A Technical I.T./DevOps Blog
Problem scenario
You are running Linux SUSE in AWS. You want to have no firewalls running on the OS. How can you be sure that there is no OS-level firewall running in Linux SUSE?
Solution
#1 Become root with this command: sudo su –
#2 Enter this command: yast firewall
#3 You will see either a screen that warns you about another firewall running or you’ll see the YaST2 screen for a firewall.
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Continue reading “How Do You Turn off OS Firewalls in an AWS Instance of Linux SUSE?”
Problem scenario
You have installed Chef server on a RedHat Enterprise Linux (RHEL) server in AWS. You have installed Chef client on another RHEL instance in AWS. You simply want your Chef client to receive configuration management changes (e.g., you want Chef recipes to work). The command “chef node list” on your Chef client server returns no servers. You ran this command from the Chef client:
sudo chef-client -S https://<FQDN of Chef server>/organization/contint
But you received an error like this:
Chef encountered an error attempting to create the client “<FQDN of Chef Client computer>”
================================================================================
System Info:
————
chef_version=13.4.19
ruby=ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]
program_name=chef-client worker: ppid=5156;start=14:10:31;
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Problem scenario
You want to run a Boto program. But there is an error about necessary parameters not being assigned.
You see a message like this:
botocore.exceptions.ClientError: An error occurred (ValidationError) when calling the CreateStack operation: Parameters: [KeyName, DBPassword, DBUser] must have values
Where can you see an example of parameters being passed?
Solution
Updated on 3/15/21.
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Problem scenario
You installed Docker (on either Ubuntu or RedHat, see the links if you actually need help with that). You do not want to create a Docker network on your server. How do you create a simple Docker container with Nginx without creating a user-defined network?
Solution
#1 Run these two commands:
docker pull nginx
docker run –name docker-nginx -p 80:80 nginx
# If the command hangs,
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Continue reading “How Do You Deploy Nginx to a Docker Container on an AWS Linux Server?”
Problem scenario
You are running Ubuntu Linux in AWS. You want to monitor it with your Zabbix server. (To set up a Zabbix server in AWS, see this posting.) How do you install the Zabbix client on an Ubuntu server?
Solution
Section 1
Make sure your AWS Security group allows for inbound connections from the internal IP address of the Zabbix server on any TCP port.
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Continue reading “How Do You Install the Zabbix Client on an Ubuntu AWS Instance?”
Problem scenario
You have a RedHat Linux server with only 1 vCPU and 1 GB of RAM. You want to install Zabbix Server to monitor other servers. How do you deploy Zabbix server to an AWS instance of RHEL?
Solution
1. Install the LAMP stack components by running this command:
sudo yum -y install php httpd mariadb-server
2. Install essential Zabbix components with these four commands:
sudo rpm –import http://repo.zabbix.com/RPM-GPG-KEY-ZABBIX
sudo rpm -Uv
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Continue reading “How Do You Install Zabbix Server on RHEL 7.x Running in AWS?”
Problem scenario
You have set up Zabbix server (i.e., using these directions). How do you configure another RedHat Linux server in AWS to be configured with the client so the Zabbix will monitor it?
Solution
Section 1
1. Make sure your AWS Security group (that governs this AWS instance that will be a client) allows for inbound connections from the internal IP address of the Zabbix server on any TCP port.
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Continue reading “How Do You Install the Zabbix Client on a RHEL 7.x Server in AWS?”
Problem scenario
You want to deploy Apache Tomcat in a Docker container on an AWS instance of Ubuntu Linux. How do you do this?
Solution
1. Install Docker. See this link if you need assistance.
2. Start the Docker service with this command: sudo service docker start
3. Run these two commands:
docker pull consol/tomcat-8.0
docker run consol/tomcat-8.0
4.
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Problem scenario
You are running Linux SUSE in AWS. You want to install and run Apache Tomcat. How do you do this?
Solution
Install it with this command: sudo zypper -n in tomcat
Start it with this command: sudo service tomcat start
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Continue reading “How Do You Install Apache Tomcat an AWS Instance of SUSE Linux?”
Problem scenario
You want to create several Docker containers each supporting Nginx. You want to be able to browse to the different instances of Nginx from a web browser. How do you have multiple Docker containers support Nginx on one RedHat Enterprise Linux host server?
Solution
These directions are geared toward a RHEL host server instance in AWS.
#1 Install Docker.
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