Reading an attribute value into an ansible variable is not documented

[ssbarnea]

The documentation should include a code sample that loads an attribute value into an ansible variable. I may make sense to provide a simple example for reading the charset attribute from insite HTML page. html>headers>meta>charset. Maybe even specifying what happens if it is missing.

[cmprescott]

That should definitely be included.

[wheelq]

is it possible to read the value? what is the syntax?

[kenthua]

Looks like it's "xmlstring" from the source

[hdimitriou]

The xmlstring is inaccurate:

    - name: xml test
      xml:
        file: "{{ some_file }}"
        xpath: //some_xpath
        content: text
      register: xml_hits

[glzavert]

So it has been months since this issue was opened and identified as a bug. What is the status of an example on how to load an attribute or element value into an ansible variable. Examples with and with out namespaces are relevant as many users simply need to access the values and do not need to manipulate the XML.

I have spent many many days trying to do this and the closest I have gotten returns the following

TASK [test : Print patch] ******************************************************
ok: [capiis.ibm.com] => {
"get_element_attribute.matches[0]['PatchManifest']['patchName']": "patch_JR55554_ISD_all_11500-1"
}

or

TASK [test : Print hist] *******************************************************
ok: [capiis.ibm.com] => {
"get_applied_patches.matches[21]['{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent']['installerId']": "patch_JR55554_ISD_all_11500-1"
}

I have been unable to get the values "patch_JR55554_ISD_all_11500-1" into variables so that I can compare a patch manifest to a list of applied patches in order to determine if a patch has been applied. This is to prevent what is apparent in the attached Version.xml file where a patch has been repeatedly applied. I like many, don't want to manipulate the xml files, I simply need the values in the attributes.

Here are my files:
PatchManifest.xml.txt
Version.xml.txt

Here is my main.yml

• name: Get patch name attributes
  xml:
  file: "/opt/IBM/install/tmp/PatchManifest.xml"
  xpath: /PatchManifest
  content: 'attribute'
  register: get_element_attribute

• name: print get_element_attribute
  debug: var=get_element_attribute

• name: pring patchName attributes
  debug: var=get_element_attribute.matches[0]['PatchManifest']['patchName']

• name: Count applied patches
  xml:
  file: "/opt/IBM/InformationServer/Version.xml"
  xpath: /iis:History/iis:HistoricalEvent
  namespaces:
  iis: http://www.ibm.com/LocalInstallRegistry
  count: true
  register: applied_patches

• name: Print count of applied patches
  debug: var=applied_patches.count

• name: Get applied patches
  xml:
  file: "/opt/IBM/InformationServer/Version.xml"
  xpath: //iis:HistoricalEvent
  namespaces:
  iis: http://www.ibm.com/LocalInstallRegistry
  content: 'attribute'
  register: get_applied_patches

• name: Print applied patch for first patch
  debug: var=get_elements.matches[0]['{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent']['installerId']

• name: iterate over applied patches applied patchs
  include: inner.yml
  vars:
  patch: get_element_attribute.matches[0]['PatchManifest']['patchName']
  hist: get_applied_patches.matches[{{item}}]['{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent']['installerId']
  with_sequence: start=0 end={{ get_applied_patches.count|int - 1}}

Here is my inner.yml

• name: Print patch
  debug: var="{{ patch }}"

• name: Print hist
  debug: var="{{ hist }}"

I have no idea why this has to be so difficult but any prompt resolution to this bug or direction on how to get the values into variables for testing would be appreciated.

[glzavert]

Ok, I finally figured it out. I had to use json_query in order to search the nested data that is returned as json data. This is not well documented and I only figured it out be looking at the code. However, the method I took is a kludge at best and a real set of methods and examples that a user can implement to read an attribute or element into a variable is needed.

I should be able to use an xpath like "/PatchManifest/@patchName" and get back only "patch_JR55554_ISD_all_11500-1" from my PatchManifest.xml and an xpath like "//iis:HistoricalEvent/@installerId" with a defined namespace and get back "patch_JR55554_ISD_all_11500-1" from my Version.xml file as well as a loop construct that would allow me to iterate of the items in all "//iis:HistoricalEvent" elements under "//iis:History"

The files I used are above but I modified my role/tasks as follows

---

• name: Get attributes from non-namespaced file
  xml:
  file: "/opt/IBM/install/tmp/PatchManifest.xml"
  xpath: /PatchManifest
  content: 'attribute'
  register: get_element_text

• name: print get_element_text
  debug: var=get_element_text

• name: Get patch name attributes
  xml:
  file: "/opt/IBM/install/tmp/PatchManifest.xml"
  xpath: /PatchManifest
  content: 'attribute'
  register: get_element_attribute

• name: print get_element_attribute
  debug: var=get_element_attribute

• name: pring patchName attributes
  debug: var=get_element_attribute.matches[0]['PatchManifest']['patchName']

• name: Count applied patches
  xml:
  file: "/opt/IBM/InformationServer/Version.xml"
  xpath: /iis:History/iis:HistoricalEvent
  namespaces:
  iis: http://www.ibm.com/LocalInstallRegistry
  count: true
  register: applied_patches

• name: Print count of applied patches
  debug: var=applied_patches.count

• name: Get applied patches
  xml:
  file: "/opt/IBM/InformationServer/Version.xml"
  xpath: //iis:HistoricalEvent
  namespaces:
  iis: http://www.ibm.com/LocalInstallRegistry
  content: 'attribute'
  register: get_applied_patches

• name: Print applied patch for first patch
  debug: var=get_applied_patches.matches[0]['{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent']['installerId']

• name: Print attribute from nested JSON data
  debug: msg="{{get_element_attribute.matches[0]|json_query('PatchManifest.patchName')}}"

• name: Print nested JSON data for the first item in a list of namespaced data
  debug: msg="{{get_applied_patches.matches[0]}}"

# important to cast numerics to integer otherwise it is a string and no matches will be found or looping will occur

• name: Print the desired attribute value from each item in a list of namespaced data
  debug: msg="{{get_applied_patches.matches[item|int]|json_query('*.installerId')}}"
  with_sequence: start=0 end={{ get_applied_patches.count|int - 1}}

output:
TASK [test : Get attributes from non-namespaced file] **************************
ok: [capiis.ibm.com]

TASK [test : print get_element_text] *******************************************
ok: [capiis.ibm.com] => {
"get_element_text": {
"actions": {
"ensure": "present",
"namespaces": {},
"xpath": "/PatchManifest"
},
"changed": false,
"count": 1,
"matches": [
{
"PatchManifest": {
"installVersion": "11.5.0.71",
"patchName": "patch_JR55554_ISD_all_11500-1",
"specversion": "1.0"
}
}
],
"msg": 1
}
}

TASK [test : Get patch name attributes] ****************************************
ok: [capiis.ibm.com]

TASK [test : print get_element_attribute] **************************************
ok: [capiis.ibm.com] => {
"get_element_attribute": {
"actions": {
"ensure": "present",
"namespaces": {},
"xpath": "/PatchManifest"
},
"changed": false,
"count": 1,
"matches": [
{
"PatchManifest": {
"installVersion": "11.5.0.71",
"patchName": "patch_JR55554_ISD_all_11500-1",
"specversion": "1.0"
}
}
],
"msg": 1
}
}

TASK [test : pring patchName attributes] ***************************************
ok: [capiis.ibm.com] => {
"get_element_attribute.matches[0]['PatchManifest']['patchName']": "patch_JR55554_ISD_all_11500-1"
}

TASK [test : Count applied patches] ********************************************
ok: [capiis.ibm.com]

TASK [test : Print count of applied patches] ***********************************
ok: [capiis.ibm.com] => {
"applied_patches.count": "22"
}

TASK [test : Get applied patches] **********************************************
ok: [capiis.ibm.com]

TASK [test : Print applied patch for first patch] ******************************
ok: [capiis.ibm.com] => {
"get_applied_patches.matches[0]['{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent']['installerId']": "information.server"
}

TASK [test : Print attribute from nested JSON data] ****************************
ok: [capiis.ibm.com] => {
"msg": "patch_JR55554_ISD_all_11500-1"
}

TASK [test : Print nested JSON data for the first item in a list of namespaced data] ***
ok: [capiis.ibm.com] => {
"msg": {
"{http://www.ibm.com/LocalInstallRegistry}HistoricalEvent": {
"description": "Information Server Installation",
"eventDate": "2016-12-14T12:15:52.577",
"installType": "INSTALL",
"installerId": "information.server",
"rollback": "/opt/IBM/InformationServer/_uninstall",
"status": "SUCCESS",
"userId": "root",
"version": "11.5.0.1"
}
}
}

TASK [test : Print the desired attribute value from each item in a list of namespaced data] ***
ok: [capiis.ibm.com] => (item=0) => {
"item": "0",
"msg": [
"information.server"
]
}
ok: [capiis.ibm.com] => (item=1) => {
"item": "1",
"msg": [
"information.server"
]
}
ok: [capiis.ibm.com] => (item=2) => {
"item": "2",
"msg": [
"information.server"
]
}
ok: [capiis.ibm.com] => (item=3) => {
"item": "3",
"msg": [
"information.server"
]
}
ok: [capiis.ibm.com] => (item=4) => {
"item": "4",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=5) => {
"item": "5",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=7) => {
"item": "7",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=6) => {
"item": "6",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=8) => {
"item": "8",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=9) => {
"item": "9",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=10) => {
"item": "10",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=12) => {
"item": "12",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=11) => {
"item": "11",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=13) => {
"item": "13",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=14) => {
"item": "14",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=15) => {
"item": "15",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=16) => {
"item": "16",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=17) => {
"item": "17",
"msg": [
"patch_JR56156_JDBC_HIVE_all_11500-01"
]
}
ok: [capiis.ibm.com] => (item=18) => {
"item": "18",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=19) => {
"item": "19",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=20) => {
"item": "20",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}
ok: [capiis.ibm.com] => (item=21) => {
"item": "21",
"msg": [
"patch_JR55554_ISD_all_11500-1"
]
}

[dagwieers]

This issue was moved to ansible/ansible#27951

[dagwieers]

Please close this issue.