configloader

blueprint.xml

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.1.0"
           xsi:schemaLocation="
       http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
       http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.1.0 http://aries.apache.org/schemas/blueprint-cm/blueprint-cm-1.1.0.xsd">

    <cm:property-placeholder persistent-id="com.example.configloader">
        <cm:default-properties>
            <cm:property name="configPath" value=""/>
        </cm:default-properties>
    </cm:property-placeholder>

    <bean id="configLoader" class="com.example.ConfigLoader" init-method="init">
        <property name="configPath" value="${configPath}" />
    </bean>

</blueprint>

com.example.configloader.properties

configPath=profile:config.json

config.json

[
    {
        active: true
    }
]

ConfigLoader.java

package com.example;

import org.apache.commons.lang.NullArgumentException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class ConfigLoader {

    private static final Logger log = LoggerFactory.getLogger(ConfigLoader.class);

    private String configPath;
    public String getConfigPath() {
        return configPath;
    }
    public void setConfigPath(String value) {
        configPath = value;
    }

    private File configFile;
    public File getConfigFile() {
        return configFile;
    }
    public void setConfigFile(File value) {
        configFile = value;
    }

    public void init() throws FileNotFoundException, IOException {
        if (configPath == null) {
            throw new NullArgumentException("configPath");
        }

        File file = new File(configPath);
        setConfigFile(file);
        log.info("Loaded config file from: " + configPath);
        FileReader reader = new FileReader(configFile);
        char[] contents = new char[(int)file.length()];
        reader.read(contents);
        log.info("Contents: " + String.valueOf(contents));
    }
}

io.fabric8.agent.properties

attribute.parents = karaf
bundle.configloader = mvn:com.example/LoadJsonFromProfile