EMQ X Docker

TODO: ...

EMQ (Erlang MQTT Broker) is a distributed, massively scalable, highly extensible MQTT messaging broker written in Erlang/OTP.

Current docker image size: 47 MB

Build emqx from source

1. Update docker configuration to enable docker manifest command and prepare qemu to build images other then x86_64

   ./docker.sh prepare

2. Build Docker image

   ./docker.sh build

3. Test the docker image with paho

   ./docker.sh test 

4. Tag Docker image

   ./docker.sh tag 

5. Save the docker image as a zip file

    ./docker.sh save 

6. Push Docker image

    docker login
    ./docker.sh push
    ./docker.sh manifest-list
    docker logout

7. Clean up the compiled image

   ./docker.sh clear

Get emqx from the docker hub

You can pull the image on the docker hub.

docker pull emqx/emqx:latest

Run emqx

Execute some command under this docker image

docker run --rm -ti -v `pwd`:$(somewhere) emqx/emqx:$(tag) $(somecommand)

For example

docker run --rm -ti --name emqx -p 18083:18083 -p 1883:1883 emqx/emqx:latest

The emqx broker runs as linux user emqx in the docker container.

Configuration

Use the environment variable to configure the EMQ X docker container.

The environment variables which with EMQX_ prefix are mapped to configuration file, . get replaced by __.

Example:

EMQX_LISTENER__SSL__EXTERNAL__ACCEPTORS <--> listener.ssl.external.acceptors
EMQX_MQTT__MAX_PACKET_SIZE              <--> mqtt.max_packet_size

Also the environment variables which with PLATFORM_ prefix are mapped to template string in configuration file.

PLATFORM_ETC_DIR                   <--> {{ platform_etc_dir }}

Non mapped environment variables:

EMQX_NAME
EMQX_HOST

These environment variables will ignore for configuration file.

EMQ X Configuration

NOTE: All EMQ X Configuration in etc/emqx.conf could config by environment. The following list is just an example, not a complete 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
EMQX_WAIT_TIME	5	none	wait time in sec before timeout
EMQX_JOIN_CLUSTER	none	none	Initial cluster to join
EMQX_ADMIN_PASSWORD	public	none	emqx admin password
PLATFORM_ETC_DIR	/opt/emqx/etc	{{ platform_etc_dir }}	The etc directory
PLATFORM_LOG_DIR	/opt/emqx/log	{{ platform_log_dir }}	The log directory
EMQX_NODE__NAME	EMQX_NAME@EMQX_HOST	node.name	Erlang node name, name@ipaddress/host
EMQX_NODE__COOKIE	emqx_dist_cookie	node.cookie	cookie for cluster
EMQX_LOG__CONSOLE	console	log.console	log console output method
EMQX_ALLOW_ANONYMOUS	true	allow_anonymous	allow mqtt anonymous login
EMQX_LISTENER__TCP__EXTERNAL	1883	listener.tcp.external	MQTT TCP port
EMQX_LISTENER__SSL__EXTERNAL	8883	listener.ssl.external	MQTT TCP TLS/SSL port
EMQX_LISTENER__WS__EXTERNAL	8083	listener.ws.external	HTTP and WebSocket port
EMQX_LISTENER__WSS__EXTERNAL	8084	listener.wss.external	HTTPS and WSS port
EMQX_LISTENER__API__MGMT	8080	listener.api.mgmt	MGMT API port
EMQX_MQTT__MAX_PACKET_SIZE	64KB	mqtt.max_packet_size	Max Packet Size Allowed

The list is incomplete and may changed with etc/emqx.conf and plugin configuration files. But the mapping rule is similar.

If set EMQX_NAME and EMQX_HOST, and unset EMQX_NODE__NAME, EMQX_NODE__NAME=$EMQX_NAME@$EMQX_HOST.

For example, set mqtt tcp port to 1883

docker run --rm -ti --name emqx -e EMQX_LISTENER__TCP__EXTERNAL=1883 -p 18083:18083 -p 1883:1883 emqx/emqx:latest

EMQ Loaded Plugins Configuration

Oprtions	Default	Description
EMQX_LOADED_PLUGINS	see content below	default plugins emqx loaded

Default environment variable EMQX_LOADED_PLUGINS, including

• emqx_recon
• emqx_retainer
• emqx_management
• emqx_dashboard

# The default EMQX_LOADED_PLUGINS env
EMQX_LOADED_PLUGINS="emqx_recon,emqx_retainer,emqx_management,emqx_dashboard"

When you need to customize the loaded plugin, emqx_mangement must be loaded in the first place.

For example, load emqx_auth_redis plugin, set it into EMQX_LOADED_PLUGINS and use any separator to separates it.

You can use comma, space or other separator that you want.

All the plugin you defined in env EMQX_LOADED_PLUGINS will be loaded.

EMQX_LOADED_PLUGINS="emqx_mangement,emqx_auth_redis,emqx_recon,emqx_retainer,emqx_dashboard"
EMQX_LOADED_PLUGINS="emqx_mangement emqx_auth_redis emqx_recon emqx_retainer emqx_dashboard"
EMQX_LOADED_PLUGINS="emqx_mangement | emqx_auth_redis | emqx_recon | emqx_retainer | emqx_dashboard"

EMQ X Plugins Configuration

The environment variables which with EMQX_ prefix are mapped to all emqx plugins' configuration file, . get replaced by __.

Example:

EMQX_AUTH__REDIS__SERVER   <--> auth.redis.server
EMQX_AUTH__REDIS__PASSWORD <--> auth.redis.password

Don't worry about where to find the configuration file of emqx plugins, this docker image will find and config them automatically using some magic.

All plugin of emqx project could config in this way, following the environment variables mapping rule above.

Assume you are using redis auth plugin, for example:

#EMQX_AUTH__REDIS__SERVER="redis.at.yourserver"
#EMQX_AUTH__REDIS__PASSWORD="password_for_redis"

docker run --rm -ti --name emqx -p 18083:18083 -p 1883:1883 -p 4369:4369 \
    -e EMQX_LISTENER__TCP__EXTERNAL=1883 \
    -e EMQX_LOADED_PLUGINS="emqx_auth_redis,emqx_recon,emqx_retainer,emqx_management,emqx_dashboard" \
    -e EMQX_AUTH__REDIS__SERVER="your.redis.server:6379" \
    -e EMQX_AUTH__REDIS__PASSWORD="password_for_redis" \
    -e EMQX_AUTH__REDIS__PASSWORD_HASH=plain \
    emqx/emqx:latest

Cluster

You can specify a initial cluster and join.

Note: You must publsh port 4369, 5369 and range of port 6000-6999 for EMQ X Cluster.

For example, using 6000-6100 for cluster.

docker run --rm -ti --name emqx -p 18083:18083 -p 1883:1883 -p 4369:4369 -p 6000-6100:6000-6100 \
    -e EMQX_NAME="emqx" \
    -e EMQX_HOST="t.emqx.io" \
    -e EMQX_LISTENER__TCP__EXTERNAL=1883 \
    -e EMQX_JOIN_CLUSTER="[email protected]" \
    emqx/emqx:latest

Kernel Tuning

Under linux host machine, the easiest way is tuning host machine's kernel.

If you want tune linux kernel by docker, you must ensure your docker is latest version (>=1.12).

docker run --rm -ti --name emqx -p 18083:18083 -p 1883:1883 -p 4369:4369 \
    --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 EMQ X DOCKER PRIVILEGED OR MOUNT SYSTEM PROC IN CONTAINER TO TUNE LINUX KERNEL, IT IS UNSAFE.

Thanks

• @je-al
• @RaymondMouthaan