RateLimit

The rateLimit middleware ensures that services will receive a fair amount of requests, and allows you to define what fair is.

It is based on a token bucket implementation. In this analogy, the average and period parameters define the rate at which the bucket refills, and the burst is the size (volume) of the bucket

Rate and Burst¶

The rate is defined by dividing average by period. For a rate below 1 req/s, define a period larger than a second

Configuration Example¶

Structured (YAML)

# Here, an average of 100 requests per second is allowed.
# In addition, a burst of 200 requests is allowed.
# Redis distributed rate limiting is configured with all available options.
http:
  middlewares:
    test-ratelimit:
      rateLimit:
        average: 100
        period: 1s
        burst: 200
        redis:
          endpoints:
            - "redis-primary.example.com:6379"
            - "redis-replica.example.com:6379"
          username: "ratelimit-user"
          password: "secure-password"
          db: 2
          poolSize: 50
          minIdleConns: 10
          maxActiveConns: 200
          readTimeout: 3s
          writeTimeout: 3s
          dialTimeout: 5s
          tls:
            ca: "/etc/ssl/redis-ca.crt"
            cert: "/etc/ssl/redis-client.crt"
            key: "/etc/ssl/redis-client.key"
            insecureSkipVerify: false

Structured (TOML)

# Here, an average of 100 requests per second is allowed.
# In addition, a burst of 200 requests is allowed.
# Redis distributed rate limiting is configured with all available options.
[http.middlewares]
  [http.middlewares.test-ratelimit.rateLimit]
    average = 100
    period = "1s"
    burst = 200
    [http.middlewares.test-ratelimit.rateLimit.redis]
      endpoints = ["redis-primary.example.com:6379", "redis-replica.example.com:6379"]
      username = "ratelimit-user"
      password = "secure-password"
      db = 2
      poolSize = 50
      minIdleConns = 10
      maxActiveConns = 200
      readTimeout = "3s"
      writeTimeout = "3s"
      dialTimeout = "5s"
      [http.middlewares.test-ratelimit.rateLimit.redis.tls]
        ca = "/etc/ssl/redis-ca.crt"
        cert = "/etc/ssl/redis-client.crt"
        key = "/etc/ssl/redis-client.key"
        insecureSkipVerify = false

Labels

# Here, an average of 100 requests per second is allowed.
# In addition, a burst of 200 requests is allowed.
# Redis distributed rate limiting is configured with all available options.
labels:
  - "traefik.http.middlewares.test-ratelimit.ratelimit.average=100"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.period=1s"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.burst=200"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.endpoints=redis-primary.example.com:6379,redis-replica.example.com:6379"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.username=ratelimit-user"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.password=secure-password"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.db=2"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.poolSize=50"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.minIdleConns=10"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.maxActiveConns=200"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.readTimeout=3s"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.writeTimeout=3s"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.dialTimeout=5s"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.ca=/etc/ssl/redis-ca.crt"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.cert=/etc/ssl/redis-client.crt"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.key=/etc/ssl/redis-client.key"
  - "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.insecureSkipVerify=false"

Tags

// Here, an average of 100 requests per second is allowed.
// In addition, a burst of 200 requests is allowed.
// Redis distributed rate limiting is configured with all available options.
{
  "Tags": [
    "traefik.http.middlewares.test-ratelimit.ratelimit.average=100",
    "traefik.http.middlewares.test-ratelimit.ratelimit.period=1s",
    "traefik.http.middlewares.test-ratelimit.ratelimit.burst=200",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.endpoints=redis-primary.example.com:6379,redis-replica.example.com:6379",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.username=ratelimit-user",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.password=secure-password",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.db=2",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.poolSize=50",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.minIdleConns=10",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.maxActiveConns=200",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.readTimeout=3s",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.writeTimeout=3s",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.dialTimeout=5s",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.ca=/etc/ssl/redis-ca.crt",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.cert=/etc/ssl/redis-client.crt",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.key=/etc/ssl/redis-client.key",
    "traefik.http.middlewares.test-ratelimit.ratelimit.redis.tls.insecureSkipVerify=false"
  ]
}

Kubernetes

# Here, an average of 100 requests per second is allowed.
# In addition, a burst of 200 requests is allowed.
# Redis distributed rate limiting is configured with all available options.
apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-ratelimit
spec:
  rateLimit:
    average: 100
    period: 1s
    burst: 200
    redis:
      endpoints:
        - "redis-primary.example.com:6379"
        - "redis-replica.example.com:6379"
      secret: redis-credentials
      db: 2
      poolSize: 50
      minIdleConns: 10
      maxActiveConns: 200
      readTimeout: 3s
      writeTimeout: 3s
      dialTimeout: 5s
      tls:
        caSecret: redis-ca
        certSecret: redis-client-cert
        insecureSkipVerify: false

---
apiVersion: v1
kind: Secret
metadata:
  name: redis-credentials
  namespace: default
data:
  username: cmF0ZWxpbWl0LXVzZXI=  # base64 encoded "ratelimit-user"
  password: c2VjdXJlLXBhc3N3b3Jk  # base64 encoded "secure-password"

---
apiVersion: v1
kind: Secret
metadata:
  name: redis-ca
  namespace: default
data:
  tls.ca: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0t...

---
apiVersion: v1
kind: Secret
metadata:
  name: redis-client-cert
  namespace: default
data:
  tls.crt: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0t...
  tls.key: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0t...

Configuration Options¶

Field	Description	Default	Required
`average`	Number of requests used to define the rate using the `period`. 0 means no rate limiting. More information here.	0	No
`period`	Period of time used to define the rate. More information here.	1s	No
`burst`	Maximum number of requests allowed to go through at the very same moment. More information here.	1	No
`sourceCriterion.requestHost`	Whether to consider the request host as the source. More information about `sourceCriterion`here.	false	No
`sourceCriterion.requestHeaderName`	Name of the header used to group incoming requests. More information about `sourceCriterion`here.	""	No
`sourceCriterion.ipStrategy.depth`	Depth position of the IP to select in the `X-Forwarded-For` header (starting from the right). 0 means no depth. If greater than the total number of IPs in `X-Forwarded-For`, then the client IP is empty If higher than 0, the `excludedIPs` options is not evaluated. More information about `sourceCriterion`, `ipStrategy`, and `depth` below.	0	No
`sourceCriterion.ipStrategy.excludedIPs`	Allows scanning the `X-Forwarded-For` header and select the first IP not in the list. If `depth` is specified, `excludedIPs` is ignored. More information about `sourceCriterion`, `ipStrategy`, and `excludedIPs` below.		No
`sourceCriterion.ipStrategy.ipv6Subnet`	If `ipv6Subnet` is provided and the selected IP is IPv6, the IP is transformed into the first IP of the subnet it belongs to. More information about `sourceCriterion`, `ipStrategy.ipv6Subnet` below.		No
`redis`	The `redis` configuration enables distributed rate limiting by using Redis to store rate limit tokens across multiple Traefik instances. This allows you to enforce consistent rate limits across a cluster of Traefik proxies. When Redis is not configured, Traefik uses in-memory storage for rate limiting, which works only for the individual Traefik instance.		No
`redis.endpoints`	List of Redis server endpoints for distributed rate limiting. You can specify multiple endpoints for Redis cluster or high availability setups.	"127.0.0.1:6379"	No
`redis.username`	Username for Redis authentication.	""	No
`redis.password`	Password for Redis authentication. In Kubernetes, these can be provided via secrets.	""	No
`redis.db`	Redis database number to select.	0	No
`redis.poolSize`	Defines the base number of socket connections in the pool. If set to 0, it defaults to 10 connections per CPU core as reported by `runtime.GOMAXPROCS`. If there are not enough connections in the pool, new connections will be allocated beyond `poolSize`, up to `maxActiveConns`.	0	No
`redis.minIdleConns`	Minimum number of idle connections to maintain in the pool. This is useful when establishing new connections is slow. A value of 0 means idle connections are not automatically closed.	0	No
`redis.maxActiveConns`	Maximum number of connections the pool can allocate at any given time. A value of 0 means no limit.	0	No
`redis.readTimeout`	Timeout for socket reads. If reached, commands will fail with a timeout instead of blocking. Zero means no timeout.	3s	No
`redis.writeTimeout`	Timeout for socket writes. If reached, commands will fail with a timeout instead of blocking. Zero means no timeout.	3s	No
`redis.dialTimeout`	Timeout for establishing new connections. Zero means no timeout.	5s	No
`redis.tls.ca`	Path to the certificate authority used for the secure connection to Redis, it defaults to the system bundle.	""	No
`redis.tls.cert`	Path to the public certificate used for the secure connection to Redis. When this option is set, the `key` option is required.	""	No
`redis.tls.key`	Path to the private key used for the secure connection to Redis. When this option is set, the `cert` option is required.	""	No
`redis.tls.insecureSkipVerify`	If `insecureSkipVerify` is `true`, the TLS connection to Redis accepts any certificate presented by the server regardless of the hostnames it covers.	false	No

sourceCriterion¶

The sourceCriterion option defines what criterion is used to group requests as originating from a common source. If several strategies are defined at the same time, an error will be raised. If none are set, the default is to use the request's remote address field (as an ipStrategy).

ipStrategy¶

The ipStrategy option defines three parameters that configures how Traefik determines the client IP: depth, excludedIPs and ipv6Subnet.

As a middleware, rate-limiting happens before the actual proxying to the backend takes place. In addition, the previous network hop only gets appended to X-Forwarded-For during the last stages of proxying, that is after it has already passed through rate-limiting. Therefore, during rate-limiting, as the previous network hop is not yet present in X-Forwarded-For, it cannot be found and/or relied upon.

`sourceCriterion.ipStrategy.ipv6Subnet`¶

This strategy applies to Depth and RemoteAddr strategy only. If ipv6Subnet is provided and the selected IP is IPv6, the IP is transformed into the first IP of the subnet it belongs to.

This is useful for grouping IPv6 addresses into subnets to prevent bypassing this middleware by obtaining a new IPv6.

ipv6Subnet is ignored if its value is outside of 0-128 interval

Example of ipv6Subnet¶

If ipv6Subnet is provided, the IP is transformed in the following way.

`IP`	`ipv6Subnet`	clientIP
`"::abcd:1111:2222:3333"`	`64`	`"::0:0:0:0"`
`"::abcd:1111:2222:3333"`	`80`	`"::abcd:0:0:0:0"`
`"::abcd:1111:2222:3333"`	`96`	`"::abcd:1111:0:0:0"`

sourceCriterion.ipStrategy.depth¶

If depth is set to 2, and the request X-Forwarded-For header is "10.0.0.1,11.0.0.1,12.0.0.1,13.0.0.1" then the "real" client IP is "10.0.0.1" (at depth 4) but the IP used as the criterion is "12.0.0.1" (depth=2).

`X-Forwarded-For`	`depth`	clientIP
`"10.0.0.1,11.0.0.1,12.0.0.1,13.0.0.1"`	`1`	`"13.0.0.1"`
`"10.0.0.1,11.0.0.1,12.0.0.1,13.0.0.1"`	`3`	`"11.0.0.1"`
`"10.0.0.1,11.0.0.1,12.0.0.1,13.0.0.1"`	`5`	`""`

sourceCriterion.ipStrategy.excludedIPs¶

Contrary to what the name might suggest, this option is not about excluding an IP from the rate limiter, and therefore cannot be used to deactivate rate limiting for some IPs.

excludedIPs is meant to address two classes of somewhat distinct use-cases:

Distinguish IPs which are behind the same (set of) reverse-proxies so that each of them contributes, independently to the others, to its own rate-limit "bucket" (cf the token bucket). In this case, excludedIPs should be set to match the list of X-Forwarded-For IPs that are to be excluded, in order to find the actual clientIP.

Example to use each IP as a distinct source:

X-Forwarded-For	excludedIPs	clientIP
`"10.0.0.1,11.0.0.1,12.0.0.1"`	`"11.0.0.1,12.0.0.1"`	`"10.0.0.1"`
`"10.0.0.2,11.0.0.1,12.0.0.1"`	`"11.0.0.1,12.0.0.1"`	`"10.0.0.2"`

Group together a set of IPs (also behind a common set of reverse-proxies) so that they are considered the same source, and all contribute to the same rate-limit bucket.

Example to group IPs together as same source:

X-Forwarded-For	excludedIPs	clientIP
`"10.0.0.1,11.0.0.1,12.0.0.1"`	`"12.0.0.1"`	`"11.0.0.1"`
`"10.0.0.2,11.0.0.1,12.0.0.1"`	`"12.0.0.1"`	`"11.0.0.1"`
`"10.0.0.3,11.0.0.1,12.0.0.1"`	`"12.0.0.1"`	`"11.0.0.1"`