diff --git a/site/content/docs/main/backup-hooks.md b/site/content/docs/main/backup-hooks.md index 7c849cf0a..ef38dc7fe 100644 --- a/site/content/docs/main/backup-hooks.md +++ b/site/content/docs/main/backup-hooks.md @@ -24,23 +24,23 @@ You can use the following annotations on a pod to make Velero execute a hook whe * `pre.hook.backup.velero.io/container` * The container where the command should be executed. Defaults to the first container in the pod. Optional. * `pre.hook.backup.velero.io/command` - * The command to execute. If you need multiple arguments, specify the command as a JSON array, such as `["/usr/bin/uname", "-a"]` + * The command to execute. This command is not executed within a shell by default. If a shell is needed to run your command, include a shell command, like `/bin/sh`, that is supported by the container at the beginning of your command. If you need multiple arguments, specify the command as a JSON array, such as `["/usr/bin/uname", "-a"]`. See [examples of using pre hook commands](#backup-hook-commands-examples). Optional. * `pre.hook.backup.velero.io/on-error` - * What to do if the command returns a non-zero exit code. Defaults to Fail. Valid values are Fail and Continue. Optional. + * What to do if the command returns a non-zero exit code. Defaults is `Fail`. Valid values are Fail and Continue. Optional. * `pre.hook.backup.velero.io/timeout` - * How long to wait for the command to execute. The hook is considered in error if the command exceeds the timeout. Defaults to 30s. Optional. + * How long to wait for the command to execute. The hook is considered in error if the command exceeds the timeout. Defaults is 30s. Optional. #### Post hooks * `post.hook.backup.velero.io/container` - * The container where the command should be executed. Defaults to the first container in the pod. Optional. + * The container where the command should be executed. Default is the first container in the pod. Optional. * `post.hook.backup.velero.io/command` - * The command to execute. If you need multiple arguments, specify the command as a JSON array, such as `["/usr/bin/uname", "-a"]` + * The command to execute. This command is not executed within a shell by default. If a shell is needed to run your command, include a shell command, like `/bin/sh`, that is supported by the container at the beginning of your command. If you need multiple arguments, specify the command as a JSON array, such as `["/usr/bin/uname", "-a"]`. See [examples of using pre hook commands](#backup-hook-commands-examples). Optional. * `post.hook.backup.velero.io/on-error` - * What to do if the command returns a non-zero exit code. Defaults to Fail. Valid values are Fail and Continue. Optional. + * What to do if the command returns a non-zero exit code. Defaults is `Fail`. Valid values are Fail and Continue. Optional. * `post.hook.backup.velero.io/timeout` - * How long to wait for the command to execute. The hook is considered in error if the command exceeds the timeout. Defaults to 30s. Optional. + * How long to wait for the command to execute. The hook is considered in error if the command exceeds the timeout. Defaults is 30s. Optional. ### Specifying Hooks in the Backup Spec @@ -78,7 +78,9 @@ velero backup get nginx-hook-test velero backup logs nginx-hook-test | grep hookCommand ``` -## Using Multiple Commands +## Backup hook commands examples + +### Multiple commands To use multiple commands, wrap your target command in a shell and separate them with `;`, `&&`, or other shell conditional constructs. @@ -86,6 +88,23 @@ To use multiple commands, wrap your target command in a shell and separate them pre.hook.backup.velero.io/command='["/bin/bash", "-c", "echo hello > hello.txt && echo goodbye > goodbye.txt"]' ``` +#### Using environment variables + +You are able to use environment variables from your pods in your pre and post hook commands by including a shell command before using the environment variable. For example, `MYSQL_ROOT_PASSWORD` is an environment variable defined in pod called `mysql`. To use `MYSQL_ROOT_PASSWORD` in your pre-hook, you'd include a shell, like `/bin/sh`, before calling your environment variable: + +``` +pre: +- exec: + container: mysql + command: + - /bin/sh + - -c + - mysql --password=$MYSQL_ROOT_PASSWORD -e "FLUSH TABLES WITH READ LOCK" + onError: Fail +``` + +Note that the container must support the shell command you use. + [1]: api-types/backup.md [2]: https://github.com/vmware-tanzu/velero/blob/main/examples/nginx-app/with-pv.yaml