Collection of cool things I learnt today.
Today I learned how to deploy to many docker daemons usong docker contexts. # create docker context docker context create dind ‐‐docker "host=tcp://127.0.0.1:2375" # use docker context for upcoming commands docker context use dind # use docker context for one command docker --context default ps # list contexts docker context ls source
Today I learned What Ubuntu means. Ubuntu is a South African ethonophylosophy, the word translates to “Humanity” or “The essence of being human”. The philosophy gravitate towards the idea of relational identity. “A person is a person through other people”. Another thing to note abour Ubuntu is that is the way it approaches Justice. Ubuntu adopts forgiveness instead of revange as a way to end the latter’s vicious cycle. The Ubuntu philosophy has been adopted by know thinkers like Desmond Tutu and Nelson Mandela. ...
Today I learned the order Ansible follows to get variable values. Command line option -e vars_files: vars: host_vars/ group_vars/ Role specific vars (role/default/main.yml) … Source
Today I learned that when performing SSH key authentication with OpenSSH. The client will look for the default key names id_rsa or id_dsa. If you want to use a custom name you should specify it in the command line via the -i option or reference it in the config file ssh_config. More
Today I learned that swarn node does not support specifying the pid namespace unlike docker-compose. Docker does not support a lot of other option in swarm mode. The whole list here
Today I learned, how Gluster Prometheus Exporter determine the leader node (peer). It simply compares the peers UUIDs alphabetically and elect the peer with the highest UUID as the cluster leader. We should note that healing and profile metrics can only be scraped from the leader node. Source
Today I learned how to update docker configs on stack deploy. Docker configs are immutable meaning when re-deploying a stack they can not be updated. The way to update configs on re-deploys is to create a new one each time a docker stack deploy is triggered. And a good way to to that is to template the config name using a unique value like (current system time). configs: settings.yml: name: settings-${SETTINGS_TIMESTAMP}.yml file: foo.yml And then running stack deploy. ...