Edward Tanguay's questions

I need to install Jenkins on Ubuntu 20.4.1.

I've completed the following:

• apt-get -y install openjdk-8-jdk (it's Java 14.0.1)
• wget -q -O - http://pkg.jenkins-ci.org/debian-stable/jenkins-ci.org.key | apt-key add - (responds "OK")
• sudo sh -c 'echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list' (file exists and has this one line in it)
• sudo apt update, responds:

Hit:1 http://de.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://de.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:3 http://de.archive.ubuntu.com/ubuntu focal-backports InRelease
Hit:4 http://de.archive.ubuntu.com/ubuntu focal-security InRelease
Ign:5 https://pkg.jenkins.io/debian-stable binary/ InRelease
Get:6 https://pkg.jenkins.io/debian-stable binary/ Release [2,044 B]
Get:7 https://pkg.jenkins.io/debian-stable binary/ Release.gpg [833 B]
Ign:7 https://pkg.jenkins.io/debian-stable binary/ Release.gpg
Reading package lists... Done
W: GPG error: https://pkg.jenkins.io/debian-stable binary/ Release: The following signatures couldn't 
be verified because the public key is not available: NO_PUBKEY FCEF32E745F2C3D5
E: The repository 'http://pkg.jenkins.io/debian-stable binary/ Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.      
N: See apt-secure(8) manpage for repository creation and user configuration details.

• sudo apt install jenkins, responds:

root@ubuntu-server:~# sudo apt install jenkins
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package jenkins is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'jenkins' has no installation candidate

What do I have to do so that apt finds the Jenkins package so it can be installed?

I have Apache installed on an Ubuntu virtual machine.

Typing http://localhost in the browser brings up the Apache intro site, so I know Apache works.

I created the file /home/test/webs/testapp/index.html:

This is a <b>test</b>.

I changed the DocumentRoot in the file /etc/apache2/sites-available/000-default.conf so that it points to a directory under my home directory:

<VirtualHost *:80>
        ServerAdmin webmaster@localhost
        DocumentRoot /home/test/webs
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

I restarted the Apache server:

systemctl reload apache2

But when I go to http://localhost/testapp, Apache responds:

Forbidden

You don't have permission to access this resource.

Apache/2.4.41 (Ubuntu) Server at localhost Port 80

What do I have to do to give the anonymous web users permission to view this web directory via Apache?

I have Apache installed on an Ubuntu virtual machine.

Typing http://localhost in the browser brings up the Apache intro site, so I know Apache works.

I created the file /home/test/webs/testapp/index.html:

This is a <b>test</b>.

I created the file /etc/apache2/sites-available/testapp.conf:

<VirtualHost *:80>
 ServerAdmin webmaster@localhost
 ServerName testapp
 ServerAlias testapp
 DocumentRoot /home/test/webs/testapp
<Directory /home/test/webs/testapp>
 Options -Indexes +FollowSymLinks
 AllowOverride All
</Directory>
 ErrorLog ${APACHE_LOG_DIR}/error.log
 CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

I enabled the virtual host:

sudo a2ensite testapp.conf

I restarted the Apache server:

systemctl reload apache2

But when I go to http://localhost/testapp, Apache responds:

Not Found

The requested URL was not found on this server. Apache/2.4.41 (Ubuntu)

Server at localhost Port 80

What else do I have to do to get my virtual host to work on Ubuntu?

I am looking for an Ubuntu virtual machine to use in order to follow along in a basic course on the Linux command line.

I had an Ubuntu installed in VirtualBox that worked well.

But ever since I installed Docker, it doesn't work any more, keeps crashing, etc.

So I thought I would use Ubuntu in a Docker container.

I pulled the standard docker image: https://hub.docker.com/_/ubuntu and am able to enter it via docker run --name ubuntu002 -it ubuntu bash

but it is missing many commands, e.g. systemctl, less, sudo etc.

So is it possible to use a Ubuntu Docker container as a regular Ubuntu system or is it some kind of incomplete Ubuntu system?

I have a node app running on my Linux hosting server.

Sometimes the app crashes and I need to restart it, so I log in and type these commands:

pkill node
cd public_html/n49900_dpndev
node server.js &

And the app runs again.

Now I would like to put this into a script so I simply need to start the script (or can execute it from a PHP script, for instance).

I created a file called "startnode":

#!/bin/bash
pkill node
cd public_html/n49900_dpndev
node server.js &

I changed the permissions with chmod 755 startnode.

But when I execute it with ./startnode it responds with:

Terminated

What do I need to do so that the commands I type in manually also work in the bash script?

In my directory

http://tanguay.info/webtech

I have the following .htaccess file:

RewriteEngine On
RewriteRule ^$ http://127.0.0.1:49900/home [P,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ http://127.0.0.1:49900/$1 [P,L]

It routes correctly if I provide a page (a node app with .eps files)

http://tanguay.info/webtech/home

But if I don't provide a page:

http://tanguay.info/webtech

It gives this error:

Error: ENOENT: no such file or directory, open '/home/tanguay2/public_html/n49900_dpndev/systemPages/index.html.var.ejs'

It seems to be going to index.html.var.ejs instead of the http://127.0.0.1:49900/home that I specified, but I don't know where it is getting this index.html.var information.

How do I get it to correctly link to http://tanguay.info:49900 if I provide no page?

I set up an apache manually and added a second web directory with this code:

Alias /webs c:\webs
<Directory /webs>
    AllowOverride All
</Directory> 

However, this web has an .htaccess file in it and accessing the website gives the error: "500 Internal Server Error", but does not write anything in the error log file.

But when I remove the .htaccess file, I don't get this error.

I added the "AllowOverride All" line and restarted the server but this doesn't correct the error.

My .htaccess is this:

RewriteEngine On
RewriteCond %{REQUEST_URI} !(\.css|\.js|\.png|\.jpg|\.gif|robots\.txt)$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?params=$1 [L,QSA]

<Files "test">
    Order Allow,Deny
    Allow from all
</Files>

What do I have to do so that I can use an .htaccess file in this directory?

I have installed Apache and in httpd.conf have set the DocumentRoot to "c:\testweb" which is available via "http://localhost".

How can I now enable it so that "http://localhost/web2" goes to "c:\web2"?

We have a daemon running on a Mac server (10.6.6).

We want to install another newer version of the daemon along side it but not start it.

Then at a specific time, we want to reboot the server and have the old daemon not start and the new one start.

Is this possible and how do we do it?

Someone is helping me resolve a response time issue on my VPS.

He suggested I look in my resolv.conf and make sure neither of the IPs are timing out.

My resolve.conf looks like this:

nameserver 69.39.86.5
nameserver 69.39.89.9

when I do a nslookup on the second IP, it times out:

nslookup yahoo.com 69.39.86.9

1. what does this tell me? do I need to inform my vps hosting provider of this?

2. I noticed many resolv.conf examples on the web have the word "domain" or "search" followed by the domain name. Do I need that as well? My websites seem to work fine without it (domain name = tanguay.info).

I have a VPS running CentOS with some PHP sites. It's been running fine for weeks.

Recently it has become slower and slower (both website usage and when logged in via SSH). I have determined that it consistently uses more and more memory until it maxes out, then I have to reboot it, the memory usage goes back down, but then constantly climbs again.

What could be causing this and how can I analyze/solve it?

here is my top:

I'm having difficulty with memory usage on my VPS (CentOS) running PHP sites.

Until now I have been able to change things and reboot to try to analyze and fix things before the memory usage climbs again, but now when I type reboot it can't even do that.

How can I reboot my VPS machine and get out of this catch-22?

5 minutes later: now memory is almost totally maxed out, what could be causing this and how can I begin to fix it when the response time when logged in via SSH is so slow?

I've got a PHP application that is generating large amounts of warnings and notices in the log file..

I'm fixing these one at a time.

I would like to be able to fix the most frequently occurring first in order to maximize the amount of effect my changes have on the size of the log file.

How can I use grep/sed/regex etc.find out which notices are most frequent?

I can't compare the whole line since the time stamp is at the beginning, but perhaps a listing/grouping/sorting of "on line ..."?

When I log in with PuTTY, I always have to:

• change settings
• appearance
• font
• change
• 8
• resize window

so that I can see enough text to work with the log files.

I don't see where I can save these settings to my saved session. Is this possible?

Answer:

So the answer is click on change settings, change everything but then you have to also click on session the name again and save, thanks David:

I have a VPS, CentOS, was set up automatically with HyperVM.

I set up the FTP connection with lxadmin.

I've been logging into my server via FTP for weeks.

Today it says:

Status: Connecting to 74.126.30.21:21...
Status: Connection established, waiting for welcome message...
Error:  Could not connect to server
Status: Waiting to retry...
Status: Delaying connection due to previously failed connection attempt...
Status: Connecting to 74.126.30.21:21...
Status: Connection established, waiting for welcome message...
Error:  Could not connect to server

I can still log in via SSH.

• what kinds of things could have caused this?
• what are some things I can check/change so I can use FTP again?

Here's my netstat output, how can I tell from this if the "port is listening on the server itself"?

it doesn't allow me to telnet to the listed ftp port:

here's the iptables info:

I'm new at hosting my VPS on a CentOS linux server.

The following log files grow quite rapidly and I would like to have them deleted every 24 hours:

/home/httpd/tanguay.info/stats/tanguay.info-custom_log
/home/httpd/tanguay.info/stats/tanguay.info-error_log

/home/admin/__processed_stats/*

What would be the steps for me to create a cron job that deletes all of these files every night at midnight?

To enable SQLite on my Windows/Apache/PHP setup, I uncomment the following lines in the php.ini file and restart Apache:

extension=php_pdo.dll
extension=php_pdo_sqlite.dll

Now I have a VPS with Suse Linux 10.3 and Apache/PHP was set automatically. Looking through the php.ini file to make the above changes, I see that things are a little different on Linux:

• there is no list of extensions to uncomment
• I found "extension_dir = /usr/lib/php5/extensions" but in this directory find only:
  • pdo.so
  • pdo_mysql.so

How can I enable SQLite in this Linux environment?

I have a VPS account with CentOS Linux.

These two files are filling up the 20 GB hard drive every 24 hours:

This stats file:

/home/httpd/tanguay.info/stats/tanguay.info-error_log

and a file in this directory that seems to have different names when it appears but grows to 5+ GB in size:

/home/admin/__processed_stats

All I want to do right now it turn apache stats recording off so that my hard drive doesn't fill up and clobber my mail, ftp, etc.

So in the file:

/etc/httpd/conf/httpd.conf

I commented out the line:

#ErrorLog logs/error_log

Then I deleted both huge files above, rebooted the virtual machine, and saw that the first file (tanguay.info-error_log) had been recreated and was growing again.

So where do I turn off logging in Apache?

(or perhaps Apache is not even using this httpd.conf file as its configuration file, where is that saved?)

I've got a VPS account.

The file:

/home/httpd/..../stats/...-error_log

is logging so many errors that it fills up the 20 GB hard drive space within a 24-hour period which amongst other problems shuts my mail access down, etc.

Most of these errors are repetitive and minor and I'll eventually fix them but how can I first set the error recording up so that it creates various files and deletes the old ones before it makes new ones? This is how I remember it from working on linux web servers I've worked on in the past. I would have thought this would be the default set up actually, isn't it on most VPS servers (My account uses CentOS)?

I host my PHP website on shared hosting.

It's worked well for a year.

All of a sudden last week it started to randomly drop images, sometimes does not load the CSS file, and often gets 503 errors.

My provider says it is "too much traffic".

But since this has started to happen, traffic has gone down considerably of course, and it is still happening, that "heavy traffic" is the cause I find a bit illogical since if it is caused by heavy traffic, less traffic would solve the problem.

Here are 16 screenshots showing this random image dropping from the site throughout the day. http://tanguay.info/web/external/tinfoLoadingErrors.jpg (450K .jpg)

I've copied my site to another Apache/PHP server and it loads fine every time.

For those of you with experience hosting Apache/PHP site:

• what would you consider to be likely causes of random image dropping, etc.?
• what kinds of things can I ask my provider to check?
• what kinds of things could I check to find the cause of this problem (e.g. log files, create a test site of some kind, etc.)