Camel 2.24.2 : PropertiesComponent override with environment variable - apache-camel

Question

I am attempting use the PropertiesComponent and reading a property file that is in my classpath. I have built a standalone executable jar and I am using the camel Main class - no spring boot.
However, I would like to override one of those properties using environment variables, but it is not working. I am able to override it using the -D, but the documentation indicated that it is possible to override it using an environment variable.
Here is the sample code snippets
Main main = new Main();
main.addRouteBuilder(new HelloRoute());
main.bind("doWork", new DoWork());
PropertiesComponent pc = new PropertiesComponent();
pc.setLocation("classpath:app.properties");
main.bind("properties", pc);
main.run();
Here is the property file
account.route.id=account_route_get
account.route.get=account_route_get_description
startup_route=false
And here is my route where I am attempting to use it. I am attempting to override the startup_route and it does not work correctly.
rest("/account")
.get("/{name}")
.consumes("application/json")
.outType(Account.class)
.route()
.id("{{account.route.id}}")
.description("{{account.route.get}}")
.autoStartup("{{startup_route}}")
.to("log:{{account.route.get}}?level=INFO")
.to("bean:doWork?method=info(${header.name})")
.endRest()
I found this CAMEL-13502 but it is in a different Camel version, and I am wondering if this is also relevant for Camel 2.24.2
Thanks

Answer 1

I'm guessing you don't want to explicitly call out that you want the variable from the OS environment variables.
If you did want to do that, you could state
.autoStartup("${env:STARTUP_ROUTE}")
but if you are wanting a more dynamic solution, another option could be to create a
choice()
that first checks if the environment variable of that name exists, and if not, to default to the one in the properties file.
.when("${env:STARTUP_ROUTE} != null")
.autoStartup("${env:STARTUP_ROUTE}")
.otherwise()
.autoStartup("{{startup_route}}")
Finally, the Camel documentation of Property Component also states:
You can control these modes using the systemPropertiesMode and environmentVariableMode options on the properties component.
When I ran a sample in my project, I did have the ability to configure the systemPropertiesMode, but I didn't have an option for environmentVariableMode so unsure if that is a feature of a higher level Camel version than I'm using.