I would like to know if there is a sys.config file of an erlang node to be updated without restarting the node itself?
My usecase is to have variables in the env part of the sys.config configuration, where I constantly poll the sys.config to see if certain variables are true or false for various reasons like turning on or off features of a program on the fly.
The sys.config is only read at start time (and new release installation time). Are you aware of application:set_env/3? If you are, in what way does it not meet your needs?
Related
I am working on developing a solution that simplifies hands-on debugging of failed Jenkins builds. This involves SSH-ing to the right Jenkins node and going directly on the WORKSPACE so you can interactively try different changes that could solve your problem.
While I solved the problem of starting a SSH session in the right directory there is one missing bit: your shell is missing the original environment variables defined by Jenkins, and these are critical for running any commands after that. So, not the first command of the build is a set > .envrc which saves all into this shell file.
My example refers to the direnv tool which is able to auto-load .envrc files. Due to security concerns this tool does not auto-load these files and gives a message direnv: error .envrc is blocked. Rundirenv allowto approve its content.
So my current solution is to manually run direnv allow after ending up in the right folder.
How can I automate this, so I would not have to type this? A prompting could be ok because it would involve only pressing one key instead of typing ~12.
Please note that I am not forced to use direnv itself, I am open to other solution.
As of v2.15.0, you can now use direnv's whitelist configuration to achieve what you described:
Specifying whitelist directives marks specific directory hierarchies
or specific directories as "trusted" -- direnv will evaluate any
matching .envrc files regardless of whether they have been
specifically allowed. This feature should be used with great care, as
anyone with the ability to write files to that directory (including
collaborators on VCS repositories) will be able to execute arbitrary
code on your computer.
For example, say that the directory hierarchy that contains the .envrcs you want to be evaluated without having to run direnv allow is located under /home/foo/bar.
Create the file /home/foo/.config/direnv/config.toml so that it contains the following:
[whitelist]
prefix = [ "/home/foo/bar" ]
Alternatively, if there are a fixed list of specific paths you want to whitelist, you can use exact rather than prefix:
[whitelist]
exact = [ "/home/foo/projectA", "/home/foo/projectB" ]
I am currently doing an analysis whether jenkins could fit for our needs.
Therefore I need to know something about (NOT) reloading configurations:
I know that there is an explicit way to reload a configuration (via WebGUI and CLI).
BUT:
Is there also a way to PREVENT Jenkins from reloading configs?
One requirement is that the CI-System reads in all config-files (general and job-configs) ONCE at the start of the ci-system. And afterwards a modification of the config-files shall take NO effect!
Do you know whether this is already the case (except I press that button under "manage Jenkins" | "reload Configuration from hard disk" [exact options might sound a little different because I only have a German version here])
Would be very thankful for your help,
Lukas
I run a Git repo to control the config.xml files so have experience of the xml files changing while Jenkins is running.
I can confidently state that Jenkins will not reread the config.xml file unless you specifically ask it to via the UI or cli. In fact if the config is changed via the UI any changes that has been done to the config.xml file will be overwritten with the in-memory version.
How do you deal with host-specific configuration for docker containers?
Most importantly production passwords. They can't be put to container for security reasons. Also, they need to be changed on regular basis w/o redeploying anything.
I mostly use Volume containers if I really want to avoid making an image for that: http://docs.docker.com/userguide/dockervolumes/
however, I have done things like
FROM myapp
ADD password.file /etc
RUN do some cfg
to make specific images with password baked in.
That way the specific configuration list passwords is not in the general images which are re-used and known, but they are in an image that is build for and on the host that is running it. (this approach is not really very different to using puppet/chef etc to customise the files on a vm/server - it eventually needs to hit the filesystem in a safe, but repeatable way)
As one comment says, use environment variables you can pass via -e pass=abcdef. You can also save them in a fig.yml config file to avoid having to type them every time.
let's say I am developing 2 applications for 2 different clients which are, using 2 different database-configurations.
When using Openshift and CakePHP it is considered good practise to not store the real connection-info in the configs, but instead to use environment-variables.
That way the GIT-Repo is also always clean of server-specific stuff.
That is all fine as long as I have ONE project but as soon as there is another one, I need to override my local env-vars according to the current project.
Is there any way to avoid this? Is it possible to set up env-vars on my local machine per directory or something like that?
I am running OSX with Mamp Pro.
This may not be the best solution, but It would work. Create a different user on your local machine and then change to that other user when you need to access those other environment variables.
I create a 'data' directory in my git repo and set it to ignore. This way anything in there will be saved in the repo and sent to openshift. I place a config.ini file with all the info that I don't want in my repo.
I then manually put that config.ini file in Openshift's persistent DATA directory by using winSCP. You only have to do this when you change your config.ini.
When my app runs it detects if it's local or on Openshift and loads the config.ini file from the correct directory.
I would be interested if somebody has a better idea.
HTH
We have a situation where something causes our Jenkins master to start leaking memory at a certain time each night. No jobs are running at this time, so I'm not interested in logs of build jobs.
We would like to figure out what is happening around this time, but we cannot see much in the jenkins.out.log, since it doesn't log a lot and lacks timestamps.
Does anyone know if there is a way to turn on more detailed operational (not just errors) logging in Jenkins?
You could use the logs accessible from the UI (Manage Jenkins ยป System Log) and set the log level to ALL for the default log recorder in Log Levels. This log is only accessible from the UI though.
Alternatively, you could increase the log level of the regular jenkins.log by passing --debug=9 to the Jenkins command. If you're on CentOS, changing the value of JENKINS_DEBUG_LEVEL in /etc/sysconfig/jenkins has the same effect.
You could also use the Jenkins/Hudson monitoring plugin to see snapshots of memory use etc inside the JVM.
Also you could install sar (sysstat) to see how the server itself is doing over time (if Linux).