Change systemd execstart to yml conf

[P4R4DiSi4C]

Currently, '.conf' is hardcoded in the following file: https://github.com/fluent/fluent-bit/blob/master/init/systemd.in
Is there any plan to change it to '.yml' so we avoid the need of overriding the systemd configuration ?

[Unit]
Description=@FLB_PROG_NAME@
Documentation=https://docs.fluentbit.io/manual/
Requires=network.target
After=network.target

[Service]
Type=simple
EnvironmentFile=-/etc/sysconfig/@FLB_OUT_NAME@
EnvironmentFile=-/etc/default/@FLB_OUT_NAME@
ExecStart=@CMAKE_INSTALL_FULL_BINDIR@/@FLB_OUT_NAME@ -c /@CMAKE_INSTALL_SYSCONFDIR@/@FLB_OUT_NAME@/@[email protected]
Restart=always

[Install]
WantedBy=multi-user.target

[patrick-stephens]

Yes although we will have to be careful of impact on existing users who may be relying on overriding the conf file. It would have to be documented explicitly and maybe as a breaking change e.g. in 4.0 release @edsiper ?

YAML format was only completed for 3.2 as well so previous versions are still supported.

[chadmyers]

@P4R4DiSi4C How do you override the system configuration to use yaml?

[P4R4DiSi4C]

@P4R4DiSi4C How do you override the system configuration to use yaml?

I have the following Ansible task:

  ansible.builtin.template:
    src: fluent-bit-override.conf.j2
    dest: "/etc/systemd/system/fluent-bit.service.d/override.conf"
    mode: '0644'
  when: fluentbit_systemd_override is defined

With the following template:

{{ ansible_managed | comment }}

[Service]
{% for key, value in fluentbit_systemd_override.items() %}
{% if key == 'ExecStart' %}
{{ key }}=
{% endif %}
{{ key }}={{ value }}
{% endfor %}

And set the following value:

fluentbit_systemd_override:
  ExecStart: '/opt/fluent-bit/bin/fluent-bit -c //etc/fluent-bit/fluent-bit.yml'

Which results in a override.conf file being created in the folder /etc/systemd/system/fluent-bit.service.d/ with the following content:

#
# Ansible managed
#

[Service]
ExecStart=
ExecStart=/opt/fluent-bit/bin/fluent-bit -c //etc/fluent-bit/fluent-bit.yml

Hope it helps :)

[patrick-stephens]

@edsiper I think we should consider this for 4.0, main thing is to ensure we notify people so they can expect it.

See https://fluent-all.slack.com/archives/C0CTQGHKJ/p1736719725842959 as well.

[patrick-stephens]

I've prepped a PR for this: #9837

Note there are a few more places to update and missing files to add, my PR covers all targets and adds them.

[Elwell]

Minor typo for @P4R4DiSi4C's benefit - you can drop the double slash in the ExecStart (it's a typo upstream too) so it should be

[Service]
ExecStart=
ExecStart=/opt/fluent-bit/bin/fluent-bit -c /etc/fluent-bit/fluent-bit.yml

or .yaml depending on preferences :-)

[P4R4DiSi4C]

Minor typo for @P4R4DiSi4C's benefit - you can drop the double slash in the ExecStart (it's a typo upstream too) so it should be

[Service]
ExecStart=
ExecStart=/opt/fluent-bit/bin/fluent-bit -c /etc/fluent-bit/fluent-bit.yml

or .yaml depending on preferences :-)

Thanks for that @Elwell !