAX": 2097...

java.lang.IllegalArgumentException: unknown setting [node.rack] please check that any required plugins are installed, or check the breaking changes documentation for removed settings Node level attributes used for allocation filtering, forced awareness or other node identification / grouping must be prefixed with  node.attr . In previous versions it was possible to specify node attributes with the  node.  prefix. All node attributes except of  node.master ,  node.data  and  node.ingest  must be moved to the new  node.attr.  namespace. Unknown setting mlockall Replace the bootstrap.mlockall with bootstrap.memory_lock Unable to lock JVM Memory: error=12, reason=Cannot allocate memory Edit:   /etc/security/limits.conf  and add the following lines elasticsearch soft memlock unlimited elasticsearch hard memlock unlimited Edit:  /usr/lib/systemd/system/elasticsearch.service  uncomment the line Limi...

java.lang.IllegalArgumentException: unknown setting [node.rack] please check that any required plugins are installed, or check the breaking changes documentation for removed settings Node level attributes used for allocation filtering, forced awareness or other node identification / grouping must be prefixed with  node.attr . In previous versions it was possible to specify node attributes with the  node.  prefix. All node attributes except of  node.master ,  node.data  and  node.ingest  must be moved to the new  node.attr.  namespace. Unknown setting mlockall Replace the bootstrap.mlockall with bootstrap.memory_lock Unable to lock JVM Memory: error=12, reason=Cannot allocate memory Edit:   /etc/security/limits.conf  and add the following lines elasticsearch soft memlock unlimited elasticsearch hard memlock unlimited Edit:  /usr/lib/systemd/system/elasticsearch.service  uncomment the line Limi...