2232231 – kdump system role fails if kdump_ssh_user doesn't have a .ssh/authorized_keys file in home directory

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Bug 2232231 - kdump system role fails if kdump_ssh_user doesn't have a .ssh/authorized_keys file in home directory

Summary: kdump system role fails if kdump_ssh_user doesn't have a .ssh/authorized_keys...

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 9
Classification:	Red Hat
Component:	rhel-system-roles
Sub Component:
Version:	9.2
Hardware:	Unspecified
OS:	Unspecified
Priority:	unspecified
Severity:	unspecified
Target Milestone:	rc
Target Release:	9.3
Assignee:	Rich Megginson
QA Contact:	Jakub Haruda
Docs Contact:	Sujata Kurup
URL:
Whiteboard:	role:kdump
Depends On:
Blocks:	2232392
TreeView+	depends on / blocked

Reported:	2023-08-15 20:45 UTC by Brian Smith
Modified:	2023-11-07 13:33 UTC (History)
CC List:	7 users (show)
Fixed In Version:	rhel-system-roles-1.22.0-1.el9
Doc Type:	Bug Fix
Doc Text:	.The `kdump` system role does not fail if `kdump_authorized_keys` is missing Previously, the `kdump` system role failed to add `SSH` authorized keys if the user defined in the `kdump_ssh_user` variable did not have access to the `.ssh` directory in the `home` directory or an empty `.ssh/authorized_keys` file. With this fix, the `kdump` system role now correctly adds authorized keys to the `SSH` configuration. As a result, the key based authentication works reliably in the described scenario.
Clone Of:
Clones:	2232392 (view as bug list)
Environment:
Last Closed:	2023-11-07 08:29:54 UTC
Type:	Bug
Target Upstream Version:
Embargoed:
Dependent Products:
Flags:	pm-rhel: mirror+

Attachments	(Terms of Use)

Links
System	ID	Priority	Status	Summary	Last Updated
Github	linux-system-roles kdump pull 161	None	open	fix: do not fail if authorized_keys not found	2023-08-15 22:56:19 UTC
Red Hat Issue Tracker	RHELPLAN-165873	None	None	None	2023-08-15 20:49:02 UTC
Red Hat Product Errata	RHEA-2023:6390	None	None	None	2023-11-07 08:30:10 UTC

Description Brian Smith 2023-08-15 20:45:19 UTC

Description of problem:
When using kdump system role to configure a SSH kdump configuration, the role will fail if the user defined in the kdump_ssh_user variable doesn't already have both a .ssh directory in the home directory, and at least an empty .ssh/authorized_keys file.  


Version-Release number of selected component (if applicable):
rhel-system-roles-1.21.1-1.el9_2.noarch

How reproducible:
Every time


Steps to Reproduce:
1.  From my control node (rhel9-controlnode.example.com) define this inventory and run the kdump system role:

all:
  hosts:
    rhel9-server1.example.com:
  vars:
    kdump_target:
      type: ssh
      location: kdump.com
    kdump_path: "/home/kdump/crash"
    kdump_sshkey: "/root/kdump_ssh/id_rsa"
    kdump_ssh_user: kdump
    kdump_ssh_server: rhel9-controlnode.example.com


Actual results:
If the /home/kdump/.ssh directory and/or /home/kdump/.ssh/authorized_keys file don't already exist on rhel9-controlnode.example.com, the role will fail:

TASK [redhat.rhel_system_roles.kdump : Write new authorized_keys if needed] **********************************************************************************
fatal: [rhel9-server1.example.com -> {{ kdump_ssh_server }}]: FAILED! => {"msg": "The conditional check '__kdump_authorized_keys_lines != __kdump_authorized_keys_lines_new' failed. The error was: error while evaluating conditional (__kdump_authorized_keys_lines != __kdump_authorized_keys_lines_new): {{ (__kdump_authorized_keys.content | b64decode).split('\n') | reject('match', '^$') | list if __kdump_authorized_keys is defined else [] }}: 'dict object' has no attribute 'content'. 'dict object' has no attribute 'content'. {{ (__kdump_authorized_keys.content | b64decode).split('\n') | reject('match', '^$') | list if __kdump_authorized_keys is defined else [] }}: 'dict object' has no attribute 'content'. 'dict object' has no attribute 'content'\n\nThe error appears to be in '/usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/kdump/tasks/ssh.yml': line 42, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Write new authorized_keys if needed\n  ^ here\n"}

If you create the .ssh directory, and an empty .ssh/authorized_keys file, this task doesn't fail.  

Expected results:
The role attempts to configure the authorized_keys file if it isn't configured already, so it should work even if the .ssh directory and/or .ssh/authorized_keys file don't exist.

Comment 1 Rich Megginson 2023-08-15 21:04:50 UTC

@briasmit can you attach the entire ansible log?

Comment 2 Brian Smith 2023-08-15 21:42:07 UTC

[ansible@rhel9-controlnode kdump]$ ansible-playbook -i inventory.yml -b system_roles.yml  

PLAY [Run kdump RHEL system role] ****************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Ensure ansible_facts used by role] ************************************************************************************
included: /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/kdump/tasks/set_vars.yml for rhel9-server1.example.com

TASK [redhat.rhel_system_roles.kdump : Ensure ansible_facts used by role] ************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Install required packages] ********************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Ensure that kdump is enabled] *****************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Include SSH tasks] ****************************************************************************************************
included: /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/kdump/tasks/ssh.yml for rhel9-server1.example.com

TASK [redhat.rhel_system_roles.kdump : Check whether key exists] *********************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Create key] ***********************************************************************************************************
changed: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Fetch key] ************************************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Get userinfo for kdump] ***********************************************************************************************
ok: [rhel9-server1.example.com -> rhel9-controlnode.example.com]

TASK [redhat.rhel_system_roles.kdump : Set authorized_keys file path] ****************************************************************************************
ok: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Get the authorized_keys file for the user] ****************************************************************************
ok: [rhel9-server1.example.com -> rhel9-controlnode.example.com]

TASK [redhat.rhel_system_roles.kdump : Get the authorized_keys contents, if any] *****************************************************************************
skipping: [rhel9-server1.example.com]

TASK [redhat.rhel_system_roles.kdump : Write new authorized_keys if needed] **********************************************************************************
fatal: [rhel9-server1.example.com -> {{ kdump_ssh_server }}]: FAILED! => {"msg": "The conditional check '__kdump_authorized_keys_lines != __kdump_authorized_keys_lines_new' failed. The error was: error while evaluating conditional (__kdump_authorized_keys_lines != __kdump_authorized_keys_lines_new): {{ (__kdump_authorized_keys.content | b64decode).split('\n') | reject('match', '^$') | list if __kdump_authorized_keys is defined else [] }}: 'dict object' has no attribute 'content'. 'dict object' has no attribute 'content'. {{ (__kdump_authorized_keys.content | b64decode).split('\n') | reject('match', '^$') | list if __kdump_authorized_keys is defined else [] }}: 'dict object' has no attribute 'content'. 'dict object' has no attribute 'content'\n\nThe error appears to be in '/usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/kdump/tasks/ssh.yml': line 42, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Write new authorized_keys if needed\n  ^ here\n"}

PLAY RECAP ***************************************************************************************************************************************************
rhel9-server1.example.com  : ok=12   changed=1    unreachable=0    failed=1    skipped=1    rescued=0    ignored=0

Comment 3 Brian Smith 2023-08-15 21:47:42 UTC

Note that if there is no authorized_keys file, the "Get the authorized_keys contents, if any" task is skipped, and the _kdump_authorized_keys.content variable isn't defined. 

If there is an authorized_keys file (even an empty one), the "Get the authorized_keys contents, if any" task is run and the _kdump_authorized_keys.content variable is defined.

Comment 4 Rich Megginson 2023-08-15 22:19:10 UTC

(In reply to Brian Smith from comment #3)
> Note that if there is no authorized_keys file, the "Get the authorized_keys
> contents, if any" task is skipped, and the _kdump_authorized_keys.content
> variable isn't defined. 
> 
> If there is an authorized_keys file (even an empty one), the "Get the
> authorized_keys contents, if any" task is run and the
> _kdump_authorized_keys.content variable is defined.

Right.  I don't understand why this logic isn't working: https://github.com/linux-system-roles/kdump/blob/main/tasks/ssh.yml#L47

```
    __kdump_authorized_keys_lines: "{{
      (__kdump_authorized_keys.content | b64decode).split('\n') |
      reject('match', '^$') | list
      if __kdump_authorized_keys is defined else []
    }}"
```

since `__kdump_authorized_keys` is not defined, it should set `__kdump_authorized_keys_lines` to `[]` and not even evaluate the clause with `__kdump_authorized_keys.content` - looks like some sort of strange Jinja or Ansible evaluation issue

Comment 5 Rich Megginson 2023-08-15 22:56:20 UTC

@briasmit any chance you could try the fix in https://github.com/linux-system-roles/kdump/pull/161 ?

Comment 7 Brian Smith 2023-08-16 19:25:04 UTC

@rmeggins this is now working if the authorized_key file doesn't exist, but still fails if the .ssh directory doesn't exist.  

Use case for this:  My environment has an "ansible" service account setup for running playbooks.  I'd like to setup kdump to send over SSH, but I don't want to use the "ansible" user account for this.  So I created a new "kdump" user account on the host that will receive the kdumps. By default, when creating a new account, it doesn't have a ".ssh" directory created automatically, so it would be nice if the role checked this before trying to write the authorized_key file to the directory.   

Thanks for your help with this!

Comment 8 Rich Megginson 2023-08-17 00:18:55 UTC

(In reply to Brian Smith from comment #7)
> @rmeggins this is now working if the authorized_key file doesn't
> exist, but still fails if the .ssh directory doesn't exist.  
> 
> Use case for this:  My environment has an "ansible" service account setup
> for running playbooks.  I'd like to setup kdump to send over SSH, but I
> don't want to use the "ansible" user account for this.  So I created a new
> "kdump" user account on the host that will receive the kdumps. By default,
> when creating a new account, it doesn't have a ".ssh" directory created
> automatically, so it would be nice if the role checked this before trying to
> write the authorized_key file to the directory.   

https://issues.redhat.com/browse/RHEL-1397 and https://issues.redhat.com/browse/RHEL-1398

> 
> Thanks for your help with this!

Comment 16 errata-xmlrpc 2023-11-07 08:29:54 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (rhel-system-roles bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2023:6390

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