664 lines
37 KiB
Markdown
664 lines
37 KiB
Markdown
---
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layout: "docs"
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page_title: "Configuration"
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sidebar_current: "docs-agent-config"
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description: |-
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The agent has various configuration options that can be specified via the command-line or via configuration files. All of the configuration options are completely optional. Defaults are specified with their descriptions.
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---
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# Configuration
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The agent has various configuration options that can be specified via
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the command-line or via configuration files. All of the configuration
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options are completely optional. Defaults are specified with their
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descriptions.
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When loading configuration, Consul loads the configuration from files
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and directories in lexical order. For example, configuration file `basic_config.json`
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will be processed before `extra_config.js`. Configuration specified later
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will be merged into configuration specified earlier. In most cases,
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"merge" means that the later version will override the earlier. In
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some cases, such as event handlers, merging appends the handlers to the
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existing configuration. The exact merging behavior is specified for each
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option below.
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Consul also supports reloading configuration when it receives the
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SIGHUP signal. Not all changes are respected, but those that are
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are documented below in the
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[Reloadable Configuration](#reloadable-configuration) section. The
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[reload command](/docs/commands/reload.html) can also be used to trigger a
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configuration reload.
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## Command-line Options
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The options below are all specified on the command-line.
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* <a name="_advertise"></a><a href="#_advertise">`-advertise`</a> - The advertise
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address is used to change the address that we
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advertise to other nodes in the cluster. By default, the [`-bind`](#_bind) address is
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advertised. However, in some cases, there may be a routable address that cannot
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be bound. This flag enables gossiping a different address to support this.
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If this address is not routable, the node will be in a constant flapping state
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as other nodes will treat the non-routability as a failure.
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* <a name="_advertise-wan"></a><a href="#_advertise-wan">`-advertise-wan`</a> - The advertise wan
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address is used to change the address that we advertise to server nodes joining
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through the WAN. By default, the [`-advertise`](#_advertise) address is advertised.
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However, in some cases all members of all datacenters cannot be on the same
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physical or virtual network, especially on hybrid setups mixing cloud and private datacenters.
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This flag enables server nodes gossiping through the public network for the WAN while using
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private VLANs for gossiping to each other and their client agents.
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* <a name="_atlas"></a><a href="#_atlas">`-atlas`</a> - This flag
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enables [Atlas](https://atlas.hashicorp.com) integration.
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It is used to provide the Atlas infrastructure name and the SCADA connection.
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This enables Atlas features such as the dashboard and node auto joining.
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* <a name="_atlas_join"></a><a href="#_atlas_join">`-atlas-join`</a> - When set, enables auto-join
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via Atlas. Atlas will track the most
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recent members to join the infrastructure named by [`-atlas`](#_atlas) and automatically
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join them on start. For servers, the LAN and WAN pool are both joined.
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* <a name="_atlas_token"></a><a href="#_atlas_token">`-atlas-token`</a> - Provides the Atlas
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API authentication token. This can also be provided
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using the `ATLAS_TOKEN` environment variable. Required for use with Atlas.
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* <a name="_atlas_endpoint"></a><a href="#_atlas_endpoint">`-atlas-endpoint`</a> - The endpoint
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address used for Atlas integration. Used only if the `-atlas` and
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`-atlas-token` options are specified. This is optional, and defaults to the
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public Atlas endpoints. This can also be specified using the `SCADA_ENDPOINT`
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environment variable. The CLI option takes precedence, followed by the
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configuration file directive, and lastly, the environment variable.
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* <a name="_bootstrap"></a><a href="#_bootstrap">`-bootstrap`</a> - This flag is used to control if a
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server is in "bootstrap" mode. It is important that
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no more than one server *per* datacenter be running in this mode. Technically, a server in bootstrap mode
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is allowed to self-elect as the Raft leader. It is important that only a single node is in this mode;
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otherwise, consistency cannot be guaranteed as multiple nodes are able to self-elect.
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It is not recommended to use this flag after a cluster has been bootstrapped.
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* <a name="_bootstrap_expect"></a><a href="#_bootstrap_expect">`-bootstrap-expect`</a> - This flag
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provides the number of expected servers in the datacenter.
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Either this value should not be provided or the value must agree with other servers in
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the cluster. When provided, Consul waits until the specified number of servers are
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available and then bootstraps the cluster. This allows an initial leader to be elected
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automatically. This cannot be used in conjunction with the legacy [`-bootstrap`](#_bootstrap) flag.
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* <a name="_bind"></a><a href="#_bind">`-bind`</a> - The address that should be bound to
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for internal cluster communications.
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This is an IP address that should be reachable by all other nodes in the cluster.
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By default, this is "0.0.0.0", meaning Consul will use the first available private
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IP address. Consul uses both TCP and UDP and the same port for both. If you
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have any firewalls, be sure to allow both protocols.
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* <a name="_client"></a><a href="#_client">`-client`</a> - The address to which
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Consul will bind client interfaces,
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including the HTTP, DNS, and RPC servers. By default, this is "127.0.0.1",
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allowing only loopback connections. The RPC address is used by other Consul
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commands, such as `consul members`, in order to query a running Consul agent.
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* <a name="_config_file"></a><a href="#_config_file">`-config-file`</a> - A configuration file
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to load. For more information on
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the format of this file, read the [Configuration Files](#configuration_files) section.
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This option can be specified multiple times to load multiple configuration
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files. If it is specified multiple times, configuration files loaded later
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will merge with configuration files loaded earlier. During a config merge,
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single-value keys (string, int, bool) will simply have their values replaced
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while list types will be appended together.
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* <a name="_config_dir"></a><a href="#_config_dir">`-config-dir`</a> - A directory of
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configuration files to load. Consul will
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load all files in this directory with the suffix ".json". The load order
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is alphabetical, and the the same merge routine is used as with the
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[`config-file`](#_config_file) option above. This option can be specified mulitple times
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to load multiple directories. Sub-directories of the config directory are not loaded.
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For more information on the format of the configuration files, see the
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[Configuration Files](#configuration_files) section.
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* <a name="_data_dir"></a><a href="#_data_dir">`-data-dir`</a> - This flag provides
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a data directory for the agent to store state.
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This is required for all agents. The directory should be durable across reboots.
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This is especially critical for agents that are running in server mode as they
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must be able to persist cluster state. Additionally, the directory must support
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the use of filesystem locking, meaning some types of mounted folders (e.g. VirtualBox
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shared folders) may not be suitable.
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* <a name="_dc"></a><a href="#_dc">`-dc`</a> - This flag controls the datacenter in
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which the agent is running. If not provided,
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it defaults to "dc1". Consul has first-class support for multiple datacenters, but
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it relies on proper configuration. Nodes in the same datacenter should be on a single
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LAN.
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* <a name="_domain"></a><a href="#_domain">`-domain`</a> - By default, Consul responds to DNS queries
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in the "consul." domain. This flag can be used to change that domain. All queries in this domain
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are assumed to be handled by Consul and will not be recursively resolved.
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* <a name="_encrypt"></a><a href="#_encrypt">`-encrypt`</a> - Specifies the secret key to
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use for encryption of Consul
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network traffic. This key must be 16-bytes that are Base64-encoded. The
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easiest way to create an encryption key is to use
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[`consul keygen`](/docs/commands/keygen.html). All
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nodes within a cluster must share the same encryption key to communicate.
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The provided key is automatically persisted to the data directory and loaded
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automatically whenever the agent is restarted. This means that to encrypt
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Consul's gossip protocol, this option only needs to be provided once on each
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agent's initial startup sequence. If it is provided after Consul has been
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initialized with an encryption key, then the provided key is ignored and
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a warning will be displayed.
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* <a name="_http_port"></a><a href="#_http_port">`-http-port`</a> - the HTTP API port to listen on.
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This overrides the default port 8500. This option is very useful when deploying Consul
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to an environment which communicates the HTTP port through the environment e.g. PaaS like CloudFoundry, allowing
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you to set the port directly via a Procfile.
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* <a name="_join"></a><a href="#_join">`-join`</a> - Address of another agent
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to join upon starting up. This can be
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specified multiple times to specify multiple agents to join. If Consul is
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unable to join with any of the specified addresses, agent startup will
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fail. By default, the agent won't join any nodes when it starts up.
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* <a name="_retry_join"></a><a href="#_retry_join">`-retry-join`</a> - Similar
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to [`-join`](#_join) but allows retrying a join if the first
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attempt fails. This is useful for cases where we know the address will become
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available eventually.
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* <a name="_retry_interval"></a><a href="#_retry_interval">`-retry-interval`</a> - Time
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to wait between join attempts. Defaults to 30s.
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* <a name="_retry_max"></a><a href="#_retry_max">`-retry-max`</a> - The maximum number
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of [`-join`](#_join) attempts to be made before exiting
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with return code 1. By default, this is set to 0 which is interpreted as infinite
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retries.
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* <a name="_join_wan"></a><a href="#_join_wan">`-join-wan`</a> - Address of another
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wan agent to join upon starting up. This can be
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specified multiple times to specify multiple WAN agents to join. If Consul is
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unable to join with any of the specified addresses, agent startup will
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fail. By default, the agent won't [`-join-wan`](#_join_wan) any nodes when it starts up.
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* <a name="_retry_join_wan"></a><a href="#_retry_join_wan">`-retry-join-wan`</a> - Similar
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to [`retry-join`](#_retry_join) but allows retrying a wan join if the first attempt fails.
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This is useful for cases where we know the address will become
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available eventually.
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* <a name="_retry_interval_wan"></a><a href="#_retry_interval_wan">`-retry-interval-wan`</a> - Time
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to wait between [`-join-wan`](#_join_wan) attempts.
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Defaults to 30s.
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* <a name="_retry_max_wan"></a><a href="#_retry_max_wan">`-retry-max-wan`</a> - The maximum
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number of [`-join-wan`](#_join_wan) attempts to be made before exiting with return code 1.
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By default, this is set to 0 which is interpreted as infinite retries.
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* <a name="_log_level"></a><a href="#_log_level">`-log-level`</a> - The level of logging to
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show after the Consul agent has started. This defaults to "info". The available log levels are
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"trace", "debug", "info", "warn", and "err". Note that you can always connect to an
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agent via [`consul monitor`](/docs/commands/monitor.html) and use any log level. Also, the
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log level can be changed during a config reload.
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* <a name="_node"></a><a href="#_node">`-node`</a> - The name of this node in the cluster.
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This must be unique within the cluster. By default this is the hostname of the machine.
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* <a name="_pid_file"></a><a href="#_pid_file">`-pid-file`</a> - This flag provides the file
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path for the agent to store its PID. This is useful for sending signals (for example, `SIGINT`
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to close the agent or `SIGHUP` to update check definite
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* <a name="_protocol"></a><a href="#_protocol">`-protocol`</a> - The Consul protocol version to
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use. This defaults to the latest version. This should be set only when [upgrading](/docs/upgrading.html).
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You can view the protocol versions supported by Consul by running `consul -v`.
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* <a name="_recursor"></a><a href="#_recursor">`-recursor`</a> - Specifies the address of an upstream DNS
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server. This option may be provided multiple times, and is functionally
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equivalent to the [`recursors` configuration option](#recursors).
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* <a name="_rejoin"></a><a href="#_rejoin">`-rejoin`</a> - When provided, Consul will ignore a
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previous leave and attempt to rejoin the cluster when starting. By default, Consul treats leave
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as a permanent intent and does not attempt to join the cluster again when starting. This flag
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allows the previous state to be used to rejoin the cluster.
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* <a name="_server"></a><a href="#_server">`-server`</a> - This flag is used to control if an
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agent is in server or client mode. When provided,
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an agent will act as a Consul server. Each Consul cluster must have at least one server and ideally
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no more than 5 per datacenter. All servers participate in the Raft consensus algorithm to ensure that
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transactions occur in a consistent, linearizable manner. Transactions modify cluster state, which
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is maintained on all server nodes to ensure availability in the case of node failure. Server nodes also
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participate in a WAN gossip pool with server nodes in other datacenters. Servers act as gateways
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to other datacenters and forward traffic as appropriate.
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* <a name="_syslog"></a><a href="#_syslog">`-syslog`</a> - This flag enables logging to syslog. This
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is only supported on Linux and OSX. It will result in an error if provided on Windows.
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* <a name="_ui_dir"></a><a href="#_ui_dir">`-ui-dir`</a> - This flag provides the directory containing
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the Web UI resources for Consul. This must be provided to enable the Web UI. The directory must be
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readable to the agent.
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## <a name="configuration_files"></a>Configuration Files
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In addition to the command-line options, configuration can be put into
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files. This may be easier in certain situations, for example when Consul is
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being configured using a configuration management system.
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The configuration files are JSON formatted, making them easily readable
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and editable by both humans and computers. The configuration is formatted
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as a single JSON object with configuration within it.
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Configuration files are used for more than just setting up the agent,
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they are also used to provide check and service definitions. These are used
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to announce the availability of system servers to the rest of the cluster.
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They are documented separately under [check configuration](/docs/agent/checks.html) and
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[service configuration](/docs/agent/services.html) respectively. The service and check
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definitions support being updated during a reload.
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#### Example Configuration File
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```javascript
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{
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"datacenter": "east-aws",
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"data_dir": "/opt/consul",
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"log_level": "INFO",
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"node_name": "foobar",
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"server": true,
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"watches": [
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{
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"type": "checks",
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"handler": "/usr/bin/health-check-handler.sh"
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}
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]
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}
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```
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#### Configuration Key Reference
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* <a name="acl_datacenter"></a><a href="#acl_datacenter">`acl_datacenter`</a> - Only
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used by servers. This designates the datacenter which
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is authoritative for ACL information. It must be provided to enable ACLs.
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All servers and datacenters must agree on the ACL datacenter. Setting it on
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the servers is all you need for enforcement, but for the APIs to forward properly
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from the clients, it must be set on them too. Future changes may move
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enforcement to the edges, so it's best to just set `acl_datacenter` on all nodes.
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* <a name="acl_default_policy"></a><a href="#acl_default_policy">`acl_default_policy`</a> - Either
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"allow" or "deny"; defaults to "allow". The default policy controls the behavior of a token when
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there is no matching rule. In "allow" mode, ACLs are a blacklist: any operation not specifically
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prohibited is allowed. In "deny" mode, ACLs are a whitelist: any operation not
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specifically allowed is blocked.
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* <a name="acl_down_policy"></a><a href="#acl_down_policy">`acl_down_policy`</a> - Either
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"allow", "deny" or "extend-cache"; "extend-cache" is the default. In the case that the
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policy for a token cannot be read from the [`acl_datacenter`](#acl_datacenter) or leader
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node, the down policy is applied. In "allow" mode, all actions are permitted, "deny" restricts
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all operations, and "extend-cache" allows any cached ACLs to be used, ignoring their TTL
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values. If a non-cached ACL is used, "extend-cache" acts like "deny".
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* <a name="acl_master_token"></a><a href="#acl_master_token">`acl_master_token`</a> - Only used
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for servers in the [`acl_datacenter`](#acl_datacenter). This token will be created with management-level
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permissions if it does not exist. It allows operators to bootstrap the ACL system
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with a token ID that is well-known.
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<br><br>
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Note that the `acl_master_token` is only installed when a server acquires cluster leadership. If
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you would like to install or change the `acl_master_token`, set the new value for `acl_master_token`
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in the configuration for all servers. Once this is done, restart the current leader to force a
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leader election. If the acl_master_token is not supplied, then the servers do not create a master
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token. When you provide a value, it can be any string value. Using a UUID would ensure that it looks
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the same as the other tokens, but isn't strictly necessary.
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* <a name="acl_token"></a><a href="#acl_token">`acl_token`</a> - When provided, the agent will use this
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token when making requests to the Consul servers. Clients can override this token on a per-request
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basis by providing the "?token" query parameter. When not provided, the empty token, which maps to
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the 'anonymous' ACL policy, is used.
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* <a name="acl_ttl"></a><a href="#acl_ttl">`acl_ttl`</a> - Used to control Time-To-Live caching of ACLs.
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By default, this is 30 seconds. This setting has a major performance impact: reducing it will cause
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more frequent refreshes while increasing it reduces the number of caches. However, because the caches
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are not actively invalidated, ACL policy may be stale up to the TTL value.
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* <a name="addresses"></a><a href="#addresses">`addresses`</a> - This is a nested object that allows
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setting bind addresses.
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<br><br>
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Both `rpc` and `http` support binding to Unix domain sockets. A socket can be
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specified in the form `unix:///path/to/socket`. A new domain socket will be
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created at the given path. If the specified file path already exists, Consul
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will attempt to clear the file and create the domain socket in its place.
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<br><br>
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The permissions of the socket file are tunable via the [`unix_sockets` config
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construct](#unix_sockets).
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<br><br>
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When running Consul agent commands against Unix socket interfaces, use the
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`-rpc-addr` or `-http-addr` arguments to specify the path to the socket. You
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can also place the desired values in `CONSUL_RPC_ADDR` and `CONSUL_HTTP_ADDR`
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environment variables. For TCP addresses, these should be in the form ip:port.
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<br><br>
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The following keys are valid:
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* `dns` - The DNS server. Defaults to `client_addr`
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* `http` - The HTTP API. Defaults to `client_addr`
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* `https` - The HTTPS API. Defaults to `client_addr`
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* `rpc` - The RPC endpoint. Defaults to `client_addr`
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* <a name="advertise_addr"></a><a href="#advertise_addr">`advertise_addr`</a> Equivalent to
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the [`-advertise` command-line flag](#_advertise).
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* <a name="advertise_addrs"></a><a href="#advertise_addrs">`advertise_addrs`</a> Allows to set
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the advertised addresses for SerfLan, SerfWan and RPC together with the port. This gives
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you more control than (#_advertise) or (#_advertise-wan) while it serves the same purpose.
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These settings might override (#_advertise) and (#_advertise-wan).
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<br><br>
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This is a nested setting that allows the following keys:
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* `serf_lan` - The SerfLan address. Accepts values in the form of "host:port" like "10.23.31.101:8301".
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* `serf_wan` - The SerfWan address. Accepts values in the form of "host:port" like "10.23.31.101:8302".
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* `rpc` - The RPC address. Accepts values in the form of "host:port" like "10.23.31.101:8400".
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* <a name="advertise_addr_wan"></a><a href="#advertise_addr_wan">`advertise_addr_wan`</a> Equivalent to
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the [`-advertise-wan` command-line flag](#_advertise-wan).
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* <a name="atlas_acl_token"></a><a href="#atlas_acl_token">`atlas_acl_token`</a> When provided,
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any requests made by Atlas will use this ACL token unless explicitly overriden. When not provided
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the [`acl_token`](#acl_token) is used. This can be set to 'anonymous' to reduce permission below
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that of [`acl_token`](#acl_token).
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* <a name="atlas_infrastructure"></a><a href="#atlas_infrastructure">`atlas_infrastructure`</a>
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Equivalent to the [`-atlas` command-line flag](#_atlas).
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* <a name="atlas_join"></a><a href="#atlas_join">`atlas_join`</a> Equivalent to the
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[`-atlas-join` command-line flag](#_atlas_join).
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|
|
* <a name="atlas_token"></a><a href="#atlas_token">`atlas_token`</a> Equivalent to the
|
|
[`-atlas-token` command-line flag](#_atlas_token).
|
|
|
|
* <a name="atlas_endpoint"></a><a href="#atlas_endpoint">`atlas_endpoint`</a> Equivalent to the
|
|
[`-atlas-endpoint` command-line flag](#_atlas_endpoint).
|
|
|
|
* <a name="bootstrap"></a><a href="#bootstrap">`bootstrap`</a> Equivalent to the
|
|
[`-bootstrap` command-line flag](#_bootstrap).
|
|
|
|
* <a name="bootstrap_expect"></a><a href="#bootstrap_expect">`bootstrap_expect`</a> Equivalent
|
|
to the [`-bootstrap-expect` command-line flag](#_bootstrap_expect).
|
|
|
|
* <a name="bind_addr"></a><a href="#bind_addr">`bind_addr`</a> Equivalent to the
|
|
[`-bind` command-line flag](#_bind).
|
|
|
|
* <a name="ca_file"></a><a href="#ca_file">`ca_file`</a> This provides a file path to a PEM-encoded
|
|
certificate authority. The certificate authority is used to check the authenticity of client and
|
|
server connections with the appropriate [`verify_incoming`](#verify_incoming) or
|
|
[`verify_outgoing`](#verify_outgoing) flags.
|
|
|
|
* <a name="cert_file"></a><a href="#cert_file">`cert_file`</a> This provides a file path to a
|
|
PEM-encoded certificate. The certificate is provided to clients or servers to verify the agent's
|
|
authenticity. It must be provided along with [`key_file`](#key_file).
|
|
|
|
* <a name="check_update_interval"></a><a href="#check_update_interval">`check_update_interval`</a>
|
|
This interval controls how often check output from
|
|
checks in a steady state is synchronized with the server. By default, this is
|
|
set to 5 minutes ("5m"). Many checks which are in a steady state produce
|
|
slightly different output per run (timestamps, etc) which cause constant writes.
|
|
This configuration allows deferring the sync of check output for a given interval to
|
|
reduce write pressure. If a check ever changes state, the new state and associated
|
|
output is synchronized immediately. To disable this behavior, set the value to "0s".
|
|
|
|
* <a name="client_addr"></a><a href="#client_addr">`client_addr`</a> Equivalent to the
|
|
[`-client` command-line flag](#_client).
|
|
|
|
* <a name="datacenter"></a><a href="#datacenter">`datacenter`</a> Equivalent to the
|
|
[`-dc` command-line flag](#_dc).
|
|
|
|
* <a name="data_dir"></a><a href="#data_dir">`data_dir`</a> Equivalent to the
|
|
[`-data-dir` command-line flag](#_data_dir).
|
|
|
|
* <a name="disable_anonymous_signature"></a><a href="#disable_anonymous_signature">
|
|
`disable_anonymous_signature`</a> Disables providing an anonymous signature for de-duplication
|
|
with the update check. See [`disable_update_check`](#disable_update_check).
|
|
|
|
* <a name="disable_remote_exec"></a><a href="#disable_remote_exec">`disable_remote_exec`</a>
|
|
Disables support for remote execution. When set to true, the agent will ignore any incoming
|
|
remote exec requests.
|
|
|
|
* <a name="disable_update_check"></a><a href="#disable_update_check">`disable_update_check`</a>
|
|
Disables automatic checking for security bulletins and new version releases.
|
|
|
|
* <a name="dns_config"></a><a href="#dns_config">`dns_config`</a> This object allows a number
|
|
of sub-keys to be set which can tune how DNS queries are serviced. See this guide on
|
|
[DNS caching](/docs/guides/dns-cache.html) for more detail.
|
|
<br><br>
|
|
The following sub-keys are available:
|
|
|
|
* <a name="allow_stale"></a><a href="#allow_stale">`allow_stale`</a> - Enables a stale query
|
|
for DNS information. This allows any Consul server, rather than only the leader, to service
|
|
the request. The advantage of this is you get linear read scalability with Consul servers.
|
|
By default, this is false, meaning all requests are serviced by the leader, providing stronger
|
|
consistency but less throughput and higher latency.
|
|
|
|
* <a name="max_stale"></a><a href="#max_stale">`max_stale`</a> When [`allow_stale`](#allow_stale)
|
|
is specified, this is used to limit how
|
|
stale results are allowed to be. By default, this is set to "5s":
|
|
if a Consul server is more than 5 seconds behind the leader, the query will be
|
|
re-evaluated on the leader to get more up-to-date results.
|
|
|
|
* <a name="node_ttl"></a><a href="#node_ttl">`node_ttl`</a> By default, this is "0s", so all
|
|
node lookups are served with a 0 TTL value. DNS caching for node lookups can be enabled by
|
|
setting this value. This should be specified with the "s" suffix for second or "m" for minute.
|
|
|
|
* <a name="service_ttl"></a><a href="#service_ttl">`service_ttl`</a> This is a sub-object
|
|
which allows for setting a TTL on service lookups with a per-service policy. The "*" wildcard
|
|
service can be used when there is no specific policy available for a service. By default, all
|
|
services are served with a 0 TTL value. DNS caching for service lookups can be enabled by
|
|
setting this value.
|
|
|
|
* <a name="enable_truncate"></a><a href="#enable_truncate">`enable_truncate`</a> If set to
|
|
true, a UDP DNS query that would return more than 3 records will set the truncated flag,
|
|
indicating to clients that they should re-query using TCP to get the full set of records.
|
|
|
|
* <a name="only_passing"></a><a href="#only_passing">`only_passing`</a> If set to true, any
|
|
nodes whose healthchecks are not passing will be excluded from DNS results. By default (or
|
|
if set to false), only nodes whose healthchecks are failing as critical will be excluded.
|
|
|
|
* <a name="domain"></a><a href="#domain">`domain`</a> Equivalent to the
|
|
[`-domain` command-line flag](#_domain).
|
|
|
|
* <a name="enable_debug"></a><a href="#enable_debug">`enable_debug`</a> When set, enables some
|
|
additional debugging features. Currently, this is only used to set the runtime profiling HTTP endpoints.
|
|
|
|
* <a name="enable_syslog"></a><a href="#enable_syslog">`enable_syslog`</a> Equivalent to
|
|
the [`-syslog` command-line flag](#_syslog).
|
|
|
|
* <a name="encrypt"></a><a href="#encrypt">`encrypt`</a> Equivalent to the
|
|
[`-encrypt` command-line flag](#_encrypt).
|
|
|
|
* <a name="key_file"></a><a href="#key_file">`key_file`</a> This provides a the file path to a
|
|
PEM-encoded private key. The key is used with the certificate to verify the agent's authenticity.
|
|
This must be provided along with [`cert_file`](#cert_file).
|
|
|
|
* <a name="http_api_response_headers"></a><a href="#http_api_response_headers">`http_api_response_headers`</a>
|
|
This object allows adding headers to the HTTP API
|
|
responses. For example, the following config can be used to enable
|
|
[CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing) on
|
|
the HTTP API endpoints:
|
|
|
|
```javascript
|
|
{
|
|
"http_api_response_headers": {
|
|
"Access-Control-Allow-Origin": "*"
|
|
}
|
|
}
|
|
```
|
|
|
|
* <a name="leave_on_terminate"></a><a href="#leave_on_terminate">`leave_on_terminate`</a> If
|
|
enabled, when the agent receives a TERM signal,
|
|
it will send a `Leave` message to the rest of the cluster and gracefully
|
|
leave. Defaults to false.
|
|
|
|
* <a name="log_level"></a><a href="#log_level">`log_level`</a> Equivalent to the
|
|
[`-log-level` command-line flag](#_log_level).
|
|
|
|
* <a name="node_name"></a><a href="#node_name">`node_name`</a> Equivalent to the
|
|
[`-node` command-line flag](#_node).
|
|
|
|
* <a name="ports"></a><a href="#ports">`ports`</a> This is a nested object that allows setting
|
|
the bind ports for the following keys:
|
|
* <a name="dns_port"></a><a href="#dns_port">`dns`</a> - The DNS server, -1 to disable. Default 8600.
|
|
* <a name="http_port"></a><a href="#http_port">`http`</a> - The HTTP API, -1 to disable. Default 8500.
|
|
* <a name="https_port"></a><a href="#https_port">`https`</a> - The HTTPS API, -1 to disable. Default -1 (disabled).
|
|
* <a name="rpc_port"></a><a href="#rpc_port">`rpc`</a> - The RPC endpoint. Default 8400.
|
|
* <a name="serf_lan_port"></a><a href="#serf_lan_port">`serf_lan`</a> - The Serf LAN port. Default 8301.
|
|
* <a name="serf_wan_port"></a><a href="#serf_wan_port">`serf_wan`</a> - The Serf WAN port. Default 8302.
|
|
* <a name="server_rpc_port"></a><a href="#server_rpc_port">`server`</a> - Server RPC address. Default 8300.
|
|
|
|
* <a name="protocol"></a><a href="#protocol">`protocol`</a> Equivalent to the
|
|
[`-protocol` command-line flag](#_protocol).
|
|
|
|
* <a name="recursor"></a><a href="#recursor">`recursor`</a> Provides a single recursor address.
|
|
This has been deprecated, and the value is appended to the [`recursors`](#recursors) list for
|
|
backwards compatibility.
|
|
|
|
* <a name="recursors"></a><a href="#recursors">`recursors`</a> This flag provides addresses of
|
|
upstream DNS servers that are used to recursively resolve queries if they are not inside the service
|
|
domain for consul. For example, a node can use Consul directly as a DNS server, and if the record is
|
|
outside of the "consul." domain, the query will be resolved upstream.
|
|
|
|
* <a name="rejoin_after_leave"></a><a href="#rejoin_after_leave">`rejoin_after_leave`</a> Equivalent
|
|
to the [`-rejoin` command-line flag](#_rejoin).
|
|
|
|
* <a name="retry_join"></a><a href="#retry_join">`retry_join`</a> Equivalent to the
|
|
[`-retry-join` command-line flag](#_retry_join). Takes a list
|
|
of addresses to attempt joining every [`retry_interval`](#_retry_interval) until at least one
|
|
[`-join`](#_join) works.
|
|
|
|
* <a name="retry_interval"></a><a href="#retry_interval">`retry_interval`</a> Equivalent to the
|
|
[`-retry-interval` command-line flag](#_retry_interval).
|
|
|
|
* <a name="retry_join_wan"></a><a href="#retry_join_wan">`retry_join_wan`</a> Equivalent to the
|
|
[`-retry-join-wan` command-line flag](#_retry_join_wan). Takes a list
|
|
of addresses to attempt joining to WAN every [`retry_interval_wan`](#_retry_interval_wan) until at least one
|
|
[`-join-wan`](#_join_wan) works.
|
|
|
|
* <a name="retry_interval_wan"></a><a href="#retry_interval_wan">`retry_interval_wan`</a> Equivalent to the
|
|
[`-retry-interval-wan` command-line flag](#_retry_interval_wan).
|
|
|
|
* <a name="server"></a><a href="#server">`server`</a> Equivalent to the
|
|
[`-server` command-line flag](#_server).
|
|
|
|
* <a name="server_name"></a><a href="#server_name">`server_name`</a> When provided, this overrides
|
|
the [`node_name`](#_node) for the TLS certificate. It can be used to ensure that the certificate
|
|
name matches the hostname we declare.
|
|
|
|
* <a name="session_ttl_min"></a><a href="#session_ttl_min">`session_ttl_min`</a>
|
|
The minimum allowed session TTL. This ensures sessions are not created with
|
|
TTL's shorter than the specified limit. It is recommended to keep this limit
|
|
at or above the default to encourage clients to send infrequent heartbeats.
|
|
Defaults to 10s.
|
|
|
|
* <a name="skip_leave_on_interrupt"></a><a href="#skip_leave_on_interrupt">`skip_leave_on_interrupt`</a>
|
|
This is similar to [`leave_on_terminate`](#leave_on_terminate) but
|
|
only affects interrupt handling. By default, an interrupt (such as hitting
|
|
Control-C in a shell) causes Consul to gracefully leave. Setting this to true
|
|
disables that. Defaults to false.
|
|
|
|
* <a name="start_join"></a><a href="#start_join">`start_join`</a> An array of strings specifying addresses
|
|
of nodes to [`-join`](#_join) upon startup.
|
|
|
|
* <a name="start_join_wan"></a><a href="#start_join_wan">`start_join_wan`</a> An array of strings specifying
|
|
addresses of WAN nodes to [`-join-wan`](#_join_wan) upon startup.
|
|
|
|
* <a name="statsd_addr"></a><a href="#statsd_addr">`statsd_addr`</a> This provides the address of a statsd
|
|
instance. If provided, Consul will send various telemetry information to that instance for aggregation.
|
|
This can be used to capture runtime information. This sends UDP packets only and can be used with statsd
|
|
or statsite.
|
|
|
|
* <a name="statsite_addr"></a><a href="#statsite_addr">`statsite_addr`</a> This provides the address of a
|
|
statsite instance. If provided, Consul will stream various telemetry information to that instance for
|
|
aggregation. This can be used to capture runtime information. This streams via
|
|
TCP and can only be used with statsite.
|
|
|
|
* <a name="statsite_prefix"></a><a href="#statsite_prefix">`statsite_prefix`</a>
|
|
The prefix used while writing all telemetry data to statsite. By default, this
|
|
is set to "consul".
|
|
|
|
* <a name="syslog_facility"></a><a href="#syslog_facility">`syslog_facility`</a> When
|
|
[`enable_syslog`](#enable_syslog) is provided, this controls to which
|
|
facility messages are sent. By default, `LOCAL0` will be used.
|
|
|
|
* <a name="ui_dir"></a><a href="#ui_dir">`ui_dir`</a> - Equivalent to the
|
|
[`-ui-dir`](#_ui_dir) command-line flag.
|
|
|
|
* <a name="unix_sockets"></a><a href="#unix_sockets">`unix_sockets`</a> - This
|
|
allows tuning the ownership and permissions of the
|
|
Unix domain socket files created by Consul. Domain sockets are only used if
|
|
the HTTP or RPC addresses are configured with the `unix://` prefix. The
|
|
following options are valid within this construct and apply globally to all
|
|
sockets created by Consul:
|
|
<br>
|
|
* `user` - The name or ID of the user who will own the socket file.
|
|
* `group` - The group ID ownership of the socket file. Note that this option
|
|
currently only supports numeric IDs.
|
|
* `mode` - The permission bits to set on the file.
|
|
<br>
|
|
It is important to note that this option may have different effects on
|
|
different operating systems. Linux generally observes socket file permissions
|
|
while many BSD variants ignore permissions on the socket file itself. It is
|
|
important to test this feature on your specific distribution. This feature is
|
|
currently not functional on Windows hosts.
|
|
|
|
* <a name="verify_incoming"></a><a href="#verify_incoming">`verify_incoming`</a> - If
|
|
set to true, Consul requires that all incoming
|
|
connections make use of TLS and that the client provides a certificate signed
|
|
by the Certificate Authority from the [`ca_file`](#ca_file). By default, this is false, and
|
|
Consul will not enforce the use of TLS or verify a client's authenticity. This
|
|
applies to both server RPC and to the HTTPS API. Note: to enable the HTTPS API, you
|
|
must define an HTTPS port via the [`ports`](#ports) configuration. By default, HTTPS
|
|
is disabled.
|
|
|
|
* <a name="verify_outgoing"></a><a href="#verify_outgoing">`verify_outgoing`</a> - If set to
|
|
true, Consul requires that all outgoing connections
|
|
make use of TLS and that the server provides a certificate that is signed by
|
|
the Certificate Authority from the [`ca_file`](#ca_file). By default, this is false, and Consul
|
|
will not make use of TLS for outgoing connections. This applies to clients and servers
|
|
as both will make outgoing connections.
|
|
|
|
* <a name="verify_server_hostname"></a><a href="#verify_server_hostname">`verify_server_hostname`</a> - If set to
|
|
true, Consul verifies for all outgoing connections that the TLS certificate presented by the servers
|
|
matches "server.<datacenter>.<domain>" hostname. This implies `verify_outgoing`.
|
|
By default, this is false, and Consul does not verify the hostname of the certificate, only
|
|
that it is signed by a trusted CA. This setting is important to prevent a compromised
|
|
client from being restarted as a server, and thus being able to perform a MITM attack
|
|
or to be added as a Raft peer. This is new in 0.5.1.
|
|
|
|
* <a name="watches"></a><a href="#watches">`watches`</a> - Watches is a list of watch
|
|
specifications which allow an external process to be automatically invoked when a
|
|
particular data view is updated. See the
|
|
[watch documentation](/docs/agent/watches.html) for more detail. Watches can be
|
|
modified when the configuration is reloaded.
|
|
|
|
## Ports Used
|
|
|
|
Consul requires up to 5 different ports to work properly, some on
|
|
TCP, UDP, or both protocols. Below we document the requirements for each
|
|
port.
|
|
|
|
* Server RPC (Default 8300). This is used by servers to handle incoming
|
|
requests from other agents. TCP only.
|
|
|
|
* Serf LAN (Default 8301). This is used to handle gossip in the LAN.
|
|
Required by all agents. TCP and UDP.
|
|
|
|
* Serf WAN (Default 8302). This is used by servers to gossip over the
|
|
WAN to other servers. TCP and UDP.
|
|
|
|
* CLI RPC (Default 8400). This is used by all agents to handle RPC
|
|
from the CLI. TCP only.
|
|
|
|
* HTTP API (Default 8500). This is used by clients to talk to the HTTP
|
|
API. TCP only.
|
|
|
|
* DNS Interface (Default 8600). Used to resolve DNS queries. TCP and UDP.
|
|
|
|
## <a id="reloadable-configuration"></a>Reloadable Configuration</a>
|
|
|
|
Reloading configuration does not reload all configuration items. The
|
|
items which are reloaded include:
|
|
|
|
* Log level
|
|
* Checks
|
|
* Services
|
|
* Watches
|
|
* HTTP Client Address
|
|
* Atlas Token
|
|
* Atlas Infrastructure
|
|
* Atlas Endpoint
|