Configuration

Without configuration, PostgREST won’t be able to serve requests. At the minimum it needs either a role to serve anonymous requests with - or a secret to use for JWT authentication. Config parameters can be provided via Config File, via Environment Variables or through In-Database Configuration.

To connect to a database it uses a libpq connection string. The connection string can be set in the configuration file or via environment variable or can be read from an external file. See db-uri for details. Any parameter that is not set in the connection string is read from libpq environment variables. The default connection string is postgresql://, which reads all parameters from the environment.

The user with whom PostgREST connects to the database is also known as the authenticator role. For more information about the anonymous vs authenticator roles see Overview of Role System.

Config parameters are read in the following order:

  1. From the config file.

  2. From environment variables, overriding values from the config file.

  3. From the database, overriding values from both the config file and environment variables.

Config File

PostgREST can read a config file. There is no predefined location for this file, you must specify the file path as the one and only argument to the server:

./postgrest /path/to/postgrest.conf

备注

Configuration can be reloaded without restarting the server. See Configuration Reloading.

The configuration file must contain a set of key value pairs:

# postgrest.conf

# The standard connection URI format, documented at
# https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
db-uri       = "postgres://user:pass@host:5432/dbname"

# The database role to use when no client authentication is provided.
# Should differ from authenticator
db-anon-role = "anon"

# The secret to verify the JWT for authenticated requests with.
# Needs to be 32 characters minimum.
jwt-secret           = "reallyreallyreallyreallyverysafe"
jwt-secret-is-base64 = False

# Port the postgrest process is listening on for http requests
server-port = 80

You can run postgrest --example to display all possible configuration parameters and how to use them in a configuration file.

Environment Variables

You can also set these configuration parameters using environment variables. They are capitalized, have a PGRST_ prefix, and use underscores. For example: PGRST_DB_URI corresponds to db-uri and PGRST_APP_SETTINGS_* to app.settings.*.

In-Database Configuration

By adding settings to the authenticator role (see Overview of Role System), you can make the database the single source of truth for PostgREST’s configuration. This is enabled by db-config.

For example, you can configure db-schemas and jwt-secret like this:

ALTER ROLE authenticator SET pgrst.db_schemas = "tenant1, tenant2, tenant3"
ALTER ROLE authenticator IN DATABASE <your_database_name> SET pgrst.jwt_secret = "REALLYREALLYREALLYREALLYVERYSAFE"

You can use both database-specific settings with IN DATABASE and cluster-wide settings without it. Database-specific settings will override cluster-wide settings if both are used for the same parameter.

Note that underscores(_) need to be used instead of dashes(-) for the in-database config parameters.

重要

For altering a role in this way, you need a SUPERUSER. You might not be able to use this configuration mode on cloud-hosted databases.

When using both the configuration file and the in-database configuration, the latter takes precedence.

危险

If direct connections to the database are allowed, then it’s not safe to use the in-db configuration for storing the jwt-secret. The settings of every role are PUBLIC - they can be viewed by any user that queries the pg_catalog.pg_db_role_setting table. In this case you should keep the jwt-secret in the configuration file or as environment variables.

Configuration Reloading

It’s possible to reload PostgREST’s configuration without restarting the server. You can do this via signal or via notification.

It’s not possible to change Environment Variables for a running process and reloading a Docker container configuration will not work. In these cases, you need to restart the PostgREST server or use In-Database Configuration as an alternative.

重要

The following settings will not be reloaded. You will need to restart PostgREST to change those.

Reload with signal

To reload the configuration via signal, send a SIGUSR2 signal to the server process.

killall -SIGUSR2 postgrest

Reload with NOTIFY

To reload the configuration from within the database, you can use a NOTIFY command.

NOTIFY pgrst, 'reload config'

The "pgrst" notification channel is enabled by default. For configuring the channel, see db-channel and db-channel-enabled.

List of parameters

Name

Type

Default

Reloadable

admin-server-port

Int

app.settings.*

String

Y

db-anon-role

String

Y

db-channel

String

pgrst

Y

db-channel-enabled

Boolean

True

Y

db-config

Boolean

True

Y

db-extra-search-path

String

public

Y

db-max-rows

Int

Y

db-plan-enabled

Boolean

False

Y

db-pool

Int

10

db-pool-timeout

Int

3600

db-pre-request

String

Y

db-prepared-statements

Boolean

True

Y

db-schemas

String

public

Y

db-tx-end

String

commit

db-uri

String

postgresql://

db-use-legacy-gucs

Boolean

True

Y

jwt-aud

String

Y

jwt-role-claim-key

String

.role

Y

jwt-secret

String

Y

jwt-secret-is-base64

Boolean

False

Y

log-level

String

error

Y

openapi-mode

String

follow-privileges

Y

openapi-security-active

Boolean

False

Y

openapi-server-proxy-uri

String

Y

raw-media-types

String

Y

server-host

String

!4

server-port

Int

3000

server-unix-socket

String

server-unix-socket-mode

String

660

admin-server-port

Environment

PGRST_ADMIN_SERVER_PORT

In-Database

n/a

Specifies the port for the Health Check endpoints.

app.settings.*

Environment

PGRST_APP_SETTINGS_*

In-Database

pgrst.app_settings_*

Arbitrary settings that can be used to pass in secret keys directly as strings, or via OS environment variables. For instance: app.settings.jwt_secret = "$(MYAPP_JWT_SECRET)" will take MYAPP_JWT_SECRET from the environment and make it available to postgresql functions as current_setting('app.settings.jwt_secret').

db-anon-role

Environment

PGRST_DB_ANON_ROLE

In-Database

n/a

The database role to use when executing commands on behalf of unauthenticated clients. For more information, see Overview of Role System.

When unset anonymous access will be blocked.

db-channel

Environment

PGRST_DB_CHANNEL

In-Database

n/a

The name of the notification channel that PostgREST uses for Schema Cache Reloading and configuration reloading.

db-channel-enabled

Environment

PGRST_DB_CHANNEL_ENABLED

In-Database

n/a

When this is set to true, the notification channel specified in db-channel is enabled.

You should set this to false when using PostgresSQL behind an external connection pooler such as PgBouncer working in transaction pooling mode. See this section for more information.

db-config

Environment

PGRST_DB_CONFIG

In-Database

n/a

Enables the in-database configuration.

db-extra-search-path

Environment

PGRST_DB_EXTRA_SEARCH_PATH

In-Database

pgrst.db_extra_search_path

Extra schemas to add to the search_path of every request. These schemas tables, views and stored procedures don’t get API endpoints, they can only be referred from the database objects inside your db-schemas.

This parameter was meant to make it easier to use PostgreSQL extensions (like PostGIS) that are outside of the db-schemas.

Multiple schemas can be added in a comma-separated string, e.g. public, extensions.

db-max-rows

For backwards compatibility, this config parameter is also available without prefix as “max-rows”.

Environment

PGRST_DB_MAX_ROWS

In-Database

pgrst.db_max_rows

A hard limit to the number of rows PostgREST will fetch from a view, table, or stored procedure. Limits payload size for accidental or malicious requests.

db-plan-enabled

Environment

PGRST_DB_PLAN_ENABLED

In-Database

pgrst.db_plan_enabled

When this is set to true, the execution plan of a request can be retrieved by using the Accept: application/vnd.pgrst.plan header. See Execution plan.

db-pool

Environment

PGRST_DB_POOL

In-Database

n/a

Number of connections to keep open in PostgREST’s database pool. Having enough here for the maximum expected simultaneous client connections can improve performance. Note it’s pointless to set this higher than the max_connections GUC in your database.

db-pool-timeout

Environment

PGRST_DB_POOL_TIMEOUT

In-Database

n/a

Time to live, in seconds, for an idle database pool connection. If the timeout is reached the connection will be closed. Once a new request arrives a new connection will be started.

db-pre-request

For backwards compatibility, this config parameter is also available without prefix as “pre-request”.

Environment

PGRST_DB_PRE_REQUEST

In-Database

pgrst.db_pre_request

A schema-qualified stored procedure name to call right after switching roles for a client request. This provides an opportunity to modify SQL variables or raise an exception to prevent the request from completing.

db-prepared-statements

Environment

PGRST_DB_PREPARED_STATEMENTS

In-Database

pgrst.db_prepared_statements

Enables or disables prepared statements.

When disabled, the generated queries will be parameterized (invulnerable to SQL injection) but they will not be prepared (cached in the database session). Not using prepared statements will noticeably decrease performance, so it’s recommended to always have this setting enabled.

You should only set this to false when using PostgresSQL behind an external connection pooler such as PgBouncer working in transaction pooling mode. See this section for more information.

db-schemas

For backwards compatibility, this config parameter is also available in singular as “db-schema”.

Environment

PGRST_DB_SCHEMAS

In-Database

pgrst.db_schemas

The database schema to expose to REST clients. Tables, views and stored procedures in this schema will get API endpoints.

db-schemas = "api"

This schema gets added to the search_path of every request.

List of schemas

You can also specify a list of schemas that can be used for schema-based multitenancy and api versioning by Switching Schemas. Example:

db-schemas = "tenant1, tenant2"

If you don’t Switch Schemas, the first schema in the list(tenant1 in this case) is chosen as the default schema.

Only the chosen schema gets added to the search_path of every request.

警告

Never expose private schemas in this way. See Schema Isolation.

db-tx-end

Environment

PGRST_DB_TX_END

In-Database

pgrst.db_tx_end

Specifies how to terminate the database transactions.

# The transaction is always committed
db-tx-end = "commit"

# The transaction is committed unless a "Prefer: tx=rollback" header is sent
db-tx-end = "commit-allow-override"

# The transaction is always rolled back
db-tx-end = "rollback"

# The transaction is rolled back unless a "Prefer: tx=commit" header is sent
db-tx-end = "rollback-allow-override"

db-uri

Environment

PGRST_DB_URI

In-Database

n/a

The standard connection PostgreSQL URI format. Symbols and unusual characters in the password or other fields should be percent encoded to avoid a parse error. If enforcing an SSL connection to the database is required you can use sslmode in the URI, for example postgres://user:pass@host:5432/dbname?sslmode=require.

When running PostgREST on the same machine as PostgreSQL, it is also possible to connect to the database using a Unix socket and the Peer Authentication method as an alternative to TCP/IP communication and authentication with a password, this also grants higher performance. To do this you can omit the host and the password, e.g. postgres://user@/dbname, see the libpq connection string documentation for more details.

Choosing a value for this parameter beginning with the at sign such as @filename (e.g. @./configs/my-config) loads the connection string out of an external file.

db-use-legacy-gucs

Environment

PGRST_DB_USE_LEGACY_GUCS

In-Database

pgrst.db_use_legacy_gucs

Determine if GUC request settings for headers, cookies and jwt claims use the legacy names (string with dashes, invalid starting from PostgreSQL v14) with text values instead of the new names (string without dashes, valid on all PostgreSQL versions) with json values.

On PostgreSQL versions 14 and above, this parameter is ignored.

jwt-aud

Environment

PGRST_JWT_AUD

In-Database

pgrst.jwt_aud

Specifies the JWT audience claim. If this claim is present in the client provided JWT then you must set this to the same value as in the JWT, otherwise verifying the JWT will fail.

jwt-role-claim-key

For backwards compatibility, this config parameter is also available without prefix as “role-claim-key”.

Environment

PGRST_JWT_ROLE_CLAIM_KEY

In-Database

pgrst.jwt_role_claim_key

A JSPath DSL that specifies the location of the role key in the JWT claims. This can be used to consume a JWT provided by a third party service like Auth0, Okta or Keycloak. Usage examples:

# {"postgrest":{"roles": ["other", "author"]}}
# the DSL accepts characters that are alphanumerical or one of "_$@" as keys
jwt-role-claim-key = ".postgrest.roles[1]"

# {"https://www.example.com/role": { "key": "author }}
# non-alphanumerical characters can go inside quotes(escaped in the config value)
jwt-role-claim-key = ".\"https://www.example.com/role\".key"

jwt-secret

Environment

PGRST_JWT_SECRET

In-Database

pgrst.jwt_secret

The secret or JSON Web Key (JWK) (or set) used to decode JWT tokens clients provide for authentication. For security the key must be at least 32 characters long. If this parameter is not specified then PostgREST refuses authentication requests. Choosing a value for this parameter beginning with the at sign such as @filename loads the secret out of an external file. This is useful for automating deployments. Note that any binary secrets must be base64 encoded. Both symmetric and asymmetric cryptography are supported. For more info see Asymmetric Keys.

Choosing a value for this parameter beginning with the at sign such as @filename (e.g. @./configs/my-config) loads the secret out of an external file.

警告

Only when using the Config File, if the jwt-secret contains a $ character by itself it will give errors. In this case, use $$ and PostgREST will interpret it as a single $ character.

jwt-secret-is-base64

Environment

PGRST_JWT_SECRET_IS_BASE64

In-Database

pgrst.jwt_secret_is_base64

When this is set to true, the value derived from jwt-secret will be treated as a base64 encoded secret.

log-level

Environment

PGRST_LOG_LEVEL

In-Database

n/a

Specifies the level of information to be logged while running PostgREST.

# Only startup and db connection recovery messages are logged
log-level = "crit"

# All the "crit" level events plus server errors (status 5xx) are logged
log-level = "error"

# All the "error" level events plus request errors (status 4xx) are logged
log-level = "warn"

# All the "warn" level events plus all requests (every status code) are logged
log-level = "info"

Because currently there’s no buffering for logging, the levels with minimal logging(crit/error) will increase throughput.

openapi-mode

Environment

PGRST_OPENAPI_MODE

In-Database

pgrst.openapi_mode

Specifies how the OpenAPI output should be displayed.

# Follows the privileges of the JWT role claim (or from db-anon-role if the JWT is not sent)
# Shows information depending on the permissions that the role making the request has
openapi-mode = "follow-privileges"

# Ignores the privileges of the JWT role claim (or from db-anon-role if the JWT is not sent)
# Shows all the exposed information, regardless of the permissions that the role making the request has
openapi-mode = "ignore-privileges"

# Disables the OpenApi output altogether.
# Throws a `404 Not Found` error when accessing the API root path
openapi-mode = "disabled"

openapi-security-active

Environment

PGRST_OPENAPI_SECURITY_ACTIVE

In-Database

pgrst.openapi_security_active

When this is set to true, security options are included in the OpenAPI output.

openapi-server-proxy-uri

Environment

PGRST_OPENAPI_SERVER_PROXY_URI

In-Database

pgrst.openapi_server_proxy_uri

Overrides the base URL used within the OpenAPI self-documentation hosted at the API root path. Use a complete URI syntax scheme:[//[user:password@]host[:port]][/]path[?query][#fragment]. Ex. https://postgrest.com

{
  "swagger": "2.0",
  "info": {
    "version": "0.4.3.0",
    "title": "PostgREST API",
    "description": "This is a dynamic API generated by PostgREST"
  },
  "host": "postgrest.com:443",
  "basePath": "/",
  "schemes": [
    "https"
  ]
}

raw-media-types

Environment

PGRST_RAW_MEDIA_TYPES

In-Database

pgrst.raw_media_types

This serves to extend the Media Types that PostgREST currently accepts through an Accept header.

These media types can be requested by following the same rules as the ones defined in Response Formats For Scalar Responses.

As an example, the below config would allow you to request an image and a XML file by doing a request with Accept: image/png or Accept: font/woff2, respectively.

raw-media-types="image/png, font/woff2"

server-host

Environment

PGRST_SERVER_HOST

In-Database

n/a

Where to bind the PostgREST web server. In addition to the usual address options, PostgREST interprets these reserved addresses with special meanings:

  • * - any IPv4 or IPv6 hostname

  • *4 - any IPv4 or IPv6 hostname, IPv4 preferred

  • !4 - any IPv4 hostname

  • *6 - any IPv4 or IPv6 hostname, IPv6 preferred

  • !6 - any IPv6 hostname

server-port

Environment

PGRST_SERVER_PORT

In-Database

n/a

The TCP port to bind the web server.

server-unix-socket

Environment

PGRST_SERVER_UNIX_SOCKET

In-Database

n/a

Unix domain socket where to bind the PostgREST web server. If specified, this takes precedence over server-port. Example:

server-unix-socket = "/tmp/pgrst.sock"

server-unix-socket-mode

Environment

PGRST_SERVER_UNIX_SOCKET_MODE

In-Database

n/a

Unix file mode to be set for the socket specified in server-unix-socket Needs to be a valid octal between 600 and 777.

server-unix-socket-mode = "660"