How to run docker with experimental functions on Ubuntu 16.04 - docker

Question

I have following question:
How to run docker with experimental features on (like image squashing docker build --squash=true... for reduce it size) on ubuntu 16.04 ?

Answer 1

To turn on experimental docker functions create following file by:
sudo nano /etc/docker/daemon.json
and add below content to it
{
"experimental": true
}
and save file (by CTRL+X and Enter ) and exit. In terminal type:
sudo service docker restart
To check that experimental funcions are ON, type in terminal:
docker version
And you should see Experimental: true
UPDATE
Instead of nano you can use this one-liner:
echo $'{\n "experimental": true\n}' | sudo tee /etc/docker/daemon.json

Answer 2

I tried everything here on a Ubuntu 18.04 VM on my mac--nothing worked. All over the interwebs said the same thing, but the one thing that finally got experimental turned on was #Michael Haren's tiny answer:
fyi- to enable this for the client, the config file to create is ~/.docker/config.json and the value is "enabled", not true
which meant something like this for me:
$ mkdir ~/.docker
$ echo '{ "experimental": "enabled" }' > ~/.docker/config.json
$ sudo systemctl restart docker
$ docker version
...
Experimental: true
...
This should be a top-level answer. So, credit to them (except sweet internet karma points for me...).

Answer 3

If you only want to run it temporarily / without modifying files, you can export DOCKER_CLI_EXPERIMENTAL=enabled. The below turns on experimental mode for your client.
$ docker version
Experimental: false
$ export DOCKER_CLI_EXPERIMENTAL=enabled
$ docker version
Experimental: true

Answer 4

Posting this to help those who are running docker on macOS
You will need to enable experimental on two files, one is client while another is docker engine
I suggest open the file manually instead of direct echo into the file as that file might have some other configuration and you might not want to overwrite them accidentally
For client, visit ~/.docker/config.json, and add "experimental": "enabled" on top level config as below
{
"experimental" : "enabled",
"auths" : {
"harbor.xxx.com" : {
}
},
"credsStore" : "desktop"
}
For Docker Engine, visit ~/.docker/daemon.json and add "experimental": true on top level config as below
{
"features": {
"buildkit": true
},
"experimental": true,
"builder": {
"gc": {
"defaultKeepStorage": "20GB",
"enabled": true
}
}
}
Do note that the "value" of experimental is different between client and server.
Once done, restart the docker using command below
killall Docker && open /Applications/Docker.app
then verify the result
docker version

Answer 5

sudo sed -i 's/ExecStart=\/usr\/bin\/dockerd -H fd:\/\/ --containerd=\/run\/containerd\/containerd.sock/ExecStart=\/usr\/bin\/dockerd -H fd:\/\/ --containerd=\/run\/containerd\/containerd.sock --experimental/g' /lib/systemd/system/docker.service
sudo systemctl daemon-reload
sudo systemctl restart docker

Answer 6

I think you can solve this on Linux using the systemctl as described by https://stackoverflow.com/a/70460819/433814 on this SO. However, first you need to edit the correct files... Here's the way to set it up in a MacOS if you were looking for similar answers.
Docker run with Experiments MacOS
Just set the variable ENABLED=true or ENABLED=false and this script will automagically turn it on or off, writing to the file
NOTE: You MUST have jq installed to execute and update in-place.
ENABLED=true; \
CONFIG=~/.docker/config.json; DAEMON=~/.docker/daemon.json ; \
cat <<< $(jq --argjson V ${ENABLED} '.experimental = $V' ${DAEMON}) > ${DAEMON} ; \
cat <<< $(jq --arg V $(if [ "${ENABLED}" = "true" ]; then echo "enabled"; else echo "disabled"; fi) '.experimental = $V' ${CONFIG}) > ${CONFIG} ; \
cat ~/.docker/config.json ; \
cat ~/.docker/daemon.json
Output confirmation
This will be output automatically confirming
{
"auths": {
"https://index.docker.io/v1/": {},
"registry.gitlab.com": {}
},
"credsStore": "desktop",
"experimental": "enabled",
"currentContext": "default"
}
{
"builder": {
"gc": {
"defaultKeepStorage": "20GB",
"enabled": true
}
},
"experimental": true,
"features": {
"buildkit": true
}
}
Restart Docker Engine in MacOS
Just run the following
killall Docker && open /Applications/Docker.app
References
JQ convert to number, convert to boolean when generating new json from shell variables
passing arguments to jq filter