Add updatable config source

spi/src/main/java/org/cryptomator/hub/config/HubConfigPersistence.java

@@ -0,0 +1,49 @@
+package org.cryptomator.hub.config;
+
+import org.jboss.logging.Logger;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+class HubConfigPersistence {
+
+	private static final Logger LOG = Logger.getLogger(HubConfigPersistence.class);
+	private static final String HUB_CONFIG_DESCRIPTION = "Cryptomator Hub configuration persistence file";
+
+	private final Path configPath;
+
+	HubConfigPersistence(Path configPath) {
+		this.configPath = configPath;
+	}
+
+	synchronized void persist(Map<String, String> config) {
+		var prop = new Properties();
+		prop.putAll(config);
+		try (var out = Files.newOutputStream(configPath, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+			prop.store(out, HUB_CONFIG_DESCRIPTION);
+		} catch (IOException e) {
+			throw new UncheckedIOException("Unable to persist Hub config to "+configPath,e);
+		}
+	}
+
+
+	Map<String, String> load() {
+		Map<String, String> config = new HashMap<>();
+		try (var in = Files.newInputStream(configPath, StandardOpenOption.READ)) {
+			var prop = new Properties();
+			prop.load(in);
+			prop.forEach((k, v) -> config.put((String) k, (String) v));
+		} catch (IOException e) {
+			LOG.info("Unable to read hub config from {}, creating empty.", configPath, e);
+		}
+		return config;
+	}
+
+
+}

spi/src/main/java/org/cryptomator/hub/config/HubConfigSource.java

@@ -0,0 +1,65 @@
+package org.cryptomator.hub.config;
+
+import org.eclipse.microprofile.config.ConfigProvider;
+import org.eclipse.microprofile.config.spi.ConfigSource;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.StreamSupport;
+
+public class HubConfigSource implements ConfigSource {
+
+    private static final String HUB_CONFIGSOURCE_NAME = "HubConfig";
+
+    private final HubConfigPersistence persistence;
+    private final ConcurrentHashMap<String, String> config;
+
+    public HubConfigSource(HubConfigPersistence persistence) {
+        this.config = new ConcurrentHashMap<>();
+        this.persistence = persistence;
+
+        config.putAll(persistence.load());
+    }
+
+    @Override
+    public Map<String, String> getProperties() {
+        return config;
+    }
+
+    @Override
+    public Set<String> getPropertyNames() {
+        return config.keySet();
+    }
+
+    @Override
+    //for default sources and their precedence see https://quarkus.io/guides/config-reference#configuration-sources
+    public int getOrdinal() {
+        return 240;
+    }
+
+    @Override
+    public String getValue(String s) {
+        return config.get(s);
+    }
+
+    @Override
+    public String getName() {
+        return HUB_CONFIGSOURCE_NAME;
+    }
+
+    public void setProperty(String key, String value) {
+        String oldVal = config.put(key, value);
+        if (oldVal == null || !oldVal.equals(value)) {
+            persistence.persist(config);
+        }
+    }
+
+    public static HubConfigSource getInstance() {
+        return (HubConfigSource) StreamSupport.stream(ConfigProvider.getConfig().getConfigSources().spliterator(), false)
+                .filter(s -> s instanceof HubConfigSource)
+                .findFirst()
+                .get();
+    }
+
+}

spi/src/main/java/org/cryptomator/hub/config/HubConfigSourceFactory.java

@@ -0,0 +1,27 @@
+package org.cryptomator.hub.config;
+
+import io.smallrye.config.ConfigSourceContext;
+import io.smallrye.config.ConfigSourceFactory;
+import org.eclipse.microprofile.config.spi.ConfigSource;
+
+import javax.enterprise.context.ApplicationScoped;
+import java.nio.file.Path;
+import java.util.List;
+
+@ApplicationScoped
+public class HubConfigSourceFactory implements ConfigSourceFactory {
+
+    private static final String HUBCONFIG_PROPERTY_KEY = "hub.config.path";
+
+    @Override
+    public Iterable<ConfigSource> getConfigSources(ConfigSourceContext configSourceContext) {
+        var s = configSourceContext.getValue(HUBCONFIG_PROPERTY_KEY);
+        if (s.getValue() == null) {
+            throw new IllegalStateException("Property \"" + HUBCONFIG_PROPERTY_KEY + "\" to point to hub config file is missing");
+        }
+        var hubConfigPersistence = new HubConfigPersistence(Path.of(s.getValue()));
+        var hubConfig = new HubConfigSource(hubConfigPersistence);
+        return List.of(hubConfig);
+    }
+
+}

spi/src/main/resources/META-INF/services/io.smallrye.config.ConfigSourceFactory

@@ -0,0 +1 @@
+org.cryptomator.hub.config.HubConfigSourceFactory