open-consul/website/content/docs/agent/config-entries.mdx

---
layout: docs
page_title: How to Use Configuration Entries
description: >-
  Configuration entries define the behavior of Consul service mesh components. Learn how to use the `consul config` command to create, manage, and delete configuration entries.
---

# How to Use Configuration Entries

Configuration entries can be created to provide cluster-wide defaults for
various aspects of Consul.

Outside of Kubernetes, configuration entries can be specified in HCL or JSON using either
`snake_case` or `CamelCase` for key names. On Kubernetes, configuration
entries can be managed by custom resources in YAML.

Outside of Kubernetes, every configuration entry specified in HCL or JSON has at least two fields:
`Kind` and `Name`. Those two fields are used to uniquely identify a
configuration entry. Configuration entries specified as HCL or JSON objects
use either `snake_case` or `CamelCase` for key names.

<CodeBlockConfig heading="Example config specified outside of Kubernetes">

```hcl
Kind = "<supported kind>"
Name = "<name of entry>"
```

</CodeBlockConfig>

On Kubernetes, `Kind` is set as the custom resource `kind` and `Name` is set
as `metadata.name`:

<CodeBlockConfig heading="Example config specified on Kubernetes">

```yaml
apiVersion: consul.hashicorp.com/v1alpha1
kind: <supported kind>
metadata:
  name: <name of entry>
```

</CodeBlockConfig>

## Supported Config Entries

See [Service Mesh - Config Entries](/docs/connect/config-entries) for the list
of supported config entries.

## Managing Configuration Entries In Kubernetes

See [Kubernetes Custom Resource Definitions](/docs/k8s/crds).

## Managing Configuration Entries Outside Of Kubernetes

Configuration entries outside of Kubernetes should be managed with the Consul
[CLI](/commands/config) or [API](/api-docs/config). Additionally, as a
convenience for initial cluster bootstrapping, configuration entries can be
specified in all of the Consul servers's
[configuration files](/docs/agent/config/config-files#config_entries_bootstrap)

### Managing Configuration Entries with the CLI

#### Creating or Updating a Configuration Entry

The [`consul config write`](/commands/config/write) command is used to
create and update configuration entries. This command will load either a JSON or
HCL file holding the configuration entry definition and then will push this
configuration to Consul.

Example HCL Configuration File:

<CodeBlockConfig filename="proxy-defaults.hcl">

```hcl
Kind = "proxy-defaults"
Name = "global"
Config {
   local_connect_timeout_ms = 1000
   handshake_timeout_ms = 10000
}
```

</CodeBlockConfig>

Then to apply this configuration, run:

```shell-session
$ consul config write proxy-defaults.hcl
```

If you need to make changes to a configuration entry, simple edit that file and
then rerun the command. This command will not output anything unless there is an
error in applying the configuration entry. The `write` command also supports a
`-cas` option to enable performing a compare-and-swap operation to prevent
overwriting other unknown modifications.

#### Reading a Configuration Entry

The [`consul config read`](/commands/config/read) command is used to
read the current value of a configuration entry. The configuration entry will be
displayed in JSON form which is how its transmitted between the CLI client and
Consul's HTTP API.

Example:

```shell-session
$ consul config read -kind service-defaults -name web
{
   "Kind": "service-defaults",
   "Name": "web",
   "Protocol": "http"
}
```

#### Listing Configuration Entries

The [`consul config list`](/commands/config/list) command is used to
list out all the configuration entries for a given kind.

Example:

```shell-session
$ consul config list -kind service-defaults
web
api
db
```

#### Deleting Configuration Entries

The [`consul config delete`](/commands/config/delete) command is used
to delete an entry by specifying both its `kind` and `name`.

Example:

```shell-session
$ consul config delete -kind service-defaults -name web
```

This command will not output anything when the deletion is successful.

#### Configuration Entry Management with Namespaces <EnterpriseAlert inline />

Configuration entry operations support passing a namespace in
order to isolate the entry to affect only operations within that namespace. This was
added in Consul 1.7.0.

Example:

```shell-session
$ consul config write service-defaults.hcl -namespace foo
```

```shell-session
$ consul config list -kind service-defaults -namespace foo
web
api
```

### Bootstrapping From A Configuration File

Configuration entries can be bootstrapped by adding them [inline to each Consul
server's configuration file](/docs/agent/config/config-files#config_entries). When a
server gains leadership, it will attempt to initialize the configuration entries.
If a configuration entry does not already exist outside of the servers
configuration, then it will create it. If a configuration entry does exist, that
matches both `kind` and `name`, then the server will do nothing.