Talk about the difference between continuous integration, continuous delivery, and continuous deployment

CI needs to have the following:

Comprehensive automated testing. This is the basis for practicing continuous integration and continuous deployment. At the same time, choosing the right automated testing tools is also extremely important;

Flexible infrastructure. Containers and virtual machines save developers and QA personnel from the hassle of running the application.

Version control tools, such as Git, CVS, SVN, etc.;

Tools for automated build and software release processes, such as Jenkins and flow.ci;

Feedback mechanism: If a build or test fails, it can be quickly fed back to the relevant person in charge so that a more stable version can be achieved as soon as possible.

Advantages of Continuous Integration

“Fail fast”, test without risk to the product, and respond quickly;

Minimize risk and reduce the cost of fixing faulty code;

Automate repetitive manual processes, allowing engineers to focus more on code;

Maintain frequent deployments and quickly generate deployable software;

Improve project visibility and make it easier for team members to understand the progress and maturity of the project;

Increase developer confidence in software products and help build a better engineering culture.

Continuous Integration: Where to Start

The most important part is to choose the right continuous integration system. Whether to build a private deployment or choose a hosted continuous integration system depends on the infrastructure the team runs and the resources the team invests in the continuous integration system.

Comparing private deployment and hosted continuous integration systems may help you make a better choice.

Self-hosted CI means that the software is deployed in the company's computer room or intranet. Multiple servers are required to complete the operation of the CI system, and the environment configuration between different machines is required. For example, Maven or Gradle or Jenkins are free and open source, and have extensive documentation support. The advantage is that you have full control over the build environment and can fully customize it. However, the environment needs to be built and configured, and the maintenance cost is high. You need to buy special machines, which costs more manpower and material resources, and the update and migration risks are high;

Hosted CI refers to a SaaS-based CI service that performs the entire build configuration online, without having to consider the cost of installing machines, software, and environment. Common ones include CircleCI, Codeship, and TravisCI, as well as the most popular continuous integration service in China, flow.ci. The characteristic of SaaS-based CI is that it does not require additional machines and can be used in a few minutes. Resources can be dynamically scheduled according to your needs. Save time, worry, and effort.

In general, Jenkins has always been the choice of most companies in the past, but this phenomenon is changing. With the popularity of public cloud services, Docker, and SaaS, more and more companies are beginning to choose Hosted CI, which is a hosted continuous integration system.

In addition, when choosing a suitable continuous integration service, you also need to consider the flexibility of the system to adapt to the development and testing needs of the company at different stages.

Selecting a continuous integration system is only one step in the continuous integration application. It is also necessary to establish a suitable continuous integration culture, such as code quality control, testing culture, etc. Doing a good job of continuous integration can lay a solid foundation for continuous delivery and continuous deployment.

Continuous Delivery

Continuous delivery is based on continuous integration and deploys the integrated code to a "production-like environment" that is closer to the real operating environment. Continuous delivery takes precedence over software deployment throughout the product life cycle and is built on a high level of automated continuous integration.

Just imagine, if we wait until everything is completed before delivering to the next link, all problems will only erupt at a later time, and the cost of solving them will be huge or even impossible to solve. For example, after we complete the unit test, we can deploy the code to the Staging environment connected to the database for more automated testing. If there are no problems with the code, we can continue to manually deploy it to the production environment. Of course, continuous delivery does not mean that every change to the software must be deployed to the production environment as soon as possible. It means that any code modification can be deployed at any time.

Benefits of Continuous Delivery

The benefits of continuous delivery and continuous integration are very similar:

Rapid release. Ability to respond to business needs and realize software value faster.

The frequent iteration cycle of coding->testing->launching->delivery is shortened, while obtaining rapid feedback;

High-quality software release standards. The entire delivery process is standardized, repeatable, and reliable.

The progress of the entire delivery process is visualized, making it easier for team members to understand the maturity of the project;

A more advanced way of team collaboration. From demand analysis, product user experience to interaction design, development, testing, operation and maintenance, etc., close collaboration reduces waste compared to traditional waterfall software teams.

Continuous Deployment

Continuous deployment means that when the delivered code passes the review, it is automatically deployed to the production environment. Continuous deployment is the last stage of continuous delivery. This means that all changes that pass a series of automated tests will be automatically deployed to the production environment. It can also be called "Continuous Release".

Why is continuous deployment the ideal workflow?

"Developers submit code, the continuous integration server obtains the code, executes unit tests, and decides whether to deploy to the staging environment based on the test results. If it is successfully deployed to the staging environment, an overall acceptance test is performed. If the test passes, it is automatically deployed to the production environment. The entire process is automated and efficient."

In fact, in the process from demand to deployment, products will go through several different environments, such as QA environment, various automated test running environments, production environment, etc. The construction, configuration, and management of these environments, as well as the specific deployment of products in different environments, are very complex, and fully automatic continuous deployment from beginning to end is indeed difficult. So, if continuous delivery can be achieved and the code is guaranteed to be good in the simulation environment, perhaps team members will have a real psychological understanding.

Advantages of Continuous Deployment

The main benefit of continuous deployment is that new features can be deployed relatively independently and feedback from real users can be collected quickly.

“You build it, you run it” is the core secret that enables Amazon to complete 50 million deployments a year, with each engineer deploying more than 50 times a day on average.

***

"Continuous Integration", "Continuous Delivery" and "Continuous Deployment" provide an excellent DevOps environment, which brings both benefits and challenges to the entire team. In any case, frequent deployment, rapid delivery and automation of development and testing processes will become an important part of future software engineering.

Feel free to share your views.

CI needs to have the following:

Comprehensive automated testing. This is the basis for practicing continuous integration and continuous deployment. At the same time, choosing the right automated testing tools is also extremely important;

Flexible infrastructure. The existence of containers and virtual machines saves developers and QA personnel from having to go through so much trouble;

Version control tools, such as Git, CVS, SVN, etc.;

Tools for automated build and software release processes, such as Jenkins and flow.ci;

Feedback mechanism: If a build or test fails, it can be quickly fed back to the relevant person in charge so that a more stable version can be achieved as soon as possible.

Advantages of Continuous Integration

“Fail fast”, test without risk to the product, and respond quickly;

Minimize risk and reduce the cost of fixing faulty code;

Automate repetitive manual processes, allowing engineers to focus more on code;

Maintain frequent deployments and quickly generate deployable software;

Improve project visibility and make it easier for team members to understand the progress and maturity of the project;

Increase developer confidence in software products and help build a better engineering culture.

Continuous Integration: Where to Start

The most important part is to choose the right continuous integration system. Whether to build a private deployment or choose a hosted continuous integration system depends on the infrastructure the team runs and the resources the team invests in the continuous integration system.

Comparing private deployment and hosted continuous integration systems may help you make a better choice.

Self-hosted CI means that the software is deployed in the company's computer room or intranet. Multiple servers are required to complete the operation of the CI system, and the environment configuration between different machines is required. For example, Maven or Gradle or Jenkins are free and open source, and have extensive documentation support. The advantage is that you have full control over the build environment and can fully customize it. However, the environment needs to be built and configured, and the maintenance cost is high. You need to buy special machines, which costs more manpower and material resources, and the update and migration risks are high;

Hosted CI refers to a SaaS-based CI service that performs the entire build configuration online, without having to consider the cost of installing machines, software, and environment. Common ones include CircleCI, Codeship, and TravisCI, as well as the most popular continuous integration service in China, flow.ci. The characteristic of SaaS-based CI is that it does not require additional machines and can be used in a few minutes. Resources can be dynamically scheduled according to your needs. Save time, worry, and effort.

In general, Jenkins has always been the choice of most companies in the past, but this phenomenon is changing. With the popularity of public cloud services, Docker, and SaaS, more and more companies are beginning to choose Hosted CI, which is a hosted continuous integration system.

In addition, when choosing a suitable continuous integration service, you also need to consider the flexibility of the system to adapt to the development and testing needs of the company at different stages.

Selecting a continuous integration system is only one step in the continuous integration application. It is also necessary to establish a suitable continuous integration culture, such as code quality control, testing culture, etc. Doing a good job of continuous integration can lay a solid foundation for continuous delivery and continuous deployment.

Continuous Delivery

Continuous delivery is based on continuous integration and deploys the integrated code to a "production-like environment" that is closer to the real operating environment. Continuous delivery takes precedence over software deployment throughout the product life cycle and is built on a high level of automated continuous integration.

Just imagine, if we wait until everything is completed before delivering to the next link, all problems will only erupt at a later time, and the cost of solving them will be huge or even impossible to solve. For example, after we complete the unit test, we can deploy the code to the Staging environment connected to the database for more automated testing. If there are no problems with the code, we can continue to manually deploy it to the production environment. Of course, continuous delivery does not mean that every change to the software must be deployed to the production environment as soon as possible. It means that any code modification can be deployed at any time.

Benefits of Continuous Delivery

The benefits of continuous delivery and continuous integration are very similar:

Rapid release. Ability to respond to business needs and realize software value faster.

The frequent iteration cycle of coding->testing->launching->delivery is shortened, while obtaining rapid feedback;

High-quality software release standards. The entire delivery process is standardized, repeatable, and reliable.

The progress of the entire delivery process is visualized, making it easier for team members to understand the maturity of the project;

A more advanced way of team collaboration. From demand analysis, product user experience to interaction design, development, testing, operation and maintenance, etc., close collaboration reduces waste compared to traditional waterfall software teams.

Continuous Deployment

Continuous deployment means that when the delivered code passes the review, it is automatically deployed to the production environment. Continuous deployment is the last stage of continuous delivery. This means that all changes that pass a series of automated tests will be automatically deployed to the production environment. It can also be called "Continuous Release".

Why is continuous deployment the ideal workflow?

"Developers submit code, the continuous integration server obtains the code, executes unit tests, and decides whether to deploy to the staging environment based on the test results. If it is successfully deployed to the staging environment, an overall acceptance test is performed. If the test passes, it is automatically deployed to the production environment. The entire process is automated and efficient."

In fact, in the process from demand to deployment, products will go through several different environments, such as QA environment, various automated test running environments, production environment, etc. The construction, configuration, and management of these environments, as well as the specific deployment of products in different environments, are very complex, and fully automatic continuous deployment from beginning to end is indeed difficult. So, if continuous delivery can be achieved and the code is guaranteed to be good in the simulation environment, perhaps team members will have a real psychological understanding.

Advantages of Continuous Deployment

The main benefit of continuous deployment is that new features can be deployed relatively independently and feedback from real users can be collected quickly.

“You build it, you run it” is the core secret that enables Amazon to complete 50 million deployments a year, with each engineer deploying more than 50 times a day on average.

***

"Continuous Integration", "Continuous Delivery" and "Continuous Deployment" provide an excellent DevOps environment, which brings both benefits and challenges to the entire team. In any case, frequent deployment, rapid delivery and automation of development and testing processes will become an important part of future software engineering.