upgrade command and startup command

Author: thomas-tacquet

pages/serverless-jobs/concepts.mdx

@@ -10,26 +10,9 @@ import ServerlessConcepts from '@macros/serverless/serverless-concepts.mdx'
 
 ## Commands and arguments
 
-Serverless Jobs allows you to customize the `command` and `args` instructions of your container image directly from the [Scaleway console](https://console.scaleway.com) and via the [Scaleway API](https://www.scaleway.com/en/developers/api/serverless-jobs/).
+Field `command` is deprecated prior `startup_command` in `v1alpha2`.
 
-<Message type="note">
-  If `startup_command` is already filled then the `command` instruction is ignored.
-</Message>
-
-- The `command` instruction defines the command, process, or script executed when your job starts.
-- The `args` instruction defines the arguments passed to the `command` instruction. Arguments can be passed as environment variables, as shown in the example below.
-
-**Example**
-
-```yaml
-env:
-- name: MESSAGE
-  value: "hello world"
-command: ["/bin/echo"]
-args: ["$(MESSAGE)"]
-```
-
-Refer to the [official Kubernetes documentation](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/) for more information on commands and arguments behavior.
+For more details see [startup command and arguments](/serverless-jobs/concepts/#startup-commands-and-arguments) and [v1alpha2 migration guide](/serverless-jobs/reference-content/v1alpha1-to-v1alpha2/).
 
 ## Container Registry
 
@@ -91,9 +74,30 @@ For more details about advantages of using Serverless, [read the Serverless over
 
 A secret reference is a mechanism that allows you to use a secret stored in [Secret Manager](/secret-manager/) within Serverless Jobs. It allows you to securely reference sensitive data, such as API secret keys, passwords, tokens, or certificates.
 
-## Startup command
+## Startup commands and arguments
+
+Serverless Jobs allows you to customize the `startup_command` and `args` instructions to override default image instructions.
 
-Deprecated and replaced by [Commands and arguments](#commands-and-arguments).
+<Message type="note">
+  * `command` field is deprecated prior `startup_command`.
+  * If `startup_command` is already filled then the `command` instruction is ignored.
+  * `startup_command` and `args` can interpret environment variables, allowing for easier automations.
+</Message>
+
+- The `startup_command` instruction defines the command, process, or script executed when your job starts. It overrides the `ENTRYPOINT` of the image.
+- The `args` instruction defines the arguments passed to the `startup_command` instruction. Arguments can be passed as environment variables, as shown in the example below.
+
+**Example**
+
+```yaml
+env:
+- name: MESSAGE
+  value: "hello world"
+startup_command: ["/bin/echo"]
+args: ["$(MESSAGE)"]
+```
+
+Refer to the [official Kubernetes documentation](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/) for more information on commands and arguments behavior.
 
 ## Status
 

…rate-startup-command-to-command-args.mdx …o/migrate-command-to-startup-command.mdxpages/serverless-jobs/how-to/migrate-startup-command-to-command-args.mdx renamed to pages/serverless-jobs/how-to/migrate-command-to-startup-command.mdx pages/serverless-jobs/how-to/migrate-startup-command-to-command-args.mdx renamed to pages/serverless-jobs/how-to/migrate-command-to-startup-command.mdx

@@ -9,17 +9,25 @@ dates:
 
 import Requirements from '@macros/iam/requirements.mdx'
 
-The Serverless Jobs `v1alpha2` API introduces a new startup execution mechanism based on [commands and arguments](/serverless-containers/concepts/#commands-and-arguments), replacing the legacy startup command.
+The Serverless Jobs `v1alpha2` API introduces a new startup execution mechanism based on [commands and arguments](/serverless-containers/concepts/#startup-command-and-arguments), replacing the legacy `command`.
 
 The Scaleway console allows you to quickly and easily migrate your existing jobs to the new system.
 
+Migration from `command` field to `startup_command` field is mostly transparent for customers using Scaleway Console but can require some attention of API, CLI and other devtools users.
+
+The change allows for:
+- More customisation for executing complex command, by separating `startup_command` and `args`.
+- To match our underlying [Kubernetes implementation](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/).
+- It allows to compute environment variables used in command and argument strings.
+- `startup_command` is now an array of commands instead of a single string.
+
 <Requirements />
 
 - A Scaleway account logged into the [console](https://console.scaleway.com)
 - [Owner](/iam/concepts/#owner) status or [IAM permissions](/iam/concepts/#permission) allowing you to perform actions in the intended Organization
 - An existing job that uses a startup command
 
-## How to migrate from startup command to commands and arguments
+## How to migrate from command to startup commands and arguments
 
 1. Click **Jobs** in the **Serverless** section of the side menu. The jobs page displays.
 
@@ -39,7 +47,7 @@ Your Serverless Job now uses the command and arguments mechanism.
 
 ### Simple command
 
-**Legacy startup command**
+**Legacy command**
 
 ```bash
 sleep 60s
@@ -48,13 +56,13 @@ sleep 60s
 **Corresponding command and arguments**
 
 ```yaml
-command: [sleep]
+startup_command: [sleep]
 args: [60s]
 ```
 
 ### Complex command
 
-**Legacy startup command**
+**Legacy command**
 
 ```bash
 /app/migrate up --database "$DB_URL" --password "$DB_PASSWORD" --port 3002
@@ -63,8 +71,6 @@ args: [60s]
 **Corresponding command and arguments**
 
 ```yaml
- command: [/app/migrate]
-  args: [up, --database, "$(DB_URL)", --password, "$(DB_PASSWORD)", --port, 3002]
-```
-
-Refer to the [official Kubernetes documentation](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/) for more information on command and arguments behavior and syntax.
+startup_command: [/app/migrate]
+args: [up, --database, "$(DB_URL)", --password, "$(DB_PASSWORD)", --port, 3002]
+```