Quick Notes: Avoiding user interaction with tzdata

While trying to install libapache2-mod-php via apt-get, it will prompt for information regarding your geographic area. To avoid this do, put the following in your Dockerfile (configure the timezone that’s appropriate for you):

ENV TZ=Asia/Singapore
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

Quick Notes: Install Docker on CentOS 7

$ sudo yum install -y yum-utils \
  device-mapper-persistent-data \
  lvm2

$ sudo yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

$ sudo yum install docker-ce docker-ce-cli containerd.io
$ sudo systemctl start docker

Quick Notes: Install Docker CE on Ubuntu 18.04 LTS

$ sudo apt-get update

$ sudo apt-get install \
     apt-transport-https \
     ca-certificates \
     curl \
     gnupg-agent \
     software-properties-common

$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Verify that you now have the key with the fingerprint 9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88, by searching for the last 8 characters of the fingerprint.

$ sudo apt-key fingerprint 0EBFCD88

 Setup stable repository: 

$ sudo add-apt-repository \
    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
    $(lsb_release -cs) \
    stable"

$ sudo apt-get update

 $ sudo apt-get install docker-ce docker-ce-cli containerd.io

Verify that Docker CE is installed correctly by running the hello-world image.

$ sudo docker run hello-world
$ sudo systemctl enable docker

Reference:

Get Docker CE for Ubuntu

Quick Notes : Branches in Git

New branch:
git branch new_branch

Switch to new branch:
git checkout new_branch

List branches:
git branch -a

Delete a branch:
git push origin --delete branch_name

Push branch to remote repository:
git push -u origin branch_name
Clone branch from remote repository:
git clone -b branch_name https://remote-repo.git

Crashing into Docker …

I’ve worked with bare-metal servers, virtual machines, cloud (infrastructure as a service), however, I’ve never had a chance to work with containers yet – let’s see how this goes …