Installing and Configuring Grafana

In Linux, you can access and edit text files using a text editor that is designed to work with plain text. These files are not specifically coded or formatted. Linux allows one to create a file in numerous ways. The fastest is, probably, Linux Command Line or Terminal. For all users—especially server administrators—who must rapidly generate text files, scripts, or configuration files for their work, this is a very important ability. Let's proceed to the guide on four standard techniques for creating a text file on the terminal. Prerequisites for File Creation in Linux Ensure these prerequisites are met before generating files in a Linux environment using the command-line interface: Access to a Functional Linux System: You must either have a Linux-based operating system installed on your computer or secure access to a Linux server via SSH (Secure Shell) protocol. Operational Terminal Interface: Confirm that your terminal application is accessible and fully operational. The terminal serves as your primary gateway to executing commands. Adequate User Permissions: Verify you can create files within the chosen directory. You may need to use sudo (for directories with access restrictions) to escalate privileges. Fundamental Commands Proficiency: You must get familiar with essential commands, such as touch for file creation, echo for printing text, cat for viewing file contents, and text editors like nano, vim, or vi for editing files directly. Text Editing Utilities: Ensure your system includes text editing tools: nano for command line simplicity, vim for advanced configurations, or graphical options like gedit for user-friendly navigation. Directory Management Expertise: Develop familiarity with directory navigation commands like cd for changing the working directory and ls for listing directory contents. This knowledge streamlines your workflow and avoids potential errors. Using the touch Command Generally, we use the touch command to create empty files and change timestamps. It will create an empty file if it doesn't exist already.  To create a text file in the current directory with the touch command: Open your terminal emulator. Type the command: touch filename.txt Change "filename" to your desired name. The timestamps for access and modification will be updated without changes in file content if the file exists already. Otherwise, an empty file is created with a given name.  Press Enter—if it is successful, there will be no output. Use the ls command to list the directory content and verify file creation. Using the echo Command Redirection The echo command is widely used to display text on the terminal. But its capabilities go beyond that; it may also be used to write content to a file or create an empty file. For this, combine the echo command with double redirect symbols (you can also use a single >) and the desired filename. A text file can be created by redirecting the output of the echo command to a file. See how it works: Open your terminal emulator. Type the command: echo “Your text content here” > filename.txt Replace the text in double quotations (do not delete them) with yours to add it to the file.  After you press Enter, your text will be added to the file filename.txt. It will overwrite an existing file, if there is one. Otherwise, it will just create a new one. Press Enter. To verify that the file has been created and contains the desired content, use cat command to display the content.  Using the cat Command Redirection In Linux, the cat command is mostly used to concatenate and show file contents. It can, however, also be used to generate a text document by redirecting the standard output of cat to a file. Open your terminal emulator. Type the following command: cat > filename.txt Replace filename.txt with the name for your text file. This command instructs cat to receive input rom the terminal and to redirect it into the filename.txt. Press Enter. The terminal will be waiting for input.  Enter the text you want in the file. Press Enter after each line. Press Ctrl + D when you are done. This signals the end of input to the cat and saves the content.  Run the cat command to check that the file has been created and contains the desired content. Start using Hostman efficient S3 storage Using printf for Advanced File Creation The printf utility is a powerful alternative to echo, offering enhanced formatting options for structuring text. It allows users to create files with precisely formatted content. Open the terminal. Use printf to define the text layout, incorporating formatting elements like newlines (\n) or tabs (\t). Redirect the output to a file using the > operator. Example: printf "First Line\nSecond Line\nIndented\tThird Line\n" >  formatted_file.txt Run the cat command to inspect the file's content and ensure the formatting matches expectations. Append Without Overwriting: To add content to an existing file without overwriting its current data, replace > with the append operator >>: printf "Additional content here.\n" >> formatted_file.txt Using a Text Dditor You can also create new files in linux text editors. There is always at least one integrated command-line text editor in your Linux distribution. But you can choose and install a different one according to your preferences, for example, Vim, Nano, or Emacs. Each of them has its own features and advantages. Vim vim, which stands for "Vi IMproved," is a very flexible and adaptable text editor. It is well-known for its modal editing, which allows for distinct modes for various functions like text entry, navigation, and editing. It allows split windows, multiple buffers, syntax highlighting, and a large selection of plugins for extra features. To create a text file using vim, follow the steps below: Open vim, with the desired filename as an argument. Press i to switch to Insert mode. Start typing and editing the filename.txt.  To save and exit, press Esc to ensure that command mode is running. Type: wq (write and quit) and press Enter. Nano nano is ideal for short adjustments and straightforward text files because it is lightweight and requires little setup. It provides support for basic text manipulation functions, search and replace, and syntax highlighting. To create a text file using nano, follow the steps below:  Run nano with the desired filename as an argument. It will open a new buffer for editing the file filename.txt. Start typing and editing the filename.txt.  To save and exit, press Ctrl + O to write the file, confirm the filename, and then press Ctrl + X to exit Nano. Emacs emacs is a powerful and flexible text editor that supports syntax highlighting, multiple buffers, split windows, and integration with external tools and programming languages. To create a text file using emacs, follow the steps below:  Open emacs, with the desired filename as an argument. Start typing and editing the filename.txt.  To save and exit, press Ctrl + X, followed by Ctrl + S to save the file, and then Ctrl + X, followed by Ctrl + C to exit Emacs. Note: If a message states that "VIM command not found", "nano command not found" or "emacs command not found" in Linux, it typically means that the vim, nano or emacs text editor is not installed on the system, or it's not included in the PATH environment variable, which is a list of directories where the operating system looks for executable files. To resolve this, install the text editor first using the command:  apt-get install vim apt-get install nano  apt-get install emacs Gedit An intuitive text editor that supports working with plain text and has syntax highlighting for programming languages. A straightforward graphical interface makes it usable for various tasks, from quick edits to complex document preparation. Open the Gedit Application: Launch Gedit either through the applications menu or by executing the following command in the terminal: gedit example.txt Gedit will create a new file if the specified one does not exist. Input Your Text: Type or paste your desired content into the editor. Save the File: Save your work with Ctrl + S or select File > Save. If creating a new file, specify a filename and a location. Verify: Return to the terminal and confirm the file exists with the ls command or review its content with cat. Linux File Creation Recommendations Ensure you have sufficient permissions to create files in the target directory. If they are insufficient, consider working in a directory where you have full rights (or elevate privileges with sudo). Check if a file with the identical name is already present before using the > operator, as the command will overwrite existing content. To prevent data loss, opt for the append operator >>. Familiarize yourself with the printf, echo, and text editors like vim or nano. These tools will help you reduce errors when working with files in Linux, as well as boost productivity. Use printf for creating files requiring structured content, such as configuration files or scripts with precise formatting needs. Conclusion Now you have acquainted yourself with the fundamental skill of creating a file in Linux using the terminal! Using the Linux command line, several fast and efficient methods exist to create and manage text files. Apply several techniques to meet a different requirement using the touch, echo, cat, printf commands, or text editors like vim, nano, gedit, or emacs. Users can select the method that sufficiently meets their requirements, such as creating empty files, appending text, or significantly modifying material. In summary, any of these methods enable Linux users to easily and quickly handle text files straight from the command line. Hostman offers a reliable managed Linux VPS for your projects.

The SSH (Secure Shell) protocol is a network protocol for remote command-line management of operating systems, widely considered the standard for remote access to *nix machines. It allows secure login to a server, remote command execution, file management (creating, deleting, copying, etc.), and more. Most cloud and hosting providers require SSH to access their services. In this article, we’ll look at how to copy files over SSH on both Windows and Linux systems. How SSH Works SSH can securely transmit any data (audio, video, application protocol data) through an encrypted communication channel. Unlike outdated and insecure protocols like Telnet and rlogin, SSH ensures data confidentiality and authenticity — essential for internet communications. Here’s how a secure connection between a client and server is established: TCP Connection Setup: By default, the server listens on port 22. Both sides share a list of supported algorithms (compression, encryption, key exchange) and agree on which to use. Authentication: To prevent impersonation, both parties verify each other's identities using asymmetric encryption (public/private key pairs). First, the server is authenticated. On the first connection, the client sees a warning with server details. Trusted server keys are stored in /home/<username>/.ssh/known_hosts. Key Generation: Once the server is verified, both sides generate a symmetric key to encrypt all data exchanged. User Authentication: This is done using either a password or a client-sent public key stored in /home/<username>/.ssh/authorized_keys on the server. The most popular implementation on Linux is OpenSSH, which comes pre-installed on most distributions (Ubuntu, Debian, RHEL-based, etc.). Clients like PuTTY or MobaXterm are used on Windows. Since Windows 10 and Server 2019, OpenSSH tools are also available natively. You can learn more about working with SSH in our tutorial. File Copying via SSH Two main utilities for copying files over SSH in Linux are scp and sftp. Both come with OpenSSH. SSH supports two protocol versions: 1 and 2. OpenSSH supports both, but version 1 is rarely used. Autocompletion Setup To enable Tab-based autocompletion when using scp, set up public key authentication: Generate a key pair: ssh-keygen You’ll see output like: Generating public/private rsa key pair. Enter file in which to save the key (/home/user/.ssh/id_rsa): Enter passphrase (empty for no passphrase): By default, your keys (id_rsa for private and id_rsa.pub for public) are saved to ~/.ssh/. Now copy the public key to the remote machine: ssh-copy-id [username]@[ip-address] After entering the user's password, you’ll see a message confirming the key was added. Secure Copy (SCP) For small data transfers (e.g., service configs), scp is best. Copy from local to remote: scp test.txt user@192.168.1.29:/home/user/ Copy multiple files: scp test1.txt test2.txt user@192.168.1.29:/home/user/ Copy from remote to local: scp user@192.168.1.29:/home/user/test.txt ~/ Copy directories: scp -r testdir user@192.168.1.29:/home/user/ Remote-to-remote copy: scp gendo@192.168.1.25:/home/gendo/test.txt user@192.168.1.29:/home/user/ Secure FTP (SFTP) SFTP is another utility included in OpenSSH. As of OpenSSH 9.0, scp now uses SFTP by default instead of the old SCP/RCP protocol. Unlike classic FTP, sftp transmits encrypted data over a secure tunnel. It does not require a separate FTP server. Example usage: sftp misato@192.168.1.29 sftp> ls sftp> lcd testdir/ sftp> get test.txt sftp> bye Graphical file managers like Midnight Commander and Nautilus use sftp. In Nautilus, the remote server appears like a local folder, e.g., user@ip. Copying Files Over SSH on Windows Use the pscp command-line tool from PuTTY to copy files on Windows. Copy to server: pscp C:\server\test.txt misato@192.168.1.29:/home/misato/ Copy from server: pscp misato@192.168.1.29:/home/misato/test.txt C:\file.txt List files on remote server: pscp -ls user@192.168.1.29:/home/misato Use quotes for paths with spaces: pscp "C:\dir\bad file name.txt" misato@192.168.1.29:/home/misato/ To get help, run: pscp Conclusion We’ve covered how to copy files to and from a server using the secure SSH protocol. If you work with cloud servers, understanding SSH is essential — it’s the standard method for remote access to *nix machines and a vital part of everyday DevOps and system administration.

The term daemon comes from a word in ancient Greek mythology that referred to an immaterial being influencing the human world. In computing, especially in UNIX-like operating systems, a daemon is a background process that runs without direct interaction from the user. It doesn’t depend on a terminal or user interface and typically starts with the system boot or under specific conditions. What is a Daemon The main function of a daemon is to provide specific services to other processes or users. For example, a daemon might listen on network ports waiting for connections, monitor system events and respond when certain conditions are met, manage scheduled jobs (like cron), send emails (sendmail), and more. In Windows, the closest equivalent to a daemon is a service. The difference lies mainly in how they're started, registered, managed, and configured within operating systems. However, their purpose is the same: to ensure continuous background operation of certain functions or services. Key Characteristics of a Daemon Runs in the background: Users typically don’t see the daemon’s interface; it doesn’t write to standard output (or redirect it to logs), nor does it request keyboard input. Autonomous: A daemon starts either at system boot when triggered by an init system (like systemd), or manually by a user (via scripts, cron, etc.). Long-lived: Ideally, a daemon runs indefinitely unless a critical error occurs or it receives an explicit stop signal. Isolated: Usually runs under a separate user/group account to minimize privileges, making services more secure and easier to manage. Logging: Instead of using standard input/output, daemons log information to log files or the system logger (journald, syslog, etc.), which is helpful for debugging and diagnostics. Daemons in Linux Historically, nearly all system background tasks in Linux are implemented as daemons. The OS includes dozens of them, each responsible for a specific function. Here are some examples: sshd (Secure Shell Daemon): Listens on port 22 (by default) and allows remote users to connect via encrypted SSH. Without sshd, remote terminal access is almost impossible. cron: A job scheduler daemon. It checks crontab entries and runs scripts or commands on a schedule, such as log cleanup, sending reports, system checks, etc. syslogd / rsyslog / journald: System logging daemons that collect messages from the kernel, utilities, other daemons, and apps, and save them in log files or the journal. NetworkManager or Wicd: Daemons that manage network settings — automating connections to wired/wireless networks, switching, configuring VPNs, and more. These daemons start at system boot and are registered with the system service manager (e.g., systemd). They run until the system is shut down or rebooted. Users interact with them indirectly — through config files, terminal commands (service, systemctl), or network requests (if the daemon provides HTTP/S, SSH, or another network interface). How to Create and Manage Daemons To implement a daemon, follow these steps: Forking the process: The parent process calls fork() and continues running the daemon code in the child process. Detach from controlling terminal (setsid): To avoid user interference (e.g., closing the terminal), the daemon calls setsid() to start a new session and become its leader. Close standard input/output descriptors: Since the daemon shouldn't write to the screen or wait for input, stdin, stdout, and stderr are closed or redirected to log files. Handle signals and logging: To support graceful shutdown or config reloads, the daemon must handle signals (SIGTERM, SIGHUP, etc.). Logging is usually done via syslog or files. Main loop:  After initialization, the daemon enters its main loop: waiting for events, handling them, and repeating until stopped. Let’s see how to create a daemon on Ubuntu 22.04 using a Hostman cloud server 1. Write the Daemon in C Create a file called mydaemon.c and insert the following code: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <syslog.h> int main() { // Open syslog openlog("mydaemon", LOG_PID, LOG_DAEMON); syslog(LOG_NOTICE, "Daemon started"); // Main infinite loop while (1) { // Your background tasks: monitoring, queue handling, etc. syslog(LOG_NOTICE, "Performing task..."); sleep(60); } // If we ever exit the loop syslog(LOG_NOTICE, "Daemon stopped"); closelog(); return 0; } 2. Compile the Program First, update your packages: sudo apt update && sudo apt upgrade Install the GCC compiler if not already installed: sudo apt install gcc Compile the daemon: gcc mydaemon.c -o mydaemon 3. Move the Executable Move the binary to /usr/local/bin/, a standard location for custom utilities: mv mydaemon /usr/local/bin/mydaemon 4. Create a systemd Service Create a unit file called mydaemon.service: sudo nano /etc/systemd/system/mydaemon.service Insert the following content: [Unit] Description=My Daemon After=network.target [Service] Type=simple ExecStart=/usr/local/bin/mydaemon Restart=on-failure [Install] WantedBy=multi-user.target Explanation of the fields: Description: Description shown in systemctl status. After=network.target: Ensures the daemon starts after the network is up. Type=simple: The daemon doesn’t fork, it runs as a single process. ExecStart: Path to the daemon executable. Restart=on-failure: Restart automatically if the daemon crashes. WantedBy=multi-user.target: Makes the service start in the standard multi-user environment. 5. Start and Monitor the Daemon sudo systemctl daemon-reload # Reload systemd configuration sudo systemctl start mydaemon # Start the daemon sudo systemctl status mydaemon # Check its status If everything works, the status will show active. To view logs: journalctl -u mydaemon.service -e Examples of Daemon Usage Web Servers Their job is to listen on a network port (usually 80 or 443), accept HTTP/HTTPS requests, generate a response (an HTML page, JSON data, etc.), and send the result back to the client. In most cases, a web server starts with the system and continues running until the server is shut down or a stop command is issued (e.g., systemctl stop nginx). Database Daemons MySQL/MariaDB, PostgreSQL, MongoDB — all of these are also daemons. They start with the system and continue running in the background, accepting requests from client applications or web services. These daemons typically log activity, support configuration via files, and are managed using special utilities (or systemd). Job Schedulers (cron, atd) The cron daemon checks the schedule table (crontab) and runs programs at the times or intervals specified by the user. This makes it possible to automate backups, system updates, health checks, and many other routine tasks. atd is a similar daemon but executes tasks only once at a specific time (unlike cron, which runs tasks on a regular schedule). Access and Control Services (sshd, xrdp) sshd (Secure Shell Daemon) provides remote access via the SSH protocol. xrdp enables remote desktop connections using the RDP protocol. It acts as a daemon that listens for network connections on a specified port. Init System Daemons (systemd, init, Upstart) In modern systems, the role of the "main daemon" is fulfilled by systemd (replacing the older SysV init system). systemd is the first process to start after the kernel and is responsible for launching and managing all other services and processes. It starts them in parallel and handles their dependencies. Simply put, systemd is itself a daemon that “orchestrates” all others in the system. Advantages and Disadvantages of Daemons Advantages: Automation: Daemons enable system behavior to be automated — from responding to network requests to scheduling tasks — without user intervention. Isolation: Running under separate user/group accounts and detaching from terminals enhances security by limiting potential damage in case of compromise. Continuous Operation: A daemon can keep servicing requests (like a web server) without interruption even if the user logs out or the console is closed. Manageability: Linux provides system tools (e.g., systemd, init scripts) to centrally manage all daemons: starting, stopping, restarting, and logging. Disadvantages: Debugging Complexity: Since daemons run in the background and don’t output to the console, debugging requires thorough logging and more complex setups (debug flags, tracing, etc.). Security Risks: If a daemon runs with elevated privileges (e.g., as root), any vulnerability can potentially compromise the entire system. It's best to run daemons under limited accounts. Dependency Management: Some daemons may fail if, for example, they need network access before the network is up. Modern init systems solve this, but with classic SysV init scripts, this used to be a common issue. Increased Resource Usage: Any constantly running background process consumes system resources (memory, CPU time). If there are too many daemons, this can impact performance, especially on systems with limited resources. Conclusion Daemons are central to Linux operating systems' architecture, offering vast automation and background services capabilities. They allow administrators to flexibly configure network operations, scheduled tasks, logging, security systems, and many other components. Writing your own daemon requires understanding processes, signals, system calls, and careful attention to logging and security. Modern init systems (especially systemd) have simplified daemon management and service logic, making the creation of custom services more structured and flexible. However, it remains a complex field that demands careful design, debugging, and ongoing maintenance.