December 19, 2016

Spring Sweets: Add Git Info To Info Endpoint

With Spring Boot Actuator we get some endpoints that display information about our application. One of the endpoints is the /info endpoint. If our project uses Git we can add information about Git to the /info endpoint. By default Spring Boot will look for a file git.properties in the classpath of our application. The file is a Java properties file with keys that start with git. and have values like the branch name, commit identifier and commit message. Spring Boot uses this information and when we request the /info endpoint we get a response with the information. This can be very useful to check the Git information that was used to build the application. To create the git.properties file we can use a Gradle (or Maven) plugin that will do the work for us.

In the following example we use the Gradle plugin to generate the git.properties file for our project. The Gradle Git properties plugin is added in the plugins configuration block. The plugin adds a Gradle extension gitProperties that can be used to customize the output in git.properties. We could even change the location, but we keep it to the default location which is build/resources/main/git.properties.

// File: build.gradle
plugins {
    id 'org.springframework.boot' version '1.4.2.RELEASE'
    // Add Git properties plugin.
    id 'com.gorylenko.gradle-git-properties' version '1.4.17'
}

// Customize Git properties plugin.
gitProperties {
    // Change date format in git.properties file.
    dateFormat = "yyyy-MM-dd HH:mm:ssZ"
    dateFormatTimeZone = 'GMT'
}

That is all we need to do. The Git properties plugin generates the git.properties file that is need by Spring Boot. Let's run our application and send a request for the /info endpoint:

$ http -b localhost:8080/info
{
    "git": {
        "branch": "feature/dsl-hapi",
        "commit": {
            "id": "511d269",
            "time": "2016-12-15 12:28:20+0000"
        }
    }
}
$

We can even show more information by changing the Spring Boot configuration property management.git.info.mode. The default value is SIMPLE, but we can also use the value FULL. Then we get the Git commit message and user details. We can set the configuration property in different ways for our Spring Boot application. For example in application.yml, Java system property or environment variable. In our example we add a Java system property to the Gradle bootRun task:

// File: build.gradle
...
bootRun {
    systemProperty 'management.info.git.mode', 'FULL'
}
...

We execute the bootRun task and send a new request for the /info endpoint:

$ http -b localhost:8080/info
{
    "git": {
        "branch": "feature/dsl-hapi",
        "commit": {
            "id": "511d2693cbabc34449f838bf856fa2b9989cbca6",
            "id.abbrev": "511d269",
            "message": {
                "full": "Enable Codenarc checks for integration test code",
                "short": "Enable Codenarc checks for integration test code"
            },
            "time": "2016-12-15 12:28:20+0000",
            "user": {
                "email": "mrhaki@server",
                "name": "Hubert Klein Ikkink"
            }
        }
    }
}
$

This time we see more information about Git.

Written with Spring Boot 1.4.2.RELEASE