How to use the command 'cs launch' (with examples)

This article will guide you through the various use cases of the ‘cs launch’ command, which allows you to launch an application directly from one or more Maven dependencies without the need for installation.

Use case 1: Launch a specific application with arguments

Code:

cs launch application_name -- argument1 argument2 ...

Motivation: This use case is useful when you want to quickly launch a specific application and provide additional arguments to it.

Explanation: The ‘cs launch’ command is followed by the name of the application you want to launch. After that, you can specify any additional arguments you want to pass to the application.

Example Output:

cs launch myapp --arg1 value1 --arg2 value2

The command will launch the ‘myapp’ application with the provided arguments ‘–arg1 value1’ and ‘–arg2 value2’.

Use case 2: Launch a specific application version with arguments

Code:

cs launch application_name:application_version -- argument1 argument2 ...

Motivation: Sometimes you may need to launch a specific version of an application. This use case allows you to do just that while also providing additional arguments.

Explanation: In this use case, you need to specify the application name followed by a colon ‘:’ and the desired version number. Then, you can pass any additional arguments to the application.

Example Output:

cs launch myapp:1.0.0 --arg1 value1 --arg2 value2

The command will launch version 1.0.0 of the ‘myapp’ application with the provided arguments ‘–arg1 value1’ and ‘–arg2 value2’.

Use case 3: Launch a specific version of an application specifying main file

Code:

cs launch group_id:artifact_id:artifact_version --main-class path/to/main_class_file

Motivation: This use case is useful when you want to specify the main file of the application explicitly.

Explanation: Here, you need to provide the group ID, artifact ID, and version of the application separated by colons. Additionally, you can specify the main class file by using the ‘–main-class’ option followed by the path to the main class file.

Example Output:

cs launch com.example:myapp:1.0.0 --main-class com.example.Main

The command will launch version 1.0.0 of the ‘myapp’ application with the main class ‘com.example.Main’.

Use case 4: Launch an application with specific java options and JVM memory ones

Code:

cs launch --java-opt -Doption_name1:option_value1 -Doption_name2:option_value2 ... 
    --java-opt -Xjvm_option1 -Xjvm_option2 ... application_name

Motivation: This use case allows you to launch an application with specific Java options and JVM memory options, giving you fine-grained control over the execution environment.

Explanation: The ‘–java-opt’ flag followed by ‘-D’ allows you to specify Java system properties. You can provide the option name and its value separated by a colon. The ‘–java-opt’ flag followed by ‘-X’ allows you to specify JVM options. Similarly, you can provide the option name and its value separated by a colon. Finally, you need to specify the name of the application you want to launch.

Example Output:

cs launch --java-opt -Denv=production --java-opt -Dlog.level=debug --java-opt -Xmx2g myapp

The command will launch the ‘myapp’ application with the Java system properties ’env=production’ and ’log.level=debug’, as well as the JVM option ‘-Xmx2g’ (2 gigabytes of maximum heap memory).

Conclusion:

The ‘cs launch’ command is a powerful tool for launching applications from Maven dependencies. With its versatile use cases, you can easily launch specific applications with various options and arguments, providing you with flexibility and control.