# EMQX ## Quick reference + **Where to get help**: or + **Where to file issues:** + **Supported architectures** `amd64`, `arm64v8` + **Supported Docker versions**: [the latest release](https://github.com/docker/docker-ce/releases/latest) ## What is EMQX [EMQX](https://emqx.io/) is the world's most scalable open-source MQTT broker with a high performance that connects 100M+ IoT devices in 1 cluster, while maintaining 1M message per second throughput and sub-millisecond latency. EMQX supports multiple open standard protocols like MQTT, HTTP, QUIC, and WebSocket. It's 100% compliant with MQTT 5.0 and 3.x standard, and secures bi-directional communication with MQTT over TLS/SSL and various authentication mechanisms. With the built-in powerful SQL-based rules engine, EMQX can extract, filter, enrich and transform IoT data in real-time. In addition, it ensures high availability and horizontal scalability with a masterless distributed architecture, and provides ops-friendly user experience and great observability. EMQX boasts more than 20K+ enterprise users across 50+ countries and regions, connecting 100M+ IoT devices worldwide, and is trusted by over 400 customers in mission-critical scenarios of IoT, IIoT, connected vehicles, and more, including over 70 Fortune 500 companies like HPE, VMware, Verifone, SAIC Volkswagen, and Ericsson. ## How to use this image ### Run EMQX Execute some command under this docker image ```console $ docker run -d --name emqx emqx/emqx:${tag} ``` For example ```console $ docker run -d --name emqx -p 18083:18083 -p 1883:1883 emqx/emqx:latest ``` The EMQX broker runs as Linux user `emqx` in the docker container. ### Configuration All EMQX Configuration in [`etc/emqx.conf`](https://github.com/emqx/emqx/blob/master/apps/emqx/etc/emqx.conf) can be configured via environment variables. By default, the environment variables with `EMQX_` prefix are mapped to key-value pairs in configuration files. You can change the prefix by overriding `HOCON_ENV_OVERRIDE_PREFIX`. Example: ```bash EMQX_LISTENERS__SSL__DEFAULT__ACCEPTORS <--> listeners.ssl.default.acceptors EMQX_ZONES__DEFAULT__MQTT__MAX_PACKET_SIZE <--> zones.default.mqtt.max_packet_size ``` + Prefix `EMQX_` is removed + All upper case letters is replaced with lower case letters + `__` is replaced with `.` If `HOCON_ENV_OVERRIDE_PREFIX=DEV_` is set: ```bash DEV_LISTENER__SSL__EXTERNAL__ACCEPTORS <--> listener.ssl.external.acceptors DEV_MQTT__MAX_PACKET_SIZE <--> mqtt.max_packet_size DEV_LISTENERS__TCP__DEFAULT__BIND <--> listeners.tcp.default.bind ``` For example, set MQTT TCP port to 1883 ```console $ docker run -d --name emqx -e DEV_LISTENERS__TCP__DEFAULT__BIND=1883 -p 18083:18083 -p 1883:1883 emqx/emqx:latest ``` Please read more about EMQX configuration in the [official documentation](https://www.emqx.io/docs/en/v5.0/admin/cfg.html). #### EMQX node name configuration | Options | Default | Mapped | Description | | ---------------------------| ------------------ | ------------------------- | ------------------------------------- | | `EMQX_NAME` | container name | none | EMQX node short name | | `EMQX_HOST` | container IP | none | EMQX node host, IP or FQDN | These environment variables are used during container startup phase only in [docker-entrypoint.sh](./docker-entrypoint.sh). If `EMQX_NAME` and `EMQX_HOST` are set, and `EMQX_NODE_NAME` is not set, `EMQX_NODE_NAME=$EMQX_NAME@$EMQX_HOST`. Otherwise `EMQX_NODE_NAME` is taken verbatim. ### Cluster EMQX supports a variety of clustering methods, see our [documentation](https://www.emqx.io/docs/en/latest/deploy/cluster/intro.html) for details. Let's create a static node list cluster from docker-compose. + Create `docker-compose.yaml`: ```yaml version: '3' services: emqx1: image: emqx/emqx:latest environment: - "EMQX_NAME=emqx" - "EMQX_HOST=node1.emqx.io" - "EMQX_CLUSTER__DISCOVERY_STRATEGY=static" - "EMQX_CLUSTER__STATIC__SEEDS=[emqx@node1.emqx.io, emqx@node2.emqx.io]" networks: emqx-bridge: aliases: - node1.emqx.io emqx2: image: emqx/emqx:latest environment: - "EMQX_NAME=emqx" - "EMQX_HOST=node2.emqx.io" - "EMQX_CLUSTER__DISCOVERY_STRATEGY=static" - "EMQX_CLUSTER__STATIC__SEEDS=[emqx@node1.emqx.io, emqx@node2.emqx.io]" networks: emqx-bridge: aliases: - node2.emqx.io networks: emqx-bridge: driver: bridge ``` + Start the docker-compose cluster ```bash docker-compose -p my_emqx up -d ``` + View cluster ```bash $ docker exec -it my_emqx_emqx1_1 sh -c "emqx_ctl cluster status" Cluster status: #{running_nodes => ['emqx@node1.emqx.io','emqx@node2.emqx.io'], stopped_nodes => []} ``` ### Persistence If you want to persist the EMQX docker container, you need to keep the following directories: + `/opt/emqx/data` + `/opt/emqx/etc` + `/opt/emqx/log` Since data in these folders are partially stored under the `/opt/emqx/data/mnesia/${node_name}`, the user also needs to reuse the same node name to see the previous state. In detail, one needs to specify the two environment variables: `EMQX_NAME` and `EMQX_HOST`, `EMQX_HOST` set as `127.0.0.1` or network alias would be useful. In if you use docker-compose, the configuration would look something like this: ```YAML volumes: vol-emqx-data: name: foo-emqx-data vol-emqx-etc: name: foo-emqx-etc vol-emqx-log: name: foo-emqx-log services: emqx: image: emqx/emqx:latest restart: always environment: EMQX_NAME: foo_emqx EMQX_HOST: 127.0.0.1 volumes: - vol-emqx-data:/opt/emqx/data - vol-emqx-etc:/opt/emqx/etc - vol-emqx-log:/opt/emqx/log ``` Note that `/opt/emqx/etc` contains some essential configuration files. If you want to mount a host directory in the container to persist configuration overrides, you will need to bootstrap it with [default configuration files](https://github.com/emqx/emqx/tree/master/apps/emqx/etc). ### Kernel Tuning Under Linux host machine, the easiest way is [Tuning guide](https://www.emqx.io/docs/en/latest/deploy/tune.html). If you want tune Linux kernel by docker, you must ensure your docker is latest version (>=1.12). ```bash docker run -d --name emqx -p 18083:18083 -p 1883:1883 \ --sysctl fs.file-max=2097152 \ --sysctl fs.nr_open=2097152 \ --sysctl net.core.somaxconn=32768 \ --sysctl net.ipv4.tcp_max_syn_backlog=16384 \ --sysctl net.core.netdev_max_backlog=16384 \ --sysctl net.ipv4.ip_local_port_range=1000 65535 \ --sysctl net.core.rmem_default=262144 \ --sysctl net.core.wmem_default=262144 \ --sysctl net.core.rmem_max=16777216 \ --sysctl net.core.wmem_max=16777216 \ --sysctl net.core.optmem_max=16777216 \ --sysctl net.ipv4.tcp_rmem=1024 4096 16777216 \ --sysctl net.ipv4.tcp_wmem=1024 4096 16777216 \ --sysctl net.ipv4.tcp_max_tw_buckets=1048576 \ --sysctl net.ipv4.tcp_fin_timeout=15 \ emqx/emqx:latest ``` > REMEMBER: DO NOT RUN EMQX DOCKER PRIVILEGED OR MOUNT SYSTEM PROC IN CONTAINER TO TUNE LINUX KERNEL, IT IS UNSAFE. ### Thanks + [@je-al](https://github.com/emqx/emqx-docker/issues/2) + [@RaymondMouthaan](https://github.com/emqx/emqx-docker/pull/91) + [@zhongjiewu](https://github.com/emqx/emqx/issues/3427)