mirror of https://github.com/status-im/consul.git
148 lines
4.7 KiB
Markdown
148 lines
4.7 KiB
Markdown
---
|
||
layout: "docs"
|
||
page_title: "Configuration Entry Definitions"
|
||
sidebar_current: "docs-agent-cfg_entries"
|
||
description: |-
|
||
Consul allows storing configuration entries centrally to be used as defaults for configuring other aspects of Consul.
|
||
---
|
||
|
||
# Configuration Entries
|
||
|
||
Configuration entries can be created to provide cluster-wide defaults for
|
||
various aspects of Consul. Every configuration entry has at least two fields:
|
||
`Kind` and `Name`. Those two fields are used to uniquely identify a
|
||
configuration entry. When put into configuration files, configuration entries
|
||
can be specified as HCL or JSON objects using either `snake_case` or `CamelCase`
|
||
for key names.
|
||
|
||
Example:
|
||
|
||
```hcl
|
||
Kind = "<supported kind>"
|
||
Name = "<name of entry>"
|
||
```
|
||
|
||
The supported `Kind` names for configuration entries are:
|
||
|
||
* [`service-router`](/docs/agent/config-entries/service-router.html) - defines
|
||
where to send layer 7 traffic based on the HTTP route
|
||
|
||
* [`service-splitter`](/docs/agent/config-entries/service-splitter.html) - defines
|
||
how to divide requests for a single HTTP route based on percentages
|
||
|
||
* [`service-resolver`](/docs/agent/config-entries/service-resolver.html) - matches
|
||
service instances with a specific Connect upstream discovery requests
|
||
|
||
* [`service-defaults`](/docs/agent/config-entries/service-defaults.html) - configures
|
||
defaults for all the instances of a given service
|
||
|
||
* [`proxy-defaults`](/docs/agent/config-entries/proxy-defaults.html) - controls
|
||
proxy configuration
|
||
|
||
## Managing Configuration Entries
|
||
|
||
Configuration entries should be managed with the Consul
|
||
[CLI](/docs/commands/config.html) or [API](/api/config.html). Additionally, as a
|
||
convenience for initial cluster bootstrapping, configuration entries can be
|
||
specified in all of the Consul servers's
|
||
[configuration files](/docs/agent/options.html#config_entries_bootstrap)
|
||
|
||
### Managing Configuration Entries with the CLI
|
||
|
||
#### Creating or Updating a Configuration Entry
|
||
|
||
The [`consul config write`](/docs/commands/config/write.html) 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 - `proxy-defaults.hcl`:
|
||
|
||
```hcl
|
||
Kind = "proxy-defaults"
|
||
Name = "global"
|
||
Config {
|
||
local_connect_timeout_ms = 1000
|
||
handshake_timeout_ms = 10000
|
||
}
|
||
```
|
||
|
||
Then to apply this configuration, run:
|
||
|
||
```bash
|
||
$ 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`](/docs/commands/config/read.html) 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:
|
||
|
||
```bash
|
||
$ consul config read -kind service-defaults -name web
|
||
{
|
||
"Kind": "service-defaults",
|
||
"Name": "web",
|
||
"Protocol": "http"
|
||
}
|
||
```
|
||
|
||
#### Listing Configuration Entries
|
||
|
||
The [`consul config list`](/docs/commands/config/list.html) command is used to
|
||
list out all the configuration entries for a given kind.
|
||
|
||
Example:
|
||
|
||
```bash
|
||
$ consul config list -kind service-defaults
|
||
web
|
||
api
|
||
db
|
||
```
|
||
|
||
|
||
#### Deleting Configuration Entries
|
||
|
||
The [`consul config delete`](/docs/commands/config/delete.html) command is used
|
||
to delete an entry by specifying both its `kind` and `name`.
|
||
|
||
Example:
|
||
|
||
```bash
|
||
$ consul config delete -kind service-defaults -name web
|
||
```
|
||
|
||
This command will not output anything when the deletion is successful.
|
||
|
||
### Bootstrapping From A Configuration File
|
||
|
||
|
||
Configuration entries can be bootstrapped by adding them inline to each Consul
|
||
server’s configuration file. 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.
|
||
|
||
|
||
## Using Configuration Entries For Service Defaults
|
||
|
||
When the agent is
|
||
[configured](/docs/agent/options.html#enable_central_service_config) to enable
|
||
central service configurations, it will look for service configuration defaults
|
||
that match a registering service instance. If it finds any, the agent will merge
|
||
those defaults with the service instance configuration. This allows for things
|
||
like service protocol or proxy configuration to be defined globally and
|
||
inherited by any affected service registrations.
|