mirror of https://github.com/hashicorp/consul
161 lines
5.1 KiB
Markdown
161 lines
5.1 KiB
Markdown
---
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layout: "docs"
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page_title: "Configuration Entry Definitions"
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sidebar_current: "docs-agent-cfg_entries"
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description: |-
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Consul allows storing configuration entries centrally to be used as defaults for configuring other aspects of Consul.
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---
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# Configuration Entries
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Configuration entries can be created to provide cluster-wide defaults for various aspects of Consul. Every configuration
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entry has at least two fields: `Kind` and `Name`. Those two fields are used to uniquely identify a configuration entry.
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When put into configuration files, configuration entries can be specified as HCL or JSON objects.
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Example:
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```hcl
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Kind = "<supported kind>"
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Name = "<name of entry>"
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```
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The two supported `Kind` configuration entries are detailed below.
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## Configuration Entry Kinds
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### Proxy Defaults - `proxy-defaults`
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Proxy defaults allow for configuring global config defaults across all services for Connect proxy configuration. Currently,
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only one global entry is supported.
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```hcl
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Kind = "proxy-defaults"
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Name = "global"
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Config {
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local_connect_timeout_ms = 1000
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handshake_timeout_ms = 10000
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}
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```
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* `Kind` - Must be set to `proxy-defaults`
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* `Name` - Must be set to `global`
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* `Config` - An arbitrary map of configuration values used by Connect proxies. See
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#### Proxy Configuration References
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* [Consul's Builtin Proxy](/docs/connect/configuration.html#built-in-proxy-options)
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* [Envoy](/docs/connect/proxies/envoy.html#bootstrap-configuration)
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### Service Defaults - `service-defaults`
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Service defaults control default global values for a service, such as its protocol.
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```hcl
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Kind = "service-defaults"
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Name = "web"
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Protocol = "http"
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```
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* `Kind` - Must be set to `service-defaults`
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* `Name` - Set to the name of the service being configured.
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* `Protocol` - Sets the protocol of the service. This is used by Connect proxies for things like observability features.
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## Managing Configuration Entries
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Configuration entries should be managed with the Consul [CLI](/docs/commands/config.html) or [API](/api/config.html). Additionally,
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as a convenience for initial cluster bootstrapping, configuration entries can be specified in all of the Consul servers's
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[configuration files](/docs/agent/options.html#config_entries_bootstrap)
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### Managing Configuration Entries with the CLI
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#### Creating or Updating a Configuration Entry
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The [`consul config write`](/docs/commands/config/write.html) command is used to create and update configuration entries. This command
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will load either a JSON or HCL file holding the configuration entry definition and then will push this configuration to Consul.
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Example HCL Configuration File - `proxy-defaults.hcl`:
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```hcl
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Kind = "proxy-defaults"
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Name = "global"
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Config {
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local_connect_timeout_ms = 1000
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handshake_timeout_ms = 10000
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}
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```
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Then to apply this configuration, run:
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```bash
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$ consul config write proxy-defaults.hcl
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```
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If you need to make changes to a configuration entry, simple edit that file and then rerun the command.
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This command will not output anything unless there is an error in applying the configuration entry.
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The `write` command also supports a `-cas` option to enable performing a compare-and-swap operation to
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prevent overwriting other unknown modifications.
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#### Reading a Configuration Entry
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The [`consul config read`](/docs/commands/config/read.html) command is used to read the current value of a configuration entry. The
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configuration entry will be displayed in JSON form which is how its transmitted between the CLI client and Consul's HTTP API.
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Example:
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```bash
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$ consul config read -kind service-defaults -name web
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{
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"Kind": "service-defaults",
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"Name": "web",
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"Protocol": "http"
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}
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```
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#### Listing Configuration Entries
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The [`consul config list`](/docs/commands/config/list.html) command is used to list out all the configuration entries for a
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given kind.
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Example:
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```bash
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$ consul config list -kind service-defaults
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web
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api
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db
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```
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#### Deleting Configuration Entries
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The [`consul config delete`](/docs/commands/config/delete.html) command is used to delete an entry by specifying both its
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`kind` and `name`.
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Example:
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```bash
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$ consul config delete -kind service-defaults -name web
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```
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This command will not output anything when the deletion is successful.
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### Bootstrapping From A Configuration File
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Configuration entries can be bootstrapped by adding them inline to each Consul server’s configuration file. When a server
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gains leadership, it will attempt to initialize the configuration entries. If a configuration entry does not already exist
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outside of the servers configuration, then it will create it. If a configuration entry does exist, that matches both `kind`
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and `name`, then the server will do nothing.
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## Using Configuration Entries For Service Defaults
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When the agent is [configured](/docs/agent/options.html#enable_central_service_config) to enable central service configurations,
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it will look for service configuration defaults that match a registering service instance. If it finds any, the agent will merge
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those defaults with the service instance configuration. This allows for things like service protocol or proxy configuration to
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be defined globally and inherited by any affected service registrations.
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