How to define pipelines in Codefresh
Before reading this page make sure that you are familiar with the theory behind Codefresh pipelines.
The aim of Codefresh pipelines is to have re-usable sequences of steps that can be used for different applications (or micro-services) via the use of git triggers.
All the main concepts are shown below:
Projects are the top-level concept in Codefresh. You can create projects to group pipelines that are related. In most cases a single project will be a single application (that itself contains many micro-services). You are free to use projects as you see fit. For example, you could create a project for a specific Kubernetes cluster or a specific team/department.
Each project can have multiple pipelines. Pipelines that belong to a single project are easily managed all together. It is also very easy to create a new pipeline in a project by copying an existing pipeline. Notice that unlike other CI solutions a pipeline in Codefresh is NOT tied to a specific git repository. You should try to make your pipelines generic enough so that they can be reused for similar applications even when they exist in different git repositories (a fairly typical setup for microservices).
Each pipeline has a definition that defines the pipeline steps that are executed each time this pipeline is triggered. The definition of a pipeline is described in a special codefresh.yml file. The
codefresh.ymlfile can be fetched from the same repository of the source code, from a completely different repository or even defined in-place in the Codefresh pipeline editor. Again, notice that it is possible to have a pipeline that checks out its source code from git repository A, but actually defines its steps in a
codefresh.ymlfile that is fetched from git repository B.
Each pipeline can have zero, one or more triggers. Codefresh supports several kinds of triggers such as Git, Cron or Docker push triggers. Triggers that happen with Git webhooks can come from the same git repository that contains the git code OR any other completely different repository. Triggers are the linking medium between a pipeline and a git repository. You can have a pipeline with many triggers so it will be executed when a code happens to any of them.
With these basic building blocks, you can define many complex workflows. In particular, it is very easy in Codefresh to create a scenario where:
- A pipeline is launched because a trigger exists for Git repository A
- The pipeline reads its
codefresh.ymlfile from Git repository B
- The pipeline clones source code from Git repository C (and starts packaging/compiling it)
Of course, it also possible to have a simpler scenario where the trigger, the pipeline steps and the source code of the application are all defined for the same GIT repository.
Creating new pipelines
You can create new projects by clicking on Projects in the left sidebar and then selecting the New Project button on the top right corner. A dialog will appear that will ask you for the project name and optional tags that you can use for access control.
Once you are inside the project view you can start editing pipelines with a UI environment that works similar to a traditional IDE.
On the top left you can see your current project. You can also change it by clicking on the drop-down on the top left corner.
On the left side of the screen you can see all pipelines that currently belong to this project. Click on each one to edit it. On the bottom part of this panel the New pipeline button allows you to create a new pipeline on the same project either from scratch or by copying an existing one from the same project or a completely different project.
The name of the currently edited pipeline is shown at the top of the window.
The main window shows the definition of the current pipeline. The screenshot shows the inline editor but pipelines can also be defined from external files (checked into source control) as explained later.
Using the inline pipeline editor
When first creating a pipeline you will see an inline editor that allows you to define the pipeline yml right there in the Codefresh UI. This is great when you are starting a new project because it offers you really quick feedback. You can edit the yml steps, run a build, edit again, run a build and so on.
On the top right of the panel you have additional controls:
- The import button allows you to bring a
codefresh.ymlfrom your local workstation into the editor
- The comment button allows you to quickly comment/uncomment the currently selected text. The hotkey
Ctrl-/also performs the same action
- The formatting button enriches the editor with special symbols for line breaks, spaces and tabs. This allows you to easily fix common formatting errors
- The copy button quickly copies the whole pipeline text in your clipboard
Notice that in the editor you can expand/collapse individual yaml blocks using the arrow triangles on the left of each blocks. The initial pipeline presented in the editor is suggested by Codefresh according to the contents of your Git repository.
You can also see the suggested Codefresh pipeline for any public git repository by using the analyze option of the Codefresh CLI.
Loading codefresh.yml from version control
Working with the inline editor is very convenient in the beginning, but it makes your pipeline definition only exist within the Codefresh UI and therefore goes against the basic principles of infrastructure as code. Once you are happy with how your pipeline works you should commit it to a Git repository (which can be the same one that has the source code of the application or a completely different one).
You can click on the Inline YAML header and switch it to Use YAML from repository.
You can then select any Git repository accessible to you and load the
codefresh.yml from there. You also setup two additional settings:
- The path of the file inside the repository. This allows you to have special folders for pipeline definitions
- The branch of the repository to use for loading the
codefresh.ymlfile if you have more than one
In the branch drop down you can also choose the option DYNAMIC. This will use the same branch as the one mentioned in the trigger event. If for example your pipeline is triggered by a commit in the
staging branch of the source code, the pipeline definition will also be loaded from the
staging branch of the git repository that contains the
This allows you to have complex pipeline definitions per branch, but you have to be careful to match Git branch names between the repository that holds the source code and the repository that holds the pipeline definition. It is much easier to pick a specific branch for the pipeline definitions that will always be the same.
It is also possible to switch the header to Use YAML from URL. This will allow you to load a Codefresh yaml from any public URL. Notice that a raw URL is needed in the case of GitHub. As an example, instead of using
https://github.com/codefresh-contrib/example-voting-app/blob/master/codefresh.yml you should enter
Once you create your pipeline you can also click on the top tab called Settings for some extra parameters.
Here you can also see the name and ID of the pipeline (useful information if you want to work with the Codefresh CLI).
The other options are:
- A freetext pipeline description
- One or more tags used for access control
- Concurrency limits
- Build termination settings
- The runtime environment that will run this pipeline
- The size of the machine that will run this pipeline (available options depend on your pricing plan)
- The public logs and badges information which are very useful for open source projects developed with Codefresh
The concurrency limits are very important as they allow you to define how many instances of a pipeline can run in parallel when multiple commits or multiple pull requests take place.
Some common scenarios are
- a pipeline that uses a shared resource such as a database or queue and you want to limit how many pipelines can access it and
- a pipeline that deploys to a single production environment (in most cases you only want one active pipeline touching production).
The first setting Pipeline concurrency specifies how many builds for this pipeline can run at any given time. If your pipeline has only one trigger this is the setting that you need to change to enforce concurrency. If your pipeline has multiple triggers then the second setting Trigger concurrency allows you to restrict pipeline builds for each trigger.
The second set of parameters for build termination are useful for pipelines where you commit too fast (i.e. faster then the actual runtime of the pipeline).
Some commong scenarios here are:
- You are interested only on the latest commit of a branch. If pipelines from earlier commits are still running you want to terminate them.
- You don’t want for children pipeline to finish (i.e. when a pipeline calls another pipeline), when a new build starts for a parent pipeline.
These settings are:
- Terminate all other builds from the same branch when a new commit happens
- Terminate all other builds from a specific branch (name matches a regular expression)
- Terminate all other pipeline from a pipeline regardless of branches when a new build starts
- Terminate all children pipelines if the parent is also terminated
All these settings allow you to lesser the build instance for pipelines when too many triggers are launched at the same time. You will find them very useful in cases where too many developers are performing small commits and builds take a long time to finish (i.e. build takes 10 minutes to finish and developers perform multiple pushes every 2 minutes)
Pipelines that do not belong to any project
Although we recommend adding all your pipelines to a project, this is not a hard requirement. You can create pipelines that do not belong to a project from the Pipelines section on the left sidebar. If you have a Codefresh account created before May 2019 you might already have several pipelines that are like this.
If you change your mind, you can also add detached pipelines (i.e. pipelines that are not part of a project) manually from the 3-dot menu that is found on the right of each pipeline.
Pipelines that belong to a project will mention it bellow their name so it is very easy to understand which pipelines belong to a project and which do not.