Here is the log files. I just want to inform you that I have that problem now also on Ubuntu 14.40 and Debian 8.
On Ubuntu ipa client version is 3.3, maybe problem is there.

In mean time I enrolled several more Ubuntu 18.04 instances without problem. 

On this Debian 8 and Ubuntu 14.40 I just try with options —ca-cert-file which I copied from master but same error.

Thank you

Petar




2019-05-20T11:13:47Z DEBUG [IPA Discovery]

2019-05-20T11:13:47Z DEBUG Starting IPA discovery with domain=example.com, servers=['myipaserver.example.com'], hostname=myclient.example.net

2019-05-20T11:13:47Z DEBUG Server and domain forced

2019-05-20T11:13:47Z DEBUG [Kerberos realm search]

2019-05-20T11:13:47Z DEBUG Search DNS for TXT record of _kerberos.example.com

2019-05-20T11:13:47Z DEBUG DNS record not found: NXDOMAIN

2019-05-20T11:13:47Z DEBUG [LDAP server check]

2019-05-20T11:13:47Z DEBUG Verifying that myipaserver.example.com (realm None) is an IPA server

2019-05-20T11:13:47Z DEBUG Init LDAP connection to: myipaserver.example.com

2019-05-20T11:13:48Z DEBUG Search LDAP server for IPA base DN

2019-05-20T11:13:49Z DEBUG Check if naming context 'dc=example,dc=com' is for IPA

2019-05-20T11:13:49Z DEBUG Naming context 'dc=example,dc=com' is a valid IPA context

2019-05-20T11:13:49Z DEBUG Search for (objectClass=krbRealmContainer) in dc=example,dc=com (sub)

2019-05-20T11:13:49Z DEBUG Found: cn=example.com,cn=kerberos,dc=example,dc=com

2019-05-20T11:13:49Z DEBUG Discovery result: Success; server=myipaserver.example.com, domain=example.com, kdc=None, basedn=dc=example,dc=com

2019-05-20T11:13:49Z DEBUG Validated servers: myipaserver.example.com

2019-05-20T11:13:49Z DEBUG will use discovered domain: example.com

2019-05-20T11:13:49Z DEBUG Using servers from command line, disabling DNS discovery

2019-05-20T11:13:49Z DEBUG will use provided server: myipaserver.example.com

2019-05-20T11:13:49Z DEBUG will use discovered realm: example.com

2019-05-20T11:13:49Z DEBUG will use discovered basedn: dc=example,dc=com

2019-05-20T11:13:49Z INFO Hostname: myclient.example.net

2019-05-20T11:13:49Z DEBUG Hostname source: Provided as option

2019-05-20T11:13:49Z INFO Realm: example.com

2019-05-20T11:13:49Z DEBUG Realm source: Discovered from LDAP DNS records in myipaserver.example.com

2019-05-20T11:13:49Z INFO DNS Domain: example.com

2019-05-20T11:13:49Z DEBUG DNS Domain source: Forced

2019-05-20T11:13:49Z INFO IPA Server: myipaserver.example.com

2019-05-20T11:13:49Z DEBUG IPA Server source: Provided as option

2019-05-20T11:13:49Z INFO BaseDN: dc=example,dc=com

2019-05-20T11:13:49Z DEBUG BaseDN source: From IPA server ldap://myipaserver.example.com:389

2019-05-20T11:13:49Z DEBUG Starting external process

2019-05-20T11:13:49Z DEBUG args=/usr/sbin/ipa-rmkeytab -k /etc/krb5.keytab -r example.com

2019-05-20T11:13:49Z DEBUG Process finished, return code=5

2019-05-20T11:13:49Z DEBUG stdout=

2019-05-20T11:13:49Z DEBUG stderr=realm not found


2019-05-20T11:13:49Z DEBUG Starting external process

2019-05-20T11:13:49Z DEBUG args=/bin/hostname myclient.example.net

2019-05-20T11:13:49Z DEBUG Process finished, return code=0

2019-05-20T11:13:49Z DEBUG stdout=

2019-05-20T11:13:49Z DEBUG stderr=

2019-05-20T11:13:49Z DEBUG Backing up system configuration file '/etc/hostname'

2019-05-20T11:13:49Z DEBUG Saving Index File to '/var/lib/ipa-client/sysrestore/sysrestore.index'

2019-05-20T11:13:49Z DEBUG Saving StateFile to '/var/lib/ipa-client/sysrestore/sysrestore.state'

2019-05-20T11:13:49Z INFO Synchronizing time with KDC...

2019-05-20T11:13:49Z DEBUG Search DNS for SRV record of _ntp._udp.example.com

2019-05-20T11:13:50Z DEBUG DNS record not found: NXDOMAIN

2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=/usr/sbin/ntpdate -s -b -v myipaserver.example.com

2019-05-20T11:13:50Z DEBUG Process finished, return code=1

2019-05-20T11:13:50Z DEBUG stdout=

2019-05-20T11:13:50Z DEBUG stderr=

2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=/usr/sbin/ntpdate -s -b -v myipaserver.example.com

2019-05-20T11:13:50Z DEBUG Process finished, return code=1

2019-05-20T11:13:50Z DEBUG stdout=

2019-05-20T11:13:50Z DEBUG stderr=

2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=/usr/sbin/ntpdate -s -b -v myipaserver.example.com

2019-05-20T11:13:50Z DEBUG Process finished, return code=1

2019-05-20T11:13:50Z DEBUG stdout=

2019-05-20T11:13:50Z DEBUG stderr=

2019-05-20T11:13:50Z WARNING Unable to sync time with IPA NTP server, assuming the time is in sync. Please check that 123 UDP port is opened.

2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=keyctl get_persistent @s 0

2019-05-20T11:13:50Z DEBUG Process finished, return code=2

2019-05-20T11:13:50Z DEBUG stdout=

2019-05-20T11:13:50Z DEBUG stderr=Unknown command


2019-05-20T11:13:50Z DEBUG Writing Kerberos configuration to /tmp/tmpJH6hjP:

2019-05-20T11:13:50Z DEBUG #File modified by ipa-client-install


includedir /var/lib/sss/pubconf/krb5.include.d/


[libdefaults]

  default_realm = example.com

  dns_lookup_realm = false

  dns_lookup_kdc = false

  rdns = false

  ticket_lifetime = 24h

  forwardable = yes


[realms]

  example.com = {

    kdc = myipaserver.example.com:88

    master_kdc = myipaserver.example.com:88

    admin_server = myipaserver.example.com:749

    default_domain = example.com

    pkinit_anchors = FILE:/etc/ipa/ca.crt

  }


[domain_realm]

  .example.com = example.com

  example.com = example.com

  .clientexample.com = example.com

  clientexample.com = example.com


2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=kinit admin@example.com

2019-05-20T11:13:50Z DEBUG Process finished, return code=0

2019-05-20T11:13:50Z DEBUG stdout=Password for admin@example.com:


2019-05-20T11:13:50Z DEBUG stderr=

2019-05-20T11:13:50Z DEBUG trying to retrieve CA cert from file /tmp/ca.crt

2019-05-20T11:13:50Z DEBUG CA cert provided by user, use it!

2019-05-20T11:13:50Z DEBUG Starting external process

2019-05-20T11:13:50Z DEBUG args=/usr/sbin/ipa-join -s myipaserver.example.com -b dc=example,dc=com -h myclient.example.net -f

2019-05-20T11:13:54Z DEBUG Process finished, return code=0

2019-05-20T11:13:54Z DEBUG stdout=

2019-05-20T11:13:54Z DEBUG stderr=Keytab successfully retrieved and stored in: /etc/krb5.keytab

Certificate subject base is: O=example.com


2019-05-20T11:13:54Z INFO Enrolled in IPA realm example.com

2019-05-20T11:13:54Z DEBUG Starting external process

2019-05-20T11:13:54Z DEBUG args=kdestroy

2019-05-20T11:13:54Z DEBUG Process finished, return code=0

2019-05-20T11:13:54Z DEBUG stdout=

2019-05-20T11:13:54Z DEBUG stderr=

2019-05-20T11:13:54Z DEBUG Starting external process

2019-05-20T11:13:54Z DEBUG args=/usr/bin/kinit -k -t /etc/krb5.keytab host/myclient.example.net@example.com

2019-05-20T11:13:54Z DEBUG Process finished, return code=0

2019-05-20T11:13:54Z DEBUG stdout=

2019-05-20T11:13:54Z DEBUG stderr=

2019-05-20T11:13:54Z DEBUG Backing up system configuration file '/etc/ipa/default.conf'

2019-05-20T11:13:54Z DEBUG   -> Not backing up - '/etc/ipa/default.conf' doesn't exist

2019-05-20T11:13:54Z INFO Created /etc/ipa/default.conf

2019-05-20T11:13:54Z DEBUG importing all plugin modules in '/usr/lib/python2.7/dist-packages/ipalib/plugins'...

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/aci.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/automember.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/automount.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/baseldap.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/batch.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/cert.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/config.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/delegation.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/dns.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/group.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/hbacrule.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/hbacsvc.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/hbacsvcgroup.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/hbactest.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/host.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/hostgroup.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/idrange.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/internal.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/kerberos.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/krbtpolicy.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/migration.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/misc.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/netgroup.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/passwd.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/permission.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/ping.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/pkinit.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/privilege.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/pwpolicy.py'

2019-05-20T11:13:54Z DEBUG Starting external process

2019-05-20T11:13:54Z DEBUG args=klist -V

2019-05-20T11:13:54Z DEBUG Process finished, return code=0

2019-05-20T11:13:54Z DEBUG stdout=Kerberos 5 version 1.12


2019-05-20T11:13:54Z DEBUG stderr=

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/realmdomains.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/role.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/selfservice.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/selinuxusermap.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/service.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/sudocmd.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/sudocmdgroup.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/sudorule.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/trust.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/user.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/virtual.py'

2019-05-20T11:13:54Z DEBUG importing plugin module '/usr/lib/python2.7/dist-packages/ipalib/plugins/xmlclient.py'

2019-05-20T11:13:55Z DEBUG Backing up system configuration file '/etc/sssd/sssd.conf'

2019-05-20T11:13:55Z DEBUG   -> Not backing up - '/etc/sssd/sssd.conf' doesn't exist

2019-05-20T11:13:55Z INFO New SSSD config will be created

2019-05-20T11:13:55Z INFO Configured /etc/sssd/sssd.conf

2019-05-20T11:13:55Z DEBUG Starting external process

2019-05-20T11:13:55Z DEBUG args=/usr/bin/certutil -A -d sql:/etc/pki/nssdb -n IPA CA -t CT,C,C -a -i /etc/ipa/ca.crt

2019-05-20T11:13:55Z DEBUG Process finished, return code=0

2019-05-20T11:13:55Z DEBUG stdout=

2019-05-20T11:13:55Z DEBUG stderr=

2019-05-20T11:13:55Z DEBUG Backing up system configuration file '/etc/krb5.conf'

2019-05-20T11:13:55Z DEBUG Saving Index File to '/var/lib/ipa-client/sysrestore/sysrestore.index'

2019-05-20T11:13:55Z DEBUG Starting external process

2019-05-20T11:13:55Z DEBUG args=keyctl get_persistent @s 0

2019-05-20T11:13:55Z DEBUG Process finished, return code=2

2019-05-20T11:13:55Z DEBUG stdout=

2019-05-20T11:13:55Z DEBUG stderr=Unknown command


2019-05-20T11:13:55Z DEBUG Writing Kerberos configuration to /etc/krb5.conf:

2019-05-20T11:13:55Z DEBUG #File modified by ipa-client-install


includedir /var/lib/sss/pubconf/krb5.include.d/


[libdefaults]

  default_realm = example.com

  dns_lookup_realm = false

  dns_lookup_kdc = false

  rdns = false

  ticket_lifetime = 24h

  forwardable = yes


[realms]

  example.com = {

    kdc = myipaserver.example.com:88

    master_kdc = myipaserver.example.com:88

    admin_server = myipaserver.example.com:749

    default_domain = example.com

    pkinit_anchors = FILE:/etc/ipa/ca.crt

  }


[domain_realm]

  .example.com = example.com

  example.com = example.com

  .clientexample.com = example.com

  clientexample.com = example.com


2019-05-20T11:13:55Z INFO Configured /etc/krb5.conf for IPA realm example.com

2019-05-20T11:13:55Z DEBUG Starting external process

2019-05-20T11:13:55Z DEBUG args=keyctl search @s user ipa_session_cookie:host/myclient.example.net@example.com

2019-05-20T11:13:55Z DEBUG Process finished, return code=1

2019-05-20T11:13:55Z DEBUG stdout=

2019-05-20T11:13:55Z DEBUG stderr=keyctl_search: Required key not available


2019-05-20T11:13:55Z DEBUG Starting external process

2019-05-20T11:13:55Z DEBUG args=keyctl search @s user ipa_session_cookie:host/myclient.example.net@example.com

2019-05-20T11:13:55Z DEBUG Process finished, return code=1

2019-05-20T11:13:55Z DEBUG stdout=

2019-05-20T11:13:55Z DEBUG stderr=keyctl_search: Required key not available


2019-05-20T11:13:55Z DEBUG failed to find session_cookie in persistent storage for principal 'host/myclient.example.net@example.com'

2019-05-20T11:13:56Z DEBUG trying https://myipaserver.example.com/ipa/xml

2019-05-20T11:13:56Z DEBUG Created connection context.xmlclient

2019-05-20T11:13:56Z DEBUG Try RPC connection

2019-05-20T11:13:56Z DEBUG Forwarding 'ping' to server 'https://myipaserver.example.com/ipa/xml'

2019-05-20T11:13:56Z DEBUG NSSConnection init myipaserver.example.com

2019-05-20T11:13:56Z DEBUG Connecting: 94.130.154.230:0

2019-05-20T11:13:56Z DEBUG auth_certificate_callback: check_sig=True is_server=False

Data:

        Version: 3 (0x2)

        Serial Number: 337206521890680437858189420391339302183775 (0x3def5fdcb91c7146fc7d3cb8c096bd5e35f)

        Signature Algorithm:

            Algorithm: PKCS #1 SHA-256 With RSA Encryption

        Issuer: CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US

        Validity:

            Not Before: Fri Apr 05 07:19:18 2019 UTC

            Not After : Thu Jul 04 07:19:18 2019 UTC

        Subject: CN=myipaserver.example.com

        Subject Public Key Info:

            Public Key Algorithm:

                Algorithm: PKCS #1 RSA Encryption

            RSA Public Key:

                Modulus:

                    b4:68:c6:c8:b4:4f:df:50:5a:f0:00:4b:ea:09:9d:77:

                    1c:20:20:b6:ce:d7:64:24:c8:ec:65:ad:69:de:a1:ea:

                    b4:a1:d6:4e:46:88:d5:e5:ea:e6:9c:70:d8:8a:00:7e:

                    cd:c0:0f:2e:e7:e5:1f:3e:72:00:81:ab:b8:58:90:89:

                    f6:81:ee:6a:87:f4:85:34:32:46:5f:0e:45:5c:05:69

                Exponent: 65537 (0x10001)

    Signed Extensions: (9)

        Name: Certificate Key Usage

        Critical: True

        Usages:

            Digital Signature

            Key Encipherment


        Name: Extended Key Usage

        Critical: False

        Usages:

            TLS Web Server Authentication Certificate

            TLS Web Client Authentication Certificate


        Name: Certificate Basic Constraints

        Critical: True

        Is CA: False

        Path Length: 0


        Name: Certificate Subject Key ID

        Critical: False

        Data:

            cb:c7:a1:bc:07:0a:ba:f9:d6:55:85:ea:e4:13:3a:e6:

            6d:1c:64:93


        Name: Certificate Authority Key Identifier

        Critical: False

        Key ID:

            a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:

            f3:a8:ec:a1

        Serial Number: None

        General Names: [0 total]


        Name: Authority Information Access

        Critical: False


        Name: Certificate Subject Alt Name

        Critical: False

        Names:

            myipaserver.example.com


        Name: Certificate Policies

        Critical: False


        Name: OID.1.3.6.1.4.1.11129.2.4.2

        Critical: False


    Signature:

        Signature Algorithm:

            Algorithm: PKCS #1 SHA-256 With RSA Encryption

        Signature:

            1b:9b:b3:c8:cb:c6:2b:1c:e9:f5:4b:6b:f2:2f:81:56:

            55:00:33:bc:02:ba:e9:c4:58:76:b5:1b:05:ed:bc:d7:

            94:4d:45:42:78:82:b1:77:5c:d6:c5:a3:92:e1:b6:5a:

            d7:b1:b0:25:6b:c9:5c:bb:37:a8:f5:56:c4:1e:b2:cb:

            a7:18:78:fc:a4:5c:a1:38:c0:39:bc:3c:7b:22:34:30:

            32:02:07:12:15:16:38:c6:8d:c2:4c:e0:7d:b8:66:74:

            84:44:23:eb:3f:8d:11:5e:92:77:cc:e0:ee:c4:59:12

        Fingerprint (MD5):

            a4:df:06:9a:a3:e1:61:93:40:cc:8e:ea:6d:2

        Fingerprint (SHA1):

            23:88:55:80:b7:6f:0f:d0:86:c0:4f:c3:c8:92:67:c3:

2019-05-20T11:13:56Z ERROR cert validation failed for "CN=myipaserver.example.com" ((SEC_ERROR_UNKNOWN_ISSUER) Peer's Certificate issuer is not recognized.)

2019-05-20T11:13:56Z ERROR Cannot connect to the server due to generic error: cannot connect to 'https://myipaserver.example.com/ipa/xml': [Errno -8179] (SEC_ERROR_UNKNOWN_ISSUER) Peer's Certificate issuer is not recognized.

2019-05-20T11:13:56Z ERROR Installation failed. Rolling back changes.

2019-05-20T11:13:56Z DEBUG Loading Index file from '/var/lib/ipa/sysrestore/sysrestore.index'

2019-05-20T11:13:56Z DEBUG Starting external process

2019-05-20T11:13:56Z DEBUG args=ipa-client-automount --uninstall --debug

2019-05-20T11:13:58Z DEBUG Process finished, return code=0

2019-05-20T11:13:58Z DEBUG stdout=Restoring configuration


On May 17, 2019 at 4:40:47 PM, Rob Crittenden (rcritten@redhat.com) wrote:

Petar Kozić via FreeIPA-users wrote:
>
>> Petar Kozić via FreeIPA-users wrote: 
>> > Hi folks, 
>> > one question. 
>> > These days I join my machine into IPA. Almost all machine have Ubuntu 
>> > 18.04. I jointed about 10 machine in last two days. Today I tried to 
>> > join Debian 8 jessie but I have problem. 
>> > 
>> > All machine I join with same command: 
>> > 
>> > ipa-client-install -U —domain=example.com <http://example.com> <http://example.com
>> > —hostname=clientexample.com <http://clientexample.com> <http://clientexample.com
>> > —server=ipa.example.com <http://ipa.example.com> <http://ipa.example.com>
>> —realm=EXAMPLE.com 
>> > —password=XXXxxxXXX --principal=admin —mkhomedir 
>> > 
>> > On Debian machine I got this error in process of join: 
>> > 
>> > Forwarding 'ping' to json server 'https://ipa.example.com/ipa/json
>> > cert validation failed for “CN=ipa.example.com <http://ipa.example.com> <http://ipa.example.com>" 
>> > ((SEC_ERROR_UNKNOWN_ISSUER) Peer's Certificate issuer is not recognized.) 
>> > Cannot connect to the server due to generic error: cannot connect to 
>> > 'https://ipa.example.com/ipa/json': (SEC_ERROR_UNKNOWN_ISSUER) Peer's 
>> > Certificate issuer is not recognized. 
>> > Installation failed. Rolling back changes. 
>> > 
>> > Some help? 
>>
>> We need more information on your CA chain configuration and what 
>> version's of IPA you're using. 
>>
>> For example, is your CA a typical IPA self-signed CA or did you sign it 
>> with another CA? 
>>
>> rob 
>
>
> Ipa version:
>
> FreeIPA 4.7
>
> CA isn’t self-signed. I generate Let’s encrypt SSL and make chain CA
> which is imported in IPA.
>
> On all Ubuntu 18.04 works perfect but this Debian 8 jessie don’t support
> native from repo freeipa-client and maybe that is also problem. I found
> some repo for freeipa client
>
> deb http://apt.numeezy.fr jessie main
>
> deb-src http://apt.numeezy.fr jessie main
>
> and I installed from there.

Assuming it picks the latest it means you have 4.6.4.

You might try installing the Let's Encrypt root CA's onto your client
prior to running ipa-client-install.

Otherwise I think we'd need to see /var/log/ipaclient-install.log to see
the CA chain being retrieved. Sounds like it is incomplete but unclear why.

rob