Bartosz – Page 4 – Bartosz Bierkowski

Aug302017 by BartoszNo Comments

Learning Scala: Coursera

Featured, Scala

I want to share several Scala resources that help learning it. You should find something for yourself independent of your programming background. Today something about Coursera. This is my favourite "go to" learning resource since before it was created. I can recommend it to anyone and I did go through several courses. There is a high variety of course choices - not only in programming or STEM. As for Scala, you can find the whole specialization Functional Programming in Scala Specialization. You can sign up to single courses, but I believe you can benefit from all of them and get certification. I took the course "Functional Programming Principles in Scala" during one of the first installments. It was very popular and you will find many people in Scala community, who have taken it...

Jul12017 by BartoszNo Comments

OpenShift CLI morsels: tagging images

After building a docker image, it is added to the Image Stream in OpenShift. It can be identified by a unique ID and/or a tag. Tags can be added to any existing Image Stream. Discovering information about tags After listing image streams, you can see a short list of tags. In my case the [crayon-69e78588f0ca3843310457-i/] image stream has image tagged as [crayon-69e78588f0cb8908044481-i/] . [crayon-69e78588f0cbb168447864/] You can retrieve information about all existing tags using oc describe [crayon-69e78588f0cbe293239894/] Tagging images New Image Stream can be created immediately based on the existing tag. Below you can see creation of [crayon-69e78588f0cc2917979744-i/] IS with [crayon-69e78588f0cc6886654629-i/] tag based on [crayon-69e78588f0cc9086024092-i/] image. [crayon-6...

Jun92017 by BartoszNo Comments

OpenShift CLI morsels: Building application from private git repository

morsels, OpenShift, OpenShift CLI morsels

Having a public repository is a great thing, but not always possible or useful. OpenShift supports git access using ssh private keys and password. Below you can find the few steps on how you can use basic authentication (more…)

Mar222017 by BartoszNo Comments

OpenShift: working with multiple accounts, projects and servers

Featured, OpenShift

I often find myself switching between projects or using a service account to test something. To work with multiple projects I usually create an alias per namespace to quickly execute commands. [crayon-69e78588f2181392254967/] To use multiple accounts similar aliases can be created [crayon-69e78588f218e108809996/] To work with other clusters, you will can add --server besides the token parameter. [crayon-69e78588f2192184334404/] The more contexts, the more fun to manage and store them. Instead of doing it in shell files it might be easier to learn about [crayon-69e78588f2195791271196-i/] file. Kubernetes config file It contains information used during [crayon-69e78588f2198050542510-i/] . There are three main components: users, clusters and contexts. You can configure them individua...

Mar12017 by BartoszNo Comments

OpenShift CLI morsels: enable oc shell completion

morsels, OpenShift, OpenShift CLI morsels

The command and resource completion is built into oc client. You can generate it for bash and zsh. (more…)

Feb222017 by BartoszNo Comments

OpenShift CLI morsels: updating objects non-interactively

morsels, OpenShift, OpenShift CLI morsels

Recently, when I tried to answer the question: Openshift: how to edit scc non-interactively? I learned about nice feature of [crayon-69e78588f28bd217317436-i/] . It allows to change single values in OpenShift objects. Patching the resources For this scenario, let's say we have a deployment config called paprika. Standard way to update it is to run [crayon-69e78588f28ca960378240-i/] and change fields. That works only until it is not a repeatable task or something that needs to be done often. Changing single value Using [crayon-69e78588f28cd261907003-i/] you can easily automate simple tasks. Setting the rolling update timeout using this approach looks like this: [crayon-69e78588f28d0082572352/] The patch is an array of objects with the following fields: op - one of the operation...

Feb152017 by BartoszNo Comments

OpenShift CLI morsels: importing images

morsels, OpenShift, OpenShift CLI morsels

Usually I build images directly inside OpenShift. Sometimes it is useful to import an existing image into OpenShift's ImageStream. (more…)

Feb82017 by BartoszNo Comments

OpenShift CLI morsels: getting docs from oc client

morsels, OpenShift, OpenShift CLI morsels

The documentation is not the only place with information about OpenShift CLI. The tool itself contains a huge amount of data about the managed resources itself. Finding the managed resources A good starting point is to read output of [crayon-69e78588f2fb4200875236-i/] that returns description of used concept and types. These are not all of them, but the ones used during development. You will not find there details about [crayon-69e78588f2fbe362176182-i/] or [crayon-69e78588f2fc0349900062-i/] . For the listed types you can run [crayon-69e78588f2fc2565446669-i/] Exploring type's details Armed with the knowledge of various types, further details can be displayed for it with[crayon-69e78588f2fc4091803917-i/] . The command prints our all the fields, their types and descriptions. [crayon...

Feb12017 by BartoszNo Comments

OpenShift CLI morsels: showing labels of nodes in columns

morsels, OpenShift, OpenShift CLI morsels

With more than one node and more advanced setup than in minishift, you can use labels to add metadata to nodes. There are two ways to display later this information. Showing all labels of a node The following command returns all labels of all nodes. Normally the labels are not displayed and the [crayon-69e78588f3311824653535-i/] flag has to be used to show them. [crayon-69e78588f331d161286228/] Displaying only selected labels As the number of labels and nodes grows, the output becomes unreadable. Usually just some of the metadata is useful at a time. The displayed labels can be then narrowed just to few that are helpful. Lets show only architecture and os. [crayon-69e78588f3320073242843/] I like that the selected labels are shortened and presented in columns. This adds a lot to t...

Jan252017 by BartoszNo Comments

OpenShift CLI morsels: sudo and user impersonation

morsels, OpenShift, OpenShift CLI morsels

On linux machine you can use sudo to execute commands and so far I thought there is no equivalent approach in OpenShift. How mistaken I was! It looks like since OpenShift 3.1 the APIs allow to pass additional argument with the name of the user to impersonate. Give the developer a sudoers role On my minishift instance I add[crayon-69e78588f360b356077067-i/] role to the default[crayon-69e78588f3614112584794-i/] user. [crayon-69e78588f3617000396639/] Using the new role Starting from now, the [crayon-69e78588f3619575228204-i/] user can execute commands as a [crayon-69e78588f361b212231392-i/]. For example listing all nodes is possible, which does not work without the impersonation. [crayon-69e78588f361d944665451/] Environment I executed the commands using minishift and the following cli...