Update Docker on CoreOS using torcx

coreos-docker-update.sh

#!/bin/bash -e
# Select which Docker version to use on CoreOS with torcx.

# Specify the available Docker version to enable.
version=17.09

# Create modifiable torcx paths if they don't exist already.
mkdir -p /etc/torcx/profiles /var/lib/torcx/store

# Download the torcx manifest file for the currently running OS version.
. /usr/share/coreos/release
manifest="https://tectonic-torcx.release.core-os.net/manifests/$COREOS_RELEASE_BOARD/$COREOS_RELEASE_VERSION/torcx_manifest.json"
wget -P /tmp "$manifest".asc "$manifest"

# Verify its signature with the CoreOS application signing key.
export GNUPGHOME=$(mktemp -d)
trap 'rm -fr "$GNUPGHOME"' EXIT
gpg2 --keyserver pool.sks-keyservers.net --recv-keys 18AD5014C99EF7E3BA5F6CE950BDD3E0FC8A365E
gpg2 --verify /tmp/torcx_manifest.json.asc /tmp/torcx_manifest.json

# Download the selected Docker image at its URL in the manifest.
wget -P /var/lib/torcx/store $(jq -r ".value.packages[] | select(.name == \"docker\") | .versions[] | select(.version == \"${version}\") | .locations[] | select(.url).url" < /tmp/torcx_manifest.json)
test "x$(jq -r ".value.packages[] | select(.name == \"docker\") | .versions[] | select(.version == \"${version}\") | .hash" < /tmp/torcx_manifest.json)" = "xsha512-$(sha512sum "/var/lib/torcx/store/docker:${version}.torcx.tgz" | sed 's/ .*//')"

# Write a new profile named "docker" that selects the desired version on boot.
sed "s/com.coreos.cl/$version/g" /usr/share/torcx/profiles/vendor.json > /etc/torcx/profiles/docker.json
echo docker > /etc/torcx/next-profile

# Reboot to start using the new version.
reboot

Is there a way to do this for Docker 19? It seems Docker 18 is the newest in the manifest given above

@lpil No, Container Linux is in maintenance mode and stopped updating Docker. You could try building your own torcx image from the upstream release binaries, but Fedora CoreOS is the actively maintained distro.

Hi @dm0- , thank you for your help!

I was under the impression that Fedora CoreOS is not yet released and is unsuitable for production use at this time? Perhaps I'm wrong. There doesn't seem to be an AMI on AWS for it.

I was unable to find any information on how to make a torcx image, could you point me in the right direction?

Thanks!

@lpil I think Fedora CoreOS only has "preview" releases at the moment, but I no longer work for Red Hat / IBM so I don't know the status anymore.

The easiest way to build a new torcx image is probably just to extract the existing Docker image and recreate its layout with the new binaries. There are some specs in the torcx repo that might help, and I wrote an example from scratch a while ago.

How do you remove the torcx config if you want to go back to OS included Docker version ?