【Ansible】ansible迴圈
阿新 • • 發佈：2018-12-27
Ansible 迴圈
一、簡單介紹
在ansible2.5之前，大多數人使”with_XXX”型別的關鍵字來操作迴圈，但是從2.6版本開始，官方推薦是”loop”關鍵字代替” with_XXX”。
1.我們先看下一個小例子，使用loop關鍵字進行最簡單的迴圈：
[[email protected] cycle]# cat cycle.1.yml --- - name: cycletest hosts: test gather_facts: no tasks: - name: debug cycle debug: msg:"{{ item }}" loop: - test1 - test2
結果：
[[email protected] cycle]# ansible-playbook cycle.1.yml PLAY [cycle test] *************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=test1) => { "msg": "test1" } ok: [192.168.15.10] => (item=test2) => { "msg": "test2" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.17s Playbook finished: Mon Dec 24 17:57:25 2018, 1 total tasks. 0:00:00 elapsed.
例項中所以loop關鍵字，替換之前的with_XXX關鍵字，它們的效果是完全相同的。
2.我們可以使用loop關鍵字和dict外掛代替”with_dict”關鍵字，示例如下：
[[email protected] cycle]# cat cycle.2.yml --- - name: cycle test2 hosts: test gather_facts: no vars: dicts: China: 1 America: 2 tasks: - name: debug cycle debug: msg: "{{ item.key }} is no.{{ item.value }}" loop: "{{ lookup('dict',dicts) }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.2.yml PLAY [cycle test2] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item={'key': u'America', 'value': 2}) => { "msg": "America is no.2" } ok: [192.168.15.10] => (item={'key': u'China', 'value': 1}) => { "msg": "China is no.1" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.18s Playbook finished: Mon Dec 24 17:59:58 2018, 1 total tasks. 0:00:00 elapsed
示例已經在上一個例子中講述，再次不在講述
3.上個例子中使用”loop+lookup”的方式完成迴圈，而在2.6版本的官網中推薦使用”loop+filter”方式老代替”loop+loopup”的方式，什麼意思呢? 我們來看個小例子，如下:
--- - name: cycle test3 hosts: test gather_facts: no vars: dicts: China: 1 America: 2 tasks: - name: debug cycle debug: msg: "{{ item.key }} is no.{{ item.value }}" loop: "{{ dicts | dict2items }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.3.yml PLAY [cycle test3] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item={'key': u'America', 'value': 2}) => { "msg": "America is no.2" } ok: [192.168.15.10] => (item={'key': u'China', 'value': 1}) => { "msg": "China is no.1" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.18s Playbook finished: Mon Dec 24 18:05:21 2018, 1 total tasks. 0:00:00 elapsed.
如上例所示，在使用loop關鍵字操作對於的字典變數users時，並沒有藉助dict外掛，而是使用dict2items的過濾器。
二、具體示例
1.With_list
#loop可以替代with_list，當處理巢狀的列表時，列表不會被拉平
[[email protected] cycle]# cat cycle.4.yml --- - name: cycle test4 hosts: test gather_facts: no vars: dicts: - A - B - [c,D] tasks: - name: debug cycle debug: msg: "{{ item }}" loop: "{{ dicts }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.4.yml PLAY [cycle test4] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=A) => { "msg": "A" } ok: [192.168.15.10] => (item=B) => { "msg": "B" } ok: [192.168.15.10] => (item=[u'c', u'D']) => { "msg": [ "c", "D" ] } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.19s Playbook finished: Mon Dec 24 18:25:41 2018, 1 total tasks. 0:00:00 elapsed.
2.With_flattened
#flatten過濾器可以替代with_flattened，當處理多層巢狀的列表時，列表中所有的巢狀層級都會被拉平
[[email protected] cycle]# cat cycle.5.yml --- - name: cycle test5 hosts: test gather_facts: no vars: dicts: - A - B - [c,D] tasks: - name: debug cycle debug: msg: "{{ item }}" loop: "{{ dicts | flatten }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.5.yml PLAY [cycle test5] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=A) => { "msg": "A" } ok: [192.168.15.10] => (item=B) => { "msg": "B" } ok: [192.168.15.10] => (item=c) => { "msg": "c" } ok: [192.168.15.10] => (item=D) => { "msg": "D" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.19s Playbook finished: Mon Dec 24 18:31:47 2018, 1 total tasks. 0:00:00 elapsed.
3.With_items
#flatten過濾器（加引數）可以替代with_items，當處理多層巢狀的列表時，只有列表中的第一層會被拉平
[[email protected] cycle]# cat cycle.6.yml --- - name: cycle test6 hosts: test gather_facts: no vars: dicts: - A - B - [c,D] tasks: - name: debug cycle debug: msg: "{{ item }}" loop: "{{ dicts | flatten(levels=1) }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.6.yml PLAY [cycle test6] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=A) => { "msg": "A" } ok: [192.168.15.10] => (item=B) => { "msg": "B" } ok: [192.168.15.10] => (item=c) => { "msg": "c" } ok: [192.168.15.10] => (item=D) => { "msg": "D" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.29s Playbook finished: Mon Dec 24 18:34:31 2018, 1 total tasks. 0:00:00 elapsed.
#PS 嗯 處理下客戶問題先。Weblogic真毒~
4.With_indexed_items
#flatten過濾器（加引數），再配合loop_control關鍵字，可以替代with_indexed_items
#當處理多層巢狀的列表時，只有列表中的第一層會被拉平，flatten過濾器的bug暫且忽略
[[email protected] cycle]# cat cycle.7.yml --- - name: cycle test7 hosts: test gather_facts: no vars: dicts: - A - B - [c,D] tasks: - name: debug cycle debug: msg: " {{ index}}--{{ item }}" loop: "{{ dicts | flatten(levels=1) }}" loop_control: index_var: index
結果：
[[email protected] cycle]# ansible-playbook cycle.7.yml PLAY [cycle test7] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=A) => { "msg": " 0--A" } ok: [192.168.15.10] => (item=B) => { "msg": " 1--B" } ok: [192.168.15.10] => (item=c) => { "msg": " 2--c" } ok: [192.168.15.10] => (item=D) => { "msg": " 3--D" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.21s Playbook finished: Mon Dec 24 20:29:57 2018, 1 total tasks. 0:00:00 elapsed.
“loop_control”關鍵字可以用於控制迴圈的行為，比如在迴圈是獲取元素的索引。
“index_var “是”loop_control”的一個設定選項，”index_var”可以讓我們指定變數,”loop_control”會將元素索引值存放在指定變數中
5.With_togeher
[[email protected] cycle]# cat cycle.8.yml --- - name: cycle test8 hosts: test gather_facts: no vars: testlist1: [ A,B,C,D ] testlist2: [ 110,120,911 ] testlist3: [ x,y ] tasks: - name: debug cycle with_together debug: msg: " {{ item.0 }} - {{ item.1 }} - {{ item.2 }}" with_together: - "{{ testlist1 }}" - "{{ testlist2 }}" - "{{ testlist3 }}" - name: debug cycle loop+zip_logest debug: msg: " {{ item.0 }} - {{ item.1 }} - {{ item.2 }}" loop: "{{ testlist1 | zip_longest(testlist2,testlist3) | list }}
結果：
[[email protected] cycle]# ansible-playbook cycle.8.yml PLAY [cycle test8] ************************************************************************************** TASK [debug cycle with_together] ************************************************************************ ok: [192.168.15.10] => (item=[u'A', 110, u'x']) => { "msg": " A - 110 - x" } ok: [192.168.15.10] => (item=[u'B', 120, u'y']) => { "msg": " B - 120 - y" } ok: [192.168.15.10] => (item=[u'C', 911, None]) => { "msg": " C - 911 - " } ok: [192.168.15.10] => (item=[u'D', None, None]) => { "msg": " D - - " } TASK [debug cycle loop+zip_logest] ********************************************************************** ok: [192.168.15.10] => (item=[u'A', 110, u'x']) => { "msg": " A - 110 - x" } ok: [192.168.15.10] => (item=[u'B', 120, u'y']) => { "msg": " B - 120 - y" } ok: [192.168.15.10] => (item=[u'C', 911, None]) => { "msg": " C - 911 - " } ok: [192.168.15.10] => (item=[u'D', None, None]) => { "msg": " D - - " } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 debug cycle with_together ----------------------------------------------- 0.25s debug cycle loop+zip_logest --------------------------------------------- 0.21s Playbook finished: Mon Dec 24 20:44:42 2018, 2 total tasks. 0:00:00 elapsed.
示例中同時寫出2中方法方便進行比較。
但多個列表使用”with_together”進行對比合並時，如果列表長度不同，這使用最長的列表長度進行對其，由於短列表中元素不足，所以使用空值與長列表中元素進行對齊，zip_longest過濾器也和”with_together”一樣，對列表進行組合，但是還需要藉助list過濾器，將組合的資料列表化。
可以指定字元代替空值
- debug: msg: "{{ item.0 }} - {{ item.1 }} - {{item.2}}" loop: "{{ testlist1 | zip_longest(testlist2,testlist3,fillvalue='None') | list }}" 和最短的列表進行對齊 - debug: msg: "{{ item.0 }} - {{ item.1 }} - {{item.2}}" loop: "{{ testlist1 | zip(testlist2,testlist3) | list }}" 6.With_nested/With_cartesian #product過濾器配合list過濾器，可以替代with_nested和with_cartesian [[email protected] cycle]# cat cycle.9.yml --- - name: cycle test4 hosts: test gather_facts: no vars: list1: [ 1,2,3 ] list2: [ a,b,c,d ] tasks: - name: debug cycle debug: msg: "{{ item.0 }} ---- {{ item.1 }}" loop: "{{ list1 | product(list2) | list }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.9.yml PLAY [cycle test4] ************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=[1, u'a']) => { "msg": "1 ---- a" } ok: [192.168.15.10] => (item=[1, u'b']) => { "msg": "1 ---- b" } ok: [192.168.15.10] => (item=[1, u'c']) => { "msg": "1 ---- c" } ok: [192.168.15.10] => (item=[1, u'd']) => { "msg": "1 ---- d" } ok: [192.168.15.10] => (item=[2, u'a']) => { "msg": "2 ---- a" } ok: [192.168.15.10] => (item=[2, u'b']) => { "msg": "2 ---- b" } ok: [192.168.15.10] => (item=[2, u'c']) => { "msg": "2 ---- c" } ok: [192.168.15.10] => (item=[2, u'd']) => { "msg": "2 ---- d" } ok: [192.168.15.10] => (item=[3, u'a']) => { "msg": "3 ---- a" } ok: [192.168.15.10] => (item=[3, u'b']) => { "msg": "3 ---- b" } ok: [192.168.15.10] => (item=[3, u'c']) => { "msg": "3 ---- c" } ok: [192.168.15.10] => (item=[3, u'd']) => { "msg": "3 ---- d" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.31s Playbook finished: Mon Dec 24 20:55:19 2018, 1 total tasks. 0:00:00 elapsed.
7.With_random_choice
#使用random函式可以替代with_random_choice，由於random函式是隨機取出列表中的一個值，並不涉及迴圈操作，所以並不用使用loop關鍵字。
[[email protected] cycle]# cat cycle.10.yml --- - name: cycle test hosts: test gather_facts: no vars: list: [a,b,c] tasks: - name: debug cycle debug: msg: "{{ list | random }}" - debug: msg: "{{ list | random }}" - debug: msg: "{{ list | random }}
結果：
[[email protected] cycle]# ansible-playbook cycle.10.yml PLAY [cycle test] *************************************************************************************** TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => { "msg": "a" } TASK [debug] ******************************************************************************************** ok: [192.168.15.10] => { "msg": "a" } TASK [debug] ******************************************************************************************** ok: [192.168.15.10] => { "msg": "c" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=3 changed=0 unreachable=0 failed=0 skipped=0 debug cycle ------------------------------------------------------------- 0.18s ------------------------------------------------------------------------ 0.16s Playbook finished: Mon Dec 24 21:06:32 2018, 2 total tasks. 0:00:00 elapsed.
8.with_dict
#除了上文總結的dict2items過濾器，dictsort過濾器也可以替代with_dict
[[email protected] cycle]# cat cycle.11.yml --- - name: cycle test2 hosts: test gather_facts: no vars: dicts: China: 1 America: 2 aaa: 3 bbb: 4 ccc: 5 tasks: - name: debug cycle dict2items debug: msg: "{{ item.key }} is no.{{ item.value }}" loop: "{{ dicts | dict2items }}" - name: debug cycle debug: msg: "{{ item.0 }} is no.{{ item.1 }}" loop: "{{ dicts | dictsort }}"
結果：
[[email protected] cycle]# ansible-playbook cycle.11.yml PLAY [cycle test2] ************************************************************************************** TASK [debug cycle dict2items] *************************************************************************** ok: [192.168.15.10] => (item={'key': u'China', 'value': 1}) => { "msg": "China is no.1" } ok: [192.168.15.10] => (item={'key': u'America', 'value': 2}) => { "msg": "America is no.2" } ok: [192.168.15.10] => (item={'key': u'aaa', 'value': 3}) => { "msg": "aaa is no.3" } ok: [192.168.15.10] => (item={'key': u'bbb', 'value': 4}) => { "msg": "bbb is no.4" } ok: [192.168.15.10] => (item={'key': u'ccc', 'value': 5}) => { "msg": "ccc is no.5" } TASK [debug cycle] ************************************************************************************** ok: [192.168.15.10] => (item=[u'aaa', 3]) => { "msg": "aaa is no.3" } ok: [192.168.15.10] => (item=[u'America', 2]) => { "msg": "America is no.2" } ok: [192.168.15.10] => (item=[u'bbb', 4]) => { "msg": "bbb is no.4" } ok: [192.168.15.10] => (item=[u'ccc', 5]) => { "msg": "ccc is no.5" } ok: [192.168.15.10] => (item=[u'China', 1]) => { "msg": "China is no.1" } PLAY RECAP ********************************************************************************************** 192.168.15.10 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 debug cycle dict2items -------------------------------------------------- 0.26s debug cycle ------------------------------------------------------------- 0.22s Playbook finished: Mon Dec 24 21:10:40 2018, 2 total tasks. 0:00:00 elapsed.