YAML 裡的字串很長該怎麼做？
Playbook 是使用 YAML 格式，在使用上難免會遇到要放很長的字串的情況，想保留可讀性又不想有多餘的換行符號，該怎麼辦呢？
在 YAML 裡已經有規範此部份，在這種情況有四種方法可以幫助我們：
|: 其下內容的換行，就是換行，最後一行會有換行。>: 其下內容的換行，不會是換行，會變為一個很長的字串，最後會有換行。|-: 其下內容的換行，就是換行，但最後一行不會有換行。>-: 其下內容的換常，不會是換行，最後一行也不會有換行。
直接來看看範例
---
- name: Test long string
hosts: all
vars:
s1: "hello"
s2: |
s2
this is my very very very
long string
line1
line2
line3
s3: >
s3
this is my very very very
long string
line1
line2
line3
s4: |-
s4
this is my very very very
long string
line1
line2
line3
s5: >-
s5
this is my very very very
long string
line1
line2
line3
tasks:
- name: s1
copy:
content: "{{ s1 }}"
dest: "/tmp/s1.txt"
- name: s2
copy:
content: "{{ s2 }}"
dest: "/tmp/s2.txt"
- name: s3
copy:
content: "{{ s3 }}"
dest: "/tmp/s3.txt"
- name: s4
copy:
content: "{{ s4 }}"
dest: "/tmp/s4.txt"
- name: s5
copy:
content: "{{ s5 }}"
dest: "/tmp/s5.txt"
s2~s5 這四個變數裡的內容分別以 |, >, |-, >- 來定義。
接著來看看執行結果
$ cat /tmp/s1.txt
hello%
$ cat /tmp/s2.txt
s2
this is my very very very
long string
line1
line2
line3
$ cat /tmp/s3.txt
s3 this is my very very very long string line1 line2 line3
$ cat /tmp/s4.txt
s4
this is my very very very
long string
line1
line2
line3%
$ cat /tmp/s5.txt
s5 this is my very very very long string line1 line2 line3%
從執行結果，就可以看到如同之前所描述的情況。
簡單的說，> 跟 >- 可以增加 YAML 的可讀性，又不會有多餘的換行符號。而 | 跟 |- 則可以讓字串跟定義的一致，在 YAML 裡看到換行，那字串裡就會有換行符號。