how do i use ansible to remotely comment out a line in a docker-compose file and add a line
like this
#image: gralog/graylog:4.2.5
image: graylog/graylog4.2.8
then do a docker compose down
and docker-compose up -d
i need to run this on multiple nodes
I assume, the expected result is below. If not confirm your example
and ignore the rest here
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
For example, create a dictionary of the disabled and enabled versions
versions:
4.2.5: false
4.2.8: true
Then the *lineinfile* task below should comment out disabled versions
and add enabled versions
- lineinfile:
path: docker-compose
regex: '^\s*#*\s*image: graylog/graylog{{ item.key }}\s*$'
line: '{{ hash }}image: graylog/graylog{{ item.key }}'
loop: "{{ versions|dict2items }}"
vars:
hash: "{{ item.value|ternary('', '#') }}"
do ytou mean like this
See the complete example below
cat docker-compose
image: graylog/graylog4.2.5
Got it, thanks!
I was abl to get my first node changed but the other 2 had this added
image: gralog/graylog:4.2.5
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
I don’t think you can get line_in_file to do what you want. line_in_file is designed to operate on a single line. Keeping the commented out line greatly complicates matters. How many patchlevels to you intend to maintain as comments?
You may be able to do it with replace and a lot of testing. But I’d strongly encourage you to reconsider using # as a poor replacement for revision control.
'y' is missing in 'gralog/graylog:4.2.5' in the first line. This is
the reason why the first line wasn't replaced. Instead, the second
line was added.
it only works for first node. When i run the playbook against 3 nodes the 2nd and 3rd node have this
image: graylog/graylog:4.2.5
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
this is the playbook
I tested with another pb and it works fine on all 3 nodes
it only works for first node. When i run the playbook against 3 nodes the
2nd and 3rd node have thisimage: graylog/graylog:4.2.5
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
Quoting from *lineinfile* parameter *regexp*
https://docs.ansible.com/ansible/latest/collections/ansible/builtin/lineinfile_module.html#parameter-regexp
For state=present, the pattern to replace if found. Only the last
line found will be replaced.
For state=absent, the pattern of the line(s) to remove.
Note the difference between the states *present/absent*. If *absent*
all matches are removed. If *present* only the last one is replaced.
The default state is *present*.
One of the scenarios on how to proceed might be removing all redundant
lines first. For example, given the file
cat docker-compose
image: graylog/graylog4.2.5
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
The playbook
cat pb.yml
- hosts: localhost
vars:
versions:
4.2.5: false
4.2.8: true
tasks:
- name: Remove versions
lineinfile:
state: absent
path: docker-compose
regexp: '^\s*#*\s*image: graylog/graylog{{ item.key }}\s*$'
loop: "{{ versions|dict2items }}"
when: force_remove_versions|d(false)|bool
- name: Add versions
lineinfile:
path: docker-compose
regexp: '^\s*#*\s*image: graylog/graylog{{ item.key }}\s*$'
line: '{{ hash }}image: graylog/graylog{{ item.key }}'
loop: "{{ versions|dict2items }}"
vars:
hash: "{{ item.value|ternary('', '#') }}"
removes all matching lines and creates the specified ones
ansible-playbook pb.yml -e force_remove_versions=true
PLAY [localhost]
> cat pb.yml
- hosts: localhost
vars:
versions:
4.2.5: false
4.2.8: true
tasks:
- name: Remove versions
lineinfile:
state: absent
path: docker-compose
regexp: '^\s*#*\s*image: graylog/graylog{{ item.key }}\s*$'
loop: "{{ versions|dict2items }}"
when: force_remove_versions|d(false)|bool
- name: Add versions
lineinfile:
path: docker-compose
regexp: '^\s*#*\s*image: graylog/graylog{{ item.key }}\s*$'
line: '{{ hash }}image: graylog/graylog{{ item.key }}'
loop: "{{ versions|dict2items }}"
vars:
hash: "{{ item.value|ternary('', '#') }}"
The playbook is idempotent
cat docker-compose
#image: graylog/graylog4.2.5
image: graylog/graylog4.2.8
ansible-playbook pb.yml
PLAY [localhost]
i got it to work the simple way with multiple tasks
I have another requirement to down the container on node01 first
docker-compose down
then run the pb,
then docker-compose up -d
wait 30secs or so
repeat with node02
repeat with node03
is there docker module or I should just use shell module?
I believe it’s always better to use designated Modules over or that said … you may want to get familiar (or at least be aware of ) where you can find any modules. that said … here is the (from that list) you can study it online or with the built-in help like one last comment … just like using designated modules for designated tasks in Ansible it’s always best to use designated Threads for different problems. This may not make a difference for you just now, but others who may be following the list have a chance to benefit from the solution somebody is digging out
does this mean I cannot keep the old commented line?
#image: graylog/graylog4.2.5
requirement is I need to have this line commented
Assuming you only have one line for each version, it will assure that the line for any version that’s marked false will be commented, and any line for a version marked true will be uncommented.
Where it gets hairy is when you have more than one line for any version. In that case, the second task only manages the first of the lines for that version. That shouldn’t happen, but you’ve already seen that it does sometimes. When it does, you can run the playbook with force_remove_versions set to true, and it will remove all the matching lines - both good and bad - before the second task puts the single entries back in the file, properly commented or not as the case may be.
does this mean I cannot keep the old commented line?
#image: graylog/graylog4.2.5
It's tricky. You can write scripting to do anything you want to do,
but it's not necessarily built-in precisely the way you want it to
behave.
It's why many config files, such as those in /etc/sudoers.d/, deploy
files rather than editing lines of /etc/sudoers.
Quoting from *lineinfile* parameter *regexp*
https://docs.ansible.com/ansible/latest/collections/ansible/builtin/lineinfile_module.html#parameter-regexp
For state=present, the pattern to replace if found. Only the last
line found will be replaced.
Thank you!
Assuming you only have one line for each version, it will assure
that the line for any version that's marked false will be
commented, and any line for a version marked true will be
uncommented.
Where it gets hairy is when you have more than one line for any
version. In that case, the second task only manages the first of
^^^^^
last