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如何使用 Ansible 处理 SSH 端口变化？

tag-icon • tag-icon ssh configuration-management ansible
如何使用 Ansible 处理 SSH 端口变化？

我正在尝试使用 Ansible 来自动执行新服务器实例的设置过程。其中一项设置任务会更改默认 SSH 端口，因此需要我更新主机列表。

如果无法与默认 SSH 端口建立连接，是否可以通过让 Ansible 回退到指定端口来实现自动执行此操作？

答案1

您可以在主机上尝试 local_action，看看是否可以连接到相应的端口，然后注册成功的端口并将其设置为事实。您需要关闭收集事实，因为否则设置模块在尝试连接已重新配置的主机时会失败。完成此操作后，只需使用 gather_facts 和所有其他内容在下面添加其他内容即可。

- name: determine ssh port
  hosts: all
  gather_facts: false
  vars:
    custom_ssh_port: 222
  tasks:
    - name: test default ssh port
      local_action: wait_for port=22 timeout=5 host={{inventory_hostname}}
      register: default_ssh
      ignore_errors: true
    - name: set ansible_ssh_port to default
      set_fact: ansible_ssh_port=22
      when: default_ssh.elapsed < 5
    - name: test ssh on high port
      local_action: wait_for port={{custom_ssh_port}} timeout=5 host={{inventory_hostname}}
      register: high_ssh
      when: default_ssh.elapsed >= 5
      ignore_errors: true
    - name: set ansible_ssh_port high
      set_fact: ansible_ssh_port={{custom_ssh_port}}
      when: default_ssh.elapsed >= 5 and high_ssh.elapsed < 5

有人向我指出，这将浪费您使用它的剧本的时间。您还可以在剧本的 vars 部分中设置 ansible_ssh_port，该剧本应仅在具有重新配置的 ssh 端口的主机上运行。例如

- name: change ssh ports
  tasks:
    - name: edit sshd_config
      lineinfile ..
      notify: restart ssh
   handlers:
     - name: restart ssh
       service: sshd state=restarted
- name: continue setup
  vars:
    - ansible_ssh_port : 5422
  tasks:
    ...

答案2

@RichardSalts 感谢你让我开始使用这个。我使用 nc 检查端口，这样应该会快得多。这是我的 bootstrap.xml：

使用 ansible 1.5 (devel 3b8fd62ff9) 进行测试，最后更新于 2014/01/28 20:26:03

---
# Be sure to set the following variables for all hosts:
# vars:
#   oldsshport: 22
#   sshport: 555
# Might fail without setting remote_tmp = /tmp/ansible/$USER in your ansible.cfg. Also fix for directly below.
# Once host is setup most of the checks are skipped and works very quickly.
# Also, be sure to set non-standard shells in a different playbook later. Stick with /bin/bash until you can run apt install.
# Assumes root user has sshkey setup already. Not sure how to utilize the --ask-pass option. For now, use ssh-copy-id prior to running playbook on new host for root user (if needed).

# Test new ssh port
- name: ssh test nc {{ sshport }}
  local_action: shell nc -z -w5 {{ inventory_hostname }} {{ sshport }}
  register: nc_ssh_port
  failed_when: nc_ssh_port.stdout.find('failed') != -1
  changed_when: nc_ssh_port.stdout == ""
  ignore_errors: yes

# Set port to new port if connection success
- name: set ansible_ssh_port
  set_fact: ansible_ssh_port={{ sshport }}
  when: nc_ssh_port|success

# Fail back to old port if new ssh port fails
- name: ssh test nc port {{ oldsshport }}
  local_action: shell nc -z -w5 {{ inventory_hostname }} {{ oldsshport }}
  register: nc_ssh_default
  changed_when: nc_ssh_default.stdout == ""
  ignore_errors: yes
  when: nc_ssh_port|changed

# Set ansible to old port since new failed
- name: set ansible_ssh_port to {{ oldsshport }}
  set_fact: ansible_ssh_port={{ oldsshport }}
  when: nc_ssh_default|success and nc_ssh_port|changed

# Check if root user can ssh
- name: find user
  local_action: shell ssh -o StrictHostKeyChecking=no -o BatchMode=yes -o ConnectTimeout=5 -p {{ ansible_ssh_port }} root@{{ inventory_hostname }} exit
  register: ssh_as_root
  failed_when: ssh_as_root.stdout.find('failed') != -1
  changed_when: ssh_as_root.stderr.find('Permission denied') == -1

# If root user success, set this up to change later
- name: first user
  set_fact: first_user={{ ansible_ssh_user }}
  when: ssh_as_root|changed

# Set ssh user to root
- name: root user
  set_fact: ansible_ssh_user=root
  when: ssh_as_root|changed

# ANSIBLE FIX: /tmp/ansible isn't world-writable for setting remote_tmp = /tmp/ansible/$USER in ansible.cfg
- name: /tmp/ansible/ directory exists with 0777 permission
  file: path=/tmp/ansible/ owner=root group=root mode=0777 recurse=no state=directory
  changed_when: False
  sudo: yes

# Setup user accounts
- include: users.yml

# Set ssh user back to default user (that was setup in users.yml)
- name: ansible_ssh_user back to default
  set_fact: ansible_ssh_user={{ first_user }}
  when: ssh_as_root|changed

# Reconfigure ssh with new port (also disables non-ssh key logins and disable root logins)
- name: sshd.conf
  template: src=sshd_config.j2 dest=/etc/ssh/sshd_config owner=root group=root mode=0644
  register: sshd_config
  sudo: yes

# Force changes immediately to ssh
- name: restart ssh
  service: name=ssh state=restarted
  when: sshd_config|changed
  sudo: yes

# Use updated ssh port
- name: set ansible_ssh_port
  set_fact: ansible_ssh_port={{ sshport }}
  when: nc_ssh_port|changed

答案3

由于您可能很早就部署了 ssh 配置，因此您确实应该保持简单。只需使用目标配置您的清单，并在首次部署 ssh 配置时ansible_ssh_port使用：-e

ansible-playbook bootstrap_ssh.yml -e 'ansible_ssh_port=22'

请注意，ansible_ssh_port在 2.0 中已弃用（由 取代ansible_port）

答案4

如果您有端口列表，并且想要检查所有端口并使用一个可以正常工作的端口，则可以在剧本中使用它：

- name: just test
  hosts: server
  gather_facts: false
  vars:
    list_of_ssh_ports: [22, 222, 234]
  tasks:
    - name: test ssh on port
      sudo: no
      local_action: wait_for port={{item}} timeout=5 host={{inventory_hostname}}
      register: ssh_checks
      with_items: "{{list_of_ssh_ports}}"
      ignore_errors: true
    - debug: msg = "{{item}}"
      with_items: "{{ssh_checks.results}}"
    - name: set available ansible_ssh_port 
      sudo: no
      set_fact: ansible_ssh_port={{item.item}}
      when: ssh_checks is defined and {{item.elapsed}} < 5
      with_items: "{{ssh_checks.results}}"

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