A Step by Step Guide on How to Configure a Proxy in Docker- NetNut

Introduction

Docker is an open source software platform that can be used to create, deploy and manage virtualized application containers. Founded in 2013, it was designed to support a commercial edition of container management software. However, it was acquired by the Docker Enterprise business in November 2019. 

Subsequently, Docker provides a faster and more effective option for building and testing containerized portions of software. In addition, each container contains all elements required to build a software component and ensure it is tested for smooth operations. One feature that makes Docker stand out is that it offers portability, which is crucial when the packaged containers are moved to a different environment or server.

Therefore, this guide will examine essentials about how a Docker works and how to configure a proxy in Docker, choosing the best proxy provider, and other frequently asked questions.

How Does Docker Work?

Docker packages, provides, and runs containers. The container technology is available via the operating system. Subsequently, the container packages the function or application service with all of the libraries, configuration files, dependencies, and other necessary parameters. However, each container shares the services of one underlying operating system. 

Originally, Docker was designed to only function with Linux operating system. However, it has extended its functionality to support non-Linux users such as Microsoft Windows and iOS. In addition, Docker is compatible with Microsoft Azure and Amazon Web Services.

Containers are generated by process isolation and virtualization capabilities built into the Linux kernel. Subsequently, they allow multiple application components to share the resources of a single instance of the host operating system. Although the container technology is quite similar to virtual machines (VM), it offers some additional advantages, including:

• Containers are lightweight- they have faster startup times and use lesser hardware capacity.

• It optimizes developers’ productivity as containerized applications can be written once and run anywhere.
• Containers offer better resource management, which significantly reduces cloud spending.

Applications of Docker

Generally, Docker can be used for the development and deployment of any kind of software application. Here are some other use cases of Docker:

Deploy software

A crucial Docker application is deploying software and applications in a few seconds. This is possible thanks to the powerful Docker technology, which is lightweight unlike traditional applications that are bulky and take so much longer to load. In addition, modifications made to an application are implemented and deployed very fast when using containers that are a part of a continuous delivery pipeline.

Hybrid cloud and multi-cloud applications

One exciting feature of Docker containers is that they operate the same way whether deployed on cloud computing technology or on premises. In other words, Docker allows easy movement of applications to various production and testing environments. Subsequently, a Docker app that uses multiple cloud offerings can be described as a multi-cloud or hybrid cloud.

Moving legacy applications to a containerized infrastructure

Another Docker application is migrating legacy applications to a containerized infrastructure. This use case arises when the development team wants to modernize a pre-existing legacy software application to a containerized infrastructure.

Creating a microservice-based architecture

Docker is the ideal choice when you need a microservice-based architecture rather than a traditional, monolithic application. Developers often build and deploy multiple microservices, each with their own container. Subsequently, they integrate them to assemble a full software application via a container orchestration tool like Docker Swarm.

How to Set up a Proxy on Docker

A Docker proxy acts as an intermediary between your device and the internet. It masks your IP address by routing your network traffic through a proxy server. Subsequently, a proxy is required when the Docker does not have direct access to the internet. However, the proxy used for Docker is not active by default. Therefore, you must configure the proxy settings on Docker before using it for online activities. 

This guide will examine three common methods that you can use to configure Docker to use a proxy.

Prerequisites to configuring a proxy in Docker

There are two essential things you need to prepare before we proceed- Docker and Proxy. Many people use Docker on their computers, so it supports Windows, macOS, and Linux. In addition, you can get a reliable proxy that ensures a fast internet connection.

Manual configuration on Docker Desktop

This method is quite straightforward since the app contains the proxy settings in its window. Follow these steps to get started:

Step 1: Install Docker Desktop

The first thing to do is to download and install the Docker Desk on your system. Bear in mind that the main Docker app window may be slightly different for each user due to differences in the operating system. Subsequently, when you open the app on your system, it should be like this:

Step 2: Navigate to Settings

Step 3: From the drop-down menu, select Resources

Step 4: Toggle on the “Manual Proxy Configuration” and enter your proxy details. Docker supports HTTP, HTTPS, hosts and Domains.

Understanding NetNut Proxy Configuration

There are various proxy types  so when integrating NetNut proxies, choose HTTP or SOCKS5 protocol.

This is an example of a proxy string for a browser : 

USERNAME-stc-uk-sid-123456789:PASSWORD@gw-am.ntnt.io:5959

Step 1: Hostname Configuration

Copy the hostname/server address provided by NetNut

Example: Type gw-am.ntnt.io into the host field if you are using HTTP protocol. Alternatively, type gw-socks-am.ntnt.io for SOCKS5 protocol

Step 2: Port number Configuration

The Port number for NetNut HTTP proxies is 5959 and 9595 for SOCKS5

Step 3: Username Configuration

Username is your login, which you can find in your NetNut account in Settings -> Billing.

Proxy-type is the proxy type that you use. NetNut provides three different proxy types depending on your subscription plan. Your username should have three components including your user ID, type of proxy( residential, datacenter, static) and target country.

•         dc — datacenter;
•         res — rotating residential proxy;
•         stc — static residential proxy.

Country is the country whose IP addresses will be used for connection. You can choose “Any,” in which case any available country will be used, or you can provide the ISO code of a specific country from the list of NetNut’s available countries: e.g., jp (Japan), fr (France).

Example: ticketing123-res-us 

This is where you get the proxy username and password from the customer portal. You can also get in touch with your account manager if you’d like additional assistance.

Step 4: Consistent IP session

While NetNut provides rotating IP addresses, you may want a static IP address. This can be useful when you want to maintain your  session via the same IPs. Then you need to incorporate a session id (SID) with your username.

How do you choose a SID?

Choose a number between 4 to 8 digits

 Ensure the numbers are random and non-sequential to protect your IP address

For example: ticketing123-stc-us-SID-435765

Step 5: Proxy password

Insert the confidential NetNut proxy password. However, Octoparse does not support authentication through username and password. Instead, choose IP whitelisting from the NetNut options

Manual proxy variable configuration in the Docker Configuration file

The Docker Configuration file is a file you can find as /etc/sysconfig/docker. Subsequently, you can modify how Docker works with this configuration file. Let us examine how to use the config file for setting up proxies with Docker config file:

Step 1: Add a configuration code in the Docker Configuration file. You can use a text editor to add some codes to the Docker configuration like this:

# Cat/etc/sysconfig/docker

Export HTTP_PROXY = “https:// USERNAME:PASSWORD @ server address: port

However, you need to use JSON format in editing the configuration file. In addition, ensure you supply the correct proxy IP details.

Step 2: Now, you are ready to start setting up the proxy, provided you are done with the edits on the file. The configuration process may differ slightly based on the proxy type and operating system of your device. In addition, ensure you match the proxy server details with the edits you will make in the configuration file. 

Step 3: Once you have set up the proxy, save the edit on the file and restart the Docker application. 

Tips for successfully using this method:

• Ensure you correctly match proxy server details in the JSON-formatted Docker Configuration file (/etc/sysconfig/docker) to avoid connectivity issues.
• Be sure to validate the proxy settings before restarting the Docker application to minimize errors that could affect how the app works.
• Monitor logs post-restart or any misconfiguration hints to troubleshoot some challenges as they arise.

Manual Environment Variables Configuration

This method involves externalizing the app configurations. Subsequently, these variables allow you to define several settings or values. In addition, it keeps your apps organized and flexible. You can add an environment variable to support HTTP proxy with the following steps:

Step 1: Make a drop-in in Docker. You can make this in a Docker subdirectory file via the following code:

#mkdir/ etc/systemd/system/docker.services.d

Step 2: Create a document that provides a proxy environment variable. The next step is to name the file like this:

/etc/systemd/system/docker.service.d/http-proxy.conf

Subsequently, doing this allows you to add the HTTP_PROXY environment variable in the drop-in. 

Step 3: After setting the environment variable, reload the systemd daemon with this code:

# systemctl daemon-reload

Once that is done, you have to restart Docker manually or initiate this command:

#systemctl restart docker

Step 4: The last step involves verifying the variable. You can do it once the Docker app has successfully restarted.

Choosing the Best Proxy for Docker- NetNut

There are various free proxies in the market. However, choosing a proxy involves considering factors like speed, reliability, cost, and coverage. The purpose of proxies is to provide security, privacy, and anonymity. Therefore, using free proxies does not provide a guarantee of security and reliability. The solution is to get premium proxies from providers like NetNut– an industry-leading proxy provider that caters to all your proxy needs.

NetNut has a large pool of residential IPs that offers unlimited concurrency for infinite scalability. Moreover, you can leverage the power of over 1 million mobile IPs, amplifying your web coverage exponentially. 

NetNut provides you with different proxy solutions ranging from ISP proxies to static residential proxies, to US residential proxies. Static residential proxies allow you to maintain one IP address for a certain session. ISP proxies, on the other hand, come in handy to bypass CAPTCHA and geo-restrictions.

Conclusion

This guide has examined Docker, how it works, choosing the best proxy service, as well as three different methods of configuring proxies on Docker. Subsequently, Docker provides a fast and effective solution for building, testing and running applications and software. Sometimes, access may be necessary but limited, and this is where proxies come into play. Using proxies ensures that the program and software can remain online when Docker has limited or no internet.

NetNut offers various proxy solutions that cater to multiple use cases. Be sure to check out how to integrate NetNut proxies with other applications. Feel free to contact us to get started!

Frequently Asked Question

What is a Docker daemon?

Docker daemon is a service that creates and manages Docker images, using the commands from the client. In simpler terms, the Docker daemon serves as the control center of the Docker implementation. In addition, the server on which Docker daemon runs is called the Docker host.

Why use Docker?

Here are some reasons why you developers choose Docker:

• It offers improved and seamless container portability, which means it can run across any cloud environment or desktop without modification.
• Docker is a lightweight option that allows for combining multiple processes in a single container.
• It comes with automated container creation features, meaning it can automatically build a container based on application source code.
• Another reason why many developers choose Docker is that it can track versions of a container image, roll back to previous versions and trace who built it and when it was designed. In addition, it can upload deltas between an existing and a new version.
• Finally, developers can access an open-source registry that contains thousands of user-contributed containers.

What are the advantages and disadvantages of using Docker?

Some of the advantages of using Docker include:

• A high degree of portability, which allows users to share containers over various hosts
• Faster deployment
• Lower resource use
• Container reuse
• Container versioning
• Shared container libraries

Some of the disadvantages of using Docker include:

• Managing the number of containers possible in an enterprise can be challenging
• Since container use is changing from granular virtual hosting to orchestration of resources, the distribution and interconnection of componentized applications is becoming difficult.