I am looking for a solution to the problem, which is that having an external Tomcat server with several different applications (war),
I would like to use application Spring Profile (dev, prod) to choose application.properties for a given profile.
To avoid keeping the database configuration in the git repository, I didn't store in the application
application.properties, but I kept them in the $catalina.base directory, where in common.loader
I indicated the path to this directory. This worked until I started deploying several different applications. Then each of them began to use
from the same datasource. One solution is to keep the application.properties in Jenkins and directly in Jobie indicating which one to use,
but I am not sure if this is a good solution.
Option 1: Create a separate instance of tomcat (using same tomcat binary) and place application.properties in instance's classpath. As classpath is separate for every instance, applications don't refer to same application.properties file. Refer to this article to see how to create multiple instances on same tomcat server.
Option 2: Create JNDI datasource on tomcat server and use it in your application to access database. This way, should you choose to, same datasource can be shared across different related applications and/or modules. For more information on how to create JNDI datasource in Tomcat, refer to this link
Related
We have multiple web applications in one tomcat instance on 1 server, all running a spring-boot application inside.
Whenever we start tomcat and it starts to boot up all the spring-boot applications we mostly see that each application might use property files/settings from another application.
What especially happens is that we see it sometimes use the database information from other applications being used, resulting in a database which holds tables from other applications. This is scary since we might start a database migration or something.
We also see that the logs are written to the wrong project log file.
We define these settings using a application.properties like (or sometimes application-test.properties or application-secret.properties):
spring.datasource.username
spring.datasource.password
logging.file.name
Anyone have an idea why this is happening?
We found 2 possible causes for this behavior:
if Tomcat is started in a directory where application property files are present, or where application property files are placed in a /config subdirectory, like a WEB-INF/classes directory, these application property files are used by every Spring Boot application deployed in the tomcat instance. To fix this, make sure the Tomcat start script changes the working directory to a directory not containing application property files.
if the 'startStopThreads' attribute of the Tomcat Engine element in server.xml is set to values higher than 1, Spring Boot applications seem to occasionally and randomly use application property files of other Spring Boot applications deployed in the Tomcat instance. When 'startStopThreads' is set to 1, we don't see this behavior.
I am trying to find the best way to configure my Spring Boot Web application to easily switching between the following data sources for both local testing and deployment.
H2 in memory db. Local testing only.
Dev oracle. Local testing and deployment.
Prod oracle. Deployment only.
By local testing, I mean to test in IDE environment (Eclipse). Dev and prod oracle databases are set up on two remote servers.
After some research, there are different ways to switch from one data source to another.
Use Spring profile. Using H2 and Oracle with Spring Boot. Set up the following files in classpath, application.properties, application-h2. properties and application-dev.properties. While connections for h2 and dev are defined in corresponding properties files, spring.profiles.active is set in application.properties. My understanding is this property can be overridden during build process by specifying spring.profiles.active. However, it seems to be a JVM variable, how do I set it running maven?
Maven profile. Create multiple profiles in pom and a filter pointing to application properties files. The profile specified by -P option during maven build will determine which application properties file to look. However, according to maven application with multi environment configuration can't deploy on tomcat, this will generate multiple wars for different deployment. So method 1 is preferred. Plus, it does not apply to switching datasources while testing locally.
Persistence units. Define different persistence units for different data sources in persistence.xml. Use EntityManager by choosing a specific unit. Variation of this method include having a variable in unit names which is determined in application.properties.
JNDI lookup. Set up a jndi name in application.properties with spring.datasource.jndi-name. The actual database information including url and credentials will be specified in context.xml in the tomcat folder where the war will be deployed.
My mind is set on local testing environment. Gonna go with method 1. Switching between H2 in memory and oracle is so easy just by changing the property in application.properties. Since the testing is usually done in IDE, war does not need to be generated, although answers are welcome for run maven install with spring.profiles.active.
As far as deployment, JNDI is definitely the way to go. However, I am concerned that the two properties in application.properties: spring.profiles.active and spring.datasource.jndi-name may be conflicting with each other. If I have spring.profiles.active=h2 and then tried to deploy the war to prod server, does it try to connect to h2 based on the spring profile or to prod db based on jdni-name? What is the best practice to accommodate all scenarios with enough flexibility?
Also is a explicit configuration class for DataSource required such as Configure Mutiple DataSource in Spring Boot with JNDI? My understanding is application.properties and spring profile should be enough to handle it, right?
Definitely use Spring profiles.
You don't want to use Maven profiles as it creates different artifacts. Ask your QA/Release engineers how they feel about having different artifacts for different environments :). They wouldn't be happy.
H2 is what you want to use in CI server integration testing as well. Such integration testing is fast and easy.
Instead of changing profile in application.properties, consider defining profile via command line parameter. So that configuration file changes are not required to run your application in different profiles.
Having something like
security.user.password = plainTextPassword
inside Spring Boot’s application.properties is obviously an anti-pattern as it prevents the code from being pushed to a public SCM. In my non-Spring Boot projects I use
security.user.password = ${myPasswordFromMavenSettingsXML}
and put a corresponding <properties/> reference inside my pom.xml.
Using Maven’s resource filter plugin the passwords are replaced at build time so the application have access to actual plain text passwords after it has been build and deployed.
For some reason Maven’s resource filter plugin does not work in this case. Is there a way to not commit plain text passwords to an SCM and let Spring Boot to insert them at build time?
Spring boot has multiple mechanisms to provided externalized configuration. Some examples are command line arguments, environment variables and also application properties outside of your packaged JAR.
What I usually do:
Locally we configured several environment variables. Most (if not all) IDE's allow you to configure environment variables from within the run configuration.
For example if you don't want to expose the spring.datasource.password property you could set an environment variable called SPRING_DATASOURCE_PASSWORD.
When we deploy on another environment, we usually choose to add another application.properties or application.yml file within the same folder as the application JAR/WAR, since Spring boot picks that up as well.
Another solution is to use Spring cloud since it has a config service which can be used as a microservice to provide configuration. The configuration can be versioned using SCM as well, but you can put it on a separate system that is not connected to your source code.
I have externalized all my application needed property files from webapps in tomcat. Now i can simply change a property file value without a need of rebuilding the war file and deploy it again. However each change to property file is associated with server recyling.
Is there a way how the recycling can be avoided for a property file change.
I am using spring to read the property files for few webapps and java property traditional way for few webapps.
Please suggest how to acheive
You may want to consider spring-cloud-config-server or spring-cloud-consul all of these options supports distributed properties management as well as value changes refresh without a need to recycle app servers.
And you can use #RefreshScope for Spring #Beans that want to be reinitialized when configuration changes, they also provide the following Management endpoints out of the box and many more as explained on the project git page
/refresh for refreshing the #RefreshScope beans
/restart for restarting the Spring context (disabled by default)
This is supported by either option (spring-cloud-config-server or spring-cloud-consul)
You may also give cfg4j a try. It supports reloading configuration from local files as well as remote services (git repository, Consul, etc.).
I currently have a number of deployable applications that work in a distributed fashion to solve a business problem. We are currently using a number of property configuration files to provide changing configuration per environment based off a system environment variable. All these deployable application share common configuration for database and messaging. This is currently achieved by picking up property files from the class path and having both deployed apps share a common jar for each connection (db, jms) containing property files.
I am looking to start using Spring Config Server to externalize this configuration if possible. I have a question about how to share this common config.
Currently it looks something like this:-
Web1
- database
- jms
Messaging1
- database
- jms
In this situation both deployed apps share the same connections and these connections change per environment (lab, prf, prd, etc). How can I achieve the same with the Spring Configuration Server where I have app config for each deployable app?
Application.yml
Web1.yml
Web1-dev.yml
Messaging1.yml
Messaging1-dev.yml
If a connection property changed for an environment I would need to make the change to each deployable app configuration rather than making it just once.
Is there currently anyway to achieve this? Am I just missing a simple point?
I found working solution here https://cloud.spring.io/spring-cloud-config/single/spring-cloud-config.html, paragraph "2.1.5 Sharing Configuration With All Applications". It says:
With file-based (i.e. git, svn and native) repositories, resources
with file names in application* are shared between all client
applications (so application.properties, application.yml,
application-*.properties etc.). You can use resources with these file
names to configure global defaults and have them overridden by
application-specific files as necessary.
You should create application.properties or application.yml at the top level of configuration repository (if it is git or svn based). Don't forget to commit the changes.
This is how I have configured for my setup.
1 All Common properties across all services and environments will be in root->application.properties files
2 All Common properties across all environments specific to service will be root->service-X.properties files
3: Similarly, to have common properties across specific environment use env->application.properties file
server:
port: 8888
spring:
cloud:
config:
server:
git:
uri:[git repo]
search-paths: /,/{profile}/
Finally found a solution. It's buried in the issues at github ...
https://github.com/spring-cloud/spring-cloud-config/issues/32
It worked liked described. I only noticed, that you need to put the files in a /config folder to make it work. If you put it in the root the file ist used by the configserver itself and is not included in the config requests.
application.properties/application.yml will be shared across all applications.
application-DEV.properties/application-DEV.yml will be shared across all DEV environment applications. You can replace DEV with any spring profile.
{applicationName}.properties/{applicationName}.yml will be shared across the give application.