LUKI NOTES

GitLab allows us to deploy CI/CD pipeline runners on our own resources within our environment. This option is available not only for the self-hosted plan but also for the cloud service plan (gitlab.com). With this setup, unlike GitHub Action, we can avoid incurring additional costs for extended pipeline runtime. This is because we can deploy the runner on an on-demand server and optimize its usage. GitLab CI offers several options for setting up resources to run CI/CD pipelines. A runner can be configured to handle jobs for specific groups or projects using designated tags. It can also be set to use different executors, such as Shell, Docker, Kubernetes, or VirtualBox. A comparison table of the supported executors is available in the executor documentation . Some executors offer greater flexibility and ease of use, while others may be more rigid but enhance server security. Installing the runner in our machine For example, we will deploy the runner on an Ubuntu serve...

DevSecOps stands for development, security, and operations. By its name, we can guess it is more like DevOps with the integration of security tools. The more formal definition, it is an approach to design and automate the integration of security at every phase of the software development lifecycle. This term became more popular when many cloud providers and code management tools started to use the name in many places on their platforms. As it integrates security tools in every phase of SDLC and automates the process, this approach can help developers catch vulnerabilities early. Besides it can help us to ensure that our project aligns with regulatory compliance from the beginning. This state can lead to cost-effective software delivery by reducing time to market and can help organizations build a security-aware culture. Security become a concern of more companies nowadays as the increasing of cyber incidents. Traditional DevOps may lack in a few aspects. First, in traditio...

Terraform has become more mature and can help us in many scenarios in provisioning infrastructure. These are a few scenarios that might be quite common for us in day-to-day jobs. Take values from another state as a data source This might be used when we already maintain a base state, and then a few child configurations need to access certain values from the base state. First, define the data source with attributes for accessing another state data "terraform_remote_state" "SOME_NAME" { backend = "local" config = { path = "/path/to/another/terraform.tfstate" } } Then, we can pass the value into any resources. For example, we output a value into another output value. output "public_ip" { value = data.terraform_remote_state.SOME_NAME.outputs.public_ip } Redeploy a resource This might be useful when we find an error in our resource that requires us to redeploy the resource. terraform apply -replace=...

Terraform is a tool to help us deploy infrastructures on any cloud provider such as AWS, GCP, DigitalOcean, and many more. Unlike Amazon CloudFormation which is specific only for AWS, Terraform supports many cloud providers found in Terraform's registry. It uses a domain-specific language built clearly for provisioning and configuring infrastructures named HCL or HashiCorp Configuration Language. Meanwhile, UpCloud is an alternative cloud provider for SMEs. It targets a quite similar segment to DigialOcean and Linode. It provides a variety of popular solutions in the cloud such as managed Redis database, S3-compatible storage, private network, load balancer, and so on. Even though its cost is a little bit higher than DigitaOcean or others, it provides quite complete features on each service like the features of the load balancer that we will use in this post. Moreover, it actively publishes new features like the managed OpenSearch database published rece...

Ansible is a reliable configuration management tool. It is shipped with a lot of modules including those provided by the communities. Some modules are essential and come in very handy in everyday tasks. Ansible is pushed-based and works by generating a Python script that will be run on the target server. It means the target server is required to have Python which is also commonly shipped in any Linux distros. package The module is used to manage packages in the target host. It is like running apt , yum , or aptitude . The following snippet is an example of its usage to install the Nginx package using the package manager. tasks: - name: Install Nginx package: name: nginx state: present update_cache: True file It is used to manage files, symlinks, links, or folders on the target host. These are the two examples. tasks: - name: Create a directory file: path: "/home/luki/mydir" state: directory mode: 0750 - name: C...

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...