Bui Ha's Notes

In a time when every cool developer talks about infrastructure software, a meetup of infrastructure technology is certainly getting a lot of attention. In Tokyo, Tokyo k8s meetup is one of the most popular community, where k8s enthusiasts gather and share their knowledge about this new rising infrastructure technology. This week's Monday, Tokyo Kubernetes Meetup #18 was held in Tokyo and I and my colleague Wenhan fortunately have chance to join it. Never before I realize that k8s is becoming such a hot technology. The attention for this technology can be felt by the number of event registration. The event halls' capacity was solely 170 people, yet there were more than 500 people made registration (at the time I register). The organizer had to make a ticket lottery and select participants by random. I was lucky enough to get the lottery for the event. The number of registrations is 5 times over the capacity of event hall. The organizer had to randomly select participan

1. System Degradation Issue As usual, after installing some modules and modifying some user privileges, I performed a reboot for my home desktop computer. After the reboot, I always check for system start health and today is no different. $ systemctl status ● stark State: degraded Jobs: 0 queued Failed: 1 units Since: Tue 2019-04-23 13:37:13 JST; 0h 4min ago CGroup: / ├─user.slice │ ├─user-1000.slice │ │ ├─user@1000.service ...    2. What was the problem? hm... I was quite surprised at this degradation of my system, so I look for the unit that fails to start at boot time. $ systemctl list-units --failed UNIT LOAD ACTIVE SUB DESCRIPTION ● apparmor.service loaded failed failed AppArmor initialization LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, v

I'm familiar with MySQL yet I have always wanted to use PosegreSQL due to its feature richness. Due to differences between the 2 databases, I always find it hard to remember initial setups. Today, It took me a while to re-navigate Postgres official documentation again, before I can create a role and grant permissions to newly created roles. I think it's useful to note those tasks for my future references. Steps to setup Postgres Allow local role to access using password Create Role and Grant Permission  Manual 1. Allow password authentication to local role Postgres comes with different role management mechanisms from MySQL's. By default, local users connect with Postgres throught Unix socket without password. Postgres delegates user authentication to Linux, which means that user connect to Postgres locally needs not only a role in Postgres but also a Linux account. For a local development, this setting is quite inconvenient so I switch local user authencation t