This is a Docker container for Firefox.
The GUI of the application is accessed through a modern web browser (no installation or configuration needed on the client side) or via any VNC client.
For simple use cases, this container is a drop-in replacement for jlesage/firefox. It improves on that image in the following ways:
- Support for
amd64andarm64. - The Firefox window will resize to the browser or VNC client.
Mozilla Firefox is a free and open-source web browser developed by Mozilla Foundation and its subsidiary, Mozilla Corporation.
- Docker container for Firefox
NOTE: The Docker command provided in this quick start is given as an example and parameters should be adjusted to your need.
Launch the Firefox docker container with the following command:
docker run -d \
--name=firefox \
-p 5800:5800 \
-v /docker/appdata/firefox:/config:rw \
--shm-size 2g \
fhriley/firefox
Where:
/docker/appdata/firefox: This is where the application stores its configuration, log and any files needing persistency.
Browse to http://your-host-ip:5800 to access the Firefox GUI.
docker run [-d] \
--name=firefox \
[-e <VARIABLE_NAME>=<VALUE>]... \
[-v <HOST_DIR>:<CONTAINER_DIR>[:PERMISSIONS]]... \
[-p <HOST_PORT>:<CONTAINER_PORT>]... \
--shm-size VALUE \
fhriley/firefox
| Parameter | Description |
|---|---|
| -d | Run the container in the background. If not set, the container runs in the foreground. |
| -e | Pass an environment variable to the container. See the Environment Variables section for more details. |
| -v | Set a volume mapping (allows to share a folder/file between the host and the container). See the Data Volumes section for more details. |
| -p | Set a network port mapping (exposes an internal container port to the host). See the Ports section for more details. |
| --shm-size | Set the size of /dev/shm to VALUE. The format of VALUE is <number><unit>, where number must be greater than 0 and unit can be b (bytes), k (kilobytes), m (megabytes), or g (gigabytes). NOTE: To avoid crashes, it is recommended to set this value to 2g. |
To customize some properties of the container, the following environment
variables can be passed via the -e parameter (one for each variable). Value
of this parameter has the format <VARIABLE_NAME>=<VALUE>.
| Variable | Description | Default |
|---|---|---|
USER_ID |
ID of the user the application runs as. See User/Group IDs to better understand when this should be set. | 1000 |
GROUP_ID |
ID of the group the application runs as. See User/Group IDs to better understand when this should be set. | 1000 |
TZ |
TimeZone of the container. Timezone can also be set by mapping /etc/localtime between the host and the container. |
Etc/UTC |
The following table describes data volumes used by the container. The mappings
are set via the -v parameter. Each mapping is specified with the following
format: <HOST_DIR>:<CONTAINER_DIR>[:PERMISSIONS].
| Container path | Permissions | Description |
|---|---|---|
/config |
rw | This is where the application stores its configuration, log and any files needing persistency. |
Here is the list of ports used by the container. They can be mapped to the host
via the -p parameter (one per port mapping). Each mapping is defined in the
following format: <HOST_PORT>:<CONTAINER_PORT>. The port number inside the
container cannot be changed, but you are free to use any port on the host side.
| Port | Mapping to host | Description |
|---|---|---|
| 5800 | Mandatory | Port used to access the application's GUI via the web interface. |
| 5900 | Optional | Port used to access the application's GUI via the VNC protocol. Optional if no VNC client is used. |
As can be seen, environment variables, volume and port mappings are all specified while creating the container.
The following steps describe the method used to add, remove or update parameter(s) of an existing container. The general idea is to destroy and re-create the container:
- Stop the container (if it is running):
docker stop firefox
- Remove the container:
docker rm firefox
- Create/start the container using the
docker runcommand, by adjusting parameters as needed.
NOTE: Since all application's data is saved under the /config container
folder, destroying and re-creating a container is not a problem: nothing is lost
and the application comes back with the same state (as long as the mapping of
the /config folder remains the same).
Here is an example of a docker-compose.yml file that can be used with
Docker Compose.
Make sure to adjust according to your needs. Note that only mandatory network ports are part of the example.
version: '3'
services:
firefox:
image: fhriley/firefox
ports:
- "5800:5800"
volumes:
- "/docker/appdata/firefox:/config:rw"Because features are added, issues are fixed, or simply because a new version of the containerized application is integrated, the Docker image is regularly updated. Different methods can be used to update the Docker image.
The system used to run the container may have a built-in way to update containers. If so, this could be your primary way to update Docker images.
An other way is to have the image be automatically updated with Watchtower. Watchtower is a container-based solution for automating Docker image updates. This is a "set and forget" type of solution: once a new image is available, Watchtower will seamlessly perform the necessary steps to update the container.
Finally, the Docker image can be manually updated with these steps:
- Fetch the latest image:
docker pull fhriley/firefox
- Stop the container:
docker stop firefox
- Remove the container:
docker rm firefox
- Create and start the container using the
docker runcommand, with the the same parameters that were used when it was deployed initially.
For owners of a Synology NAS, the following steps can be used to update a container image.
- Open the Docker application.
- Click on Registry in the left pane.
- In the search bar, type the name of the container (
fhriley/firefox). - Select the image, click Download and then choose the
latesttag. - Wait for the download to complete. A notification will appear once done.
- Click on Container in the left pane.
- Select your Firefox container.
- Stop it by clicking Action->Stop.
- Clear the container by clicking Action->Reset (or Action->Clear if you don't have the latest Docker application). This removes the container while keeping its configuration.
- Start the container again by clicking Action->Start. NOTE: The container may temporarily disappear from the list while it is re-created.
For unRAID, a container image can be updated by following these steps:
- Select the Docker tab.
- Click the Check for Updates button at the bottom of the page.
- Click the update ready link of the container to be updated.
When using data volumes (-v flags), permissions issues can occur between the
host and the container. For example, the user within the container may not
exist on the host. This could prevent the host from properly accessing files
and folders on the shared volume.
To avoid any problem, you can specify the user the application should run as.
This is done by passing the user ID and group ID to the container via the
USER_ID and GROUP_ID environment variables.
To find the right IDs to use, issue the following command on the host, with the user owning the data volume on the host:
id <username>
Which gives an output like this one:
uid=1000(myuser) gid=1000(myuser) groups=1000(myuser),4(adm),24(cdrom),27(sudo),46(plugdev),113(lpadmin)
The value of uid (user ID) and gid (group ID) are the ones that you should
be given the container.
Assuming that container's ports are mapped to the same host's ports, the graphical interface of the application can be accessed via:
- A web browser:
http://<HOST IP ADDR>:5800
- Any VNC client:
<HOST IP ADDR>:5900
To get shell access to the running container, execute the following command:
docker exec -ti CONTAINER sh
Where CONTAINER is the ID or the name of the container used during its
creation (e.g. crashplan-pro).
To prevent crashes from happening when running Firefox
inside a Docker container, the size of the shared memory located at /dev/shm
must be increased. The issue is documented here.
By default, the size is 64MB, which is not enough. It is recommended to use a
size of 2GB. This value is arbitrary, but known to work well. Setting the
size of /dev/shm can be done via two method:
- By adding the
--shm-size 2gparameter to thedocker runcommand. See the Usage section for more details. - By using shared memory of the host, by mapping
/dev/shmvia the parameter-v /dev/shm:/dev/shmof thedocker runcommand.
To properly work, recent versions of Firefox need the
membarrier system call. Without it, tabs would frequently crash.
Docker uses seccomp profile to restrict system calls available to the
container. Before Docker version 20.10.0, the membarrier system call was
not allowed in the default profile. If you run a such version, you can use one
of the following solutions, from the most to the least secure, to provide the
container permission to use this sytem call:
- Run the container with a custom seccomp profile allowing the
membarriersystem call. The latest official seccomp profile can be used. Download the file and then add the following parameter when creating the container:--security-opt seccomp=/path/to/seccomp_profile.json. - Run the container without the default seccomp profile (thus allowing all
system calls). Use the following parameter when creating the container:
--security-opt seccomp=unconfined. - Run the container in privileged mode. This effectively disables usage of
seccomp. Add the
--privilegedparameter when creating the container.
For Firefox to be able to use the audio device available on
the host, /dev/snd must be exposed to the container by adding the
--device /dev/snd parameter to the docker run command.
Firefox preferences can be set via environment variables passed to the container. During the startup, a script process all these variables and modify the preference file accordingly.
The name of the environment variable must start with FF_PREF_, followed by a
string of your choice. For example, FF_PREF_MY_PREF is a valid name.
The content of the variable should be in the format NAME=VAL, where NAME is
the name of the preference (as found in the about:config page) and VAL is
its value. A value can be one of the following types:
- string
- integer
- boolean
It is important to note that a value of type string should be surrounded by
double quotes. Other types don't need them.
For example, to set the network.proxy.http preference, one would pass the
environment variable to the container by adding the following argument to the
docker run command:
-e "FF_PREF_HTTP_PROXY=network.proxy.http=\"proxy.example.com\""
If a preference needs to be removed, its value should be set to UNSET. For
example:
-e "FF_PREF_HTTP_PROXY=network.proxy.http=UNSET"
NOTE: This is an advanced usage and it is recommended to set preferences via Firefox directly.
If Firefox is crashing frequently, make sure that:
- The size of the shared memory located at
/dev/shmhas been increased. See the Increasing Shared Memory Size section for more details. - The
membarriersystem call is not blocked by Docker. See the Allowing the membarrier System Call for more details. - Make sure the kernel of your Linux distribution is up-to-date.
Having troubles with the container or have questions? Please create a new issue.
Thanks to jlesage for writing an excellent README.