Configure the relay proxy
Getting Started
The configuration of the relay proxy is based on a configuration file that you have to provide.
The only mandatory information you need to start the server is to provide where to retrieve your feature flags configuration.
retriever:
kind: file
path: /goff/flags.yaml # Location of your feature flag files
Global configuration
You can override file configurations using environment variables.
Note that all environment variables should be uppercase.
If you want to replace a nested fields, please use _
to separate each field (ex: RETRIEVER_KIND
).
Field name | Type | Default | Description |
---|---|---|---|
retriever | retriever | none | (mandatory) This is the configuration on how to retrieve the configuration of the files. Note: this field is mandatory only if retrievers is not set. |
retrievers | []retriever | none | (mandatory) Exactly the same things as retriever except that you can provide more than 1 retriever.Note: this field is mandatory only if retriever is not set. |
listen | int | 1031 | This is the port used by the relay proxy when starting the HTTP server. |
pollingInterval | int | 60000 | This is the time interval in millisecond when the relay proxy is reloading the configuration file. The minimum time accepted is 1000 millisecond. |
enablePollingJitter | boolean | false | Set to true if you want to avoid having true periodicity when retrieving your flags. It is useful to avoid having spike on your flag configuration storage in case your application is starting multiple instance at the same time. We ensure a deviation that is maximum ±10% of your polling interval. Default: false |
hideBanner | boolean | false | Should we display the beautiful go-feature-flag banner when starting the relay proxy |
enableSwagger | boolean | false | Enables Swagger for testing the APIs directly. If you are enabling Swagger you will have to provide the host configuration and the Swagger UI will be available at http://<host>:<listen>/swagger/ . |
host | string | localhost | This is the DNS you will use to access the relay proxy. This field is used by Swagger to query the API at the right place. |
restApiTimeout | int | 5000 | Timeout in milliseconds for API calls. |
logLevel | string | info | The log level to use for the relay proxy. Available values are ERROR , WARN , INFO , DEBUG . |
fileFormat | string | yaml | This is the format of your go-feature-flag configuration file. Acceptable values are yaml , json , toml . |
startWithRetrieverError | boolean | false | By default the relay proxy will crash if it is not able to retrieve the flags from the configuration. If you don't want your relay proxy to crash, you can set startWithRetrieverError to true. Until the flag is retrievable the relay proxy will only answer with default values. |
exporter | exporter | none | Exporter is the configuration used to export data. |
notifier | notifier | none | Notifiers is the configuration on where to notify a flag change. |
authorizedKeys | authorizedKeys | none | List of authorized API keys. |
evaluationContextEnrichment | object | none | It is a free field that will be merged with the evaluation context sent during the evaluation. It is useful to add common attributes to all the evaluations, such as a server version, environment, etc. These fields will be included in the custom attributes of the evaluation context. If in the evaluation context you have a field with the same name, it will be overriden by the evaluationContextEnrichment . |
openTelemetryOtlpEndpoint | string | none | Endpoint of your OpenTelemetry OTLP collector, used to send traces to it and you will be able to forward them to your OpenTelemetry solution with the appropriate provider. |
kafka | object | none | Settings for the Kafka exporter. Mandatory when using the 'kafka' exporter type, and ingored otherwise. |
projectID | string | none | ID of GCP project. Mandatory when using PubSub exporter. |
topic | string | none | Name of PubSub topic on which messages will be published. Mandatory when using PubSub exporter. |
type authorizedKeys
To be able to control who can access your relay proxy, you can set a list of authorized keys.
Field name | Type | Default | Description |
---|---|---|---|
evaluation | []string | none | If set, we will check for each evaluation if an authorized key is provided. Each request will need to provide one of authorized key inside Authorization header with format Bearer <api-key> .Note: there will be no authorization when this config is not set. |
admin | []string | none | You need to set API keys in this field if you want to access the /v1/admin/* endpoints.If no api key is configured the endpoint will be unreachable. Each request will need to provide one of authorized key inside Authorization header with format Bearer <api-key> . |
type retriever
go-feature-flag
supports different kind of retriever types such as S3, Google store, etc ...
In this section we will present all the available retriever configurations available.
S3
If you are using the S3 provider, the easiest way to provide credentials is to set environment variables. It will be used by GO Feature Flag to identify to your S3 bucket.
export AWS_SECRET_ACCESS_KEY=xxxx
export AWS_ACCESS_KEY_ID=xxx
export AWS_DEFAULT_REGION=eu-west-1
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be s3 .This field is mandatory and describes which retriever you are using. |
bucket | string | none | (mandatory) This is the name of your S3 bucket (ex: my-featureflag-bucket ). |
item | string | none | (mandatory) Path to the file inside the bucket (ex: config/flag/my-flags.yaml ). |
GitHub
GitHub has rate limits, be sure to correctly set your PollingInterval
to avoid reaching the limit.
If the rate limit is reached, the retriever will return an error and will stop polling until GitHub allows it again.
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be github .This field is mandatory and describes which retriever you are using. |
repositorySlug | string | none | (mandatory) The repository slug of the GitHub repository where your file is located (ex: thomaspoignant/go-feature-flag ). |
path | string | none | (mandatory) Path to the file inside the repository (ex: config/flag/my-flags.yaml ). |
branch | string | main | The branch we should check in the repository. |
token | string | none | Github token used to access a private repository, you need the repo permission (how to create a GitHub token). |
timeout | string | 10000 | Timeout in millisecond used when calling GitHub. |
GitLab
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be gitlab .This field is mandatory and describes which retriever you are using. |
repositorySlug | string | none | (mandatory) The repository slug of the GitLab repository where your file is located (ex: thomaspoignant/go-feature-flag ). |
path | string | none | (mandatory) Path to the file inside the repository (ex: config/flag/my-flags.yaml ). |
baseUrl | string | https://gitlab.com | The base URL of your GitLab instance. |
branch | string | main | The branch we should check in the repository. |
token | string | none | GitLab personal access token used to access a private repository (Create a personal access token). |
timeout | string | 10000 | Timeout in millisecond used when calling GitLab. |
File
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be file .This field is mandatory and describes which retriever you are using. |
path | string | none | (mandatory) Path to the file in your local computer (ex: /goff/my-flags.yaml ). |
HTTP
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be http .This field is mandatory and describes which retriever you are using. |
url | string | none | (mandatory) Location to retrieve the file. |
method | string | GET | The HTTP Method you are using to call the HTTP endpoint. |
body | string | none | The HTTP Body you are using to call the HTTP endpoint. |
headers | map[string][]string | none | The HTTP headers used when calling the HTTP endpoint (useful for authorization). |
timeout | string | 10000 | Timeout in millisecond when calling the HTTP endpoint. |
Google Storage
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be googleStorage .This field is mandatory and describes which retriever you are using. |
bucket | string | none | (mandatory) This is the name of your Google Storage bucket (ex: my-featureflag-bucket ). |
object | string | none | (mandatory) Path to the file inside the bucket (ex: config/flag/my-flags.yaml ). |
Kubernetes ConfigMap
Note that relay proxy is only supporting this while running inside the kubernetes cluster.
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be configmap .This field is mandatory and describes which retriever you are using. |
namespace | string | none | (mandatory) This is the name of the namespace where your configmap is located (ex: default ). |
configmap | string | none | (mandatory) Name of the configmap we should read (ex: feature-flag ). |
key | string | none | (mandatory) Name of the key in the configmap which contains the flag. |
MongoDB
To understand the format in which a flag needs to be configured in MongoDB, check the example available.
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be mongodb .This field is mandatory and describes which retriever you are using. |
uri | string | none | (mandatory) This is the MongoDB URI used in order to connect to the MongoDB instance. |
database | string | none | (mandatory) Name of the database where flags are stored. |
collection | string | none | (mandatory) Name of the collection where flags are stored. |
Redis
To understand the format in which a flag needs to be configured in Redis, check the doc available.
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be redis .This field is mandatory and describes which retriever you are using. |
options | object | none | (mandatory) Options used to connect to your redis instance. All the options from the go-redis SDK are available (check redis.Options ) |
prefix | string | none | Prefix used before your flag name in the Redis DB. |
type exporter
Webhook
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be webhook .This field is mandatory and describes which retriever you are using. |
endpointUrl | string | none | (mandatory) EndpointURL of your webhook. |
flushInterval | int | 60000 | The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval we will call the webhook before). |
maxEventInMemory | int | 100000 | If we hit that limit we will call the webhook. |
secret | string | none | Secret used to sign your request body and fill the X-Hub-Signature-256 header.See signature section for more details. |
meta | map[string]string | none | Add all the information you want to see in your request. |
headers | map[string][]string | none | Add all the headers you want to add while calling the endpoint |
File
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be file .This field is mandatory and describes which retriever you are using. |
outputDir | string | none | (mandatory) OutputDir is the location of the directory where to store the exported files. It should finish with a / . |
flushInterval | int | 60000 | The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval we will call the webhook before). |
maxEventInMemory | int | 100000 | If we hit that limit we will call the webhook. |
format | string | JSON | Format is the output format you want in your exported file. Available format: JSON , CSV , Parquet . |
filename | string | flag-variation-{{ .Hostname}}-{{ .Timestamp}}.{{ .Format}} | You can use a templated config to define the name of your exported files. Available replacements are {{ .Hostname}} , {{ .Timestamp}} and {{ .Format} |
csvTemplate | string | {{ .Kind}};{{ .ContextKind}};{{ .UserKey}};{{ .CreationDate}};{{ .Key}};{{ .Variation}};{{ .Value}};{{ .Default}};{{ .Source}}\n | CsvTemplate is used if your output format is CSV. This field will be ignored if you are using format other than CSV. You can decide which fields you want in your CSV line with a go-template syntax, please check internal/exporter/feature_event.go to see the fields available. |
parquetCompressionCodec | string | SNAPPY | ParquetCompressionCodec is the parquet compression codec for better space efficiency. Available options |
Log
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be log .This field is mandatory and describes which retriever you are using. |
flushInterval | int | 60000 | The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval, we will call the webhook before). |
maxEventInMemory | int | 100000 | If we hit that limit we will call the webhook. |
logFormat | string | [{{ .FormattedDate}}] user="{{ .UserKey}}", flag="{{ .Key}}", value="{{ .Value}}" | LogFormat is the template configuration of the output format of your log. You can use all the key from the exporter.FeatureEvent + a key called FormattedDate that represent the date with the RFC 3339 Format. |
S3
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be s3 .This field is mandatory and describes which retriever you are using. |
bucket | string | none | (mandatory) Name of your S3 Bucket. |
flushInterval | int | 60000 | The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval we will call the webhook before). |
maxEventInMemory | int | 100000 | If we hit that limit we will call the webhook. |
format | string | JSON | Format is the output format you want in your exported file. Available format: JSON , CSV , Parquet . |
filename | string | flag-variation-{{ .Hostname}}-{{ .Timestamp}}.{{ .Format}} | You can use a config template to define the name of your exported files. Available replacements are {{ .Hostname}} , {{ .Timestamp}} and {{ .Format} |
csvTemplate | string | {{ .Kind}};{{ .ContextKind}};{{ .UserKey}};{{ .CreationDate}};{{ .Key}};{{ .Variation}};{{ .Value}};{{ .Default}};{{ .Source}}\n | CsvTemplate is used if your output format is CSV. This field will be ignored if you are using format other than CSV. You can decide which fields you want in your CSV line with a go-template syntax, please check internal/exporter/feature_event.go to see what are the fields available. |
path | string | bucket root level | The location of the directory in S3. |
parquetCompressionCodec | string | SNAPPY | ParquetCompressionCodec is the parquet compression codec for better space efficiency. Available options |
Google Storage
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be s3 .This field is mandatory and describes which retriever you are using. |
bucket | string | none | (mandatory) Name of your Google Cloud Storage Bucket. |
flushInterval | int | 60000 | The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval we will call the webhook before). |
maxEventInMemory | int | 100000 | If we hit that limit we will call the webhook. |
format | string | JSON | Format is the output format you want in your exported file. Available format: JSON , CSV , Parquet . |
filename | string | flag-variation-{{ .Hostname}}-{{ .Timestamp}}.{{ .Format}} | You can use a templated config to define the name of your exported files. Available replacement are {{ .Hostname}} , {{ .Timestamp}} and {{ .Format} |
csvTemplate | string | {{ .Kind}};{{ .ContextKind}};{{ .UserKey}};{{ .CreationDate}};{{ .Key}};{{ .Variation}};{{ .Value}};{{ .Default}};{{ .Source}}\n | CsvTemplate is used if your output format is CSV. This field will be ignored if you are using format other than CSV. You can decide which fields you want in your CSV line with a go-template syntax, please check internal/exporter/feature_event.go to see what are the fields available. |
path | string | bucket root level | The location of the directory in S3. |
parquetCompressionCodec | string | SNAPPY | ParquetCompressionCodec is the parquet compression codec for better space efficiency. Available options |
SQS
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be sqs .This field is mandatory and describes which retriever you are using. |
queueUrl | string | none | (mandatory) URL of your SQS queue. You can find it in your AWS console. |
Kafka
Field name | Type | Default | Description |
---|---|---|---|
kafka.topic | string | none | (mandatory) Kafka topic to bind to. |
kafka.addresses | []string | none | (mandatory) List of bootstrap addresses for the Kafka cluster. |
kafka.config | object | see description | This field allows fine tuning of the Kafka reader. This object should contain the Sarama configuration that the reader will use. On empty, a sensible default is created using sarama.NewConfig() |
Google PubSub
Field name | Type | Default | Description |
---|---|---|---|
projectID | string | none | (mandatory) Value should be ID of GCP project you are using. |
topic | string | none | (mandatory) Topic name on which messages will be published. |
type notifier
Slack
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be slack .This field is mandatory and describe which retriever you are using. |
slackWebhookUrl | string | none | (mandatory) The complete URL of your incoming webhook configured in Slack. |
Webhook
Field name | Type | Default | Description |
---|---|---|---|
kind | string | none | (mandatory) Value should be webhook .This field is mandatory and describes which retriever you are using. |
endpointUrl | string | none | (mandatory) The complete URL of your API (we will send a POST request to this URL, see format |
secret | string | none | Secret used to sign your request body and fill the X-Hub-Signature-256 header.See signature section for more details. |
meta | map[string]string | none | Add all the information you want to see in your request. |
headers | map[string][]string | none | Add all the headers you want to add while calling the endpoint |