What does the command line arguments for PM2 startup mean precisely - pm2

I am a little confused about start up scripts and the command line options. I am building a small raspberry pi based server for my node applications. In order to provide maximum protection against power failures and flash write corruption, the root file system is read only, and that embraces the home directory of my main user, were the production versions of my apps (two of them) are stored. Because the .pm2 directory here is no good for logs etc I currently set PM2_HOME environment variable to a place in /var (which has 512kb unused space around it to ensure writes to i. The eco-system.json file reads this environment variable also to determine where to place its logs.
In case I need to, I also have a secondary user with a read write home directory in another (protected by buffer space around it) partition. This contains development versions of my application code which because of the convenience of setting environments up etc I also want to monitor with PM2. If I need to investigate a problem I can log in to that user and run and test the application there.
Since this is a headless box, and with watchdog and kernel panic restarts built in, I want pm2 to start during boot and at minimum restart the two production apps. Ideally it should also starts the two development versions of the app also but I can live without that if its impossible.
I can switch the read only root partition to read/write - indeed it does so automatically when I ssh into my production user account. It switches back to read only automatically when I log out.
So I went to this account to try and create a startup script. It then said (unsurprisingly) that I had to run a sudo command like so:-
sudo su -c "env PATH=$PATH:/usr/local/bin pm2 startup ubuntu -u pi --hp /home/pi"
The key issue for me here is the --hp switch. I went searching for some clue as to what it means. Its clearly a home directory, but it doesn't match PM2_HOME - which is set to /var/pas in my case to take it out of the read only area. I don't want to try and and spray my home directory with files that shouldn't be there. So am asking for some guidance here

I found out by experiment what it does with an "ubuntu" start up script. It uses it to set PM2_HOME in the script by appending "/.pm2" to it.
However there is nothing stopping you editing the script once it has created it and setting PM2_HOME to whatever you want.
So effectively its a helper for the script, but only that and nothing more special.

Related

White space issues with Automated DB configuration script

I am trying to instigate some configuration control tools for our mysql databases. To start with we trained and installed GIT on all dev machines including DBA. I got a php script written that extract the definition of all db, all tables, functions,SP, views, and triggers and puts this is a directory structure.
My initial intention was to automate the scrip to run at fixed interval and recreate the directory based on the state of the db server at that time and have git commit the differences.
During testing, I realized that every time I run the script and do a git status, all the files are found to be modified. When I do a git diff I find that it is due to white spaces. Mostly at the end of line. During the previous commit they are trimmed off I think and when the configuration script runs they all come back therefore git thinks all files have change. So I can't do a simple git add .
The configuration management script itself runs on a windows machine but the databases it analyses can be on any platform.
The current git config is autocrlf true and core.white-space all off
What should the configuration be so that all these white spaces do not appear as a diff to git. Remember this is to be completely automated.
I would recommending setting core.autocrlf to false. Having Git automatically try to convert line endings causes no end of problems.
Git does not automatically trim whitespace at the end of lines (unless you explicitly use --whitespace=fix) - from the information you have provided, it seems more likely that the problem is line ending handling.

Clone Openshift application in scalable

I have an application in Openshift free plan with only one gear. I want to change it to scalabe and take usage of all of 3 free gears.
I read this blog post from openshift and I found that there is a way to do it. I should clone my current application to a new one as a scalable which will use the 2 remaining gears and then I will delete the original application. Thus, the new one will have 3 free gears.
The way that blog suggest is: rhc create-app <clone> --from-app <existing> --scaling
I have the following error: invalid option --from-app
Update
After running the command gem update rhc, I don't have the error above but...A new application with the given name has created with the same starting package (Python 2.7) just like the existing one, but all the files are missing. It actually create a blank application and not a clone of the existing.
Update 2
Here is the structure of the folder:
-.git
-.openshift
-wsgi
---static
---views
---application
---main.py
-requirements.txt
-setup.py
From what we've talked on IRC, your problem was around missing SSH configuration on Windows machine:
Creating application xxx ... done
Waiting for your DNS name to be available ...done
Setting deployment configuration ... done
No system SSH available. Please use the --ssh option to specify the path to your SSH executable, or install SSH.
I've double checked it, and it appears to be working without any problem.
The only requirement is to have the latest rhc client and putty or any other
SSH client. I'd recommend going through this tutorial once again and double-check everything to make sure everything is working properly.
Make sure you are using the newest version of the rhc gem with "gem update rhc" to make sure that you have access to that feature from the command line.
The --from-app will essentially do a 'rhc snapshot save & snapshot restore` (amoung other things) as you can see here from the source:
if from_app
say "Setting deployment configuration ... "
rest_app.configure({:auto_deploy => from_app.auto_deploy, :keep_deployments => from_app.keep_deployments , :deployment_branch => from_app.deployment_branch, :deployment_type => from_app.deployment_type})
success 'done'
snapshot_filename = temporary_snapshot_filename(from_app.name)
save_snapshot(from_app, snapshot_filename)
restore_snapshot(rest_app, snapshot_filename)
File.delete(snapshot_filename) if File.exist?(snapshot_filename)
paragraph { warn "The application '#{from_app.name}' has aliases set which were not copied. Please configure the aliases of your new application manually." } unless from_app.aliases.empty?
end
However this will not copy over anything in your $OPENSHIFT_DATA_DIR directory so if you're storing files there, you'll need to copy them over manually.

MySQL SELinux conflict Fedora 19

I've successfully installed MySQL 5.6 on my F19. Although the installation was successful, I'm unable to start the mysql service.
When I ran
service mysql start
It returns the following error:
Starting MySQL..The server quit without updating PID file (/var/lib/mysql/sandboxlabs.pid).
I disabled SELinux (permissive mode), and the service started smoothly. But I did some research about disabling SELinux, and found that disabling SELinux is a bad idea. So, is there any way to add custom MySQL policy? Or should I leave the SELinux to permissive mode?
The full answer depends on your server configuration and how you're using MySQL. However, it's completely feasible to modify your SELinux policy to allow MySQL to run. In most cases, this sort of operation can be performed with a small number of shell commands.
Start by looking at /var/log/audit/audit.log. You can use audit2allow to generate a permission-granting policy around the log messages themselves. On Fedora 19, this utility is in the policycoreutils yum package.
The command
# grep mysql /var/log/audit/audit.log | audit2allow
...will output the policy code that would need to be compiled in order to allow the mysql operations that were prevented and logged in audit.log. You can review this output to determine whether you'd like to incorporate such permissions into your system's policy. It can be a bit esoteric but you can usually make out a few file permissions that mysql would need in order to run.
To enable these changes, you need to create the policy module as a compiled module:
# grep mysql /var/log/audit/audit.log | audit2allow -M mysql
...will output the saved plaintext code to mysql.te and the compiled policy code to mysql.pp. You can then use the semodule tool to import this into your system's policy.
# semodule -i mysql.pp
Once you've done this, try starting mysqld again. You might need to repeat this process a few times since mysqld might still falter on some new access permission that wasn't logged in previous runs. This is because the server daemon encounters these permission checks sequentially and if it gets tripped on one, it won't encounter the others until you allow access to the initial ones. Have patience -- sometimes you will need to create mysql1.pp mysql2.pp mysql3.pp ... and so on.
If you're really interested in combining these into a unified policy, you can take the .te files and "glue" these together to create a unified .te file. Compiling this file is only slightly more work -- you need the Makefile from /usr/share/selinux/devel/Makefile in order to convert this into a .pp file.
For more information:
If you're a more graphical type, there's also a great article by RedHat magazine on compiling policy here. There's also a great blog article which takes you through the creation of a policy here. Note the emphasis on using /usr/share/selinux/devel/Makefile to compile your own .te, .fc, and .if files (selinux source written in M4).

making an XML dump of a MediaWiki using dumpBackup.php

Using the MediaWiki maintenance script called dumpBackup.php I want to create an XML dump of my MediaWiki.
To do this you have to login to the server using an SSH client, I'm using Putty (Windows), but I also tried it on OSX using Terminal.
According to the MediaWiki Manual for dumpBackup.php this is done using these commands:
cd w/maintenance
php dumpBackup.php --full >d:\backup.xml
Since I am using GoDaddy hosting the last line is a bit different for me. The reason is that SSH for GoDaddy by default still uses php4 (unlike the HTTP server). For this reason my command is (assuming you are also in the maintenance folder):
usr/local/php5/bin/php dumpBackup --full >d:\backup.xml
The however, all this does for me is print everything on the screen and no file is created. Does anybody know why this is and how to make sure the file is created.
You left out the > from the original example:
php dumpBackup.php --full >d:\backup\dump.xml
The > tells the shell to redirect the output of the script to the file d:\backup\dump.xml instead of the screen.
By the way, d:\backup\dump.xml is a Windows file name. Since your server seems to be using a Unixish OS (probably Linux), you probably don't want to use that filename. However, if you don't mind having the file created in your current directory, just plain dump.xml will work fine on both Windows and *nix.
You could also try e.g. ~/dump.xml or $HOME/dump.xml (both of which create the file in your home directory) or $TMP/dump.xml (which creates it in the directory designed for temporary files, usually /tmp.) This could be useful if you don't have enough space available in the directory you installed MediaWiki in.
To see how much space you do have, try the commands df -h (which shows the amount of actual free space) and quota -vs (which shows how much of that space you're allowed to use, if that has been limited). For more help with these commands, try man df and/or man quota.

run jenkins as user "hudson"

we've updated hudson to jenkins and have a few dependencies upon the "hudson" user we used to have.
Now that we have jenkins running (works fine) we'd like it to run as the user "hudson" in order to keep our other processes intact without having to rewrite them.
We found instructions on how to do this BEFORE installing jenkins, but we're already past that point. Jenkins is installed and up and running. Is there a way to let jenkins run as the user "hudson"?
We are running CENTOS
Jenkins usually runs with it's own user, so there are two main issues to handle:
Make sure user 'hudson' has full access to the files of user 'jenkins' (or whatever user it was set to run as).
Start the Jenkins-daemon (or other initiator) with the 'hudson' user.
(another approach is to change the user-ID so it is actually the same user but with two names)
Good luck!
If you've installed Jenkins from RPM, there should be an /etc/sysconfig/jenkins file with a JENKINS_USER setting that defaults to 'jenkins' that you can change to 'hudson'.
I second Gonen's comment above about making sure you change the ownership of the 'jenkins' owned files to 'hudson'. Don't forget about the /var/log/jenkins logs.
Also don't forget to restart the Jenkins service after updating the files.