NOTES:
- This image does not support nested docker containers or IOU images. QEMU/KVM only!
- This image is only the "server" component of GNS3, for the GUI component, I recommend pip3 (ie. just run:
sudo pip3 install sip pyqt5 gns3-gui), more info here: https://docs.gns3.com/1QXVIihk7dsOL7Xr7Bmz4zRzTsJ02wklfImGuHwTlaA4/index.html#h.xo8m7q5xitv6
The container installs gns3-server, creates a dummy "user" account, mounts the dummy user /home folder to the specified local folder, and runs the server as that user.
For QEMU/KVM to work, the dummy user needs to be able to access /dev/kvm on the host machine. To do this we need to know the GID of the "kvm" group on the host. Execute:
grep kvm /etc/group
And you will get an output similar to:
kvm:x:130:
So we know the GID for /dev/kvm is "130"
NOTE: Some distros don't have a kvm group even if /dev/kvm exists. Don't ask me why. If this is the case, your best bet is to install the qemu-kvm package.
Next, we need to make a gns3 user on the local machine.
useradd -m -s /usr/sbin/nologin -d /var/lib/gns3 gns3
We need to know the UID and home folder for the gns3 user. Execute:
grep gns3 /etc/passwd
And you will get an output similar to:
gns3:x:1001:1001::/var/lib/gns3:/usr/sbin/nologin
So we know the UID for the user gns3 is "1001" and the home folder is "/var/lib/gns3"
Finally, execute the following command, remembering to substitute the values you found out in the previous steps:
docker run -d --name=gns3_session --dns=8.8.8.8 --restart=always --privileged -e LOCAL_USER_ID=<localuserid> -e LOCAL_GROUP_ID=<localgroupid> -v <localfolder>:/home/user billyball1517/gns3server
So in our example, we get:
docker run -d --name=gns3_session --dns=8.8.8.8 --restart=always --privileged -e LOCAL_USER_ID=1001 -e LOCAL_GROUP_ID=130 -v /var/lib/gns3:/home/user billyball1517/gns3server
To find the ip address of the running container, run:
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' gns3_session
When you run the GNS3 GUI, simply point it to that IP address.
Since the gns3 data is made persistent in the /var/lib/gns3 folder, upgrading is easy. Simply delete the running container, pull the image again, and start the container with the same command you used previously.
Make sure the path when creating projects is /home/user/...... rather than your local user account home folder.