Ansible-查找文件并比较它们的哈希

Question

实践：

我有一个文件files.yml，其中包含文件列表和它们各自的md5_sum哈希，如：

files:
- name: /opt/file_compare1.tar
hash: 9cd599a3523898e6a12e13ec787da50a  /opt/file_compare1.tar
- name: /opt/file_compare2tar.gz
hash: d41d8cd98f00b204e9800998ecf8427e  /opt/file_compare2.tar.gz 

我需要创建一个剧本来检查这个文件列表，如果当前哈希是相同的，或者如果它被更改了，剧本应该有一个调试消息，如下所示：

---
- hosts: localhost
connection: local
vars_files:
- files.yml 
tasks: 
- name: Use md5 to calculate checksum
stat:
path: "{{ item.name }}"
checksum_algorithm: md5
register: hash_check
with_items:
- "{{ files }}"
- name: Debug files - Different 
debug:
msg: | 
"Hash changed: {{  item.name  }}"
when: 
- item.hash != hash_check 
with_items:
- "{{ files }}"
- name: Debug files - Equal
debug:
msg: | 
"Hash NOT changed: {{  item.name  }}"
when: 
- item.hash == hash_check 
with_items:
- "{{ files }}"

- debug:
msg: | 
-  "{{ hash_check }}  {{ item.name }}"
with_items:
- "{{ files }}"

Answer 1

例如，给定文件

files:
- name: /scratch/file_compare1.tar
hash: 4f8805b4b64dcc575547ec1c63793aec  /scratch/file_compare1.tar
- name: /scratch/file_compare2.tar.gz
hash: 2dc4f1e9ca4081cc49d25195627982ef  /scratch/file_compare2.tar.gz

以下的任务

- name: Use md5 to calculate checksum
stat:
path: "{{ item.name }}"
checksum_algorithm: md5
register: hash_check
loop: "{{ files }}"
- name: Debug files - Different
debug:
msg: |
Hash NOT changed: {{ item.0.name }}
{{ item.0.hash.split()|first }}
{{ item.1 }}
with_together:
- "{{ files }}"
- "{{ hash_check.results|map(attribute='stat.checksum')|list }}"
when: item.0.hash.split()|first == item.1

给出

msg: |-
Hash NOT changed: /scratch/file_compare1.tar
4f8805b4b64dcc575547ec1c63793aec
4f8805b4b64dcc575547ec1c63793aec
msg: |-
Hash NOT changed: /scratch/file_compare2.tar.gz
2dc4f1e9ca4081cc49d25195627982ef
2dc4f1e9ca4081cc49d25195627982ef

---

一个更稳健的选择是创建一个具有计算哈希的字典

- name: Use md5 to calculate checksum
stat:
path: "{{ item.name }}"
checksum_algorithm: md5
register: hash_check
loop: "{{ files }}"
- set_fact:
path_hash: "{{ dict(_path|zip(_hash)) }}"
vars:
_path: "{{ hash_check.results|map(attribute='stat.path')|list }}"
_hash: "{{ hash_check.results|map(attribute='stat.checksum')|list }}"

给出

path_hash:
/scratch/file_compare1.tar: 4f8805b4b64dcc575547ec1c63793aec
/scratch/file_compare2.tar.gz: 2dc4f1e9ca4081cc49d25195627982ef

然后用这本字典来比较散列。例如，下面的任务给出了相同的结果

- name: Debug files - Different
debug:
msg: |
Hash NOT changed: {{ item.name }}
{{ item.hash.split()|first }}
{{ path_hash[item.name] }}
loop: "{{ files }}"
when: item.hash.split()|first == path_hash[item.name]

---

下一个选项是创建一个包含原始哈希以及原始和计算哈希列表的字典

- name: Use md5 to calculate checksum
stat:
path: "{{ item.name }}"
checksum_algorithm: md5
register: hash_check
loop: "{{ files }}"
- set_fact:
hash_name: "{{ dict(_hash|zip(_name)) }}"
hash_orig: "{{ _hash }}"
hash_stat: "{{ hash_check.results|map(attribute='stat.checksum')|list }}"
vars:
_hash: "{{ files|map(attribute='hash')|map('split')|map('first')|list }}"
_name: "{{ files|map(attribute='name')|list }}"

给出

hash_name:
2dc4f1e9ca4081cc49d25195627982ef: /scratch/file_compare2.tar.gz
4f8805b4b64dcc575547ec1c63793aec: /scratch/file_compare1.tar
hash_orig:
- 4f8805b4b64dcc575547ec1c63793aec
- 2dc4f1e9ca4081cc49d25195627982ef
hash_stat:
- 4f8805b4b64dcc575547ec1c63793aec
- 2dc4f1e9ca4081cc49d25195627982ef

然后计算列表的差异，并使用它来提取更改和未更改文件的列表

- set_fact:
files_diff: "{{ _diff|map('extract', hash_name)|list }}"
files_orig: "{{ _orig|map('extract', hash_name)|list }}"
vars:
_diff: "{{ hash_orig|difference(hash_stat) }}"
_orig: "{{ hash_orig|difference(_diff) }}"
- name: Debug files changed
debug:
var: files_diff
- name: Debug files NOT changed
debug:
var: files_orig

给出

files_diff: []
files_orig:
- /scratch/file_compare1.tar
- /scratch/file_compare2.tar.gz

Answer 2

我用了你的建议来补充剧本，现在它正在发挥作用。

这个想法是获得一个文件列表，读取每个文件，并与哈希、文件和当前哈希进行比较。

---
- hosts: localhost
connection: local
gather_facts: false
vars_files:
- files3.yml
tasks:
- stat:
path: "{{ item.file }}"
checksum_algorithm: md5
loop: "{{ files }}"
register: stat_results
- name: NOT changed files
debug:
msg: "NOT changed: {{ item.stat.path }}"
when: item.stat.checksum ==  item.item.checksum.split()|first
loop: "{{ stat_results.results }}"
loop_control:
label: "{{ item.stat.path }}"
- name: Changed files
debug:
msg: "CHANGED: {{ item.stat.path }}"
when: item.stat.checksum != item.item.checksum.split()|first
loop: "{{ stat_results.results }}"
loop_control:
label: "{{ item.stat.path }}"

结果：

>> ansible-playbook playbooks/check-file3.yml 
PLAY [localhost] ********************************************************************************************************************************************************************************************************************
TASK [stat] *************************************************************************************************************************************************************************************************************************
ok: [localhost] => (item={'file': '/opt/file_compare1.tar', 'checksum': '9cd599a3523898e6a12e13ec787da50a  /opt/file_compare1.tar'})
ok: [localhost] => (item={'file': '/opt/file_compare2.tar.gz', 'checksum': 'd41d8cd98f00b204e9800998ecf8427e  /opt/file_compare2.tar.gz'})
TASK [NOT changed files] ************************************************************************************************************************************************************************************************************
skipping: [localhost] => (item=/opt/file_compare1.tar) 
ok: [localhost] => (item=/opt/file_compare2.tar.gz) => {
"msg": "NOT changed: /opt/file_compare2.tar.gz"
}
TASK [Changed files] ****************************************************************************************************************************************************************************************************************
ok: [localhost] => (item=/opt/file_compare1.tar) => {
"msg": "CHANGED: /opt/file_compare1.tar"
}
skipping: [localhost] => (item=/opt/file_compare2.tar.gz) 
PLAY RECAP **************************************************************************************************************************************************************************************************************************
localhost                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0