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* docs: update plugin docs for secrets/auth multiplexing * update index * update plugin development * fix spacing in code snippet * update links to multiplexing resources * add note on sdk version and update db example text * Update website/content/docs/plugins/plugin-architecture.mdx Co-authored-by: Loann Le <84412881+taoism4504@users.noreply.github.com> * reword index intro * Update website/content/docs/plugins/plugin-development.mdx Co-authored-by: Loann Le <84412881+taoism4504@users.noreply.github.com> * Update website/content/docs/plugins/plugin-development.mdx Co-authored-by: Loann Le <84412881+taoism4504@users.noreply.github.com> * remove word and fix code format Co-authored-by: Loann Le <84412881+taoism4504@users.noreply.github.com>
127 lines
4.3 KiB
Plaintext
127 lines
4.3 KiB
Plaintext
---
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layout: docs
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page_title: Plugin Development
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description: Learn about Vault plugin development.
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---
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# Plugin Development
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~> Advanced topic! Plugin development is a highly advanced topic in Vault, and
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is not required knowledge for day-to-day usage. If you don't plan on writing any
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plugins, we recommend not reading this section of the documentation.
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Because Vault communicates to plugins over a RPC interface, you can build and
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distribute a plugin for Vault without having to rebuild Vault itself. This makes
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it easy for you to build a Vault plugin for your organization's internal use,
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for a proprietary API that you don't want to open source, or to prototype
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something before contributing it back to the main project.
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In theory, because the plugin interface is HTTP, you could even develop a plugin
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using a completely different programming language! (Disclaimer, you would also
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have to re-implement the plugin API which is not a trivial amount of work.)
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Developing a plugin is simple. The only knowledge necessary to write
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a plugin is basic command-line skills and basic knowledge of the
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[Go programming language](http://golang.org).
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Your plugin implementation needs to satisfy the interface for the plugin
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type you want to build. You can find these definitions in the docs for the
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backend running the plugin.
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~> Note: Plugins should be prepared to handle multiple concurrent requests
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from Vault.
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## Serving A Plugin
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### Serving A Plugin with Multiplexing
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~> Plugin multiplexing requires `github.com/hashicorp/vault/sdk v0.5.4` or above.
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The following code exhibits an example main package for a Vault plugin using
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the Vault SDK for a secrets engine or auth method:
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```go
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package main
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import (
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"os"
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myPlugin "your/plugin/import/path"
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"github.com/hashicorp/vault/api"
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"github.com/hashicorp/vault/sdk/plugin"
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)
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func main() {
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apiClientMeta := &api.PluginAPIClientMeta{}
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flags := apiClientMeta.FlagSet()
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flags.Parse(os.Args[1:])
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tlsConfig := apiClientMeta.GetTLSConfig()
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tlsProviderFunc := api.VaultPluginTLSProvider(tlsConfig)
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err := plugin.ServeMultiplex(&plugin.ServeOpts{
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BackendFactoryFunc: myPlugin.Factory,
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TLSProviderFunc: tlsProviderFunc,
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})
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if err != nil {
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logger := hclog.New(&hclog.LoggerOptions{})
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logger.Error("plugin shutting down", "error", err)
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os.Exit(1)
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}
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}
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```
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And that's basically it! You would just need to change `myPlugin` to your actual
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plugin.
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## Plugin Backwards Compatibility with Vault
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Let's take a closer look at a snippet from the above main package.
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```go
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err := plugin.ServeMultiplex(&plugin.ServeOpts{
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BackendFactoryFunc: myPlugin.Factory,
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TLSProviderFunc: tlsProviderFunc,
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})
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```
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The call to `plugin.ServeMultiplex` ensures that the plugin will use
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Vault's [plugin
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multiplexing](/docs/plugins/plugin-architecture#plugin-multiplexing) feature.
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However, this plugin will not be multiplexed if it is run by a version of Vault
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that does not support multiplexing. Vault will simply fall back to a plugin
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version that it can run. Additionally, we set the `TLSProviderFunc` to ensure
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that our plugin is backwards compatible with versions of Vault that do not
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support automatic mutual TLS for secure [plugin
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communication](/docs/plugins/plugin-architecture#plugin-communication). If you
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are certain your plugin does not need backwards compatibility, this field can
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be omitted.
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[api_addr]: /docs/configuration#api_addr
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## Building a Plugin from Source
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To build a plugin from source, first navigate to the location holding the
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desired plugin version. Next, run `go build` to obtain a new binary for the
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plugin. Finally,
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[register](/docs/plugins/plugin-architecture#plugin-registration) the
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plugin and enable it.
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## Plugin Development - Resources
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For more information on how to register and enable your plugin, refer to the
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[Building Plugin Backends](https://learn.hashicorp.com/vault/developer/plugin-backends)
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tutorial.
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Other HashiCorp plugin development resources:
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* [vault-auth-plugin-example](https://github.com/hashicorp/vault-auth-plugin-example)
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* [Custom Secrets Engines](https://learn.hashicorp.com/collections/vault/custom-secrets-engine)
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### Plugin Development - Resources - Community
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See the [Plugin Portal](/docs/plugins/plugin-portal#community) to find
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Community plugin examples/guides developed by community members. HashiCorp does
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not validate these for correctness.
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