模板化字符串时出现模板错误:应为名称或数字.字符串:使用Ansible读取JSON时

Question

下面是我的示例this1.json

[
{
"?xml": {
"attributes": {
"encoding": "UTF-8",
"version": "1.0"
}
}
},
{
"domain": [
{
"name": "mydom"
},
{
"domain-version": "12.2.1.3.0"
},
{
"server": [
{
"name": "AdminServer"
},
{
"ssl": {
"name": "AdminServer"
}
},
{
"listen-port": "12400"
},
{
"listen-address": "mydom.host1.bank.com"
}
]
},
{
"server": [
{
"name": "myserv1"
},
{
"ssl": [
{
"name": "myserv1"
},
{
"login-timeout-millis": "25000"
}
]
},
{
"log": [
{
"name": "myserv1"
},
{
"file-name": "/web/bea_logs/domains/mydom/myserv1/myserv1.log"
}
]
}
]
},
{
"server": [
{
"name": "myserv2"
},
{
"ssl": {
"name": "myserv2"
}
},
{
"reverse-dns-allowed": "false"
},
{
"log": [
{
"name": "myserv2"
},
{
"file-name": "/web/bea_logs/domains/mydom/myserv2/myserv2.log"
}
]
},
{
"server-start": [
{
"name": "CANVL01"
},
{
"java-vendor": "Sun"
},
{
"java-home": "/web/bea/platform1221/jdk"
}
]
}
]
}
]
}
]

下面的代码能够从log数组中提取file-name元素。

- hosts: localhost
gather_facts: no
vars:
json: "{{ lookup('file', './this1.json') | from_json }}"
tasks:
- name: display
debug:
msg: "{{ server.0.name }} -> {{ filename.0.log[1]['file-name'] }}"
loop: "{{ json[1].domain }}"
vars:
server: "{{ item.server | selectattr('name', 'defined') }}"
filename:  "{{ item.server | selectattr('log', 'defined') }}"
when: item.server is defined and (item.server | selectattr('log', 'defined')) != []

在类似的行上，我希望提取server-start阵列的java-home元素。以下是相同的代码：

- name: display CPATH
debug:
msg: "{{ server.0.name }} -> {{ cpath.0.'server-start'[2]['java-home'] }}"
loop: "{{ jsondata[1].domain }}"
vars:
server: "{{ item.server | selectattr('name', 'defined') }}"
cpath:  "{{ item.server | selectattr('server-start', 'defined') }}"
when: item.server is defined and (item.server | selectattr('server-start', 'defined')) != []

然而，我得到了这个错误：

skipping: [localhost] => (item={'server': [{'name': 'myserv1'}, {'ssl': [{'name': 'myserv1'}, {'login-timeout-millis': '25000'}]}, {'log': [{'name': 'myserv1'}, {'file-name': '/web/bea_logs/domains/mydom/myserv1/myserv1.log'}]}]})
fatal: [localhost]: FAILED! => {"msg": "template error while templating string: expected name or number. String: {{ server.0.name }} -> {{ cpath.0.'server-start'[2]['java-home'] }}"}

我尝试了以下方法，但都不起作用：

msg: "{{ server.0.name }} -> {{ cpath.0."server-start"[2]['java-home'] }}"
msg: "{{ server.0.name }} -> {{ cpath.0.server-start[2]['java-home'] }}"
msg: "{{ server.0.name }} -> {{ cpath.0.'[server-start]'[2]['java-home'] }}"
msg: "{{ server.0.name }} -> {{ cpath.0.[server-start][2]['java-home'] }}"
msg: "{{ server.0.name }} -> {{ cpath.0.['server-start'][2]['java-home'] }}"

这些都不起作用。你能提出建议吗？

注意：这只是一个示例json，server-start的位置可能会有所不同。因此使用selectattr

Answer 1

试试这个剧本：

- hosts: localhost
gather_facts: no
vars:
json: "{{ lookup('file', './file2.json') | from_json }}"
tasks:
- name: display
debug:
msg: "{{ server.0.name }} -> {{ cpath[0]['server-start'][2]['java-home'] }}"
loop: "{{ json[1].domain }}"
vars:
server: "{{ item.server | selectattr('name', 'defined') }}"
cpath:  "{{ item.server | selectattr('server-start', 'defined') }}"
when: item.server is defined and (item.server | selectattr('server-start', 'defined')) != []

结果：

skipping: [localhost] => (item={'name': 'mydom'}) 
skipping: [localhost] => (item={'domain-version': '12.2.1.3.0'}) 
skipping: [localhost] => (item={'server': [{'name': 'AdminServer'}, {'ssl': {'name': 'AdminServer'}}, {'listen-port': '12400'}, {'listen-address': 'mydom.host1.bank.com'}]}) 
skipping: [localhost] => (item={'server': [{'name': 'myserv1'}, {'ssl': [{'name': 'myserv1'}, {'login-timeout-millis': '25000'}]}, {'log': [{'name': 'myserv1'}, {'file-name': '/web/bea_logs/domains/mydom/myserv1/myserv1.log'}]}]}) 
ok: [localhost] => (item={'server': [{'name': 'myserv2'}, {'ssl': {'name': 'myserv2'}}, {'reverse-dns-allowed': 'false'}, {'log': [{'name': 'myserv2'}, {'file-name': '/web/bea_logs/domains/mydom/myserv2/myserv2.log'}]}, {'server-start': [{'name': 'CANVL01'}, {'java-vendor': 'Sun'}, {'java-home': '/web/bea/platform1221/jdk'}]}]}) => {
"msg": "myserv2 -> /web/bea/platform1221/jdk"
}