Major Change

As of 10 Jan 2019 (v3.4.3), the build mechanism for this image has changed from the historical method to using multi-stage builds, which has several advantages for the image maintainers. This change should NOT impact image users, but please test and validate your deployment before pushing the new image directly into production. If you do find issues, please submit them at https://github.com/Unicon/shibboleth-idp-dockerized/issues.

Overview

This Docker image contains a deployed Shibboleth IdP 3.4.3 running on OpenJDK-based Zulu 8 Update 212 and Jetty 9.3.27 running on the latest CentOS 7 base. This image is a base image and should be used to set the configuration with local changes.

Every component (Java, Jetty, Shibboleth IdP, and extensions) in this image is verified using cryptographic hashes obtained from each vendor and stored in the Dockerfile directly. This makes the build essentially deterministic.

A working example of how this image can be used can be found at https://github.com/UniconLabs/dockerized-idp-testbed.

Creating a Shibboleth IdP Configuration

Assuming that you do not already have one, create your initial IdP configuration by run with:

docker run -it -v $(pwd):/ext-mount --rm unicon/shibboleth-idp init-idp.sh

This downloads the base image, if it does not already exists, creates a temporary container, and exports the new configuration to the local (Docker Host) file system. After the process completes, the temporary Docker container is deleted as it is no longer needed.

The files in the customized-shibboleth-idp/ directory are your IdP specific files. Safe guard them, especially the credentials/ directory. You will apply these files to the IdP base image in your own custom image.

Also, included are directories that one would often customized, such as the images, css, and page templates themselves. The baseline files have been exported and can be modified.

This image expects to find the TLS certificate and key for browser based communication in /opt/shibboleth-idp/credentials/idp-browser.p12. This certificate can be self-signed or be signed by a commerical certificate authority. If signed by the later, the appropriate intermediate certificate(s) should be included in the .p12 file. The appopriate openssl commands can be found on http://www.eclipse.org/jetty/documentation/current/configuring-ssl.html. The container will not start without this file.

Changes to the key store type, location, etc. can be changed by modifying shib-jetty-base/etc/jetty-ssl-context.xml.

To create a sample keystore, use:

openssl req -newkey rsa:2048 -nodes -keyout key.pem -x509 -days 365 -out certificate.pem
openssl x509 -text -noout -in certificate.pem
openssl pkcs12 -inkey key.pem -in certificate.pem -export -out idp-browser.p12

Move the idp-browser.p12 file into the credentials directory.

Using the Image

You can use this image as a base image for one's own IdP deployment. Assuming that you have a layout with your configuration, credentials, and war customizations (see above). The directory structure could look like:

[basedir]
|-- .dockerignore
|-- Dockerfile
|-- shibboleth-idp/
|   |-- conf/
|   |   |-- attribute-filter.xml
|   |   |-- attribute-resolver.xml
|   |   |-- credentials.xml
|   |   |-- idp.properties
|   |   |-- ldap.properties
|   |   |-- login.config
|   |   |-- metadata-providers.xml
|   |   |-- relying-party.xml
|   |   |-- services.xml
|   |-- credentials/
|   |   |-- idp-backchannel.crt
|   |   |-- idp-backchannel.p12
|   |   |-- idp-browser.p12
|   |   |-- idp-encryption.crt
|   |   |-- idp-encryption.key
|   |   |-- idp-signing.crt
|   |   |-- idp-signing.key
|   |   |-- sealer.jks
|   |   |-- sealer.kver
|   |-- metadata/
|   |   |-- idp-metadata.xml
|   |   |-- [sp metadatafiles]
|   |-- webapp/
|   |   |-- images/
|   |   |   |-- dummylogo-mobile.png
|   |   |   |-- dummylogo.png
|   |   |-- WEB-INF/
|   |   |   |-- web.xml
|   |-- views/
|   |   |   |-- login.vm
|   |   |   |-- logout.vm

Next, assuming you create a Dockerfile similar to this example:

FROM unicon/shibboleth-idp

MAINTAINER <your_contact_email>

ADD shibboleth-idp/ /opt/shibboleth-idp/

The dependant image can be built by running:

docker pull centos:centos7
docker build --tag="<org_id>/shibboleth-idp:<version>" .

This will download the base image from the Docker Hub repository. Next, your files are overlaid replacing the base image's counter-parts.

Now, execute the new/customized image:

$ docker run -d --name="shib-local-test" <org_id>/shibboleth-idp

This is the base command-line used to start the container. The container will likely fail to initialize if this limited command-line is used. You'll likely need to specify additional parameters to start-up the IdP.

Run-time Parameters

Start the IdP will take several parameters. The following parameters can be specified when running a new IdP container:

Port Mappings

The image exposes two ports. 4443 is the for standard browser-based TLS communication. 8443 is the backchannel TLS communication port. These ports will need to be mapped to the Docker host so that communication can occur.

-P: Used to indicate that the Docker Service should map all exposed container ports to ephemeral host ports. Use docker ps to see the mappings.
-p <host>:<container>: Explicitly maps the host ports to the container's exposed ports. This parameters can be used multiple times to map multiple sets of ports. -p 443:4443 would make the IdP accessible on https://<docker_host_ip>/idp/.

Environmental variables

The container will use environmental variables to control IdP functionality at runtime. Currently there are 3 such variables that can be set from the docker run command:

-e JETTY_BROWSER_SSL_KEYSTORE_PASSWORD=<changeme>: The password for the browser TLS p12 key store (/opt/shibboleth-idp/credentials/idp-browser.p12). Defaults to changeme.
-e JETTY_BACKCHANNEL_SSL_KEYSTORE_PASSWORD=<changeme>: The password for the browser TLS p12 key store (/opt/shibboleth-idp/credentials/idp-backchannel.p12). Defaults to changeme.
-e JETTY_MAX_HEAP=<2048m>: Specifies the maximum heap sized used by Jetty's child process to run the IdP application.

Volume Mount

The IdP container does not explicitally need any volumes mapped for operation, but the option does exist using the following format:

-v <hostDir>:<containerDir>

It maybe desirable to map things like /opt/shibboleth-idp/logs or /opt/shibboleth-idp/credentials to host-side storage.

Notables

There are a few things that implementors should be aware of.

Externalizing Secrets and Credentials

Some adopters will not want to include their secrets (key files and passwords) in their customized images. This image has been enhanced to faciliate externalizing those and connecting them in at runtime.

To do this, you will NOT want to include the credentials directory in your image. Put that directory on the Docker host. When starting the container specify -v <Host_credentials_directory>:/opt/shibboleth-idp/credentials. This will mount the local credentials directory into the image.

To extract out passwords, you'll want to modify the conf/idp.properties file, by moving sensitive entries out of the file and into a file named idp-secrets.properties. Save the idp-secrets.properties and ldap.properties files onto the docker host into their own directory. Also, change the conf/idp.properties's idp.additionalProperties setting to look something like:

# Load any additional property resources from a comma-delimited list
idp.additionalProperties= /ext-conf/idp-secrets.properties, /ext-conf/ldap.properties, /conf/saml-nameid.properties, /conf/services.properties

Note the /ext-conf/ changes/additions in the property.

This tells the IdP to look into the /opt/shibboleth-idp/ext-conf/ directory for the idp-secrets.properties and ldap.properties files. To mount the ext-conf directory, add -v <Host_ext-config_directory>:/opt/shibboleth-idp/ext-conf to the start-up parameters.

When the container starts up, if the /opt/shibboleth-idp/ext-conf/idp-secrets.properties file is found the TLS key files passwords will be read from the file as properties: jetty.sslContext.keyStorePassword (browser) and jetty.backchannel.sslContext.keyStorePassword (backchannel). This will preclude needing to specify them via the -e parameter.

Logging

Jetty Logs and Shibboleth IdP's idp-process.logare redirected to the console and are exposed via the docker logs command and other Docker logging methods.

Removing the /opt/shib-jetty-base/etc/jetty-logging.xml (or setting it to your own configuration) will cause Jetty's default behavior to occur. Restoring the IdP's baseline logback.xml via overlaying will cause the default IdP file logging behavior to occur.

Building from Source

$ docker build --tag="<org_id>/shibboleth-idp" github.com/unicon/shibboleth-idp-dockerized

Recipes

Instructions for things like using the Oracle JVM and JCE with this image can be found at https://github.com/Unicon/shibboleth-idp-dockerized/wiki/.

Authors/Contributors

This project was developed as part of Unicon's Open Source Support program, which is funded by our program subscribers. Professional support/integration assistance for this module is available. For more information, visit https://unicon.net/opensource/shibboleth.

John Gasper (jgasper@unicon.net)

LICENSE

The contents of the built image are subject to their respective licenses. The following applies license applies to the Docker-based project files:

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

jakelandis/shibboleth-idp-dockerized