What are cloud containers ?
A cloud container is a portable, lightweight unit of software that packages an application along with its dependencies, such as libraries, binaries, and configuration files, allowing it to run consistently in any environment, including various cloud platforms.
This packaging is achieved through a form of operating system (OS) virtualization, where features of the OS kernel are leveraged to isolate processes and control the amount of CPU, memory, and disk that those processes can access.
Cloud containers are designed to virtualize a single application, creating an isolation boundary at the application level rather than at the server level. This means that each container holds just one application, allowing developers to adjust various features as needed without affecting the entire application.
Unlike virtual machines (VMs), which require a full OS and a virtual copy of the host server’s hardware, cloud containers do not. They virtualize the underlying OS and allow containerized apps to function as if they have a dedicated OS for themselves, including CPU, memory, file storage, and network connections.
This makes containers smaller, faster, and more portable than VMs. Cloud containers can run virtually anywhere. This portability and consistency across environments make containers a popular choice for deploying and managing software in the cloud.
Definition of cloud container
A cloud container is a stand-alone, executable package that includes everything needed to run a piece of software, including the code, a runtime, libraries, environment variables, and system tools.
Containers are designed to provide a consistent and efficient way to package and run applications across different computing environments, from a developer's laptop to a private data centre or a public cloud. Common characteristics of cloud containers include:
- Lightweight: Containers share the host system's operating system, unlike virtual machines (VMs) that require a full copy of an operating system. This makes containers more lightweight and faster to start than VMs.
- Portability: Containers encapsulate everything an application needs to run, which makes them highly portable across different computing environments.
- Isolation: Containers virtualize CPU, memory, storage, and network resources at the operating system level, providing an isolated environment for the application to run.
- Scalability and efficiency: Containers can be easily scaled up or down to match demand, making them suitable for applications with variable workloads; containers can share resources, which makes them more efficient in terms of resource utilization compared to VMs.
Containers ensure consistency across multiple development, testing, and production environments, making it easier to develop and deploy applications.
That said, containers are not the same as virtual machines. Here are characteristics that cloud containers do not have:
- Full operating system: Unlike VMs, containers do not include a full guest operating system. Instead, they share the host's operating system. Containers do not virtualize hardware, as VMs do. They only virtualize the operating system above the hardware level.
- Strong isolation: While containers provide a level of isolation, it is not as strong as the isolation provided by VMs. If an application requires strong isolation for security or other reasons, a VM might be a better choice.
- Persistent storage: Containers are designed to be ephemeral, meaning their storage does not persist when they are terminated. Any data that needs to persist should be stored outside the container.
- Full system services: Containers are designed to run a single application, so they do not include full system services that a complete operating system would provide.
How do cloud containers work?
Cloud containers work by virtualizing the operating system (OS) and providing an isolated environment for applications to run. They package the application code along with its dependencies, such as specific versions of programming language runtimes, libraries, and environment variables, into a single executable unit. The process of creating and running a cloud container typically involves the following steps:
Image creation
The container image is created from a base image, which is a lightweight version of an OS. The application code and its dependencies are added to this base image. The resulting container image includes everything the application needs to run.
Runtime
The container image is run on a container runtime, which is software that executes containers and manages container lifecycle. Examples of container runtimes include Docker and containers.
Execution
When the container is executed, it runs in isolation from other containers, even though it shares the host OS and, in some cases, the binaries and libraries. This isolation is achieved through namespaces and control groups (cgroups) in Linux, which isolate the processes, file system, and network stack of each container.
Orchestration
For managing multiple containers, especially in a distributed environment like a cloud, container orchestration tools like Kubernetes are used. These tools handle the deployment, scaling, networking, and availability of containers.
It's important to note that while containers share the host OS, they appear to the application as a separate OS. This is achieved by abstracting the host OS's interfaces and presenting them to the application as if it's running on its OS.
What are the benefits of containers?
Cloud containers offer several benefits that make them an attractive choice for deploying and managing applications. Here are some of the key benefits:
Efficiency
Containers are lightweight and share the host system's resources, which allows multiple containers to run on the same host without consuming many resources. This makes running more applications on the same hardware possible, reducing costs. The lightweight nature means containers can be easily scaled up or down to match demand, making them suitable for applications with variable workloads.
Agility and productivity
Using containers can increase build velocity, enable faster maintenance cycles, and ensure consistency across environments. This can lead to improved agility and productivity. As a result, containers can accelerate the delivery of applications, thanks to their portability and ease of deployment.
Improved security
While containers share the same host kernel, which can pose a security risk, container-specific security measures, such as container isolation and network segmentation, can mitigate this risk.
Easier management
Containers can be managed more easily than traditional virtual machines, especially when using container orchestration tools like Kubernetes. Containers offer flexibility in deployment, allowing certain elements to be hosted on bare metal and others to be deployed to virtual cloud environments.
It's important to note that while containers share the host OS, they appear to the application as a separate OS. This is achieved by abstracting the host OS's interfaces and presenting them to the application as if it's running on its OS.
Cloud containers vs. VMs
Cloud containers and virtual machines (VMs) are both technologies used to isolate software applications and their dependencies, but they do so in different ways and offer different advantages and disadvantages.
Both containers and VMs provide an environment where applications can run in isolation from other applications, which can improve security and prevent conflicts between different applications or between applications and their host system.
That said, containers share the host system's operating system, while each VM runs its guest operating system. This makes containers more lightweight and faster to start than VMs, but it also means that all containers on a host must use the same operating system.
Because they don't need to run a full operating system, containers typically use fewer system resources (CPU, memory, storage) than VMs. This can allow more containers to run on a given host compared to VMs.
VMs provide stronger isolation than containers because they run on separate operating systems. This can make VMs a better choice for applications that require high security or isolation.
Containers are more portable than VMs because they encapsulate the application and its dependencies into a single, self-contained unit. This allows a container to run on any system that has the appropriate container runtime installed, regardless of the underlying operating system
The choice between containers and VMs depends on the specific needs of the application and the infrastructure. Containers are generally a good choice for applications that need to be lightweight, portable, and scalable, while VMs are often better for applications that require strong isolation or need to run on different operating systems.
Containers and virtual machines together
Cloud containers and virtual machines (VMs) are both forms of virtualization technology that can coexist and work together in a data centre environment, even on the same server. They have different approaches to virtualization and serve different purposes, but they can be integrated to achieve the most desirable results for a business.
Containers are often used for deploying microservices, as they provide isolated environments that can be easily scaled and managed independently.
Integrating VMs and containers
One common way to integrate VMs and containers is to run containers within a VM. This is possible because a VM uses its operating system, which can support a container engine like Docker, and run an array of containers within the VM instance.
This approach combines the isolation and security benefits of VMs with the portability and efficiency of containers. Another approach is to have VMs and containers coexist side-by-side within the same infrastructure, orchestrated by the same platform.
This allows for the hosting of all types of projects using a single point of management and enables a gradual transformation based on current needs and possibilities.
In summary, while VMs and containers have different approaches to virtualization, they can be used together in a complementary manner to leverage the strengths of both technologies. This can provide businesses with a flexible, efficient, and secure environment for deploying and managing their workloads.
Cloud container security
Container security is a critical aspect of modern software development and deployment practices. It involves implementing security measures throughout the entire lifecycle of a container, from development to runtime. Here are some key principles around cloud container security:
Secure the build pipeline
Security should be integrated into the entire software development lifecycle (SDLC). This includes securing the build pipeline, which involves practices like code scanning and dependency scanning to identify and mitigate potential vulnerabilities early in the development process.
Scan images for vulnerabilities
Regularly scan your container images for vulnerabilities. This can help identify and fix security issues before they can be exploited.
Reduce the attack surface
Minimize the components and services running in your containers to only what is necessary for your application. This reduces the potential points of entry for attackers.
Limit container privileges
Containers should be given the least privileges necessary to perform their functions. Overly permissive privileges can lead to security risks.
Implement access controls
Use authentication and authorization mechanisms to ensure that only authorized users can access the containers. This helps prevent unauthorized access and potential attacks.
Runtime
The container image is run on a container runtime, which is software that executes containers and manages container lifecycle. Examples of container runtimes include Docker and containers.
Implement network security
Use container networking solutions to increase the security of your application. This includes practices like segregating network traffic and implementing firewalls.
Always keep track of what's happening within your containers. This can help identify suspicious activity and respond to potential security incidents more quickly.
Containers: Related products
OVHCloud offers a range of cloud container services designed to help businesses manage and orchestrate their containerized applications. The Managed Kubernetes Service is a free offering that allows users to orchestrate containers using Kubernetes, which is a widely used container orchestration tool. This service is suitable for companies of all sizes and can be used to deploy applications, scale them, and enhance their resilience, even in hybrid or multi-cloud infrastructures.
The Managed Kubernetes Service is powered by OVHcloud Public Cloud instances and includes integrated OVHcloud Load Balancers and additional disks.
OVHcloud takes responsibility for deploying, hosting, and maintaining all the necessary components for Kubernetes to function, including updates and security patches. Users can download a kubeconfig file and get all the features of a certified Kubernetes administrator, allowing them to focus on their business rather than infrastructure management.
Managed Kubernetes Service
Orchestrate your containerised applications with a CNCF-certified Kubernetes cluster.
In addition to the Managed Kubernetes Service, OVHcloud provides orchestration and industrialization tools to automate actions such as deployments, maintenance, or scaling up during peak loads.
These tools help manage processes and software stacks, whether they are virtualized or containerized. OVHcloud's orchestration solutions include a CNCF-certified Kubernetes cluster, a repository for Docker images or Helm charts, and the ability to manage variations in activity by distributing traffic across multiple resources.
Innovate faster with cloud automation tools
A cloud platform not only provides on-demand computing resources connected to the network, but flexible storage as well. It also offers tools to operate and automate actions, such as deployments, maintenance or scaling up during peak loads.
The various tools and services below will help your to better manage your processes and software stacks, whether they are virtualised or containerised.