commit 8514f86e3704dd0c103aea4197f51c20edab42b9
Author: RuscalWorld <me@ruscalworld.ru>
Date:   Mon May 24 19:20:19 2021 +0300

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3c37caf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,118 @@
+# User-specific stuff
+.idea/
+
+*.iml
+*.ipr
+*.iws
+
+# IntelliJ
+out/
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+.gradle
+build/
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Cache of project
+.gradletasknamecache
+
+**/build/
+
+# Common working directory
+run/
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..1f12b57
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2021 RuscalWorld
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..f496da9
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,116 @@
+import net.fabricmc.loom.task.RemapJarTask
+
+buildscript {
+    dependencies {
+        classpath 'com.github.jengelman.gradle.plugins:shadow:6.1.0'
+    }
+}
+
+plugins {
+    id 'com.github.johnrengelman.shadow' version '6.1.0'
+    id 'fabric-loom' version '0.6-SNAPSHOT'
+    id 'maven-publish'
+}
+
+repositories {
+    mavenCentral()
+    maven {
+        name = 'Bortexel'
+        url = 'https://maven.pkg.github.com/bortexel/bortexel4j'
+        credentials {
+            username = BortexelUsername
+            password = BortexelPassword
+        }
+    }
+    maven {
+        name = 'RuscalWorld'
+        url = 'https://maven.pkg.github.com/ruscalworld/storagelib'
+        credentials {
+            username = BortexelUsername
+            password = BortexelPassword
+        }
+    }
+    maven {
+        name 'm2-dv8tion'
+        url 'https://m2.dv8tion.net/releases'
+    }
+    maven {
+        url 'https://oss.sonatype.org/content/repositories/snapshots'
+    }
+}
+
+apply plugin: 'com.github.johnrengelman.shadow'
+
+sourceCompatibility = JavaVersion.VERSION_1_8
+targetCompatibility = JavaVersion.VERSION_1_8
+
+archivesBaseName = project.archives_base_name
+version = project.mod_version
+group = project.maven_group
+
+dependencies {
+    //to change the versions see the gradle.properties file
+    minecraft "com.mojang:minecraft:${project.minecraft_version}"
+    mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
+    modImplementation "net.fabricmc:fabric-loader:${project.loader_version}"
+
+    // Fabric API. This is technically optional, but you probably want it anyway.
+    modImplementation "net.fabricmc.fabric-api:fabric-api:${project.fabric_version}"
+
+    // PSA: Some older mods, compiled on Loom 0.2.1, might have outdated Maven POMs.
+    // You may need to force-disable transitiveness on them.
+    compile "io.prometheus:simpleclient:${project.prometheus_version}"
+    compile "io.prometheus:simpleclient_httpserver:${project.prometheus_version}"
+
+    compileOnly "me.lucko:spark-api:0.1-SNAPSHOT"
+}
+
+processResources {
+    inputs.property "version", project.version
+
+    from(sourceSets.main.resources.srcDirs) {
+        include "fabric.mod.json"
+        expand "version": project.version
+    }
+
+    from(sourceSets.main.resources.srcDirs) {
+        exclude "fabric.mod.json"
+    }
+}
+
+// ensure that the encoding is set to UTF-8, no matter what the system default is
+// this fixes some edge cases with special characters not displaying correctly
+// see http://yodaconditions.net/blog/fix-for-java-file-encoding-problems-with-gradle.html
+tasks.withType(JavaCompile) {
+    options.encoding = "UTF-8"
+}
+
+// Loom will automatically attach sourcesJar to a RemapSourcesJar task and to the "build" task
+// if it is present.
+// If you remove this task, sources will not be generated.
+task sourcesJar(type: Jar, dependsOn: classes) {
+    classifier = "sources"
+    from sourceSets.main.allSource
+}
+
+jar {
+    from "LICENSE"
+}
+
+shadowJar {
+    archiveClassifier = "all-dev"
+
+    dependencies {
+        include dependency("io.prometheus:simpleclient:${project.prometheus_version}")
+        include dependency("io.prometheus:simpleclient_httpserver:${project.prometheus_version}")
+    }
+}
+
+task remapShadowJar(type: RemapJarTask, dependsOn: shadowJar) {
+    input = shadowJar.archiveFile
+    archiveFileName = shadowJar.archiveFileName.get().replaceAll("-dev\\.jar\$", ".jar")
+    addNestedDependencies = true
+    remapAccessWidener = true
+}
+
+assemble.dependsOn(remapShadowJar)
diff --git a/gradle.properties b/gradle.properties
new file mode 100644
index 0000000..39ed8a2
--- /dev/null
+++ b/gradle.properties
@@ -0,0 +1,15 @@
+# Done to increase the memory available to gradle.
+org.gradle.jvmargs=-Xmx1G
+# Fabric Properties
+# check these on https://modmuss50.me/fabric.html
+minecraft_version=1.16.5
+yarn_mappings=1.16.5+build.9
+loader_version=0.11.3
+# Mod Properties
+mod_version=1.0
+maven_group=ru.ruscalworld
+archives_base_name=fabricexporter
+# Dependencies
+# check this on https://modmuss50.me/fabric.html
+fabric_version=0.25.1+build.416-1.16
+prometheus_version=0.10.0
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..62d4c05
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..bb8b2fc
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..fbd7c51
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..5093609
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,104 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..5b60df3
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,10 @@
+pluginManagement {
+    repositories {
+        jcenter()
+        maven {
+            name = 'Fabric'
+            url = 'https://maven.fabricmc.net/'
+        }
+        gradlePluginPortal()
+    }
+}
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java b/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java
new file mode 100644
index 0000000..378ad89
--- /dev/null
+++ b/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java
@@ -0,0 +1,43 @@
+package ru.ruscalworld.fabricexporter;
+
+import io.prometheus.client.exporter.HTTPServer;
+import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
+import net.minecraft.server.MinecraftServer;
+import ru.ruscalworld.fabricexporter.metrics.OnlinePlayers;
+
+import java.io.IOException;
+import java.util.Timer;
+
+public class FabricExporter implements ModInitializer {
+    private MinecraftServer server;
+
+    @Override
+    public void onInitialize() {
+        ServerLifecycleEvents.SERVER_STARTED.register(this::setServer);
+
+        try {
+            HTTPServer httpServer = new HTTPServer(1337);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        MetricUpdater metricUpdater = new MetricUpdater(this);
+        metricUpdater.registerMetric(new OnlinePlayers());
+
+        Timer timer = new Timer();
+        timer.schedule(metricUpdater, 1000, 1000);
+    }
+
+    public static String getMetricName(String name) {
+        return "mc_" + name;
+    }
+
+    public MinecraftServer getServer() {
+        return server;
+    }
+
+    private void setServer(MinecraftServer server) {
+        this.server = server;
+    }
+}
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/Metric.java b/src/main/java/ru/ruscalworld/fabricexporter/Metric.java
new file mode 100644
index 0000000..4c49d57
--- /dev/null
+++ b/src/main/java/ru/ruscalworld/fabricexporter/Metric.java
@@ -0,0 +1,17 @@
+package ru.ruscalworld.fabricexporter;
+
+import io.prometheus.client.Gauge;
+
+public abstract class Metric {
+    private final Gauge gauge;
+
+    public Metric(String name, String help) {
+        this.gauge = new Gauge.Builder().name("minecraft_" + name).help(help).create().register();
+    }
+
+    public abstract double getCurrentValue(FabricExporter exporter);
+
+    public Gauge getGauge() {
+        return gauge;
+    }
+}
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/MetricUpdater.java b/src/main/java/ru/ruscalworld/fabricexporter/MetricUpdater.java
new file mode 100644
index 0000000..2c5ca0e
--- /dev/null
+++ b/src/main/java/ru/ruscalworld/fabricexporter/MetricUpdater.java
@@ -0,0 +1,37 @@
+package ru.ruscalworld.fabricexporter;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.TimerTask;
+
+public class MetricUpdater extends TimerTask {
+    private final List<Metric> metrics = new ArrayList<>();
+    private final FabricExporter exporter;
+
+    public MetricUpdater(FabricExporter exporter) {
+        this.exporter = exporter;
+    }
+
+    @Override
+    public void run() {
+        for (Metric metric : this.getMetrics()) {
+            try {
+                metric.getGauge().set(metric.getCurrentValue(this.getExporter()));
+            } catch (Exception exception) {
+                exception.printStackTrace();
+            }
+        }
+    }
+
+    public void registerMetric(Metric metric) {
+        this.metrics.add(metric);
+    }
+
+    public FabricExporter getExporter() {
+        return exporter;
+    }
+
+    public List<Metric> getMetrics() {
+        return metrics;
+    }
+}
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/metrics/OnlinePlayers.java b/src/main/java/ru/ruscalworld/fabricexporter/metrics/OnlinePlayers.java
new file mode 100644
index 0000000..9f5f575
--- /dev/null
+++ b/src/main/java/ru/ruscalworld/fabricexporter/metrics/OnlinePlayers.java
@@ -0,0 +1,16 @@
+package ru.ruscalworld.fabricexporter.metrics;
+
+import ru.ruscalworld.fabricexporter.FabricExporter;
+import ru.ruscalworld.fabricexporter.Metric;
+
+public class OnlinePlayers extends Metric {
+    public OnlinePlayers() {
+        super("players_online", "Amount of currently online players on the server");
+    }
+
+    @Override
+    public double getCurrentValue(FabricExporter exporter) {
+        System.out.println(exporter.getServer().getCurrentPlayerCount());
+        return exporter.getServer().getCurrentPlayerCount();
+    }
+}
diff --git a/src/main/resources/fabric.mod.json b/src/main/resources/fabric.mod.json
new file mode 100644
index 0000000..1a3b16b
--- /dev/null
+++ b/src/main/resources/fabric.mod.json
@@ -0,0 +1,28 @@
+{
+  "schemaVersion": 1,
+  "id": "fabricexporter",
+  "version": "${version}",
+  "name": "FabricExporter",
+  "description": "Mod that adds a Prometheus exporter with general metrics of your server",
+  "authors": [
+    "RuscalWorld"
+  ],
+  "contact": {
+    "repo": "https://github.com/ruscalworld/fabricexporter"
+  },
+  "license": "MIT",
+  "environment": "server",
+  "entrypoints": {
+    "main": [
+      "ru.ruscalworld.fabricexporter.FabricExporter"
+    ]
+  },
+  "mixins": [
+    "fabricexporter.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": ">=0.11.3",
+    "fabric": "*",
+    "minecraft": "1.16.5"
+  }
+}
diff --git a/src/main/resources/fabricexporter.mixins.json b/src/main/resources/fabricexporter.mixins.json
new file mode 100644
index 0000000..0429ae6
--- /dev/null
+++ b/src/main/resources/fabricexporter.mixins.json
@@ -0,0 +1,13 @@
+{
+  "required": true,
+  "minVersion": "0.8",
+  "package": "ru.ruscalworld.fabricexporter.mixin",
+  "compatibilityLevel": "JAVA_8",
+  "mixins": [
+  ],
+  "client": [
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}