It seems like a very easy question but I couldn't find, what the default for services in SystemD for LimitNOFILE is.
Is there a file with global defaults?
#/etc/security/limits.conf
#This file sets the resource limits for the users logged in via PAM.
#It does not affect resource limits of the system services.
#if your program startup via systemctl
#config /etc/systemd/system.conf
DefaultLimitNOFILE=
systemd imposes no such limit by default. however pam_limits generally does, configuration file is /etc/security/limits.conf
The default config is in /etc/systemd/system.conf, and the default value is DefaultLimitNOFILE=1024:524288.
Related
Hi I'm spinning out Pantheon's Localdev for testing and I'm getting this warning message on the logs
You have a lot of keys!
Any ideas what is causing this warning?
I think this is related to lando. This thread on Github suggests:
To disable the warning you can run lando config you will see a maxKeyWarning setting. This value can be overridden in a lando global config file, i.e. set the value that matches your number of used keys..
As documented in the SSH keys config page, the keys key is meant to be used in combination with a user-space Lando override file. This file is .gitignored and is meant to provide user-specific overrides, eg you would not put ALL the keys of ALL the users here, just yours.
I need to start my own systemd service, let's call it custom.service. I know how to write a recipe for it to be added and enabled on boot:
SYSTEMD_SERVICE_${PN} = "custom.service"
SYSTEMD_AUTO_ENABLE_${PN} = "enable"
However, it conflicts with one of the default systemd services - systemd-timesyncd.service.
Is there a nice preferred way to disable that default systemd service in my bitbake file even though the systemd_XX.bb actually enables it?
I can create a systemd_%.bbappend file to modify the systemd settings, but I can't locate the place where one service can be disabled leaving all others enabled.
The working solution I found is to remove the timesyncd altogether using
PACKAGECONFIG_remove = "timesyncd"
But I wonder if this is a appropriate way and if there is a way to just disable it, but leave in the system.
How about adding a .bbappend recipe for the conflicting service you want disabled. In it, you would add:
SYSTEMD_AUTO_ENABLE_${PN} = "disable"
If the system runs fine with the other package removed, then removing the package is a preferred solution. Fewer packages means a simpler system.
Usually you would set SYSTEMD_AUTO_ENABLE_${PN} = "disable" and that would let the service be part of image but disabled on boot. However for systemd which provides a lot of default service units this may not be a solution you might want to deploy. You could surgically delete the symlink in etc which will ensure that service is not started automatically on boot but the .service file is still part of image. So add following to systemd_%.bbappend file in your layer
do_install_append() {
rm -rf ${D}${sysconfdir}/systemd/system/sysinit.target.wants/systemd-timesyncd.service
}
There are other ways to disable this e.g. using systemd presets as described here
Use the systemd.preset — Service enablement presets and in particular following steps.
Create a .bbappend file meta-xxx/recipes-core/systemd/systemd_%.bbappend with this content:
do_configure_append() {
#disabling autostart of systemd-timesyncd
sed -i -e "s/enable systemd-timesyncd.service/disable systemd-timesyncd.service/g" ${S}/presets/90-systemd.preset
}
In my yocto-based Linux distribution (yocto zeus release) above steps are enough to disable the service which remains installed.
In the output distribution previous steps modify the file /lib/systemd/system-preset/90-systemd.preset.
After the modification, in that file, appear the row: disable systemd-timesyncd.service and this row substitutes the raw: enable systemd-timesyncd.service
At this link there are some information about the topic: systemd.preset — Service enablement presets.
Other useful.
I was not able to use SYSTEMD_AUTO_ENABLE_${PN} = "disable" in this context.
For other recipes (for example dnsmasq_2.82.bb) the previous assignment works correctly and I have used it to enable (or disable) a service in the yocto distribution.
I think the "official" way to do this is to have something like this somewhere in your project:
PACKAGECONFIG_append_pn-systemd = "--disable-timesyncd"
This does basically the same you already suggested. To simply not enable the service you have to do it manually since you can modify the auto enable only per recipe.
I have read the documentation concerning falling back to environment variables at https://github.com/typesafehub/config/blob/master/HOCON.md#substitution-fallback-to-environment-variables. My understanding was that it would pickup any envars. So for instance, if from the shell I was able to do echo $HOSTNAME and see a non-empty response then HOCON should do that as well.
In my application.conf I have a line
akka.remote.netty.tcp.hostname = ${HOSTNAME}
However, my app is not happy with this and fails to start with.
/conf/application.conf: 9: Could not resolve substitution to a value: ${HOSTNAME}
Is this a user issue? A shell issue? I am able to login as the user and echo $HOSTNAME
Tagging this scala and akka since that userbase probably has the most exposure to HOCON
The reason for HOCON not picking up the envar is that my app runs as a linux service (Centos 6.5) which clears away most environment variables.
See https://unix.stackexchange.com/questions/44370/how-to-make-unix-service-see-environment-variables for a relevant description of the issue
this is a shot in the dark, but are you using an older version of typesafe-config? maybe its a newer-ish feature? the feature seems to be advertised as you describe, but if you are pulling in typesafe-config as a transient dependency (say from akka), maybe you are getting an older version.
what happens if you remove the substitution in your .conf file (so parsing is successful) and then print out the contents of ConfigFactory.systemEnvironment()? for reference: http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment--
HOSTNAME isn't an environment variable. It's a bash internal variable. See https://superuser.com/questions/132489/hostname-environment-variable-on-linux for more details.
I am trying to start a google compute engine (GCE) instance with a pre-configured FQDN. We are intending to run an application that is licensed based on the contents of /etc/hosts.
I am starting the instances using the Google Cloud SDK utility - gcloud.
I have tried setting the "hostname" key using the metadata option like so:
gcloud compute instances create mynode (standard opts) --metadata hostname=mynode.example.com
Whenever I log into the developer console, under computer, instances, I can see hostname under "Custom metadata". This appears to be a new, custome key - it has no impact on what:
http://metadata.google.internal/computeMetadata/v1/instance/hostname
returns.
I have also tried setting "instance/hostname" like the below, which causes a parsing error when using gcloud.
--metadata instance/hostname=mynode.example.com
I have successfully used the startup scripts functionality of the metadata server to run a startup script that parses the new, internal IP address of the newly created instance, updated /etc/hosts. This appears to work but doesn't feel "like the google way".
Can I configure the FQDN (specifically, a domain name, as the instance name is always the hostname) of an instance, during instance creation, using the metaserver functionality?
try this:
Go to your GCE >> VM instances panel.
stop your gce instance.
clic on the instance name.
Edit your instance, adding this values on Custom metadata fields:
Key field: hostname / Value field: your.server.hostname
Key field: startup-script / Value field: sudo -s hostnamectl set-hostname your.server.hostname
setup-example-image.png
Finally, start your instance and test with a hostnamectl command.
regards!
According to this article 'hostname' is part of the default metadata entries that provide information about your instance and it is NOT possible to manually edit any of the default metadata pairs. You can also take a look at this video from the Google Team. Within the first few minutes it is mentioned that you cannot modify default metadata pairs. As such, it does not seem like you can specify the hostname upon instance creation other than through the use of a start-up script like you've done already. It is also worth mentioning that the hostname you've specified will get deleted and auto-synced by the metadata server upon reboot unless you're using a start-up script or something that would modify it every time.
If what you're currently doing works for what you're trying to accomplish, it might be the only workaround to your scenario.
Here is a patch for /usr/share/google/set-hostname to set FQDN to GCE instance.
https://gist.github.com/yuki-takeichi/3080521322f0f1d159ea6a343e2323e6
Before you use this patch, you must set your desired FQDN in your instance's metadata by specifying hostname key.
Hostname is set each time instance's IP address is renewed by dhclient. set-hostname is just a hook script which dhclient executes and serves new IP address and internal hostame to, and modifies /etc/hosts. This patch changes the source of hostname by querying instance's metadata from metadata server.
The original set-hostname script is here:
https://github.com/GoogleCloudPlatform/compute-image-packages/blob/master/google_config/bin/set_hostname.
Use this patch at your own risk.
When creating a VM, you can specify a custom FQDN hostname as an optional parameter. This feature is currently in Beta.
$ gcloud beta compute instances create INSTANCE_NAME --hostname example.hostname
This should work across OSes, and eliminate the need for workaround scripts.
More info in the docs.
-- Sirui (Product Manager, Google Compute Engine)
I've looked throughout this site to find answered questions and found a few things that work but with a couple solutions combined. This thread seems the place to answer.
1) echo example.com > /etc/hostname
2) add -- 127.0.1.1 example.com in /etc/hosts
3) add -- hostnamectl set-hostname
example.com -- command to /etc/rc.local script
4) uncomment /etc/dhcp/dhclient.conf line:
supersede domain-name "example.com";
5) profit.... Seems to stick after each reboot
(Note example.com is your domain name: fqdndomain.com - yourfqdndomain.org)
Also note this is for Ubuntu or Debian. Other Unix May slightly vary. I've tested this on Ubuntu 16.04
Always on the wording NOT possible to manually edit any of the default metadata pairs, how about the instant level default metadata "/scheduling"? we could set them manually as mentioned in this article
I have an HAProxy install which was configured by someone who left the company. It runs on Ubuntu 10.04 and it seems to use 3 configuration files in the directory /etc/haproxy
haproxy.cfg
haproxy.http.cfg
haproxy.https.cfg
I don't see the point in using the haproxy.https.cfg file as I believe (in our configuration) it can all be configured from a single haproxy.http.cfg file but when I remove that httpS file it complains bitterly and refuses to run. My question
Is this the standard configuration haproxy uses or if not, I can't find a reference to the "S" file anywhere. Can anyone suggest how HAProxy concludes it should use it?
Thanks
The very answer to your question: your haproxy is simply launched with those three config files ( -f haproxy.cfg -f haproxy.http.cfg -f haproxy.https.cfg, maybe from /etc/init.d/haproxy but mileage varies depending on your distribution ).
If you remove the file, of course it will complain.
This is not particularly standard, but ain't bad either, it helps structuring the conf rather than having a very long file.
The task of the .https version will certainly be to redirect the https traffic towards a service that can handle HTTPS (stunnel or nginx usually), since haproxy cannot terminate ssl connections. (stunnel has to be patched, see on the haproxy page)
If you want you can merge those files into one or two, just find out how haproxy is launched (check for init.d or let us know which distribution) and fix it appropriately.
I believe that it is only /etc/haproxy/haproxy.cfg that is used by default.
This may be of use to you (1.4 configuration reference):
http://haproxy.1wt.eu/download/1.4/doc/configuration.txt