Pod HTTP reset peer

Pod HTTP reset peer is a Kubernetes pod-level chaos fault that injects chaos on the service whose port is specified using the TARGET_SERVICE_PORT environment variable.

• This stops the outgoing HTTP requests by resetting the TCP connection by starting the proxy server and redirecting the traffic through the proxy server.
• It can test the application's resilience to lossy/flaky HTTP connection.

Usage

View fault usage

It can test the application's resilience to lossy/flaky HTTP connection. It simulates premature connection loss (firewall issues or other issues) between microservices (verify connection timeout), and connection resets due to resource limitations on the server side like out of memory server (or process killed or overload on the server due to a high amount of traffic).

Prerequisites

• Kubernetes > 1.16.

Default validations

The application pods should be in running state before and after chaos injection.

Fault tunables

Fault tunables

Mandatory Fields

Variables	Description	Notes
TARGET_SERVICE_PORT	Port of the service to target	Defaults to port 80
RESET_TIMEOUT	Reset Timeout specifies after how much duration to reset the connection	Defaults to 0

Optional fields

Variables	Description	Notes
PROXY_PORT	Port where the proxy will be listening for requests	Defaults to 20000
NETWORK_INTERFACE	Network interface to be used for the proxy	Defaults to `eth0`
TOXICITY	Percentage of HTTP requests to be affected	Defaults to 100
CONTAINER_RUNTIME	container runtime interface for the cluster	Defaults to containerd, supported values: docker, containerd and crio
SOCKET_PATH	Path of the containerd/crio/docker socket file	Defaults to /run/containerd/containerd.sock
TOTAL_CHAOS_DURATION	The duration of chaos injection (seconds)	Default (60s)
TARGET_PODS	Comma separated list of application pod name subjected to pod http reset peer chaos	If not provided, it will select target pods randomly based on provided appLabels
PODS_AFFECTED_PERC	The Percentage of total pods to target	Defaults to 0 (corresponds to 1 replica), provide numeric value only
LIB_IMAGE	Image used to run the netem command	Defaults to `litmuschaos/go-runner:latest`
RAMP_TIME	Period to wait before and after injection of chaos in sec	For example, 30
SEQUENCE	It defines sequence of chaos execution for multiple target pods	Default value: parallel. Supported: serial, parallel

Fault examples

Common and pod-specific tunables

Refer to the common attributes and pod-specific tunables to tune the common tunables for all fault and pod specific tunables.

Target service port

It defines the port of the targeted service that is being targeted. It can be tuned via TARGET_SERVICE_PORT ENV.

Use the following example to tune this:

## provide the port of the targeted service
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"

Proxy port

It defines the port on which the proxy server will listen for requests. It can be tuned via PROXY_PORT ENV. Use the following example to tune this:

## provide the port for proxy server
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # provide the port for proxy server
            - name: PROXY_PORT
              value: "8080"
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"

Reset timeout

It defines the reset timeout value to be added to the http request. It can be tuned via RESET_TIMEOUT ENV.

Use the following example to tune this:

## provide the reset timeout value
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # reset timeout specifies after how much duration to reset the connection
            - name: RESET_TIMEOUT #in ms
              value: "2000"
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"

Toxicity

It defines the toxicity value to be added to the http request. It can be tuned via TOXICITY ENV. Toxicity value defines the percentage of the total number of http requests to be affected.

Use the following example to tune this:

## provide the toxicity
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # toxicity is the probability of the request to be affected
            # provide the percentage value in the range of 0-100
            # 0 means no request will be affected and 100 means all request will be affected
            - name: TOXICITY
              value: "100"
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"

Network interface

It defines the network interface to be used for the proxy. It can be tuned via NETWORK_INTERFACE ENV.

Use the following example to tune this:

## provide the network interface for proxy
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # provide the network interface for proxy
            - name: NETWORK_INTERFACE
              value: "eth0"
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"

Container runtime and socket path

It defines the CONTAINER_RUNTIME and SOCKET_PATH ENV to set the container runtime and socket file path.

• CONTAINER_RUNTIME: It supports docker, containerd, and crio runtimes. The default value is containerd.
• SOCKET_PATH: It contains path of containerd socket file by default(/run/containerd/containerd.sock). For docker, specify path as /var/run/docker.sock. For crio, specify path as /var/run/crio/crio.sock.

Use the following example to tune this:

## provide the container runtime and socket file path
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  appinfo:
    appns: "default"
    applabel: "app=nginx"
    appkind: "deployment"
  chaosServiceAccount: litmus-admin
  experiments:
    - name: pod-http-reset-peer
      spec:
        components:
          env:
            # runtime for the container
            # supports docker, containerd, crio
            - name: CONTAINER_RUNTIME
              value: "containerd"
            # path of the socket file
            - name: SOCKET_PATH
              value: "/run/containerd/containerd.sock"
            # provide the port of the targeted service
            - name: TARGET_SERVICE_PORT
              value: "80"