Скачать или смотреть How to Preserve \n Characters in Jelastic Environment Variables

A comprehensive guide on preserving newline characters in Jelastic environment variables when using manifest scripts. Learn the solution step by step.
---
This video is based on the question https://stackoverflow.com/q/71034377/ asked by the user 'Laurent Michel' ( https://stackoverflow.com/u/4434140/ ) and on the answer https://stackoverflow.com/a/71285666/ provided by the user 'Laurent Michel' ( https://stackoverflow.com/u/4434140/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How can I preserve \n characters in my jelastic environment variable?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Preserve \n Characters in Jelastic Environment Variables

When working with Jelastic, particularly when dealing with environment variables in your configurations, you might encounter the issue of newline characters being interpreted incorrectly. This can be problematic as you need to preserve these characters while ensuring that they do not translate into actual line breaks. Here’s how to solve this common dilemma.

The Problem

In a recent project, I attempted to install a Jelastic manifest that involved a secret key stored in an environment variable. After running the installation, I noticed that the newline characters (\n) were being interpreted as actual new lines instead of remaining as \n. This caused the environment variable SOME_SECRET to display incorrectly, cutting off the output at the first newline.

Expected Output

Ideally, upon executing the env command on my Ubuntu image, I wanted to see:

[[See Video to Reveal this Text or Code Snippet]]

The Solution

The solution to preserving the \n characters is to modify the manifest script correctly. Here’s how you can achieve this in a few easy steps.

Step 1: Use the Right API Method

Instead of using environment.control.SetContainerEnvVars, which removes all existing environment variables, opt for environment.control.AddContainerEnvVars to ensure you are adding or updating your environment variable without deleting others.

Step 2: Adjust Your getPublicKey Action

In your getPublicKey action, leverage the sed command to properly format the response. The use of sed will replace actual newline characters with \n, maintaining the integrity of your string.

Working Manifest

Here’s a sample manifest that addresses both issues:

[[See Video to Reveal this Text or Code Snippet]]

Key Points to Note

Proper Usage of sed: The command sed ':a;N;$!ba;s/\n/\n/g' is crucial as it collects all lines and replaces actual new lines with escaped ones.

Keep getPublicKey as a Separate Action: Ensure that your getPublicKey action remains in the manifest; if it's combined into the cmd, it would not work as expected due to execution context.

Common Mistakes to Avoid

Using SetContainerEnvVars: Always prefer using AddContainerEnvVars to avoid loss of existing variable settings unless intended.

Combining Commands Incorrectly: Ensure commands within your manifest are properly isolated for effective execution.

Conclusion

By following the above methods, you can successfully preserve \n characters in your Jelastic environment variables. Keeping newline characters intact is vital for the functionality of applications that depend on these variables. Test your configurations thoroughly to confirm the output meets your expectations.

Feel free to reach out if you have further questions or run into additional issues while working with Jelastic!