mirror of https://github.com/hashicorp/consul
95 lines
2.7 KiB
Markdown
95 lines
2.7 KiB
Markdown
---
|
|
layout: docs
|
|
page_title: Sentinel in Consul
|
|
sidebar_current: docs-agent-sentinel
|
|
description: >-
|
|
Consul Enterprise uses Sentinel to augment the built-in ACL system to provide
|
|
advanced policy enforcement. Sentinel policies can currently execute on KV
|
|
modify and service registration.
|
|
---
|
|
|
|
# Sentinel Overview
|
|
|
|
[//]: # ' ~> The Sentinel functionality described here is available only in '
|
|
|
|
[//]: # ( [Consul Enterprise](https://www.hashicorp.com/products/consul/) version 1.0.0 and later. )
|
|
|
|
<%= enterprise_alert :consul %>
|
|
|
|
Consul 1.0 adds integration with [Sentinel](https://hashicorp.com/sentinel) for policy enforcement.
|
|
Sentinel policies help extend the ACL system in Consul beyond the static "read", "write", and "deny"
|
|
policies to support full conditional logic and integration with external systems.
|
|
|
|
## Sentinel in Consul
|
|
|
|
Sentinel policies are applied during writes to the KV Store.
|
|
|
|
An optional `sentinel` field specifying code and enforcement level can be added to [ACL policy definitions](/docs/agent/acl-rules.html#sentinel-integration) for Consul KV. The following policy ensures that the value written during a KV update must end with "dc1".
|
|
|
|
```text
|
|
key "datacenter_name" {
|
|
policy = "write"
|
|
sentinel {
|
|
code = <<EOF
|
|
import "strings"
|
|
main = rule { strings.has_suffix(value, "dc1") }
|
|
EOF
|
|
enforcementlevel = "soft-mandatory"
|
|
}
|
|
}
|
|
```
|
|
|
|
If the `enforcementlevel` property is not set, it defaults to "hard-mandatory".
|
|
|
|
## Imports
|
|
|
|
Consul imports all the [standard imports](https://docs.hashicorp.com/sentinel/imports/) from Sentinel _except_ [`http`](https://docs.hashicorp.com/sentinel/imports/http/). All functions in these imports are available to be used in policies.
|
|
|
|
## Injected Variables
|
|
|
|
Consul passes some context as variables into Sentinel, which are available to use inside any policies you write.
|
|
|
|
#### Variables injected during KV store writes
|
|
|
|
| Variable Name | Type | Description |
|
|
| ------------- | -------- | --------------------------- |
|
|
| `key` | `string` | Key being written |
|
|
| `value` | `string` | Value being written |
|
|
| `flags` | `uint64` | [Flags](/api/kv.html#flags) |
|
|
|
|
## Sentinel Examples
|
|
|
|
The following are two examples of ACL policies with Sentinel rules.
|
|
|
|
### Required Key Suffix
|
|
|
|
Any values stored under the key prefix "dc1" must end with "dev"
|
|
|
|
```text
|
|
key "dc1" {
|
|
policy = "write"
|
|
sentinel {
|
|
code = <<EOF
|
|
import "strings"
|
|
main = rule { strings.has_suffix(value, "dev") }
|
|
EOF
|
|
}
|
|
}
|
|
```
|
|
|
|
### Restricted Update Time
|
|
|
|
The key "haproxy_version" can only be updated during business hours.
|
|
|
|
```text
|
|
key "haproxy_version" {
|
|
policy = "write"
|
|
sentinel {
|
|
code = <<EOF
|
|
import "time"
|
|
main = rule { time.now.hour > 8 and time.now.hour < 17 }
|
|
EOF
|
|
}
|
|
}
|
|
```
|