2b67e97cec
Follow-up to https://github.com/dagger/dagger/pull/1683 Part of https://github.com/dagger/dagger/issues/1327 Signed-off-by: Gerhard Lazu <gerhard@lazu.co.uk>
100 lines
3.0 KiB
Markdown
100 lines
3.0 KiB
Markdown
---
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slug: /1202/plan
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displayed_sidebar: europa
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---
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# It all starts with a plan
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A CI/CD pipeline declared in Dagger starts with a plan, specifically `dagger.#Plan`
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This plan is the entrypoint for everything that runs within a pipeline. The simplest plan will usually:
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- interact with the client filesystem to read (e.g. source code) or write files (e.g. build output)
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- read environment variables
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- declare a few actions, e.g. deps, test & build
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This is our **Getting Started** example app plan structure:
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```cue
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dagger.#Plan & {
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client: {
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filesystem: {
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// ...
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}
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env: {
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// ...
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}
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}
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actions: {
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deps: docker.#Build & {
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// ...
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}
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test: bash.#Run & {
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// ...
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}
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build: {
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run: bash.#Run & {
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// ...
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}
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contents: dagger.#Subdir & {
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// ...
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}
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}
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}
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}
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```
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When the above plan gets executed via `dagger do build`, it produces the following output:
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```shell
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[✔] client.filesystem.".".read 0.0s
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[✔] actions.deps 1.1s
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[✔] actions.test.script 0.0s
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[✔] actions.test 0.0s
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[✔] actions.build.run.script 0.0s
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[✔] actions.build.run 0.0s
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[✔] actions.build.contents 0.0s
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[✔] client.filesystem.build.write 0.1s
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```
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Since these actions have run before, they are cached and take less than 1 second to complete.
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While the names used for the actions above - `deps`, `test` & `build` - are short & descriptive,
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any other names would have worked. Put differently, action naming does not affect plan execution.
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In the example above, the `deps` action is an instance of the docker package build definition.
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This is written as `deps: docker.#Build`
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Default definition configuration - `docker.#Build` in this case - can be modified via curly brackets, e.g.
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```cue
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deps: docker.#Build & {
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// ...
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}
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```
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We can build complex pipelines efficiently by referencing any definition, from any package in our actions.
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This is one of the fundamental concepts that makes Dagger a powerful language for CI/CD.
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Before we can use a package in a plan, we need to declare it at the top of the pipeline configuration, like this:
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```cue
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import (
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"universe.dagger.io/docker"
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)
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```
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Since we are using the plan definition from the dagger package - `dagger.#Plan` - we also need to declare it at the top of the pipeline configuration:
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```cue
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import (
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"dagger.io/dagger"
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"universe.dagger.io/docker"
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)
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```
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:::tip
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Now that we understand the basics of a Dagger plan, we are ready to learn more about how to interact with the client environment.
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This will enable us to configure plans just-in-time, save build artefacts, and perform other interactions with the environment within which Dagger runs.
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:::
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