I'm trying to replace a value in a config file, using the replace module.
However, I was wondering if there is an OR function or similar.
Currently, I have the following play:
- name: Replace "DebugLevel" variable-value"
become: yes
replace:
path: /etc/zabbix/zabbix_proxy.conf
regexp: '^# DebugLevel=3'
replace: 'DebugLevel=3'
This play uncomments DebugLevel=3, but when the playbook is run a second time the replace wont work because the regex does not match (value already uncommeted).
I want to always replace the value even if DebugLevel=3 already was uncommented.
This will make any manual changes made by a person to be overwritten and the Ansible playbook sets it back to original config.
By creating a new play with a regex that is using the value that is already uncommented, I can accomplish this, but is there a shorter version by using an "OR" after the first regex value or something similar?
Example of what I mean:
- name: Replace "DebugLevel" variable-value"
become: yes
replace:
path: /etc/zabbix/zabbix_proxy.conf
regexp: '^# DebugLevel=3' OR '^DebugLevel=.*'
replace: 'DebugLevel=3'
if you want to use regex the or is |
- name: Replace "DebugLevel" variable-value"
replace:
path: /etc/zabbix/zabbix_proxy.conf
regexp: '^# DebugLevel=3|^DebugLevel=.*'
replace: 'DebugLevel=3'
If the configuration file should contain every time a certain debug level you could probably declare just that the line exists independent of comment and value. To do so
- name: Replace "DebugLevel" variable-value"
lineinfile:
path: /etc/zabbix/zabbix_proxy.conf
regexp: 'DebugLevel'
line: 'DebugLevel=3'
It will make sure that the debug level is set with the given value and active.
Documentation
lineinfile module – Manage lines in text files
Related
I am using below code to replace old hostname with new one, it is working except for hostnames starting with numbers.(OLD_HOSTNAME and NEW_HOSTNAME are vars)
tasks:
- name: "Updating file"
replace:
name: /tmp/interfaces
backup: yes
regexp: '(\s+){{ OLD_HOSTNAME }}(\s+)'
replace: '\1{{ NEW_HOSTNAME }}\2'
If I replace \1 with \g<1>, the hostnames starting with numbers will also get placed. But as per the ansible doc, \1 is used ambiguously, and \g<1> used explicitly.
Question: Will this change impact any other format of hostname?
No, using the explicit form will not affect other hostname formats.
The reason why you have a problem when NEW_HOSTNAME begins with a number is that the replace string would become something like \123-server\2 if NEW_HOSTNAME was 23-server and there is no backreference \123. Using the explicit form preserves your original intent. In my example, replace would become \g<1>23-server\g<2>.
I'd like to use Ansible's lineinfile or replace module in order to add the word splash to the cmdline in GRUB.
It should work for all the following examples:
Example 1:
Before: GRUB_CMDLINE_DEFAULT=""
After: GRUB_CMDLINE_DEFAULT="splash"
Example 2:
Before: GRUB_CMDLINE_DEFAULT="quiet"
After: GRUB_CMDLINE_DEFAULT="quiet splash"
Example 3:
Before: GRUB_CMDLINE_DEFAULT="quiet nomodeset"
After: GRUB_CMDLINE_DEFAULT="quiet nomodeset splash"
The post Ansible: insert a single word on an existing line in a file explained well how this could be done without quotes. However, I can't get it to insert the word within the quotes.
What is the required entry in the Ansible role or playbook in order to add the word splash to the cmdline as shown?
You can do this without a shell output, with 2 lineinfiles modules.
In your example you're searching for splash:
- name: check if splash is configured in the boot command
lineinfile:
backup: true
path: /etc/default/grub
regexp: '^GRUB_CMDLINE_LINUX=".*splash'
state: absent
check_mode: true
register: grub_cmdline_check
changed_when: false
- name: insert splash if missing
lineinfile:
backrefs: true
path: /etc/default/grub
regexp: "^(GRUB_CMDLINE_LINUX=\".*)\"$"
line: '\1 splash"'
when: grub_cmdline_check.found == 0
notify: update grub
The trick is to try to remove the line if we can find splash somewhere, but doing a check only check_mode: true. If the term was found (found > 0) then we don't need to update the line. If it's not found, it means we need to insert it. We append it at the end with the backrefs.
Inspired by Adam's answer, I use this one to enable IOMMU:
- name: Enable IOMMU
ansible.builtin.lineinfile:
path: /etc/default/grub
regexp: '^GRUB_CMDLINE_LINUX_DEFAULT="((:?(?!intel_iommu=on).)*?)"$'
line: 'GRUB_CMDLINE_LINUX_DEFAULT="\1 intel_iommu=on"'
backup: true
backrefs: true
notify: update-grub
Please note I've had to set backrefs to true in order to \1 reference to work otherwise the captured group was not replaced.
Idempotency works fine as well.
EDIT: Please note this snippet only works with an Intel CPU and might to be updated to fit your platform.
A possible solution is the definition of two entries as follows:
- name: "Checking GRUB cmdline"
shell: "grep 'GRUB_CMDLINE_LINUX_DEFAULT=.*splash.*' /etc/default/grub"
register: grub_cfg_grep
changed_when: false
failed_when: false
- name: "Configuring GRUB cmdline"
replace:
path: '/etc/default/grub'
regexp: '^GRUB_CMDLINE_LINUX_DEFAULT="((\w.?)*)"$'
replace: 'GRUB_CMDLINE_LINUX_DEFAULT="\1 splash"'
when: '"splash" not in grub_cfg_grep'
Explanation: We first check if the splash keyword is present in the required line using grep. Since grep gives a negative return code when a string is not found, we suppress the errors using failed_when: false. The output of grep is saved to the grub_cfg_grep variable.
Next, we bind the replace module to the condition that the keyword splash is in the standard output of grep. The regular expression takes the old content in the quotes and adds the splash keyword behind it.
Note: In the case of an empty string before the execution, the result reads " splash" (with a space in front) but it is still a valid cmdline.
The difficulty is this line in the replace module page: "It is up to the user to maintain idempotence by ensuring that the same pattern would never match any replacements made."https://docs.ansible.com/ansible/latest/modules/replace_module.html#id4 It's easy to insert the item but actually quite tricky to make it idempotent, so the target file doesn't grow every time you run the task.
I found a way to do it in one shot with the replace module. You should be able to adapt this. My task checks the GRUB_CMDLINE_LINUX_DEFAULT line for "vt.default_red" and inserts some colour codes if not found.
My method was to copy-and-paste various nearly-there examples into the regex tester website and fiddle until it worked. I still don't grok the result, but it worked in my tests at https://www.regextester.com/ and it works in my playbook.
One problem I had was that Ansible's regex implementation apparently doesn't support conditionals, which gave me odd errors for a while.
- name: colours | configured grub command
replace:
path: /etc/default/grub
regexp: '^GRUB_CMDLINE_LINUX_DEFAULT="((:?(?!vt\.default_red).)*?)"$'
replace: 'GRUB_CMDLINE_LINUX_DEFAULT="\1 vt.default_red=0xee,..."'
The regex matches the literal string ("GRUB_CMDLINE_LINUX_DEFAULT=" and a double quote mark) at the start and the double quote mark at the end. Deconstructing the rest...
( - open capture group #1 (creates backref #1)
(:? - open a non-capturing group (not sure what the question mark is here)
(?! - negative lookahead (ie. don't match if the following string comes next)
vt\.default_red - the string to look for, literal dot is escaped
) - close negative lookahead
.) - match a single char (why?) and close the non-capturing group
* - try to match the non-capturing group zero or more times
? - ... lazily (ie. get the smallest possible match)
) - close capture group #1
What about doing this in Ansible, use perl to address your need.
- name: Change items in the file
ansible.builtin.command:
command: perl -i pe 's/DEFAULT="/DEFAULT="splash"/'
Another way of looking at it. This is an old conversation, but it is still relevant.
Trying to add a valid python regex as a parameter for the patterns option in the find module, but it's not working.
tasks:
- name: Obtain a list of auto* files in /etc
find:
path: /etc
patterns: "^auto(_|\\.)([a-zA-Z]+\n)"
use_regex: yes
register: etc_auto_files
The problem appears to be with the "\n", I have tried multiple backslashes, single quotes, and square brackets, but haven't been able to get it working.
I am running ansible 2.3.2.0.
Try (not tested)
patterns: "^auto(_|\\.)([a-zA-Z]+{{'\n'}})"
Solved this. The pattern was meant to match filenames that are as follows:
/etc/auto_(one or more letters, end of filename)
/etc/auto.(one or more letters, end of filename)
The following filenames are examples that would match the pattern:
/etc/auto.master or /etc/auto_master
The following filenames are examples that would not match the pattern:
/etc/old.auto.master
/etc/old.auto_master
/etc/auto.master.20180101
/etc/auto_master.20180101
The ansible pattern that ended up working:
"^auto(_|\\.)([a-zA-Z]+)$"
Here is how the pattern was successfully used in a find task:
- name: Obtain a list of auto* files in /etc
find:
path: /etc
patterns:
- "^auto(_|\\.)([a-zA-Z]+)$"
- "^fstab$"
- "^vfstab$"
use_regex: yes
register: etc_auto_files
Thanks to those who commented and attempted to answer this question.
I am using the replace module in ansible to replace a line in my file
original line is #listen_addresses = 'localhost'
I want to replace it to the following listen_addresses = '*'
This my playbook entry
replace: path=/usr/pgsql-9.6/data/postgresql.conf regexp='#listen_addresses(\s)*=\'locahost'\' replace='listen_addresses = *' remote_src=yes backup=yes
The above playbook is unable to make the substituion. Pls guide me with the actual regexp
You don't need to put the full line to replace it, just match the beginning of the line (using ^) the text plus a greedy matching (.*)
tasks:
- replace:
path: /usr/pgsql-9.6/data/postgresql.conf
regexp: '^#listen_addresses.*'
replace: 'listen_addresses = *'
remote_src: yes
backup: yes
I suggest also to reformat the code this way (mind = were replaced by :) this is more readable
I have been trying to replace a option #$ActionFileEnableSync on
for /etc/rsyslog.conf file with $ActionFileEnableSync on. I have used replace module
- replace:
path: /etc/rsyslog.conf
regexp: '^#\s*^$\s*ActionFileEnableSync on.*$'
line: '$ActionFileEnableSync on'
And also I have tried to use lineinfile module
- lineinfile:
dest: /etc/rsyslog.conf
regexp: (^#\\$ActionFileEnableSync on)
line: "$ActionFileEnableSync on"
But none seems to work,either it doesn't replace or keeps on adding a new line
Use lineinfile to set a specific line in a file.
Your regexp looks wrong. Why is 'on' in the regexp? Isn't it supposed to set the value to 'on' when the existing line says 'off'?
Also, the regexp should match the line when it's already 'on', commented out or not. Otherwise, Ansible will append a line at every run.
Try something like:
regexp: ^[#\s]*\$ActionFileEnableSync
This should replace $ActionFileEnableSync following any combination of comment marks and whitespace.