WCS in Docker¶

WCS can be used in Docker with official Docker image since build 5.2.458

Docker deployment example¶

Do the following steps to deploy the simple WebRTC streaming server in Docker container:

1. Pull the latest WCS image from Docker Hub

sudo docker pull flashphoner/webcallserver

2. Set up docker bridge network

sudo docker network create \
 --subnet 192.168.1.1/24 \
 --gateway=192.168.1.1 \
 --driver=bridge \
 --opt com.docker.network.bridge.name=br-testnet testnet

3. Start WCS docker container with your own trial or commercial license number

docker run \
-e PASSWORD=password \
-e LICENSE=license_number \
-e LOCAL_IP=192.168.1.10 \
--net testnet --ip 192.168.1.10 \
--name wcs-docker-test --rm -d flashphoner/webcallserver:latest

4. Check if the container available by SSH

ssh root@192.168.1.10

5. Open Two Way Streaming example in local browser, publish a stream

6. Close the page, stop the container

sudo docker stop wcs-docker-test

License will be deactivated on container stop to prevent unnecessary billing.

Docker container configuration¶

Networking issues¶

By default, IP address will be set dynamically to the container. So if you suppose to use fixed IP address, you should set it with docker run options and pass to the container using LOCAL_IP variable:

docker run -e LICENSE=license_number -e PASSWORD=secret \
 -e LOCAL_IP=static_ip \
 --net your-docker-network \
 --ip static_ip \
 --name webcallserver-instance -d webcallserver:latest

If your docker host is behind NAT, and your WCS is supposed to be available from outside, you should set external IP address to EXTERNAL_IP variable:

docker run -e LICENSE=license_number -e PASSWORD=secret \
 -e LOCAL_IP=static_ip \
 -e EXTERNAL_IP=external_ip \
 --net your-docker-network \
 --ip static_ip \
 --name webcallserver-instance -d webcallserver:latest

Dynamic IP address detection issues¶

When IP address should be set dynamically to the container, and the container has more than one network interface (this can happen for example when docker host interfaces are used), IP address to bind WCS server should be chosen manually while the container is launching. In this case, the container should be started in interacrive mode

docker run \
-e PASSWORD=password \
-e LICENSE=license_number \
--net host \
--name wcs-docker-test --rm -it flashphoner/webcallserver:latest

Container enrty point script detects all the IP addresses and asks to enter the address for WCS to bind to

The address chosen will be written to ip_local parameter, for example

ip_local=172.17.0.1

Environment variables reference¶

The following environment variables can be passed to the container:

PASSWORD - SSH password to access the container. If this variable is not defined, container will not be accessible by SSH using password
LICENSE - Web Call Server license number. If this variable is not defined, license can be entered on first web interface logon
LOCAL_IP - local IP address to set to ip_local parameter in flashphoner.properties configuration file. If this variable is not defined, container IP address will be detected automatically
EXTERNAL_IP - external IP address to set to ip parameter in flashphoner.properties configuration file. If this variable is not defined and LOCAL_IP is not defined,external IP address will be detected automatically.
CDN_ROLE - container role in CDN. If this variable is not defined, container will act as standalone server
CDN_ENTRY_POINT - CDN entry point server address for the container. If this variable is not defined, CDN entry point will not be set
CDN_GROUPS - CDN groups to which the container should belong. If this variable is not defined, the container will not belong to any CDN group

Volumes reference¶

The following docker volumes can be mounted to the container

/conf - additional configuration files folder, the path startsfrom container root. This volume can be mounted as read-only
/usr/local/FlashphonerWebCallServer/hls - HLS segments folder. This volume must be mounted with write access
/usr/local/FlashphonerWebCallServer/logs - logging folder. This volume must be mounted with write access
/usr/local/FlashphonerWebCallServer/media - media files for VOD playback folder. This volume can be mounted as read-only. This volume can be shared with another Web Call Server instances
/usr/local/FlashphonerWebCallServer/records - stream recoding files folder. This volume must be mounted with write access. This volume can be shared with another Web Call Server instances

The container launch example with all the volumes mounted:

docker run -e LICENSE=license_number -e CDN_ROLE=origin \
 -v /opt/wcs/conf:/conf \
 -v /opt/wcs/logs:/usr/local/FlashphonerWebCallServer/logs \
 -v /opt/wcs/hls:/usr/local/FlashphonerWebCallServer/hls \
 -v /opt/wcs/media:/usr/local/FlashphonerWebCallServer/media \
 -v /opt/wcs/records:/usr/local/FlashphonerWebCallServer/records \
 --name webcallserver-instance -d webcallserver:latest

Do not mount whole folder /usr/local/FlashphonerWebCallServer/conf or separate files from this folder as volumes!

For example, this is not allowed:

docker run -e LICENSE=license_number -e PASSWORD=secret \
 -v /opt/wcs/conf:/usr/local/FlashphonerWebCallServer/conf \
 --name webcallserver-instance -d webcallserver:latest

and this too:

docker run -e LICENSE=license_number -e PASSWORD=secret \
 -v /opt/wcs/conf/flashphoner.properties:/usr/local/FlashphonerWebCallServer/conf/flashphoner.properties \
 --name webcallserver-instance -d webcallserver:latest

Additional instance configuration¶

The following additional configuration files can be placed to the host folder mounted as /conf volume:

id_rsa.pub - public SSH access key. If this file is found during the container start, the container will be accessible with corresponding private key. Otherwise, if PASSWORD variable is defined, the container will be accesible by password. If neiher key, nor password are defined, SSH daemon will not be started
flashphoner.properties - main server configuration file. It can be used for detailed Web Call Server instance configuration
wcs-core.properties - Java configuration file. It can be used for memory tuning and JMC connection configuration
log4j.properties - logging configuration file
wss.jks - SSL certificates key storage file. This file can be prepared with keytool
cdn_profiles.yml - CDN transcoding profiles configuration file
database.yml - user accounts and REST hook applications configuration
*.sdp - SDP settings files

All those files can be used for example to restore Web Call Server instance configuration from backup and automatic deployment. The files will be copied to the container 'as is', except flashphoner.properties:

ip and ip_local parameters will be changed (see IP_LOCAL variable description above)
if CDN_ROLE variable is set, but the file contains no CDN settings, the default settings will be added

Container ports¶

The following ports are available by default:

22/tcp - SSH (this port is active only if password or key access is set)
554/tcp - RTSP server port
1935/tcp - RTMP server port
1935/udp - RTMFP server port
2001/tcp - server CLI port
7777/tcp - server monitoring port
8080-8084/tcp - WS, HTTP, CDN ports
8443-8445/tcp - WSS, HTTPS ports
8888/tcp - HTTPS port (for older versions compatibility)
9091/tcp - HTTP port (for older versions compatibility)
30000-35000/tcp - TCP media ports
30000-35000/udp - UDP media ports
50999/tcp - JMX port

The ports can be changed using docker run --expose parameters if necessary. In this case, the actual port values should be set to flashphoner.properties and wcs-core.properties files, see description above

Building a custom Docker image based on WCS¶

Sometimes the official image features is not enough out of the box, and a custom image should be built for testing or production purposes. For example, let's build the custom Docker image based on WCS with the following additional features:

a custom on_record_hook.sh script
a volume to mount configuration folder directly

1. Prepare the following Dockerfile

FROM flashphoner/webcallserver:latest
VOLUME /usr/local/FlashphonerWebCallServer/conf
COPY on_record_hook.sh /usr/local/FlashphonerWebCallServer/bin/on_record_hook.sh
RUN chmod +x /usr/local/FlashphonerWebCallServer/bin/on_record_hook.sh

2. Prepare the example on_record_hook.sh script and place it near th Dockerfile

# This script logs a stream name and a recording file name to records.log file
STREAM_NAME=$1
FILE_NAME=$2

echo "Hello, I'm recording from docker" >> /usr/local/FlashphonerWebCallServer/logs/records.log
echo $STREAM_NAME >> /usr/local/FlashphonerWebCallServer/logs/records.log
echo $FILE_NAME >> /usr/local/FlashphonerWebCallServer/logs/records.log

3. Build the custom image named wcs-custom-image

sudo docker build -t wcs-custom-image .

4. All done! You can run a container from the custom image, for example

sudo docker network create \
 --subnet 192.168.1.1/24 \
 --gateway=192.168.1.1 \
 --driver=bridge \
 --opt com.docker.network.bridge.name=br-testnet testnet
sudo chmod -R og+w /opt/wcs/logs /opt/wcs/records /opt/wcs/conf
docker run \
 -e PASSWORD=password \
 -e LICENSE=license_number \
 -e LOCAL_IP=192.168.1.10 \
 -v /opt/wcs/logs:/usr/local/FlashphonerWebCallServer/logs \
 -v /opt/wcs/records:/usr/local/FlashphonerWebCallServer/records \
 -v /opt/wcs/conf:/usr/local/FlashphonerWebCallServer/conf
 --net testnet --ip 192.168.1.10 \
 --name wcs-docker-test --rm -d wcs-custom-image:latest

Known issues¶

1. Open files limit cannot be changed from inside container¶

Symptoms

The following message is displaing when container starts in interactive mode

ulimit: open files: cannot modify limit: Operation not permitted

Solution

Set open files limit in container parameters when launching it

docker run --ulimit nofile=100000:100000 \
-e LICENSE=license_number -e PASSWORD=secret \
--name webcallserver-instance --rm webcallserver:latest

2. It is not recommended to use Docker on Windows due to port forwarding issues¶

Symptoms

WCS container is running but not available via SSH, HTTP/HTTPS, or WebRTC connection is not establishing when container is deployed in Docker on Windows

Solution

Use Docker on Linux, or launch WCS in WSL 2