In this lab you will learn how to use an LDAP server as an authentication provider in OpenShift.
NOTE: If you do not have access to an LDAP server you can look at Apendix A. This shows you how to deploy an LDAP server inside of OpenShift for testing.
OpenShift takes a "hands off" approach to user authentication. That is, it "offloads" the authentication part to an "external" provider.
Take a note of the users
oc get users
NAME UID FULL NAME IDENTITIES
demo 72455092-6dad-11e7-b505-5254005e6599 Local Authentication:demo
You will note in the IDENTITIES field that it lists where the user demo is being authenticated to. You can look at this config on the master config file.
root@master# grep -A4 "Local Authentication" /etc/origin/master/master-config.yaml
name: "Local Authentication"
provider:
apiVersion: v1
file: /etc/origin/openshift-passwd
kind: HTPasswdPasswordIdentityProvider
Here OpenShift is "offloading" the auth with a flat htpasswd file.
cat /etc/origin/openshift-passwd
demo:$apr1$tuMj6pjc$uHo8IoNUoK0mGx6omnI1l1
It is useful to keep this as an authentication method in case your LDAP server goes down. So we will be adding (not replacing) authentcation backends. This will show how you can "stack" your authentication methods.
First, make a backup copy of the config file so we can come back to it.
cp -a /etc/origin/master/master-config.yaml /etc/origin/master/master-config.yaml.bk
You will need to get a "bind" password and account from LDAP provider.
If you deployed the Apendix A LDAP server, get your password like so
oc rsh freeipa-server-1-dp1sv
sh-4.2# echo $PASSWORD
Edit the /etc/origin/master/master-config.yaml config file to look like something similar to this. If you would like to obfuscate your password please see this config. Remember to add this as an additional provider.
identityProviders:
- name: "LDAP Authentication"
challenge: true
login: true
provider:
apiVersion: v1
kind: LDAPPasswordIdentityProvider
attributes:
id:
- dn
email:
- mail
name:
- cn
preferredUsername:
- uid
bindDN: "cn=directory manager"
bindPassword: "d2UwNLG3kWbpUeK58JQIFbHviCmkgqtd"
insecure: true
url: "ldap://ocp-master.example.com:32389/cn=users,cn=accounts,dc=example,dc=test?uid"If you are using Active Directory; please take note of Apendix B
Next you will need to restart the service.
systemctl restart atomic-openshift-master.service
When you visit your login page you will see two options. Go ahead login to the LDAP page with an LDAP account.
Take another note of your users. Notice that you can see your users and how they are authenticating.
oc get users
NAME UID FULL NAME IDENTITIES
demo 72455092-6dad-11e7-b505-5254005e6599 Local Authentication:demo
homer a3fe512b-6dad-11e7-b505-5254005e6599 Homer Simpson LDAP Authentication:uid=homer,cn=users,cn=accounts,dc=example,dc=test
In this lab you set up OpenShift to authenticate to LDAP. Furthermore, you saw how you can use two sources of user authentication.
If you do not have an LDAP server (or cannot get access to one) you can deploy IPA on OpenShift
This assumes the following
- DNS for the domain is pointed at the OCP router
- Dynamic storage and/or a PV is available
- You have admin access to OCP
Import the community version of FreeIPA template into OpenShift.
oc login -u system:admin
oc create -f https://github.com/raw/freeipa/freeipa-container/master/freeipa-server-openshift.json -n openshift
Next, import the image as the user you will be deploying IPA as (example below)
oc login -u developer
oc import-image freeipa-server:latest --from=freeipa/freeipa-server:centos-7 --confirm
Now that you have the template and image imported; install FreeIPA on OpenShift.
First Create Service Account to run the image as root (yes it needs root to run)
oc project myproject
oc create serviceaccount useroot
oc adm policy add-scc-to-user anyuid -z useroot
Next, login to your webconsole and create your ipa server with the following parameters. Make note to add the useroot service account in the appropriate field. Also, you may want to increase the timeout to something more than 600 (I used 12000 in my testing). The rest of the defaults should be fine.
Once you are sure of the parameters; click "Create"
FreeIPA generates certificates/keys for itself so you might need to generate some activity on your system, if you look at the deployment logs and see the following
Configuring Kerberos KDC (krb5kdc). Estimated time: 30 seconds
[1/9]: adding kerberos container to the directory
[2/9]: configuring KDC
[3/9]: initialize kerberos container
WARNING: Your system is running out of entropy, you may experience long delays
Just run this to speed it along (run ^c after a minute or two)
while true; do find /; done
The fastest way to add ldap users is with oc rsh; so find out your pod name.
[root@ocp-aio ]# oc get pods
NAME READY STATUS RESTARTS AGE
freeipa-server-1-dp1sv 1/1 Running 0 2h
Now oc rsh into this pod
[root@ocp-aio ]# oc rsh freeipa-server-1-dp1sv
sh-4.2#
Obtain a Kerberos ticket
sh-4.2# echo $PASSWORD | kinit admin@$(echo ${IPA_SERVER_HOSTNAME#*.} | tr '[:lower:]' '[:upper:]')
You should be able to show your IPA config now
sh-4.2# ipa config-show
Maximum username length: 32
Home directory base: /home
Default shell: /bin/sh
Default users group: ipausers
Default e-mail domain: example.test
Search time limit: 2
Search size limit: 100
User search fields: uid,givenname,sn,telephonenumber,ou,title
Group search fields: cn,description
Enable migration mode: FALSE
Certificate Subject base: O=EXAMPLE.TEST
Password Expiration Notification (days): 4
Password plugin features: AllowNThash
SELinux user map order: guest_u:s0$xguest_u:s0$user_u:s0$staff_u:s0-s0:c0.c1023$unconfined_u:s0-s0:c0.c1023
Default SELinux user: unconfined_u:s0-s0:c0.c1023
Default PAC types: nfs:NONE, MS-PAC
IPA masters: ipa.example.test
IPA CA servers: ipa.example.test
IPA NTP servers:
IPA CA renewal master: ipa.example.test
Add a user using the following example
sh-4.2# ipa user-add homer --first=Homer --last=Simpson --gecos="Homer J. Simposon" --email=homerj@mailinator.com --homedir=/home/homer --password
Password:
Enter Password again to verify:
------------------
Added user "homer"
------------------
User login: homer
First name: Homer
Last name: Simpson
Full name: Homer Simpson
Display name: Homer Simpson
Initials: HS
Home directory: /home/homer
GECOS: Homer J. Simposon
Login shell: /bin/sh
Principal name: homer@EXAMPLE.TEST
Principal alias: homer@EXAMPLE.TEST
Email address: homerj@mailinator.com
UID: 50800003
GID: 50800003
Password: True
Member of groups: ipausers
Kerberos keys available: True
You should be able to list the users attributes
sh-4.2# ipa user-find homer
--------------
1 user matched
--------------
User login: homer
First name: Homer
Last name: Simpson
Home directory: /home/homer
Login shell: /bin/sh
Principal name: homer@EXAMPLE.TEST
Principal alias: homer@EXAMPLE.TEST
Email address: homerj@mailinator.com
UID: 50800003
GID: 50800003
Account disabled: False
----------------------------
Number of entries returned 1
----------------------------
Create a nodePort so I can access the LDAP server outside of the sdn network.
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: freeipa-server
template: freeipa-server
name: freeipa-server-np
spec:
ports:
- name: ldap-np
nodePort: 32389
port: 389
protocol: TCP
targetPort: 389
selector:
deploymentconfig: freeipa-server
sessionAffinity: None
type: LoadBalancerNow run oc create -f freeipa-nodeport.yaml to create the service and the listener. A nodePort is basically a socket that all hosts in the cluster listen on and route trafic to the specified service. (NOTE: This is also handy for databases that live inside of OpenShift)
Next you can run ldapsearch to any node in the cluster on the specified port. I use the master for consistency.
ldapsearch -x -h ocp.example.com -p 32389 -b uid=homer,cn=users,cn=accounts,dc=example,dc=test
AD usually is using sAMAccountName as uid for login. Use the following ldapsearch to validate the informaiton
ldapsearch -x -D "CN=xxx,OU=Service-Accounts,OU=DCS,DC=homeoffice,DC=example,DC=com" -W -H ldaps://ldaphost.example.com -b "ou=Users,dc=office,dc=example,DC=com" -s sub 'sAMAccountName=user1'
If the ldapsearch did not return any user, it means -D or -b may not be correct. Retry different baseDN. If there is too many entries returns, add filter to your search. Filter example is someting like (objectclass=people) or (objectclass=person) if still having issues; increase logging as OPTIONS=--loglevel=5 in /etc/sysconfig/atomic-openshift-master
A sample config might look like
identityProviders:
- name: "Active Directory"
challenge: true
login: true
provider:
apiVersion: v1
kind: LDAPPasswordIdentityProvider
attributes:
id:
- dn
email:
- mail
name:
- cn
preferredUsername:
- sAMAccountName
bindDN: "CN=LinuxSVC,OU=Service-Accounts,OU=DCS,DC=office,DC=example,DC=com"
bindPassword: "password"
ca: ad-ca.pem.crt
insecure: false
url: "ldaps://ad-server.example.com:636/CN=Users,DC=hoffice,DC=example,DC=com?sAMAccountName?sub"If you need to look for a subclass it might look like...
ldaps://ad.corp.example.com:636/OU=Users,DC=corp,DC=example,DC=com?sAMAccountName?sub?(&(objectClass=person)