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Activate python virtualenv in Dockerfile - How to perform it ?
This article covers how to Activate python virtualenv in Dockerfile.
Basically, to package Python application in a Docker image, we often use virtualenv. However, to use virtualenv, we need to activate it.
Therefore, there is no point in using virtualenv inside a Docker Container unless you are running multiple apps in the same container, if that's the case I'd say that you're doing something wrong and the solution would be to architect your app in a better way and split them up in multiple containers.
There are perfectly valid reasons for using a virtualenv within a container.
You don't necessarily need to activate the virtualenv to install software or use it.
Try invoking the executables directly from the virtualenv's bin directory instead:
FROM python:2.7
RUN virtualenv /ve
RUN /ve/bin/pip install somepackage
CMD ["/ve/bin/python", "yourcode.py"]
One solution is to explicitly use the path to the binaries in the virtualenv.
In this case we only have two repetitions, but in more complex situations you’ll need to do it over and over again.
Besides the lack of readability, repetition is a source of error.
As you add more calls to Python programs, it's easy to forget to add the magic /opt/venv/bin/ prefix.
It will (mostly) work though:
FROM python:3.8-slim-buster
RUN python3 -m venv /opt/venv
# Install dependencies:
COPY requirements.txt .
RUN /opt/venv/bin/pip install -r requirements.txt
# Run the application:
COPY myapp.py .
CMD ["/opt/venv/bin/python", "myapp.py"]
The only caveat is that if any Python process launches a sub-process, that sub-process will not run in the virtualenv.
WordPress error 'Another update currently in process' – Fix it Now ?
This article covers how to resolve WordPress error 'Another update currently in process'.
Basically, this issue usually occurs when a WordPress user, or multiple users, are simultaneously trying to perform a WordPress update while a WordPress core update is running.
During a core update, an additional row called core_updater.lock is placed within the wp_options table of the website’s database. It serves to prevent any other updates from being run while the core update is in progress.
After the WordPress core has been updated, the core_updater.lock row will be deleted, which will allow users to perform any other updates.
The error message will disappear then, or it will be gone automatically after 15 minutes.
To fix this WordPress error:
1. Log into the WordPress administration dashboard and select Plugins > Add New. Search for Fix Another Update, then install and activate the plugin.
2. Navigate to Settings > Fix Another Update In Progress and the database lock will be removed.
3. If you wish to remove the lock directly in the database, Select Databases > phpMyAdmin from the cPanel menu.
4. Select your WordPress database from the sidebar, then click the Browse button next to the wp_options database table (your database prefix may be different).
5. In the database rows that appear, look for an entry called ‘core_updater.lock’ and select the Delete button to remove. You can now proceed with your outstanding updates.
Securing Web Servers from DoS attacks - Best Practices ?
This article covers Tactics To Prevent DDoS Attacks & Keep Your Website Safe.
Basically, it is impossible to prevent DoS and DDoS attacks entirely. But we can limit them to a certain extend by implementing security actions mentioned in this guide.
Denial of service attacks are here to stay, and no business can afford to be unprotected.
Facts about DDoS Attacks:
1. DDoS stands for Distributed Denial of Service.
2. It is a form of cyber attack that targets critical systems to disrupt network service or connectivity that causes a denial of service for users of the targeted resource.
3. A DDoS attack employs the processing power of multiple malware-infected computers to target a single system.
Best Practices for Preventing DDoS attacks:
1. Develop a Denial of Service Response Plan
Develop a DDoS prevention plan based on a thorough security assessment. Unlike smaller companies, larger businesses may require complex infrastructure and involving multiple teams in DDoS planning.
2. Secure Your Network Infrastructure
Mitigating network security threats can only be achieved with multi-level protection strategies in place.
This includes advanced intrusion prevention and threat management systems, which combine firewalls, VPN, anti-spam, content filtering, load balancing, and other layers of DDoS defense techniques.
3. Practice Basic Network Security
The most basic countermeasure to preventing DDoS attacks is to allow as little user error as possible.
Engaging in strong security practices can keep business networks from being compromised.
4. Maintain Strong Network Architecture
Focusing on a secure network architecture is vital to security. Business should create redundant network resources; if one server is attacked, the others can handle the extra network traffic.
5. Leverage the Cloud
Outsourcing DDoS prevention to cloud-based service providers offers several advantages. First, the cloud has far more bandwidth, and resources than a private network likely does. With the increased magnitude of DDoS attacks, relying solely on on-premises hardware is likely to fail.
Install Bcrypt in Docker and resolve related errors
This article covers how to install Bcrypt in Docker and fix relating Docker errors.
To fix bcrypt error on Docker:
The error looks like this,
internal/modules/cjs/loader.js:807
app_1 | return process.dlopen(module, path.toNamespacedPath(filename));
To resolve, simply Add the following lines of code to the start.sh file,
#!/usr/bin/env bash
# install new dependencies if any
npm install
# uninstall the current bcrypt modules
npm uninstall bcrypt
# install the bcrypt modules for the machine
npm install bcrypt
echo "Starting API server"
npm start
Here,
i. npm uninstall bcrypt would remove bcrypt modules for the other operating system.
ii. npm install bcrypt would install for the current machine that the app would be running on.
WordPress error Failed to Load Resource - Fix it Now ?
This article covers how to resolve the WordPress error Failed to load resource in WordPress as a result of issues in WordPress URL settings.
To fix this WordPress error:
1. Replace The Missing Resource
The missing resource is an image in one of your blog posts or page, then try to look for it in the media library.
If you are able to see the media library, then try to add again by editing the post or page.
2. Replace theme or plugin files
In case, if the failed resource is a WordPress plugin or theme file, then the easiest way to replace it is by reinstalling the plugin or theme.
First, you need to deactivate your current WordPress theme.
All you have to do is visit the Appearance » Themes page.
NRPE: No Output Returned From Plugin - How to fix this Nagios error ?
This article covers how to resolve Nagios error, NRPE: No Output Returned From Plugin. This error happens as a result of Permissions or Missing plugin.
To fix this Nagios error:
1. The most common solution is to check the permissions on the check_nrpe binary on the Nagios XI server:
ls -la /usr/local/nagios/libexec/check_nrpeThe expected permissions should resemble:
-rwxrwxr-x. 1 nagios nagios 75444 Nov 21 01:38 check_nrpe2. If not, change ownership to user/group "nagios" and fix up the permissions:
$ chown nagios:nagios /usr/local/nagios/libexec/check_nrpe$ chmod u+rwx /usr/local/nagios/libexec/check_nrpe$ chmod u+rx /usr/local/nagios/libexec/check_nrpe
