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Externalized Configuration in Spring boot

I have a external configuration file(out side jar). I try to run and expected
that value in external file will override value in internal file(application.properties in \resource\ - in jar file).
I read Documentation and try this:
java -jar ccgame-1.0.jar --spring.config.location=classpath:/application.properties,file:/production.properties
This not working.
My jar file at \target\ directory and my production.properties too(at \target\)
How can I resolve my problem?
Where should I put external config file ?
And what I have to do ?

Starting from Spring Boot 2.0 it's possible to use property spring.config.additional-location. With this property, you can set external config file, but properties from that config will only override the corresponding ones from internal config, leaving other properties unchanged.
More about it in docs.
If you need to completely override the whole config, then continue to use spring.config.location property instead.

By convention, Spring Boot looks for an externalized configuration file – application.properties or application.yml – in 4 predetermined locations in the following order of precedence:
/config subdirectory of the current directory
The current directory
Classpath /config package
The classpath root
You can place your application.properties in any of the 4 locations without needing to give the location of application.properties while executing the jar. If you want to given any other custom location , then you will have to provide the path of the config location while executing the jar:
java -jar -Dspring.config.location=<path-to-file> myProject.jar
Source: https://www.baeldung.com/spring-properties-file-outside-jar

What is the loading precedence for properties from Spring Cloud Config?

Spring has an explicit order for the loading of externalized configurations.
Devtools global settings properties on your home directory (~/.spring-boot-devtools.properties when devtools is active).
#TestPropertySource annotations on your tests.
#SpringBootTest#properties annotation attribute on your tests.
Command line arguments.
Properties from SPRING_APPLICATION_JSON (inline JSON embedded in an environment variable or system property).
ServletConfig init parameters.
ServletContext init parameters.
JNDI attributes from java:comp/env.
Java System properties (System.getProperties()).
OS environment variables.
A RandomValuePropertySource that has properties only in random.*.
Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).
Profile-specific application properties packaged inside your jar (application-{profile}.properties and YAML variants).
Application properties outside of your packaged jar (application.properties and YAML variants).
Application properties packaged inside your jar (application.properties and YAML variants).
#PropertySource annotations on your #Configuration classes.
Default properties (specified by setting SpringApplication.setDefaultProperties).
However, there seems to be a glaring omission for configurations coming from Spring Cloud Config. Does anyone know where Spring Cloud Config fit above

As others have stated, the config-server comes first. If you are trying to override the config-server's properties with local properties (i.e. application-local.yml), then you need to add two properties to the config-server**:
spring.cloud.config.allowOverride=true
spring.cloud.config.overrideNone=true
Per the documentation:
The property sources that are added to you application by the
bootstrap context are often "remote" (e.g. from a Config Server), and
by default they cannot be overridden locally. If you want to allow your applications to override the remote
properties with their own System properties or config files, the
remote property source has to grant it permission by setting
spring.cloud.config.allowOverride=true (it doesn’t work to set this
locally). Once that flag is set there are some finer grained settings
to control the location of the remote properties in relation to System
properties and the application’s local configuration:
spring.cloud.config.overrideNone=true to override with any local
property source, and
spring.cloud.config.overrideSystemProperties=false if only System
properties and env vars should override the remote settings, but not
the local config files.
Also see this, regarding using spring.cloud.config.override-system-properties=false to override via system / command line properties. The documentation quoted above had/has an inconsistency, which I removed from the quote.
Note, if you want the remote config server to override your local properties file sources but not your local system properties or environment properties, add the following in the config server:
spring.cloud.config.allowOverride=true
spring.cloud.config.overrideNone=false
spring.cloud.config.overrideSystemProperties=false
** In this case the overrideSystemProperties value is ignored. See org.springframework.cloud.bootstrap.config.PropertySourceBootstrapConfiguration#insertPropertySources
Note: All the above applies to Spring Boot 2.3.x. Version 2.4.x uses an alternate loading priority. See https://github.com/spring-cloud/spring-cloud-config/issues/1856

The documentation states that:
The bootstrap properties show up in the /env endpoint as a high-priority property source, as shown in the following example
So it would be position #0

Points 12 and 14 cover Spring Cloud Config.
12.Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).
14.Application properties outside of your packaged jar (application.properties and YAML variants).

Spring boot deployed as WAR on tomcat, How to Externalize application.properties for different profiles(Dev,Test,Staging,Prod)

I am in a scenario where I am deploying by spring boot as a WAR on tomcat. Here in this application I have application.properties which has database username/password , some URL which help in consuming rest services(urls vary depending on the environment). Now I need to get the DB credentials and URL's depending on the environment it is deployed to. how to achieve it.

On external container ex tomcat
You can pass configuration using Jndi variable in context.xml
This var override local property defined in application.properties
Or pass -Dspring.profiles.active=env
in tomcat startup script ,for select environment specific application.properties
if you prefer to have configuration inside the war

As per 24. Externalized Configuration it should be enough to place a profile specific properties e.g. application-dev.properties on the classpath. The property precedence is:
...
Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).
Profile-specific application properties packaged inside your jar (application-{profile}.properties and YAML variants).
Application properties outside of your packaged jar (application.properties and YAML variants).
Application properties packaged inside your jar (application.properties and YAML variants).
...
This can however work slight differently if you are packaging as JAR as per 24.3 Application Property Files. The property precedence is:
A /config subdirectory of the current directory
The current directory
A classpath /config package
The classpath root

according to the discussion with Karol, I guess using properties sources referencing file system path should be ok:
#Configuration
#PropertySource("${mywebapp.config.dir}/application.properties")
public class SpringConfig {
}
And just path JVM args at the startup of tomcat like
-Dmywebapp.config.dir=file:/etc/mywebapp
This way you can deploy one application.properties different for each environment.
As for your comment:
#PropertySource(value={"file:C:/Users/foo/apache-tomcat-8.5.28/webapps/application.properties}"})
as it's a windows system path may you have to double backslash your path: C:\\Users\\foo ...

I am able to read the properties file from tomcat/webapp location
for every environment I can ask system engineers to drop the file at the location,
I dont know if its a good solution. Please suggest
#PropertySource(value={"file:C:/Users/foo/Downloads/apache-tomcat-8.5.28/webapps/application.properties"})

Why is Spring Boot's resource precedence ignoring my external properties files?

As part of a Spring Boot project I need to load certain properties file which, by default, is located under de src/main/resources directory. Also, I need to be able to, instead, load an external properties file (located at the root directory of the project). If this external file exists, the file path should be passed as command line property.
The file structure would be like this:
/app_project
Net.properties (external file)
/src
/main
/resources
Net.properties (default file)
The thing is that the dependency that makes use of those properties wouldn't work unless you copy/overwrite the contents of the external file into the file under the /resources directory.
UPDATED
So far I've tried:
loading the file as an external resource and loading it into a Properties object (https://docs.oracle.com/javase/7/docs/api/java/util/Properties.html)
saving the properties as System Properties
modifying the resource handler to look into other directories by overriding th addResourceHandlers() to include the location
Explicitly including the location of the file in the CLASSPATH with the -cp argument (as #veysiertekin suggested)
Loading it as a #PropertySource (as suggesed by #Nikolay Shevchenko)
Overriding the Spring Boot's config location with the spring.config.location (as suggested by #gWombat)
With all these methods I've tried, the file is indeed read and loaded but, at some point, and every time, the app resorts to the file under src/main/resources .
I suspect it may have to do with the precedence of the file (as described here https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html), but I just couldn't figure out what's happening.
Thanks in advance for your help.

Try smth like
#PropertySources({
#PropertySource(name = "default", value = "classpath:default.properties"),
#PropertySource(name = "external", value = "classpath:external.properties", ignoreResourceNotFound = true)
})
public class YourSpringBootApplication {
...
}

Based on the official doc, you can try to use the propertyspring.config.additional-location to add additional config file , or spring.config.location to override default file location.
You should pass those properties as program arguments so that Spring can use them on application startup.

When spring-boot project is running, it checks files under the builded jar file. You need to add your external file to classpath before running the application:
java -cp 'path-to/spring-boot-application.jar:Net.properties' test.SpringBootApplicationMain

spring boot: add new yml files to application config

i want developers to be able to locally override some configuration properties. (let's say we work on google drive and everyone should test it on its own account).
i don't want to override properties using command line (because it has to be set inside every IDE configuration and on every CLI run).
what i want is: application should use all the standard spring boot config files (application.yml etc) and also look for e.g. local.yml (on the classpath) or some file inside user.home. and those additional files should override other settings.
how to add new yml resources and order them correctly?
edit: i know spring's default orders and locations. question is about adding new ones

If you look in the Spring Boot documentation about the locations for configuration files (http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config), you can see, that they are loaded from the following places (amongst others):
Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants)
Application properties outside of your packaged jar (application.properties and YAML variants).
There are two default locations where they are loaded from ( see http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config-application-property-files):
A /config subdirectory of the current directory.
The current directory
Current directory in this case means the working directory for the Java process (Usually the directory where the JAR is located, or in case of running with in the IDE, usually the project root folder). So the developers just can place their own configuration files in that places and they are automatically loaded (and will override properties within the JARs). Add that files to .gitignore (or .svnignore or ...) and they won't accidentally committed into your repository.

There's a new way to do this, after Spring Boot v2.4, by using spring.config.import: https://spring.io/blog/2020/08/14/config-file-processing-in-spring-boot-2-4#importing-additional-configuration
By adding this part to your application.yml file, you should be able to import the additional configuration:
spring:
config:
import: local.yml
The article also has this section:
Imports can be considered as additional documents inserted just below the document that declares them. They follow the same top-down ordering as regular multi-document files: An import will only be imported once, no matter how many times it is declared.
So the contents of local.yml should be handled as if they were appended to the end of application.yml, thereby allowing you to override any property in application.yml.

From Spring Boot Documentation : Application property files:
SpringApplication will load properties from application.properties files in the following locations and add them to the Spring Environment:
A /config subdirectory of the current directory.
The current directory
A classpath /config package
The classpath root
The list is ordered by precedence (properties defined in locations higher in the list override those defined in lower locations).
This also goes for yaml, so you everyone can add application.yml under config directory, under the directory you run the spring boot jar from.
You can also customize the extra configuration file to be local.yml if you'd like by using spring.config.location:
--spring.config.location=classpath:/application.yml,classpath:/local.yml
Note however:
spring.config.name and spring.config.location are used very early to determine which files have to be loaded so they have to be defined as an environment property (typically OS env, system property or command line argument).

To provide the configuration from external config file in spring-boot application -
-Dspring.config.location=file:/home/vfroot/Workspace/project/MODULE_HOME/application.yaml
this command can be run with terminal:
mvn clean install -Dspring.config.location
= file:/home/vfroot/Workspace/MODULE_HOME/application.yaml
or need to set in Eclipse VM argument.
Also to set the active profiles :
-Dspring.profiles.active=dev

Well, since i am new in Spring Boot & Restfull Web Services. However, i managed to add a new .yml file to mange database and server port.
Instructions that i followed:
Project File.
Other Sources
src/main/resources
default package
right click on "default package"
add new YAML FILE
Or of YAML File option not available
5. right click on "default package"
6. then in categories: other --> File Types: YAML File