Utilizing Docker Secret

It likely happens that we need to provide some secrets like passwords, keys, or private things into our Docker containers. If we use the docker-compose tool to generate our containers, we basically can put the secrets as environment variables in the docker-compose.yaml file. But, what if we want to share our configuration with the others, they will find those secrets too. So, for overcoming that issue, we can utilize a feature provided by Docker itself which is the Docker secret, or we can just call it secret.

For instance, we want to build a container for the PostgreSQL database. The PostgreSQL image allows us to set a custom database password by providing a value for the POSTGRES_PASSWORD or POSTGRES_PASSWORD_FILE variable.

services:
  postgres:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=$3cureP4ssword

Or, we can utilize the Docker bind-mounting to store a file and instruct the Docker to read the secret information from the mounted file.

services:
  services:
    postgres:
      image: postgres
      volumes:
        - /project/path/my_secret_file:/var/lib/postgresql/my_secret_file
      environment:
        - POSTGRES_PASSWORD_FILE=/var/lib/postgresql/my_secret_file

Secret works like a special volume-mounting with a unique mechanism. First, we create a file in our project that contains a password for our database service. For example, it is stored in the /project/path/my_secret_file file. The file must contain only the password value, for example, it contains only "$3cureP4ssword". Then, it's just like a volume-mounting, we set the secret definition and enable it for the service. The specified file will be automatically available in the container in a special directory maintained by Docker which is located in the /run/secrets/ directory. Lastly, we set the environment variable to use the value stored in the deployed directory.

services:
  postgres:
    image: postgres
    secrets:
      - the_secret_name
    environment:
      - POSTGRES_PASSWORD_FILE=/run/secrets/the_secret_name

secrets:
  the_secret_name:
    file: /project/path/my_secret_file

Comments

Rangkaian Sensor Infrared dengan Photo Dioda

Keunggulan photodioda dibandingkan LDR adalah photodioda lebih tidak rentan terhadap noise karena hanya menerima sinar infrared, sedangkan LDR menerima seluruh cahaya yang ada termasuk infrared. Rangkaian yang akan kita gunakan adalah seperti gambar di bawah ini. Pada saat intensitas Infrared yang diterima Photodiode besar maka tahanan Photodiode menjadi kecil, sedangkan jika intensitas Infrared yang diterima Photodiode kecil maka tahanan yang dimiliki photodiode besar. Jika tahanan photodiode kecil maka tegangan V- akan kecil . Misal tahanan photodiode mengecil menjadi 10kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 10 / (10+10) x Vcc V- = (1/2) x 5 Volt V- = 2.5 Volt Sedangkan jika tahanan photodiode besar maka tegangan V- akan besar (mendekati nilai Vcc). Misal tahanan photodiode menjadi 150kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 150 / (150+10) x Vcc V- = (150/160) x 5

Configuring Swap Memory on Ubuntu Using Ansible

If we maintain a Linux machine with a low memory capacity while we are required to run an application with high memory consumption, enabling swap memory is an option. Ansible can be utilized as a helper tool to automate the creation of swap memory. A swap file can be allocated in the available storage of the machine. The swap file then can be assigned as a swap memory. Firstly, we should prepare the inventory file. The following snippet is an example, you must provide your own configuration. [server] 192.168.1.2 [server:vars] ansible_user=root ansible_ssh_private_key_file=~/.ssh/id_rsa Secondly, we need to prepare the task file that contains not only the tasks but also some variables and connection information. For instance, we set /swapfile as the name of our swap file. We also set the swap memory size to 2GB and the swappiness level to 60. - hosts: server become: true vars: swap_vars: size: 2G swappiness: 60 For simplicity, we only check the exi

Beautiful Rain (JDorama)

Saya selalu tertarik dengan film-film inspirasional, baik movie atau pun serial drama. Akhir-akhir ini saya tertarik untuk menonton drama serial jepang. Saya googling dengan keyword "inspirational japan dorama" kemudian saya dapati sejumlah review beberapa film bagus dari sejumlah netizen. Salah satu yang kemudian saya tonton adalah Beautiful Rain . Setiap episode film ini selalu membuat saya sangat terharu sampai meneteskan air mata. :' Yah, ini mungkin saja karena saya yang terlalu melankolis. Hahaha. Ini sedikit review dari saya tentang film ini.

Resize VirtualBox LVM Storage

VirtualBox is a free solution to host virtual machines on your computer. It provides configuration options for many components on our machine such as memory, storage, networking, etc. It also allows us to resize our machine storage after its operating system is installed. LVM is a volume manager in a Linux platform that helps us to allocate partitions in the system and configure the storage size that will be utilized for a specific volume group. There are some points to be noticed when we work with LVM on VirtualBox to resize our storage. These are some steps that need to be performed. 1. Stop your machine before resizing the storage. 2. Set new storage size using GUI by selecting " File > Virtual Media Manager > Properties " then find the desired virtual hard disk name that will be resized. OR , by running a CLI program located in " Program Files\Oracle\VirtualBox\VBoxManage.exe ". cd "/c/Program Files/Oracle/VirtualBox" ./VBoxManage.exe list

API Gateway Using KrakenD

The increasing demands of users for high-quality web services create the need to integrate various technologies into our application. This will cause the code base to grow larger, making maintenance more difficult over time. A microservices approach offers a solution, where the application is built by combining multiple smaller services, each with a distinct function. For example, one service handles authentication, another manages business functions, another maintains file uploads, and so on. These services communicate and integrate through a common channel. On the client side, users don't need to understand how the application is built or how it functions internally. They simply send a request to a single endpoint, and processes like authentication, caching, or database querying happen seamlessly. This is where an API gateway is effective. It handles user requests and directs them to the appropriate handler. There are several tools available for building an API gateway, su

How To Use Protocol Buffer in Javascript

We have understood a few advantages of protocol buffer like what I've explained in my other post . Now, let's look at how we can implement it in our code. The "transpiler" tool, named protoc , supports the generation of a helper class for managing the object instance in a variety of programming languages. In this post, we use Javascript as an example and run in a Linux environment. Preparation Before we develop our code, we should install protoc for generating the helper class. Download protoc binary from the release page . Extract the content and store the directories ( bin and includes ) in /usr/local directory so that the executable binary can be accessed directly. Run protoc --help to check its manual. Install a required dependency globally to enable protoc to generate the Javascript files by running: npm i -g protoc-gen-js . Create a proto file First, we should create an empty directory

LUKI NOTES

Search This Blog