DevOps
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Portable Operating System Interface(POSIX)DevOps/OS 2020. 9. 21. 15:07
1. Overview The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines the application programming interface (API), along with command-line shells and utility interfaces, for software compatibility with variants of Unix and other operating systems. 2. Description Unix was s..
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Program, Process, and ThreadDevOps/OS 2020. 9. 19. 23:43
1. Overview 1.1 Program A program is a set of instructions and associated data that resides on the disk and is loaded by the operating system to perform some task. An executable file or a python script file are examples of programs. In order to run a program, the operating system's kernel is first asked to create a new process, which is an environment in which a program executes. A program is an..
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Difference between Apache and NginxDevOps/MIddleware 2020. 5. 14. 12:24
1. Overview Both Apache and Nginx are open-source high-performance web servers capable of handling diverse workloads to satisfy the needs of modern web demands. They are conceptually close to each other but are close rivals in the web server business. Apache has been the leader in the web server ecosystem for 20 years and is much more popular, however, Nginx is not without its fair share of adva..
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HAProxyDevOps/MIddleware 2020. 5. 3. 01:41
1. Overview HAProxy is a reliable and high-performance load balancer that can operate on the TCP and HTTP networking layers it's a very popular free and open-source software load balancer that powers many distributed systems web applications and websites and is considered to be almost a standard for load balancers in the industry. It is actually very easy to set up but despite its simplicity and..
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Continuous integration (CI) and Continuous Delivery (CD)DevOps/CICD 2020. 2. 24. 00:43
1. Overview 1.1 What is CI Continuous integration (CI) is the practice of merging all developers' working copies to shared mainline several times a day 1.2 What is CD Continuous delivery (CD or CDE) is a software engineering approach in which teams produce software in short cycles, ensuring that the software can be reliably released at any time and, when releasing the software, doing so manually..
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User ManagementDevOps/CommandLine 2020. 1. 13. 12:54
1. Overview User management includes everything from creating a user to deleting a user on your system. User management can be done in three ways on a Linux system. 2. Description 2.1 Local user database /etc/passwd It has seven columns separated by a colon demyank:x:1000:1000:demyank:/home/demyank:/bin/bash username, an x, user id, primary group id, a description, name of home directory and a l..
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PermissionsDevOps/CommandLine 2020. 1. 13. 10:28
1. Overview chmod - modify file access rights su - temporarily become the superuser sudo - temporarily become the superuser chown - change file ownership chgrp - change a file's group ownership 2. Description 2.1 View permissions on a file [me@linuxbox me]$ ls -l /bin/bash -rwxr-xr-x 1 root root 316848 Feb 27 2000 /bin/bash The file "/bin/bash" is owned by user "root" The superuser has the right..
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Forward proxy and Reserve proxyDevOps/Server 2019. 9. 5. 08:38
1. Overview Let's distribute forward and reverse proxy used in Nginx and Apache. 2. Forward Proxy Acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some services, such as files, connection, web page, or other resources available from a different server and the proxy server evaluates the request as a way to si..