For creating your custom image you need a base Docker image of SLES. You can use any of the pre-built SLES images that you can obtain as described in Section 5.2, “Customizing SLES Docker Images”.
Usually you can pull a variety of base Docker images from the
docker hub but that does
not apply for SLES. Currently we cannot distribute SLES images for
Docker Open Source Engine because there is no way to associate an End-User License Agreement
(EULA) to a Docker image. sle2docker
enables you to
import pre-built SLES images that you can use for creating base SLES
images.
After you obtain your base docker image, you can modify the image by using a
Dockerfile
(usually placed in the build directory). Then
use the standard building tool to create your custom image:
docker build PATH_TO_BUILD_DIRECTORY
For more docker build
options, refer to the
official
Docker documentation.
You may want to write a dockerfile for your own application that should be run inside a docker container. For a procedure refer to Chapter 6, Creating Docker Images of Applications.
How to obtain a pre-built base image depends on the SUSE Linux Enterprise Server version:
tux >
sudo
zypper in sles11sp4-docker-image
docker pull registry.suse.com/suse/sles12sp4
Pre-built images do not have repositories configured. But when the Docker host has an SLE subscription that provides access to the product used in the image, Zypper will automatically have access to the right repositories.
If you have obtained the image with Zypper, you need to activate it. Proceed as follows:
Get the proper image name with sle2docker
by running
sle2docker list
Activate the image by using the image name from the previous step:
sle2docker activate PRE-BUILT_IMAGE_NAME
Check if the image was successfully activated by running
sle2docker
You can customize the docker image as described in Section 5.2, “Customizing SLES Docker Images”.
The pre-built images do not have any repository configured and do not
include any modules or extensions. They contain a
zypper
service that contacts either the SUSE Customer Center (SCC) or your Subscription Management Tool
(SMT) server, according to the configuration of
the SLE host that runs the Docker container. The service obtains the list of
repositories available for the product used by the Docker image. You can
also directly declare extensions in your Dockerfile
(for details refer to
Section 5.2.3, “Adding SLE Extensions and Modules to Images”.
You do not need to add any credentials to the Docker image because the
machine credentials are automatically injected into the container by the
Docker daemon. They are injected inside of the
/run/secrets
directory. The same applies to the
/etc/SUSEConnect
file of the host system, which is
automatically injected into the /run/secrets
directory.
The contents of the /run/secrets
directory are never
committed to a Docker image, hence there is no risk of your credentials
leaking.
To obtain the list of repositories use the following command:
zypper ref -s
It will automatically add all the repositories to your container. For each
repository added to the system a new file will be created under
/etc/zypp/repos.d
. The URLs of these repositories include
an access token that automatically expires after 12 hours. To renew the
token call the zypper ref -s
command. It is secure to
commit these files to a Docker image.
If you want to use a different set of credentials, place a custom
/etc/zypp/credentials.d/SCCcredentials
file inside of
the Docker image. It contains the machine credentials that have the
subscription you want to use. The same applies to the
SUSEConnect
file: to override the file available on the
host system that is running the Docker container, add a custom
/etc/SUSEConnect
file inside of the Docker image.
Now you can create a custom Docker image by using a
Dockerfile
. If you want to create a custom image, refer to
Section 5.2.1, “Creating a Custom SLE 11 SP4 Image” for SLE 11 SP4
In case you would like to move your application to a Docker container, refer to Chapter 6, Creating Docker Images of Applications.
The following Dockerfile
creates a simple Docker image based on
SLE 11 SP4:
FROM suse/sles11sp4:latest RUN zypper ref -s RUN zypper -n in vim
When the Docker host machine is registered against an internal SMT server, the Docker image requires the SSL certificate used by SMT:
FROM suse/sles11sp4:latest # Import the crt file of our private SMT server ADD http://smt.test.lan/smt.crt /etc/ssl/certs/smt.pem RUN c_rehash /etc/ssl/certs RUN zypper ref -s RUN zypper -n in vim
The following Dockerfile
creates a simple Docker image based on
SLE 12 SP4:
FROM registry.suse.com/suse/sles12sp4:latest RUN zypper ref -s RUN zypper -n in vim
When the Docker host machine is registered against an internal SMT server, the Docker image requires the SSL certificate used by SMT:
FROM registry.suse.com/suse/sles12sp4:latest # Import the crt file of our private SMT server ADD http://smt.test.lan/smt.crt /etc/pki/trust/anchors/smt.crt RUN update-ca-certificates RUN zypper ref -s RUN zypper -n in vim
You may have subscriptions to SLE extensions or modules that you would like to use in your custom image. To add them to the Docker image, proceed as follows:
Add the following into your Dockerfile
:
ADD *.repo /etc/zypp/repos.d/ ADD *.service /etc/zypp/services.d RUN zypper refs && zypper refresh
Copy all .service
and .repo
files that you will use into the directory where you will build the
Docker image from the Dockerfile
.