How to Use the Command 'sonar-scanner' (with examples)

The sonar-scanner command is a powerful tool designed to analyze projects with SonarQube that do not utilize build tools like Maven, Gradle, or Ant. SonarQube is an open-source platform that provides continuous inspection of code quality to perform automatic reviews with static analysis of code to detect bugs, code smells, and security vulnerabilities. The sonar-scanner is critical for ensuring code quality in environments where conventional build tools are not used, facilitating an easy and seamless way to start the analysis process.

Use case 1: Scan a project with configuration file in your project’s root directory named sonar-project.properties

Code:

sonar-scanner

Motivation:

This command is the simplest way to start a SonarQube analysis for projects that have a configuration file named sonar-project.properties in the root directory. This properties file typically includes essential details about the project, such as the project key, name, source encoding, and other relevant configurations. Running the sonar-scanner without additional arguments assumes that all necessary configurations are properly set in this default file.

Explanation:

• sonar-scanner: This invokes the generic scanner without any additional parameters, assuming that the necessary configuration file is named sonar-project.properties and is located in the root directory. The scanner processes this file to gather all required configurations for the analysis.

Example output:

INFO: Scanner configuration file: /path/to/scanner/conf/sonar-scanner.properties
INFO: Project root configuration file: /path/to/project/sonar-project.properties
INFO: Start SonarQube analysis
INFO: Downloading from http://localhost:9000
INFO: Analysis successful, view the project at http://localhost:9000/dashboard?id=your_project_key

Use case 2: Scan a project using configuration file other than sonar-project.properties

Code:

sonar-scanner -Dproject.settings=myproject.properties

Motivation:

In some cases, you might need to use a configuration file with a different name or located in a different directory. This flexibility can be useful if you are managing multiple configurations or running analyses on different environments. By specifying a custom configuration file, you can override the default sonar-project.properties and ensure the scanner reads the intended configurations.

Explanation:

• sonar-scanner: Executes the scanner process.
• -Dproject.settings=myproject.properties: This option specifies the path of the configuration file to be used by the scanner. Instead of the default sonar-project.properties, the scanner will use myproject.properties, which should include all necessary project details and configurations.

Example output:

INFO: Scanner configuration file: /path/to/scanner/conf/sonar-scanner.properties
INFO: Project root configuration file: /path/to/project/myproject.properties
INFO: Start SonarQube analysis
INFO: Downloading from http://localhost:9000
INFO: Analysis successful, view the project at http://localhost:9000/dashboard?id=your_project_key

Use case 3: Print debugging information

Code:

sonar-scanner -X

Motivation:

When problems arise during analysis, debugging helps diagnose the issues. The -X option provides detailed logging, allowing you to trace errors, warning, or failures that occur during the scan. This extended verbosity is crucial for troubleshooting, especially in complex project setups or when the scan does not complete as expected.

Explanation:

• sonar-scanner: Initiates the scan process.
• -X: Enables debug-level logging, which increases the verbosity of the output. This includes detailed diagnostic information about each step the scanner takes during the analysis, helping identify the root of any issues present.

Example output:

DEBUG: Uploading file: /path/to/project/file
DEBUG: Validating the downloaded analysis report
....
DEBUG: Analysis report generated in 350ms  
DEBUG: Analysis report compressed in 120ms, total 470ms
INFO: Analysis report uploaded
INFO: Analysis successful, view the project at http://localhost:9000/dashboard?id=your_project_key

Use case 4: Display help

Code:

sonar-scanner -h

Motivation:

For users new to the sonar-scanner or those looking to recall specific command options, the help view provides quick access to detailed usage information. This built-in command reference is invaluable for understanding the capabilities and options available within the scanner, ensuring you can efficiently utilize its features.

Explanation:

• sonar-scanner: Command to initiate the help process.
• -h: Triggers the display of help information, listing available options, and commands with a description of their functions.

Example output:

Usage: sonar-scanner [options]
Options:
  -h,--help         Display help information
  -X,--debug        Produce execution debug output
  ...

Conclusion

The sonar-scanner command is a powerful utility in a developer’s toolkit for ensuring code quality across environments that do not rely on traditional build tools. Whether using a default configuration, providing a bespoke project settings file, or generating debug information for troubleshooting, these examples illustrate how versatile and essential the sonar-scanner can be in maintaining high standards of coding practice.