I specified Spring properties inside the application.properties file. How can i populate those properties from the environment variables?
Here is what I tried, but it doesn't seem to work:
application.properties
spring.datasource.url=jdbc:postgresql://#{ systemProperties['DATABASE_HOST']}:5432/dbname
spring.datasource.username = postgres
spring.datasource.password = postgres
You can refer to environment properties in the same way you refer to Spring properties using ${...} syntax.
In your case:
spring.datasource.url=jdbc:postgresql://${DATABASE_HOST}:5432/dbname
Out of the box, as you know, spring-boot expects its Datasource details to be using a specific set of variable names. Being spring of course you can rework this if you need by a few methods:
1/ If the need to use variables from the environment comes from deployment to a cloud service such as Cloud Foundry or Horuku, there is spring-boot-starter-cloud-connector which handles allot of the plumbing out of the box. A good read is the (Binding to Data Services with Spring Boot in Cloud Foundry article and the Deploying to the cloud docs which walks you thru this
2/ Instead of relying on Spring-Boot's own auto-magical wiring mechanism, you can create a custom configuration bean to override how the DataSource information is populated. A good read explaining the annotations involved can be found here: Spring Java Config Documentation - #Bean Configuration JavaDOC. Based on your example above, here is what I spat out:
#Configuration
public class MyDataSourceConfig {
#Bean
#Primary
public DataSource getDataSource() {
String url = "jdbc:postgresql://" + System.getenv("DATABASE_HOST") + ":5432/dbname";
String username = "postgres";
String password = "postgres";
String driverClassName = "org.postgresql.Driver";
/*
* Create the datasource and return it
*
* You could create the specific DS
* implementation (ie: org.postgresql.ds.PGPoolingDataSource)
* or ask Spring's DataSourceBuilder to autoconfigure it for you,
* whichever works best in your eyes
*/
return DataSourceBuilder
.create()
.url( url )
.username( username )
.password( password )
.driverClassName( driverClassName )
.build();
}
}
Just remember that in spring, you can always override allot of the default behaviours with a little bit of digging!
Hope this helps!
You don't have to. When Spring Boot initializes its environment, it pulls stuff from both the application.properties file and any system-level variables and combines them together. The full list of locations where Spring takes them from is here, specifically points 9) and 10).
Related
I am working with spring boot. I have properties defined in application.yml.
spring:
datasource:
username: username
password: password
username and password values are stored externally which program fetches during startup. let's say the bean which fetches them during startup is dbConfig
How can I inject values from dbConfgig to application.yml?
I am using spring-data-jpa autoconfigure which automatically connects to database at startup. I want these values to be loaded to application.yml before spring connects to database.
There is no need to inject the user/password in application.yml. You can set them programmatically like this:
#Configuration
public class DataSourceConfig {
#Bean
public DataSource getDataSource() {
DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create();
dataSourceBuilder.driverClassName("org.h2.Driver");
dataSourceBuilder.url("jdbc:h2:mem:test");
// Take the values from external source, then set them
dataSourceBuilder.username("username");
dataSourceBuilder.password("password");
return dataSourceBuilder.build();
}
}
I think that first, you must create a thread to detect the change at your db Config file and then may you must re-init your bean (data source) to make your change effect.
See:
how-to-reinitialize-a-spring-bean
You may also try spring cloud to store properties. And you can then use with the help of placeholders.
https://cloud.spring.io/spring-cloud-config/reference/html/
I have mysql database and i have configured database properties in application.properties file .
Now if i do change db connection properties , i want reflect that changes into my application on the fly , means with out restarting the server
Is this possible using with spring cloud config server and actuator?
I have tested this quite a bit and here are my findings.
Spring config server works pretty well for simple key value pairs.
It also works for Database properties provided that you are creating datasource objects yourself and you are using #RefreshScope.
For example, if you have a config server with these properties.
mongodb.feed.database=kiran
mongodb.feed.host=localhost
mongodb.feed.port=27017
And you are configuring MongoTemplate in your application like this.
#Configuration
#ConfigurationProperties(prefix = "mongodb.feed")
#EnableMongoRepositories(basePackages = "in.phani.springboot.repository", mongoTemplateRef = "feedMongoTemplate")
#Setter
class FeedMongoConfig {
private String host;
private int port;
private String database;
#Primary
#Bean(name = "feedMongoTemplate")
#RefreshScope // this is the key
public MongoTemplate feedMongoTemplate() throws Exception {
final Mongo mongoClient = createMongoClient(new ServerAddress(host, port));
return new MongoTemplate(mongoClient, database);
}
Mongo createMongoClient(ServerAddress serverAddress) {
return new MongoClient(serverAddress);
}
}
And if you change the database name in your config properties and then refresh the scope with /refresh endpoint. It works pretty well.
With springboot you need not do manual configuration like this. Spring boot has Autoconfiguration for most of the stuff. Continuing with the same example above, if you were to put in config properties something like this
spring.data.mongodb.uri=mongodb://localhost:27017/phani
spring-boot will configure MongoTemplate for you(you don't need to create yourself as in 2nd point).
Here comes the hiccup.
Now if you change the database name, and refresh the scope, it doesn't work. Because in this case, MongoTemplate was configured by spring-boot Autoconfiguration(MongoAutoConfiguration)
So in conclusion, it needs extensive testing to be done, before using it on production(especially for complex beans like datasources, MongoTemplates), since there is not enough documentation on this.. But I would say, it is worth trying.
I am trying to update datasource in Spring Boot when the DB property like DB name, password or hostname changes in the spring configuration file or custom DB property file. When the property changes the application has to update by its own by listening changes to property.
I was using Spring actuator to /restart beans once the DB configuration is changed. But user has to explicitly make a post request to restart. This step has to be avoided by listening to the changes and update datasource.
Can you tell me the best way to do this in Spring boot?
Found a way to update datasource on-the-fly,
I have given external spring config file which contains DB properties to the application and then refreshed the properties using #RefreshScope for the datasource bean.
A thread monitors the file changes and makes a call to actuator refresh() method.
database.properties
dburl=jdbc://localhost:5432/dbname
dbusername=user1
dbpassword=userpwd
Creating datasource,
#RefreshScope
public class DBPropRefresh {
#Value("${dburl}")
private String dbUrl;
#Value("${dbusername}")
private String dbUserName;
#Value("${dbpassword}")
private String dbPassword;
#Bean
#RefreshScope
public DataSource getDatasource() {
return new DatasourceBuilder().create().url(dbUrl).username(dbUserName).password(dbPassword);
}
}
Giving external config file to the application,
java -jar myapplication.jar --spring.config.location=database.properties
I have created a Java thread class to monitor database.properties file changes. Followed https://dzone.com/articles/how-watch-file-system-changes
When there are changes then it makes call to refreshEndPoint.refresh().
In pom.xml,
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
<version>1.5.6.RELEASE</version>
</dependency>
You can use Spring's Dynamic Data Source routing and check if it helps? It's a very old technique and might come handy, if that serves your purpose.
But please note that - this is data source routing and not new data source configuration.
https://spring.io/blog/2007/01/23/dynamic-datasource-routing/
In my project I used multitenancy . Basically I defined several datasources in properties like this:
primary.datasource.url=jdbc:postgresql://localhost:5432/db_name?currentSchema=schema_name
primary.datasource.username=user
primary.datasource.password=password
primary.datasource.driverClassName=org.postgresql.Driver
primary.datasource.driver-class-name=org.postgresql.Driver
secondary.datasource.url=jdbc:postgresql://localhost:5432/other_db?currentSchema=schema
secondary.datasource.username=user
secondary.datasource.password=password
secondary.datasource.driverClassName=org.postgresql.Driver
secondary.datasource.driver-class-name=org.postgresql.Driver
default.datasource.url=jdbc:postgresql://localhost:5432/default_db?currentSchema=public
default.datasource.username=user
default.datasource.password=password
default.datasource.driverClassName=org.postgresql.Driver
default.datasource.driver-class-name=org.postgresql.Driver
then in configuration class defined multiple datasources:
#Bean
#Primary
#ConfigurationProperties(prefix="primary.datasource")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
#Bean
#ConfigurationProperties(prefix="secondary.datasource")
public DataSource secondaryDataSource() {
return DataSourceBuilder.create().build();
}
#Bean
#ConfigurationProperties(prefix="default.datasource")
public DataSource defaultDataSource(){
return DataSourceBuilder.create().build();
}
and configured multitenancy basing on this and this article.
Pros:
Easy tenant switch which could be triggered manually or even configured to be triggered on some specific header in request (filters).
Could be cofigured to switch between schemas or databases.
Happens dynamically ( you don't have to restart your beans )
Cons:
You have to define all db possibilities in property file.
You have to turn off schema validation because it will go nuts.
I use Spring Data LDAP and Spring Boot provides out of the box support for an embedded UnboundID server. However, when I use Spring Data LDAP's #Entry annotation, I need to specify a different base in the annotation based on whether I'm using the embedded UnboundID LDAP server, or a remote Active Directory server.
I was attempting to do this with SpEL and profile-based properties by specifying:
#Entry(base = "${ldap.person.base}", ...)
Then I have an application.propreties with ldap.person.base=OU=AD Person Base and an application-embedded.properties with ldap.person.base=OU=Embedded Person Base.
However, the #Entry annotation does not seem to support SpEL evaluation:
javax.naming.InvalidNameException: Invalid name: ${ldap.person.base}
There is an open issue in Spring LDAP to add support for this, but is there any workaround or some other way I can accomplish this until it is supported in Spring LDAP?
I'm not sure I'm following here, but assuming you're using the LDAP auto-configuration in Spring Boot, is it not enough to set the property spring.ldap.base to one or the other (OU=AD Person Base or OU=Embedded Person Base) based on the profile you're using?
Both EmbeddedLdapAutoConfiguration and LdapAutoConfiguration use an LdapProperties object to set various attributes on the LdapContextSource during bean creation, including its base. As far as I can tell, you won't have to define it for each #Entry in your codebase if LdapContextSource.base is set.
If you're not using the auto-configuration, and if I'm correct in my assumptions, you should still be able to create your own LdapContextSource bean and set its base to the desired value based on a Spring property.
Turns out the reason I needed a different base in the first place is because Spring was not setting the base on the ContextSource.
When you let Spring Boot autoconfigure the embedded LDAP server, it creates a ContextSource as such in EmbeddedLdapAutoConfiguration:
#Bean
#DependsOn("directoryServer")
#ConditionalOnMissingBean
public ContextSource ldapContextSource() {
LdapContextSource source = new LdapContextSource();
if (hasCredentials(this.embeddedProperties.getCredential())) {
source.setUserDn(this.embeddedProperties.getCredential().getUsername());
source.setPassword(this.embeddedProperties.getCredential().getPassword());
}
source.setUrls(this.properties.determineUrls(this.environment));
return source;
}
As you can see, nowhere in there does it call source.setBase(). So to solve this, I added a configuration file with #Profile("embedded") and manually created a ContextSource where I set the base myself (I leave off the credentials part because I don't use credentials for the embedded server):
#Configuration
#Profile("embedded")
#EnableConfigurationProperties({ LdapProperties.class })
public class EmbeddedLdapConfig {
private final Environment environment;
private final LdapProperties properties;
public EmbeddedLdapConfig(final Environment environment, final LdapProperties properties) {
this.environment = environment;
this.properties = properties;
}
#Bean
#DependsOn("directoryServer")
public ContextSource ldapContextSource() {
final LdapContextSource source = new LdapContextSource();
source.setUrls(this.properties.determineUrls(this.environment));
source.setBase(this.properties.getBase());
return source;
}
}
Now, I can leave the value of the base attribute in my #Entry the same for both the Active Directory server and the embedded UnboundID server and it works properly.
How to create project architecture to support multiple envionment. Each environment will have different datasource from different property file like(dev-propertfile,test-propertyFil,Production-propertyfile) with help of spring's
org.springframework.core.env.Environment;
I'll give step by step procedure for Spring boot applications.
Inside /src/main/resources/application.properties mention spring.profiles.active=dev (or Prod)
Create /src/main/resources/application-dev.properties and give your custom dev configurations here.
Create /src/main/resources/application-prod.properties and give your custom prod configurations here.
Run.
Put property file in same location as application.property and follow
the naming convention application-{profile}.properties like
application-dev.properties,application-test.properties,
application-prod.properties
And in application.properties set spring.profiles.active=dev,test etc
For Spring Boot applications it will work easily even by using a YAML File
spring:
profiles: dev
property: this is a dev env
---
spring:
profiles: prod
property: this is a production env
---
However, for a Spring MVC application, it needs more work. Have a look at this link
Basically, it involves 2 steps
Get the Spring Profile within servlet context
If you have set the profile on the server and want it to retrieve it within your application you can use System.getProperty or System.getenv methods.
Here is the code which fetches the profile and defaults it to a local profile, if no profile has been found.
private static final String SPRING_PROFILES_ACTIVE = "SPRING_PROFILES_ACTIVE";
String profile;
/**
* In local system getProperty() returns the profile correctly, however in docker getenv() return profile correctly
* */
protected void setSpringProfile(ServletContext servletContext) {
if(null!= System.getenv(SPRING_PROFILES_ACTIVE)){
profile=System.getenv(SPRING_PROFILES_ACTIVE);
}else if(null!= System.getProperty(SPRING_PROFILES_ACTIVE)){
profile=System.getProperty(SPRING_PROFILES_ACTIVE);
}else{
profile="local";
}
log.info("***** Profile configured is ****** "+ profile);
servletContext.setInitParameter("spring.profiles.active", profile);
}
To access the application-dev.properties, say now you will need to use
#Profile("dev") at the class level
The following code will fetch the application-dev.properties and common.properties
#Configuration
#Profile("dev")
public class DevPropertyReader {
#Bean
public static PropertyPlaceholderConfigurer properties() {
PropertyPlaceholderConfigurer ppc = new PropertyPlaceholderConfigurer();
Resource[] resources = new ClassPathResource[] { new ClassPathResource("properties/common.properties"), new ClassPathResource("properties/application-dev.properties") };
ppc.setLocations(resources);
ppc.setIgnoreUnresolvablePlaceholders(true);
return ppc;
}
}
For accessing say application-prod.properties you have to use #Profile("prod") at the class level. More details can be found here
Take a look at Spring Profile. You will define a set of profiles configurations, like Test, Dev, Production. And then, when you launch the application, you can define wich profile it should use.
Here are some tutorials of how to use.
And this guys had the same problem as yours: How to config #ComponentScan dynamic?
We wanted a way to load different properties from application-<your_env>.properties file depending on the environment (spring profile) in a Spring MVC project, so we implemented a configuration class something like this.
#Configuration
#PropertySource({ "classpath:application-${envTarget:dev}.properties" })
#Data
public class EnvironmentConfig {
#Value("${files.s3.accessId:}")
String s3AccessId;
#Value("${files.s3.accessToken:}")
String s3AccessToken;
.
.
.
}
Then we loaded the EnvironmentConfig in the class where we needed to use it.
While running the application, you just need to pass the -DenvTarget=<your_env>, and it will pick up the application-<your_env>.properties file from src/resources folder of the project.
In the above code, it will load values from application-dev.properties files when no envTarget is specified.
Thanks to Karthikeyan Muthurangam for suggesting this clever solution.