Just another page out of my life
To forward all root emails to a user you can add an entry in the aliases file, like:
root: sam
After updating the aliases run the command below.
newaliases /etc/aliases
Restart your mail server and you should see all root emails being sent to the user specified in the aliases file. A different process can be used to achieve the same behavior by making an entry in the .forward file of the root but I haven’t tried that as I prefer to have it done with aliases.
I run Couchpotato on my media server and since the project isn’t actively maintained it doesn’t run on python3. My linux os dropped having pip2.7 available by default likely to encourage people to migrate to python3, I decided to run it in a python virtual environment to break the apps dependency on the system python support. Below are the steps I took to get it running.
Setup virtualenv
Python3 comes with venv or creating virtual enviroments but venv doesn’t support creating environments with python2.7. Current versions of virtualenv also don’t support python2.7 so we have to install a version that has this support we will go with version 20.21.1
pip install virtualenv==20.21.1
Create your virtual environment directory I created this inside the couchpotato project but you can also place it outside if you intend to use it with more than one project.
mkdir couchpotatoserver/.venv/
Point the virtualenvironment to the actual path of your python2.7 binary
virtualenv --python=/usr/bin/python2.7 /<path>/couchpotatoserver/.venv/
This will install python2.7 and a compatible pip version in the virtual environment.
Use virtualenv
You should be able to install all your needed dependencies from the couchpotato requirements file with the pip cmd. Use the path to the pip binary to make sure the dependencies get installed in your virtual environment and not the OS.
.venv/bin/pip install -r requirements-dev.txt
Just as we had to install a specific version of virtualenv which supports Python2.7 we will need to install specific versions of 2 other libraries needed by couchpotato in our virtual environment.
.venv/bin/pip install cryptography==2.2.2 .venv/bin/pip install PyOpenSSL==17.5.0
Update whichever script you are using to startup couch potato to use the Python installed in the virtual environment, it is very important to reference the actual path otherwise by omitting the path you will be using the system level Python version which will cause startup to fail.
/<root-path>/couchpotatoserver.venv/bin/python /apps/couchpotatoserver/CouchPotato.pyYou should now be able to startup your couchpotato service using your virtual environment and should be safe from future OS updates breaking your setup. This documentation assumes you already have an existing couchpotato setup already, the setup of couchpotato is outside scope of this notes.
Upgrading from JDK8 to 17+ caused jaxb to run into this errors at run time. Solution remove older Jaxb jars and replace with newer jars that still provide “xml.bind”. When replacing try with 2.3.X jar versions as they still maintain the old sun class path, 3.XX jars have switched to the jarkarta class path which will mean updating some of your project imports and dependencies.
Remove any of the below libs
implementation group:'javax.xml.bind', name: 'jaxb-api', version: '2.3.0'
implementation group:'com.sun.xml.bind',name:'jaxb-impl', version: '2.3.0'
implementation group:'com.sun.xml.bind',name:'jaxb-core', version: '2.3.0'
replace with
implementation group: 'jakarta.xml.bind', name: 'jakarta.xml.bind-api', version: '2.3.3'
implementation group: 'org.glassfish.jaxb', name: 'jaxb-runtime', version: '2.3.3'
One problem with the Secure Shell plugin is when you need to remove an ssh key from the known_hosts file there is no direct access to the file from the file system. This issue comes up normally when you run into the error message below.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ED25519 key sent by the remote host is
SHA256:C//eoM00fEk4Z8YH6bAp7NdGyhqm24Xsmj/wDl81TEc.
Please contact your system administrator.
Add correct host key in /.ssh/known_hosts to get rid of this message.
Offending ED25519 key in /.ssh/known_hosts:9
Host key for xx.xx.xx.xx has changed and you have requested strict checking.
Host key verification failed.
Which will come up when you re-image an existing host or replace an existing host with another host using the same IP address/host name. The previous way of doing this used to be do (CTRL + SHIFT + J) to bring up the terminal and then run the command “term_.command.removeKnownHostByIndex(INDEX); ” but this doesn’t always work for me as “command” isn’t always available. The most consistent way I have found to resolve this is to bring up Secure Shell and choose Options -> SSH Files you will see your known_hosts file with the ability to modify and save it. Remember to save after your changes and you should be good to go.
I saw this error message once I updated to JDK 11 when trying to send emails initially I didn’t have time to figure out a long term solution so I took a shortcut and removed Tls 1.0 from blocked algorithms in the java.security file. (I know that was a bad move but I was on a time crunch so I wasn’t thinking clearly 🙂 )
Things were ok for a while until an update of JDK replaced my update to java.security file, at this point I figured I would have to keep repeating this dance every few months or get a long term solution.
I use apache commons library to send email and by default it uses < TLS v1.2 and JDK 11+ supports > TLS v1.2. The permanent fix just turned out to be specifying TLS version to be used and my app was able to get back to sending emails without any issues and this time it was future proofed from future update breakage due to JDK updates. Below are the parmeter updates needed.
#Method 1 adding a system property
System.setProperty("mail.smtp.ssl.protocols", "TLSv1.2");
System.setProperty("mail.pop3s.ssl.protocols", "TLSv1.2");#Method 2 setting value in a property file
spring.mail.properties.mail.smtp.ssl.protocols=TLSv1.2
spring.mail.properties.mail.pop3s.ssl.protocols=TLSv1.2I went with Method #2 as it allows easier management of properties but every bodies use case is different so you can go with whatever works for your situation.
Since Centos ships with an old PHP version, there are many tutorials on how to install Remi PHP which enables you to use more modern versions of PHP on your site. But when it came time to update from PHP72 to php73/4 I couldn’t find a lot of docs on this so I decided to put this one up to remind me next time am doing this.
First, we will need to enable the PHP version we want to install such as below.
# yum-config-manager --enable remi-php73
# yum-config-manager --enable remi-php74In my case, I was moving from php72 to 73 before 74 so I enabled 73 and disabled 72.
# yum-config-manager --enable remi-php73
# yum-config-manager --disable remi-php72After enabling the version you want to move to and disabling your current version, run yum update and restart your webserver.
# yum update
# apachectl restartTo validate the update was successful check the current version of PHP as reported in your terminal, and those are the steps needed to move from one Remi PHP version to another.
# php -v
PHP 7.3.29 (cli) (built: Jun 29 2021 09:30:31) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.29, Copyright (c) 1998-2018 Zend TechnologiesI have been running kvm with a bridge on my fedora machine for a while, when trying to run docker on the same host access to the kvm hosts would die as soon as docker came up. I read up online and most places mention that the two technologies should be able to co-exist with each other without any problems, after some further searching I was able to find an article that mentioned that if you have already setup a bridge for KVM you can tell docker to use this bridge. I was able to test this on my setup and it worked allowing docker to run without interfering with the existing bridge. Looking at the interfaces I can still see docker created an interface docker0 but it doesn’t seem to be active.
The docker configuration involved adding this file /etc/docker/daemon.jsonwith the following entry.
{ "bridge": "br0" }
Make sure the bridge number matches your existing bridge number in use by kvm.
I finally managed to migrate my wordpress DB to the new server after several weeks of making multiple db dumps and restorations which would fail to load all the content from the old DB. I tried different tools that would export the DB as sql files and used same tools to import even straight command line dumps, but somehow my posts would not display correctly the titles and dates would display but not the post body content.
While trying to trouble shoot the cause I opened the sql file and started running each tables insert query one at a time as you can expect this sucked really bad, but I was ready to do it this way as nothing else was working. When I tried to paste the insert statements for the posts table something weird happened only one character would paste into the sql console which was weird as I expected the several hundred lines I had copied to show up. To look at this some more I posted the text in an editor that could format sql and half way down the file the SQL highlighting changed and displayed half the post as text. This normally happens when there is a character that isn’t escaped properly, it also explained why the backup imports would fail. The weird part with the backup failure is none of the tools would throw an error as you would expect if there was an error with the insert queries. While the curious part of me wanted to investigate this further the rest of me was tired with several weeks of trying to migrate the wordpress data and tried to find another way of moving the data without having to export to SQL files.
The solution I went with was DBeaver which has a data export method of type database which will let you copy a table from one DB to another without having to rely on SQL dumps. This worked like a charm even though it still took a good 10 minutes to copy over everything and keep validating as I went. Like most sites I have an DB backup scripts but since it looks like the backups created in this method may not be of use if I needed them in the future am thinking of just having another offline DB and keep that synced with my main db and use the offline DB for any restorations I might need.
Of Mountains & Valleys
Like most people I used to put my 401K in safe funds when choosing safe versus risky fund options. My yearly returns also reflected my choices, most of the time I would average 5% or less (mostly less).
A big problem with this method of saving for my retirement was the fact that most of the money in my 401k was coming from the deductions on my check. This would actually be ok if I started working and funding my 401k at 21, but life happens and I started later in my twenties.
To increase my returns I started following the daily performance of all the funds available in my 401k and I would manually rebalance my account every few months. I also started having larger balances in more aggressive funds and would rebalance every few weeks. This helped raise my yearly returns a few percentage points in some years but not always.
I decided to write some code to automatically rebalance my account for me since I was loosing money in a lot of situations when things would come up or I would forget to log in and rebalance my account. In 2 and a half years that my code has been running it was able to double the balance that was there when it started running, averaging about 20% returns at this rate I will have enough to retire in about 10 yrs if I stop my contributions and less than 10 if I keep adding my contributions.
If my code had not worked my other option would have been to pay for one of the services offered to manage our company’s 401k plans for a certain fee. Right now am happy my money is working just as hard as I do, but I also understand not everyone is in the same position am in since my day job involves writing code.Â
Personally, I would suggest if you are trying to improve your 401k returns try and invest more time on a regular basis (days,weeks not months) and learn how the different funds you have available are performing and keep rebalancing your account frequently, some plans will also let you set how you want your account rebalanced every month/pay period automatically for free. If you have some more time and skill you can learn how trading systems work and build something that is able to evaluate your funds and rebalance your account accordingly. The last option which I haven’t tried would be to pay a service to automatically rebalance your account, I feel even if you are going to go with this option to first do option one so that you can use that as a baseline to gauge the paid services performance.Â
Some people argue that your 401k should be treated like a marathon where you setup your preferences and leave it and only rebalance a few times a year. This is what I did with my account for almost ten years and in 2.5 years of aggressively rebalancing as the market changed I was able to add to my account as much as I had been able to contribute in 10yrs, without having to depend on salary increases to increase my contributions. So for me am sticking with the sprint, if it means I will need fewer years to build my retirement nest to where I would like it to be.
Note: All thoughts written here are my own, and should not be taken as financial advice, am not a financial expert just someone who likes to solve real world problems using code.
Just brushing up on some Angular2 and run into this error it didn’t make sense since I was using a tutorial from the official angular site. It turns out the language is changing faster that the documentation can keep up with :). The cause for the error was using # with ngFor instead of let so instead of *ngFor="#Item of Items" do *ngFor="let Item of Items" My previous angular2 apps are locked to earlier versions of angular thats why I hadn’t run into this issue, but this time around I was starting a new project with the latest angular2 version.