How to check if a variable exists in Jinja2?
How to check if a variable exists in Jinja2?
Jinja2: Check If Variable – Empty | Exists | Defined | True. In Jinja2 templates, it is often a good practice to test if a variable exists and what value does it carry. There are several useful tests that you can make using Jinja2 builtin tests and filers.
What to expect in Part 2 of Jinja2?
Welcome to part 2 of my Jinja2 Tutorial. In part 1 we learned what Jinja2 is, what are its uses, and we started looking at templating basics. Coming up next are loops and conditionals, sprinkled with tests and a healthy dose of examples! In Jinja2 loops and conditionals come under name of control structures, since they affect flow of a program.
When to use a defined test in Jinja2?
If you simply want to check if the variable exists then is defined test, which we’ll look at shortly, is usually a better choice. Tests in Jinja2 are used with variables and return True or False, depending on whether the value passes the test or not. To use this feature add is and test name after the variable.
What kind of conditional statement does Jinja2 use?
Jinja2 implements one type of conditional statement, the if statement. For branching out we can use elif and else. Conditionals in Jinja2 can be used in a few different ways. We’ll now have a look at some use cases and how they combine with other language features. Comparisons.
How is includes and imports used in Jinja salt?
Includes and imports can be used to share common, reusable state configuration between state files and between files. This would import the test template variable or macro, not the test state element, from the file lib.sls.
What is the value of slspath in Jinja?
The value of slspath in files referenced in the current sls depends on the reference method. For jinja includes slspath is the path to the current directory of the file. For salt includes slspath is the path to the directory of the included file.
How does the raise Jinja function in SaltStack work?
Saltstack allows raising custom errors using the raise jinja function. When rendering the template containing the above statement, a TemplateError exception is raised, causing the rendering to fail with the following message: Saltstack extends builtin filters with these custom filters: