Chapter 6. APIcast environment variables

APIcast environment variables allow you to modify behavior for APIcast. The following values are supported environment variables:

ALL_PROXY

Default: no value

Value: string

Example: http://forward-proxy:80

Defines a HTTP proxy to be used for connecting to services if a protocol-specific proxy is not specified. Authentication is not supported.

APICAST_ACCESS_LOG_BUFFER

Default: no value

Value: positive integer

Allows access log writes to be included in chunks of bytes. The result is fewer system calls, which improves the performance of the gateway.

APICAST_ACCESS_LOG_FILE

Default: stdout

Defines the file that will store the access logs.

APICAST_BACKEND_CACHE_HANDLER

Default: strict

Values: strict | resilient

Deprecated: Use the Caching policy instead.

Defines how the authorization cache behaves when backend is unavailable. Strict will remove cached application when backend is unavailable. Resilient will do so only on getting authorization denied from backend.

APICAST_CACHE_MAX_TIME

Default: 1m

Value: string

When the response is selected to be cached in the system, the value of this variable indicates the maximum time to be cached. If the cache-control header is not set, the time to be cached will be the defined one.

The format for this value is defined by the proxy_cache_valid NGINX directive.

This parameter is only used by the APIs that are using a content caching policy and the request is eligible to be cached.

APICAST_CACHE_STATUS_CODES

Default: 200, 302

Value: string

When the response code from upstream matches one of the status codes defined in this environment variable, the response content is cached in NGINX. The caching time depends on one of these values: headers cache time value, or the maximum time defined by the APICAST_CACHE_MAX_TIME environment variable.

This parameter is only used by the APIs that are using a content caching policy and the request is eligible to be cached.

APICAST_CONFIGURATION_CACHE

Default: 0

Value: integer

Specifies the interval (in seconds) that the configuration will be stored for. The value should be set to 0 (not compatible with boot value of APICAST_CONFIGURATION_LOADER) or more than 60. For example, if APICAST_CONFIGURATION_CACHE is set to 120, the gateway will reload the configuration from the API manager every 2 minutes (120 seconds). A value < 0 disables reloading.

APICAST_CONFIGURATION_LOADER

Values: boot | lazy

Default: lazy

Defines how to load the configuration. Boot will request the configuration to the API manager when the gateway starts. Lazy will load it on demand for each incoming request (to guarantee a complete refresh on each request APICAST_CONFIGURATION_CACHE should be 0).

APICAST_CUSTOM_CONFIG

Deprecated: Use policies instead.

Defines the name of the Lua module that implements custom logic overriding the existing APIcast logic.

APICAST_ENVIRONMENT

Value: string[:]

Example: production:cloud-hosted

APIcast should load a list of environments (or paths), separated by colons (:). This list can be used instead of -e or --environment parameter on the CLI and for example stored in the container image as default environment. Any value passed on the CLI overrides this variable.

APICAST_EXTENDED_METRICS

Default: false

Value: boolean

Example: "true"

Enables additional information on Prometheus metrics. The following metrics have the service_id and service_system_name labels which provide more in-depth details about APIcast:

APICAST_HTTPS_CERTIFICATE

Default: no value

Path to a file with X.509 certificate in the PEM format for HTTPS.

APICAST_HTTPS_CERTIFICATE_KEY

Default: no value

Path to a file with the X.509 certificate secret key in the PEM format.

APICAST_HTTPS_PORT

Default: no value

Controls on which port APIcast should start listening for HTTPS connections. If this clashes with HTTP port it will be used only for HTTPS.

APICAST_HTTPS_PROXY_PROTOCOL

Default: false Values: boolean Example: true

This parameter enables the Proxy Protocol for the HTTPS listener.

APICAST_HTTPS_VERIFY_DEPTH

Default: 1

Values: positive integers

Defines the maximum length of the client certificate chain. If this parameter has 1 as its value, it is possible to include an additional certificate in the client certificate chain. For example, root certificate authority.

APICAST_HTTP_PROXY_PROTOCOL

Default: false

Values: boolean

Example: true

This parameter enables the proxy protocol for the HTTP listener.

APICAST_LOAD_SERVICES_WHEN_NEEDED

Default: false

Values:

This option can be used when there are many services configured. However, its performance depends on additional factors, for example, the number of services, the latency between APIcast and the 3scale Admin Portal, and the Time To Live (TTL) of the configuration.

By default, APIcast loads all the services each time it downloads its configuration from the Admin Portal. When this option is enabled, the configurations uses lazy loading. APIcast will only load the ones configured for the host specified in the host header of the request.

APICAST_LOG_FILE

Default: stderr

Defines the file that contains the OpenResty error log. The file is used by bin/apicast in the error_log directive. The file path can be either absolute, or relative to the APIcast prefix directory. Note that the default prefix directory is APIcast. Refer to NGINX documentation for more information.

APICAST_LOG_LEVEL

Default: warn

Values: debug | info | notice | warn | error | crit | alert | emerg

Specifies the log level for the OpenResty logs.

APICAST_MANAGEMENT_API

Values:

The Management API is powerful and can control the APIcast configuration. You should enable the debug level only for debugging.

APICAST_MODULE

Default: apicast

Deprecated: Use policies instead.

Specifies the name of the main Lua module that implements the API gateway logic. Custom modules can override the functionality of the default apicast.lua module. See an example of how to use modules.

APICAST_OIDC_LOG_LEVEL

Values: debug | info | notice | warn | error | crit | alert | emerg

Default: err

Allows to set the log level for the logs related to OpenID Connect integration.

APICAST_PATH_ROUTING

Values:

When this parameter is set to true, the gateway will use path-based routing in addition to the default host-based routing. The API request will be routed to the first service that has a matching mapping rule, from the list of services for which the value of the Host header of the request matches the Public Base URL.

APICAST_PATH_ROUTING_ONLY

Values:

When this parameter is set to true, the gateway uses path-based routing and will not fallback to the default host-based routing. The API request is routed to the first service that has a matching mapping rule, from the list of services for which the value of the Host header of the request matches the Public Base URL.

This parameter has precedence over APICAST_PATH_ROUTING. If APICAST_PATH_ROUTING_ONLY is enabled, APIcast will only do path-based routing regardless of the value of APICAST_PATH_ROUTING.

APICAST_POLICY_BATCHER_SHARED_MEMORY_SIZE

Default: 20m

Value: string

Sets the maximum size of shared memory used by batcher policy.

The accepted size units are k and m:

http {
     lua_shared_dict batched_reports 20m;
     ...
 }

APICAST_POLICY_LOAD_PATH

Default: APICAST_DIR/policies

Value: string[:]

Example: ~/apicast/policies:$PWD/policies

A colon (:) separated list of paths where APIcast should look for policies. It can be used to first load policies from a development directory or to load examples.

APICAST_PROXY_HTTPS_CERTIFICATE

Default:

Value: string

Example: /home/apicast/my_certificate.crt

The path to the client SSL certificate that APIcast will use when connecting with the upstream. Notice that this certificate will be used for all the services in the configuration.

APICAST_PROXY_HTTPS_CERTIFICATE_KEY

Default:

Value: string

Example: /home/apicast/my_certificate.key

The path to the key of the client SSL certificate.

APICAST_PROXY_HTTPS_PASSWORD_FILE

Default:

Value: string

Example: /home/apicast/passwords.txt

Path to a file with passphrases for the SSL cert keys specified with APICAST_PROXY_HTTPS_CERTIFICATE_KEY.

APICAST_PROXY_HTTPS_SESSION_REUSE

Default: on

Values:

APICAST_REPORTING_THREADS

Default: 0

Value: integer >= 0

Experimental: Under extreme load might have unpredictable performance and lose reports.

Value greater than 0 is going to enable out-of-band reporting to backend. This is a new experimental feature for increasing performance. Client won’t see the backend latency and everything will be processed asynchronously. This value determines how many asynchronous reports can be running simultaneously before the client is throttled by adding latency.

APICAST_RESPONSE_CODES

Default: <empty> (false)

Values:

When set to true, APIcast will log the response code of the response returned by the API backend in 3scale. For more information, see Setting up and evaluating the 3scale API Management response codes log for your API.

APICAST_SERVICE_CACHE_SIZE

Default: 1000

Values: integer >= 0

Specifies the number of services that APIcast can store in the internal cache. A high value has a performance impact because Lua’s lru cache will initialize all the entries.

APICAST_SERVICE_${ID}_CONFIGURATION_VERSION

Replace ${ID} with the actual Service ID. The value should be the configuration version you can see in the configuration history on the Admin Portal. Setting it to a particular version will prevent it from auto-updating and will always use that version.

APICAST_SERVICES_LIST

Value: a comma-separated list of service IDs

The APICAST_SERVICES_LIST environment variable is used to filter the services you configure in the 3scale API Manager. This only applies the configuration for specific services in the gateway, discarding those service identifiers that are not specified in the list. You can find service identifiers for your product in the Admin Portal under Products > [Your_product_name] > Overview, then see Configuration, Methods and Settings and the ID for API calls.

APICAST_SERVICES_FILTER_BY_URL

Value: a PCRE (Perl Compatible Regular Expression) such as .*.example.com.

Filters the services configured in the 3scale API Manager.

This filter matches with the Public Base URL, either staging or production. Services that do not match the filter are discarded. If the regular expression cannot be compiled, no services are loaded.

APICAST_UPSTREAM_RETRY_CASES

Values: error | timeout | invalid_header | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429 | non_idempotent | off

APICAST_WORKERS

Default: auto

Values: integer | auto

This is the value that will be used in the nginx worker_processes directive. By default, APIcast uses auto, except for the development environment where 1 is used.

BACKEND_ENDPOINT_OVERRIDE

URI that overrides backend endpoint from the configuration. Useful when deploying outside OpenShift deployed AMP. Example: https://backend.example.com.

HTTP_KEEPALIVE_TIMEOUT

Default: 75

Value: positive integers

Example: 1

This parameter sets a timeout during which a keep-alive client connection will stay open on the server side. The zero value disables keep-alive client connections.

By default, the gateway keeps HTTP_KEEPALIVE_TIMEOUT disabled. This configuration allows the use of the keepalive timeout from NGINX whose default value is 75 seconds.

http_proxy, HTTP_PROXY

Default: no value

Value: string

Example: http://forward-proxy:80

Defines a HTTP proxy to be used for connecting to HTTP services. Authentication is not supported.

https_proxy, HTTPS_PROXY

Default: no value

Value: string

Example: https://forward-proxy:443

Defines a HTTP proxy to be used for connecting to HTTPS services. Authentication is not supported.

no_proxy, NO_PROXY

Default: no value

Value: string\[,<string>\]; *

Example: foo,bar.com,.extra.dot.com

Defines a comma-separated list of hostnames and domain names for which the requests should not be proxied. Setting to a single * character, which matches all hosts, effectively disables the proxy.

OPENSSL_VERIFY

Values:

Controls the OpenSSL Peer Verification. It is off by default, because OpenSSL can’t use system certificate store. It requires custom certificate bundle and adding it to trusted certificates.

It is recommended to use https://github.com/openresty/lua-nginx-module#lua_ssl_trusted_certificate and point to to certificate bundle generated by export-builtin-trusted-certs.

OPENTRACING_CONFIG

This environment variable is used to determine the config file for the opentracing tracer, if OPENTRACING_TRACER is not set, this variable will be ignored.

Each tracer has a default configuration file: * jaeger: conf.d/opentracing/jaeger.example.json

You can choose to mount a different configuration than the provided by default by setting the file path using this variable.

Example: /tmp/jaeger/jaeger.json

OPENTRACING_HEADER_FORWARD

Default: uber-trace-id

This environment variable controls the HTTP header used for forwarding opentracing information, this HTTP header will be forwarded to upstream servers.

OPENTRACING_TRACER

Example: jaeger

This environment variable controls which tracing library will be loaded, right now, there’s only one opentracing tracer available, jaeger.

If empty, opentracing support will be disabled.

RESOLVER

Allows to specify a custom DNS resolver that will be used by OpenResty. If the RESOLVER parameter is empty, the DNS resolver will be autodiscovered.

THREESCALE_CONFIG_FILE

Path to the JSON file with the configuration for the gateway. You must provide either THREESCALE_PORTAL_ENDPOINT or THREESCALE_CONFIG_FILE for the gateway to run successfully. From these two environment variables, THREESCALE_CONFIG_FILE takes precedence

To build the file with the configuration for the gateway, you have two alternatives depending on the number of services:

When you deploy the gateway using a container image:

You can find sample configuration files in examples folder.

THREESCALE_DEPLOYMENT_ENV

Default: production

Values: staging | production

The value of this environment variable defines the environment from which the configuration will be downloaded from; this is either 3scale staging or production, when using new APIcast.

The value will also be used in the header X-3scale-User-Agent in the authorize/report requests made to 3scale Service Management API. It is used by 3scale solely for statistics.

THREESCALE_PORTAL_ENDPOINT

URI that includes your password and portal endpoint in the following format:

<schema>://<password>@<admin-portal>.

where:

Example: https://access-token@account-admin.3scale.net.

When the THREESCALE_PORTAL_ENDPOINT environment variable is provided and APICAST_CONFIGURATION_LOADER=boot, the gateway downloads the configuration from 3scale on initializing. The configuration includes all the settings provided on the integration page of the APIs under [Your_product_name] > Integration.

You can also use this environment variable to create a single gateway with the Master Admin Portal.

To run the gateway successfully, you must provide either THREESCALE_PORTAL_ENDPOINT or THREESCALE_CONFIG_FILE. Note that THREESCALE_CONFIG_FILE takes precedence over THREESCALE_PORTAL_ENDPOINT.

The configuration is fetched when needed by default. The following are logic specifications: