paulononato/backstage
1
0
Fork 0
Code Issues Pull Requests Actions 25 Packages Projects Releases Wiki Activity

docs(scaffolder): Remove old JSON schema version from custom action

Browse Source 
Signed-off-by: Łukasz Jernaś <lukasz.jernas@allegro.com>
This commit is contained in:
Łukasz Jernaś
2025-06-21 21:19:11 +02:00
parent ab209e4964
commit 3772e0c735
1 changed files with 18 additions and 60 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/features/software-templates/writing-custom-actions.md
+18 -60
View File
@@ -12,7 +12,7 @@ by writing custom actions which can be used alongside our
When adding custom actions, the actions array will **replace the
built-in actions too**. Meaning, you will no longer be able to use them.
If you want to continue using the builtin actions, include them in the actions
If you want to continue using the builtin actions, include them in the `actions`
array when registering your custom actions, as seen below.
:::
@@ -52,19 +52,20 @@ its generated unit test. We will replace the existing placeholder code with our
import { resolveSafeChildPath } from '@backstage/backend-plugin-api';
import { createTemplateAction } from '@backstage/plugin-scaffolder-node';
import fs from 'fs-extra';
import { z } from 'zod';
import { type z } from 'zod';
export const createNewFileAction = () => {
return createTemplateAction({
id: 'acme:file:create',
description: 'Create an Acme file.',
schema: {
input: z.object({
contents: z.string().describe('The contents of the file'),
filename: z
.string()
.describe('The filename of the file that will be created'),
}),
input: {
contents: z => z.string({ description: 'The contents of the file' }),
filename: z =>
z.string({
description: 'The filename of the file that will be created',
}),
},
},
async handler(ctx) {
@@ -95,53 +96,11 @@ The `createTemplateAction` takes an object which specifies the following:
function using `ctx.output`
- `handler` - the actual code which is run as part of the action, with a context
You can also choose to define your custom action using JSON schema instead of `zod`:
```ts title="With JSON Schema"
import { resolveSafeChildPath } from '@backstage/backend-plugin-api';
import { createTemplateAction } from '@backstage/plugin-scaffolder-node';
import { writeFile } from 'fs';
export const createNewFileAction = () => {
return createTemplateAction<{ contents: string; filename: string }>({
id: 'acme:file:create',
description: 'Create an Acme file.',
schema: {
input: {
required: ['contents', 'filename'],
type: 'object',
properties: {
contents: {
type: 'string',
title: 'Contents',
description: 'The contents of the file',
},
filename: {
type: 'string',
title: 'Filename',
description: 'The filename of the file that will be created',
},
},
},
},
async handler(ctx) {
const { signal } = ctx;
await writeFile(
resolveSafeChildPath(ctx.workspacePath, ctx.input.filename),
ctx.input.contents,
{ signal },
_ => {},
);
},
});
};
```
### Naming Conventions
Try to keep names consistent for both your own custom actions, and any actions contributed to open source. We've found
that a separation of `:` and using a verb as the last part of the name works well.
We follow `provider:entity:verb` or as close to this as possible for our built in actions. For example,
We follow `provider:entity:verb` or as close to this as possible for our built-in actions. For example,
`github:actions:create` or `github:repo:create`.
Also feel free to use your company name to namespace them if you prefer too, for example `acme:file:create` like above.
@@ -151,14 +110,14 @@ and writing of template entity definitions.
### Adding a TemplateExample
A TemplateExample is a way to document different ways that your custom action can be used. Once added it will be visible
A TemplateExample is a way to document different ways that your custom action can be used. Once added, it will be visible
in your Backstage instance under the [/create/actions](https://demo.backstage.io/create/actions) path. You can have multiple
examples for one action that can demonstrate different combinations of inputs and how to use them.
#### Define TemplateExamples
Below is a sample TemplateExample that is used for `publish:github`. The source code is available
on [github](https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend-module-github/src/actions/github.examples.ts)
on [GitHub](https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend-module-github/src/actions/github.examples.ts)
and preview on [demo.backstage.io/create/actions](https://demo.backstage.io/create/actions#publish-github)
```ts title="With JSON Schema"
@@ -222,7 +181,7 @@ return createTemplateAction({
#### Test TemplateAction examples
It is also possible to test your example TemplateActions. You can see a sample test
on [github](https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend-module-github/src/actions/github.examples.test.ts)
on [GitHub](https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend-module-github/src/actions/github.examples.test.ts)
### The context object
@@ -234,13 +193,12 @@ argument. It looks like the following:
implement [idempotency of the actions](https://github.com/backstage/backstage/tree/master/beps/0004-scaffolder-task-idempotency)
by not re-running the same function again if it was
executed successfully on the previous run.
- `ctx.logger` - a Winston logger for additional logging inside your action
- `ctx.logStream` - a stream version of the logger if needed
- `ctx.logger` - a [LoggerService](../../backend-system/core-services/logger.md) instance for additional logging inside your action
- `ctx.workspacePath` - a string of the working directory of the template run
- `ctx.input` - an object which should match the `zod` or JSON schema provided in the
`schema.input` part of the action definition
- `ctx.output` - a function which you can call to set outputs that match the
JSON schema or `zod` in `schema.output` for ex. `ctx.output('downloadUrl', myDownloadUrl)`
`zod` schema in `schema.output` for ex. `ctx.output('downloadUrl', myDownloadUrl)`
- `createTemporaryDirectory` a function to call to give you a temporary
directory somewhere on the runner, so you can store some files there rather
than polluting the `workspacePath`
@@ -249,7 +207,7 @@ argument. It looks like the following:
## Registering Custom Actions
To register your new custom action in the Backend System you will need to create a backend module. Here is a very
To register your new custom action in the Backend System, you will need to create a backend module. Here is a very
simplified example of how to do that:
```ts title="packages/backend/src/index.ts"
@@ -327,8 +285,8 @@ const res = await ctx.checkpoint?.({
});
```
You have to define the unique key in scope of the scaffolder task for your checkpoint. During the execution task engine
will check if the checkpoint with such key was already executed or not, if yes, and the run was successful, the callback
You have to define the unique key in the scope of the scaffolder task for your checkpoint. During the execution task engine
will check if the checkpoint with such a key was already executed or not, if yes, and the run was successful, the callback
will be skipped and instead the stored value will be returned.
Whenever you change the return type of the checkpoint, we encourage you to change the ID.