Container Orchestration

APIs are key to automating container management at scale. APIs are used to:

  • Validate and configure the data for pods, services, and replication controllers.

  • Perform project validation on incoming requests and invoke triggers on other major system components.

Further Reading

Authentication and Authorization

Controlling Access Using OAuth

You can use API access control via authentication and authorization for securing your container platform. The OpenShift Origin master includes a built-in OAuth server. Users can obtain OAuth access tokens to authenticate themselves to the API.

As an administrator, you can configure OAuth to authenticate using an identity provider, such as LDAP, GitHub, or Google. The Allow All identity provider is used by default for new OpenShift Origin deployments, but you can configure this at initial installation time or post-installation. See Configuring Authentication for a full list of identity providers.

For example, to configure the GitHub identity provider post-installation:

  1. Edit the master configuration file at /etc/origin/master-config.yaml.

  2. Modify the oauthConfig stanza per the following:

    oauthConfig:
      ...
      identityProviders:
      - name: github
        challenge: false
        login: true
        mappingMethod: claim
        provider:
          apiVersion: v1
          kind: GitHubIdentityProvider
          clientID: ...
          clientSecret: ...
          organizations:
          - myorganization1
          - myorganization2
          teams:
          - myorganization1/team-a
          - myorganization2/team-b

    See the GitHub section in Configuring Authentication for more detailed information and usage.

  3. After saving your changes, restart the master service for the changes to take effect:

    # systemctl restart origin-master

Further Reading

Secure Self-service Web Console

OpenShift Origin provides a self-service web console to ensure that teams do not access other environments without authorization. OpenShift Origin ensures a secure multi-tenant master by providing the following:

  • Access to the master uses Transport Layer Security (TLS)

  • Access to the API Server uses X.509 certificates or OAuth access tokens

  • Project quota limits the damage that a rogue token could do

  • Etcd is not exposed directly to the cluster

Further Reading

Managing Certificates for the Platform

OpenShift Origin has multiple components within its framework that use REST-based HTTPS communication leveraging encryption via TLS certificates. OpenShift Origin’s Ansible-based installer configures these certificates during installation. There are some primary components that generate this traffic:

  • masters (API server and controllers)

  • etcd

  • nodes

  • registry

  • router

Configuring Custom Certificates

You can configure custom serving certificates for the public host names of the API server and web console during initial installation or when redeploying certificates. You can also use a custom CA.

During initial advanced installations using Ansible playbooks, custom certificates can be configured using the openshift_master_overwrite_named_certificates Ansible variable, which is configurable in the inventory file. For example:

openshift_master_named_certificates=[{"certfile": "/path/on/host/to/custom1.crt", "keyfile": "/path/on/host/to/custom1.key", "cafile": "/path/on/host/to/custom-ca1.crt"}]

See the Advanced Installation’s Configuring Custom Certificates for more options and instructions on how to run the installation playbook.

The installer provides Ansible playbooks for checking on the expiration dates of all cluster certificates. Additional playbooks can automatically redeploy all certificates at once using the current CA, redeploy specific certificates only, or redeploy a newly generated or custom CA on its own. See Redeploying Certificates for more on these playbooks.

Further Reading