The last post shown how a playbook was able to install and configure an Apache server and also to open needed ports on the firewall. If we wanted to install a FTP server we should create a new playbook or duplicate a task, but thanks to variables we are going to see how to reuse the same task on the same playbook.
Ansible is a radically simple IT automation engine that automates cloud provisioning,configuration management, application deployment, intra-service orchestration, and many other IT needs.
Designed for multi-tier deployments since day one, Ansible models your IT infrastructure by describing how all of your systems inter-relate, rather than just managing one system at a time.
It uses no agents and no additional custom security infrastructure, so it’s easy to deploy – and most importantly, it uses a very simple language (YAML, in the form of Ansible Playbooks) that allow you to describe your automation jobs in a way that approaches plain English.
On this page, we’ll give you a really quick overview so you can see things in context. For more detail, hop over to docs.ansible.com.
The last post showed how to download a Tomcat docker image and to deploy a container from it. We were able to have a Tomcat web application server, but we could not access the manager console because it was not configured on the image. Tomcat uses a xml file to configure users and roles to access the server, is named tomcat-users.xml under the directory ${TOMCAT_DIR}/conf. The base image file content is:
>> Today is Wednesday and David didn’t publish the OpenShift tutorial’s 4th part, but now he want to talk about Docker. Is it the Armageddon?
>> I have no response for last question but I can explain why there is no tutorial this week. Due a particular labor issue I’ve decided to pause the OpenShift v3 Mega Tutorial.
>> When it will be back?
>>I neither have the response but maybe two or three weeks from now
>>And what I will do meanwhile?
>> Well during this pause I’m going to talk about Docker and Ansible, because there were many requests and also will help us to go deeper in OpenShift v3
Start?
OpenShift offers two different ways to connect the API: command line and via Web. Lets start taking a look the CLI (Command Line Interface).
With OpenShift we have two tools to manage the cluster:
Both are availables in any host of the cluster we have been created, but it can also be downloaded and use them in a remote machine. There are two versions: oc only, for Linux/Mac/Windows platforms, and oc+oadm exclusively for Linux You can download them here.
Ansible is a radically simple IT automation engine that automates cloud provisioning,configuration management, application deployment, intra-service orchestration, and many other IT needs.
Designed for multi-tier deployments since day one, Ansible models your IT infrastructure by describing how all of your systems inter-relate, rather than just managing one system at a time.
It uses no agents and no additional custom security infrastructure, so it’s easy to deploy – and most importantly, it uses a very simple language (YAML, in the form of Ansible Playbooks) that allow you to describe your automation jobs in a way that approaches plain English.
On this page, we’ll give you a really quick overview so you can see things in context. For more detail, hop over to docs.ansible.com.
There are two installation processes:
Do we start?
OpenShift v3 brings many architectural changes and introduces new concepts and components. It is built around the applications running in Docker containers, scheduling and management support provided by the Kubernetes project, and augmented deployment, orchestration, and routing functionality on top.
The most significant changes surround the container model and how they are monitored and interconnected. Kubernetespods are a group of containers that act like a single VM: they have a single IP address, they can share a file system, and they typically have similar security settings. Grouping containers together vastly increases the number of applications that can be brought to OpenShift. Rather than focusing on a microservice model to the exclusion of all other patterns, pods enable developers to port existing applications that need to share local resources while still benefiting from a containerized model.
Second, OpenShift containers are expected to be immutable: the image contains a particular snapshot of application code and its dependent libraries, while any configuration, secrets, or persistent data is attached to the container at runtime. This allows administrators and integrators to separate code and patches from configuration and data. While it is still possible to mutate your containers, the higher level concepts of build and deployments leverage immutable containers to provide higher level guarantees about what code is running where.
The third important change is in the core system design: OpenShift and Kubernetes are built as sets of microservices working together through common REST APIs to change the system. Those same APIs are available to system integrators, and those same core components can be disabled to allow alternative implementations. A great example of this are thewatch APIs: clients can connect and receive a stream of changes to pods (or other objects) and take action on them as the pods become available (to signal errors or log changes to the system). OpenShift exposes fine-grained access control on the REST APIs to enable this integration, which means there are no actions in the system that cannot also be done by an integrator.
Oh my god!!! I do not what just happened. Well, already I do. I have been very busy with a big project related to OpenShift, something about Amadeus (I know nothing) Amadeus innovates customer service with OpenShift Enterprise by Red Hat
That is the deal, during next weeks I will be updating this site. I have something new to share with you:
Take it easy, we are on holidays season!!
Yes, after long weeks of study and preparation finally I have my rhcoe-PaaS certification (Red Hat Certificate Of Expertise in Platform-as-a-Service) which certifies my ability to install, configure and manage an Enterprise OpenShift PaaS.
Too bad, Red Hat not yet provide the logos to attach the signature of my emails.
See you soon.
