Spring Web App Deployment:: how do you hide data in application.properties? - java

everyone!
this is going to be my first time pushing a newly developed Spring Boot App and I was wondering if there is a way to protect passwords and other sensitive information written in the application.properties file.
Assuming we have the following lines:
# PostgreSQL connection settings
spring.datasource.jdbc-url=jdbc:postgresql://localhost:5432/bdreminder
spring.datasource.username=username
spring.datasource.password=password
The source code is to be first stored on GitHub and having the credentials stored in plain text does not seem to be a good idea.
So, I could probably add the file to the .gitignore one; I could set some environment variables on the host but how would it populate the .properties file afterward? Also, this seems quite cumbersome in terms of the scaling later on.
So, basically, I am trying to see how it is done in a real-life :)
Please, help :)

Simplest option is to create a profile specific application.properties file and activate that profile. So for example create application-private.properties and activate profile private. Of course you have to watch out to not commit this file.
Alternatively, and probably a safer option, is to define a file outside your project and import it in your application.properties with following line:
spring.config.import=file:../path/to/your/external.properties

Spring Boot has extensive support for external configuration. The usual approach is to use one of environment variables, configuration provided by a platform such as Kubernetes, or a specialized configuration system through Spring Cloud Config; these all keep secrets (or just environment-specific information) entirely outside of the code. They also have the advantages of providing a common style of configuration for other applications that do not use Spring Boot.

Related

Spring Boot properties that depend on profile-specific properties

I have a Spring Boot application which should connect to different servers in dev and prod, with many services running on those servers. To this point, I have created the configuration like this:
application.properties:
server.url.srv1=${server.url.base}/srv1
server.url.srv2=${server.url.base}/srv2
server.url.srv3=${server.url.base}/srv3
application-dev.properties:
server.url.base=http://192.168.86.17
application-prod.properties:
server.url.base=https://10.11.12.3
Yet when I initialize a bean argument with #Value("${server.url.srv1}"), I get a string of "${server.url.base}/srv1" and not "http://192.168.86.17/srv1" or "https://10.11.12.3/srv1" as expected.
Is this doable at all? It should be if the "${}" references are only resolved once all the config files are loaded, but this doesn't seem to be the case.
I have searched for an answer on both the Spring site, on Google (which pointed me to an otherwise useful Baeldung site), and here, but found nothing relevant to my particular question.
Placeholders in the application.properties should work. Please refer sample project I have added with your use case and it work as expected: https://github.com/itsprav/spring-profile-properties-using-placeholder
When you run your application you must have to set the specific spring-profile to be set in order to get the specific properties defined previously.
There is many ways to set these profiles.
Setting Profiles in different ways (JVM, Programmatically, Environment Variable...)

How to avoid hard coded database credentials in code

I've been searching for a way to avoid hard coding my database credentials into my code base (mainly written in Java), but I haven't found many solutions. I read this post where they said a one way hash could be the answer. Is there another way of securely connecting to a database without running into the risk of someone decompiling your code?
Just to clarify, I'm not looking for code, rather a nudge in the right direction.
If you can used spring boot application, then you can configure using cloud config method. I have added some postgresql db connection details for your further reference. Please refer following link for spring boot cloud config. spring_cloud
spring.datasource.driverClassName=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://{{db_url}}:5432/{{db_name}}
spring.datasource.username=postgres
spring.datasource.password=
spring.datasource.maxActive=3
spring.datasource.maxIdle=3
spring.datasource.minIdle=2
spring.datasource.initialSize=2
spring.datasource.removeAbandoned=true
spring.datasource.tomcat.max-wait=10000
spring.datasource.tomcat.max-active=3
spring.datasource.tomcat.test-on-borrow=true
You could load a config file in your code. Define some kind of file, such as JSON or XML, and define all of your configurations in there. You could point to the file as a command line argument, or just hardcode the file path.
Here's a post talking about parsing JSON config in Java:
How to read json file into java with simple JSON library
You can refer to these post. They are basically just saying to either hash, store it in a property file or use an API. Some of the posts are not merely on Java but you can get ideas from them.
How can I avoid hardcoding the database connection password?
https://security.stackexchange.com/questions/36076/how-to-avoid-scripts-with-hardcoded-password
https://www.codeproject.com/Articles/1087423/Simplest-Way-to-Avoid-Hardcoding-of-the-Confidenti
The solution in our team, database as a service,other application use it's API to get database credentials,the request contains simple credentials like application name.
You have several options to avoid hard code values in your source code:
Properties using Advanced Platforms
Properties from Environment variables
Properties from SCM
Properties from File System
More details here:
https://stackoverflow.com/a/51268633/3957754

How to consume properties from configmaps in Java Spring boot application deployed through Helm

I have simple Spring boot application which I need to deploy on development and prod different namespaces on a Kubernetes cluster using Helm.
I was thinking about keeping multiple application.properties (application-dev.properties, application-prod.properties) files for each environment and then create configmaps from them through values.yaml files which also will be different for each environment and specified when I execute Helm upgrade.
Now the question is how do I consume values from config.maps as I understand I can either mount the properties file inside container for example /deployment/application.properties
Or expose each property as an environment variable inside container.
But how do I consume them from Java application?
Also at the moment when I create container image it has current application .properties inside /resources/ files embedded and this is what application is using from default so I need to overwrite this behaviour when application is running inside container as opposite to then when its just build and run manually on developer desktop.
Springboot can automatically infer variables from environment variables. In your application.properties or application.yaml, just use ${MY_ENVIRONMENT_VARIABLE:my-defaultvalue}.
Use helm to populate your configmap.
Use configmap as environment variables into your deployment manifest.
This way you do not need to have multiple application.properties for dev, int ,prod inside your image. Keeping it intact across deployment.
And then in your helm chart, you can have multiple values.yaml example values-dev.yaml or values-int.yaml. you can also dynamically set helm values from command line, overriding the yaml file.
I have a demo app in github https://github.com/balchua/demo, which uses this pattern.
You could certainly use environment variables as Bal Chua suggests. If you do that you can override particular values at install time using --set or if you've a lot of config you can use the '-- values' flag and pass in a custom values.yaml file.
Another approach is to load a whole file using .Files.Glob (example in github) and load the file as part of the chart. You can then mount the file to /config to consume it in your spring boot application. Then your config file would be in the same form as a Spring boot config file, rather than a helm values.yaml. Though in many cases there needn't be much difference.
There's a discussion of how you could do similar for secrets (presumably you'll want to put your passwords in secrets) and use it for CI/CD in https://dzone.com/articles/hunting-treasure-with-kubernetes-configmaps-and-se (which is the article accompanying the github example). Basically you would use .Files.Glob with .AsSecrets instead of .AsConfig so as to encode the content. Many helm charts have the option to generate a random password if not specified but I'd guess you probably don't need that.
I'd recommend mounting the files (application.properties or application.yml) inside the ConfigMap onto somewhere on the file system that Spring Boot can automatically detect - then your app stays nice and simple

Spring use one application.properties for production and another for debug

I have a Spring application and I would like to be able to switch between configurations depending if I'm debugging the server or if the server is running in production. (the difference in configurations being things like database location.)
Ideally, I'd like to pass in a command line argument to my Spring application on boot-up and set the application configuration.
I have two separate application.properties files, one with the production values, and another with the debug values. How can I switch between the two of them?
You can have 3 properties files, application-dev.properties, application-prod.properties and application.properties. And you can specify all the development properties in your dev properties file and production cionfiguration properties in your prod file
and specify the profile in your application.properties files as below
spring.profiles.active=dev
or you can select/override the profile using -Dprofile= argument in command line.
Spring profiles seem the way to go. You can start your application with something like -Dprofile=. Have a look at this example.
EDIT: after re-reading your question, I came to the conclusion that you might actually want something more basic: put your database properties externally. Depending on your application you could use #Value of a property configurator. Have a look at the spring docs.

Spring .properties files purpose

I read #yorkw answer at this topic. He said:
The purpose of .properties file is to provide the capability of
configuring database connections at application runtime (for web
application, usually require restarting application container/server
after .properties file changes).
The question is if we can change properties on the fly without restarting container/server? Provide me an example please (I ask because in my demo it doesn't work, means value isn't changed).
I mean if we have some kind of admin tool than we can move all our configured settings to .properties files and change them via that admin tool.
Spring property files are designed to change the Spring Config of an application. The spring config is read when the spring container is initialised - this will form part of the application startup.
If a change is made to one of the spring config files (includes the *.properties files) the spring container would need to be reloaded to pick up the change.
Properties put into spring properties files should typically be properties that are tied to the life cycle of the application - i.e. the kind of properties that when changed require an application/spring container re-initialised - things like the database url/config etc.
So values that you want to change at runtime without requiring a restart of the application are not good candidates for placement in a spring properties file.

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