Transform data with filters and plugins practice questions

list

Why wrong: 'list' is not a filter; use 'list' function.

float

Why wrong: There is no 'float' filter; use 'int' or arithmetic.

string

Why wrong: Use 'string' or 'str' but it's not a standard filter; 'string' is a test.

regex

Why wrong: regex filter is for regex matching and replacement, not for extracting lines.

first

Why wrong: first returns the first item of a list, not first lines of a multiline string.

head

Why wrong: Incorrect. The `head` filter on a string returns the first N characters, not lines. To get lines, the string must first be split into a list, then `head` works; however, the question asks for a single filter, and `head` alone does not achieve the goal.

{{ output | lines | first }}

Why wrong: There is no 'lines' filter in Ansible.

{{ output | first }}

Why wrong: The 'first' filter acts on a list, not a string directly.

{{ output | head(1) }}

Why wrong: There is no 'head' filter in Ansible.

{{ result | json_query('data.users.0.name') }}

Why wrong: Incorrect. Uses `users.0`, which is not valid JMESPath. JMESPath uses bracket notation for indices like `users[0]`.

{{ result.data.users[0].name }}

Why wrong: Incorrect. Native Jinja2 dot notation would work only if `result` were a parsed dictionary of the response body, but the registered variable includes the entire HTTP response object, so `result.data` may not directly access the parsed JSON.

The playbook uses 'hosts: all' but should use 'hosts: webservers'.

Why wrong: The playbook already targets webservers, so this is not the issue.

The script is not executable.

Why wrong: If not executable, Ansible would report an error, not 'no hosts matched'.

The 'ansible_host' variable is not set in hostvars.

Why wrong: Missing ansible_host causes connection issues, but hosts would still be matched.

{{ servers | map('memory_mb') | sum }}

Why wrong: map expects a filter or lambda, not attribute name.

{{ servers | sum }}

Why wrong: Would sum the list objects, not the attribute.

{{ servers | sum(attribute='memory_mb') }}

Why wrong: The 'sum' filter does not take an attribute parameter.

The debug task uses 'var: myvar' instead of 'msg: "{{ myvar }}"'.

Why wrong: Both are valid; 'var' prints the variable directly without extra quotes.

The playbook uses 'set_fact' with quotes around the variable name.

Why wrong: Quotes around variable name are fine.

The variable contains a fact that is only available on the control node.

Why wrong: Facts are gathered on target hosts, but can be used anywhere.

connection

Why wrong: Connection plugins handle transport, not data transformation.

callback

Why wrong: Callback plugins handle output, not data transformation.

A single string: 'Alice,30\nBob,25'

Why wrong: That would be the original data without header.

A list of strings: ['name,age', 'Alice,30', 'Bob,25']

Why wrong: That would be the result of split on newline, not parse_csv.

A dictionary: {'Alice': '30', 'Bob': '25'}

Why wrong: Not the structure of parse_csv.

The 'changed' key is misspelled as 'change' in the filter.

Why wrong: It's spelled correctly.

The variable 'fw_result' is undefined because the task failed.

Why wrong: If failed, the debug would not run.

The filter 'if' condition is incorrectly evaluating 'fw_result.changed' as a string.

Why wrong: It's a boolean, no issue.

Use 'ignore_errors: yes' on the firewall task and then check the result with 'failed_when' to set a default.

Why wrong: Ignore_errors hides all failures, not just missing facts, and does not set a default port.

Use 'block' and 'rescue' to catch the error and then set the fact.

Why wrong: Block/rescue can work but is more verbose and less efficient than default filter.

Create a separate playbook for servers without the fact file, running a different role.

Why wrong: Too complex and not dynamic; does not handle individual server variations.

{{ '192.168.1.10/28' | ipsubnet }}

Why wrong: ipsubnet calculates subnet details, not a range of IPs.

{{ '192.168.1.10' | ipmath('+10') }}

Why wrong: ipmath performs arithmetic on a single IP, not generating a list.

{{ '192.168.1.10' | ipwrap }}

Why wrong: ipwrap wraps IP in brackets, not for generating ranges.

{{ my_var | mandatory }}

Why wrong: mandatory will fail if the variable is undefined.

{{ my_var | ternary('yes', 'no') }}

Why wrong: ternary is used for conditional value selection, not for defaults.

{{ my_var | dflt('fallback') }}

Why wrong: dflt is not a valid Jinja2 filter in Ansible.

{{ data | rejectattr('status', 'equalto', 'inactive') | extract('name') | list }}

Why wrong: extract is not a valid filter; map should be used.

{{ data | selectattr('status != inactive') | map(attribute='name') | list }}

Why wrong: selectattr requires a test like 'equalto', not a direct expression.

Use the 'slurp' module to read the /etc/hosts file and check if the server is listed.

Why wrong: slurp reads file content, not testing network connectivity.

Use the 'wait_for' module with 'host={{ item }}' and 'port=123' to test connectivity, since NTP uses UDP 123.

Why wrong: wait_for tests TCP connections, not UDP; NTP uses UDP, so it would fail.

Use the 'ping' module with a loop over the ntp_servers list, setting the 'data' parameter to the server IP.

Why wrong: The ping module only pings the managed node, not external hosts; it does not accept a destination parameter.

The 'follow_redirects' parameter must be set to 'all' to handle HTTP 4xx and 5xx errors gracefully.

Why wrong: Incorrect: 'follow_redirects' only handles redirects, not errors.

The 'failed_when' condition can inspect the HTTP response before the request is sent.

Why wrong: Incorrect: 'failed_when' is evaluated after the module runs.

The 'register' keyword automatically parses JSON responses into Ansible variables.

Why wrong: Incorrect: 'body_format' must be set to 'json' for automatic parsing.

set_fact: heading="{{ result.content | regex_replace('<h1>(.*)</h1>', '\1') }}"

Why wrong: Incorrect. The pattern `<h1>(.*)</h1>` only matches the tag and its content, but does not remove surrounding markup; if there is other text, it remains, so the result is not a pure extraction.

set_fact: heading="{{ result.content | regex_search('<h1>(.*)</h1>') }}"

Why wrong: Incorrect. `regex_search` returns the full match (e.g., `<h1>Text</h1>`), not just the inner group.

set_fact: heading="{{ result.content | regex_findall('<h1>(.*)</h1>') | first }}"

Why wrong: Incorrect. `regex_findall` returns a list of all matches (including tags), and `| first` returns the full match, not the inner text.

The 'python2-libselinux' package is required because Ansible uses Python 2. Install it with 'dnf install python2-libselinux'.

Why wrong: Incorrect: RHEL 8 uses Python 3 by default.

The 'ansible' user lacks sudo access to the 'seboolean' command. Add a sudoers entry to allow it.

Why wrong: Incorrect: The error is about SELinux communication, not sudo.

The 'libsemanage' package is missing. Install it with 'dnf install libsemanage'.

Why wrong: Incorrect: 'libsemanage' is not needed for the 'seboolean' module.

Edit crontab, add entry, prepare script, test, verify

Why wrong: This is incorrect because editing the crontab and adding an entry should only be done after the script is ready and tested. Adding an entry for a non-existent or untested script can lead to errors or the cron job failing silently.

Prepare script, edit crontab, add entry, test, verify

Why wrong: This is incorrect because testing the script should be done before adding it to crontab. A script that hasn't been tested may have errors, and testing after adding to cron makes debugging harder.

Test script, prepare script, edit crontab, add entry, verify

Why wrong: This is incorrect because you must prepare the script before testing it. You cannot test a script that hasn't been created yet. The logical order is to prepare first, then test.

user: The component that specifies the process's current working directory.

Why wrong: Incorrect — the current working directory is not part of the SELinux context.

role: The component that defines the hardware architecture.

Why wrong: Incorrect — hardware architecture is unrelated to SELinux contexts.