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Pod HTTP status code

Pod HTTP status code is a Kubernetes pod-level fault injects chaos inside the pod by modifying the status code of the response from the application server to the desired status code provided by the user.

  • The port for the service is specified using the TARGET_SERVICE_PORT environment variable by starting the proxy server and redirecting the traffic through the proxy server.
  • It tests the application's resilience to error code HTTP responses from the provided application server.

tip Fault execution flow chart Pod HTTP Status Code

Usage

View fault usage
It tests the application's resilience to error code HTTP responses from the provided application server. It simulates unavailability of specific API services (503, 404), unavailability of specific APIs for(or from) a given microservice (TBD or Path Filter) (404), unauthorized requests for 3rd party services (401 or 403), and API malfunction (internal server error) (50x).

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 s
TARGET_SERVICE_PORT Port of the service to targetThis should be the port on which the application container runs at the pod level, not at the service level. Defaults to port 80
STATUS_CODE Modified status code for the HTTP response If no value is provided, then a random value is selected from the list of supported values. Multiple values can be provided as comma separated, a random value from the provided list will be selected Supported values: [200, 201, 202, 204, 300, 301, 302, 304, 307, 400, 401, 403, 404, 500, 501, 502, 503, 504]. Defaults to random status code
MODIFY_RESPONSE_BODY Whether to modify the body as per the status code provided. If true, then the body is replaced by a default template for the status code. Defaults to true

Optional fields

Variables Description s
RESPONSE_BODY Body string to overwrite the http response body This will be used only if MODIFY_RESPONSE_BODY is set to true. If no value is provided, response will be an empty body. Defaults to empty body
CONTENT_ENCODING Encoding type to compress/encodde the response body Accepted values are: gzip, deflate, br, identity. Defaults to none (no encoding)
CONTENT_TYPE Content type of the response body Defaults to text/plain
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 docker, supported values: docker, containerd and crio for litmus and only docker for pumba LIB
SOCKET_PATH Path of the containerd/crio/docker socket file Defaults to `/var/run/docker.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 status code 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. This should be the port where the application runs at the pod level, not at the service level. This means if the application pod is running the service at port 8080 and we create a service exposing that at port 80, then the target service port should be 8080 and not 80, which is the port at pod-level.

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-status-code
spec:
components:
env:
# provide the port of the targeted service
- name: TARGET_SERVICE_PORT
value: "80"
# modified status code for the http response
- name: STATUS_CODE
value: "500"

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-status-code
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"
# modified status code for the http response
- name: STATUS_CODE
value: "500"

Status code

It defines the status code value for the http response. It can be tuned via STATUS_CODE ENV.

Use the following example to tune this:

## modified status code for the http response
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-status-code
spec:
components:
env:
# modified status code for the http response
# if no value is provided, a random status code from the supported code list will selected
# if multiple comma separated values are provided, then a random value from the provided list will be selected
# if an invalid status code is provided, the fault will fail
# supported status code list: [200, 201, 202, 204, 300, 301, 302, 304, 307, 400, 401, 403, 404, 500, 501, 502, 503, 504]
- name: STATUS_CODE
value: "500"
# provide the port of the targeted service
- name: TARGET_SERVICE_PORT
value: "80"

Modify response body

It defines whether to modify the respone body with a pre-defined template to match with the status code value of the http response. It can be tuned via MODIFY_RESPONSE_BODY ENV.

Use the following example to tune this:

##  whether to modify the body as per the status code provided
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-status-code
spec:
components:
env:
# whether to modify the body as per the status code provided
- name: "MODIFY_RESPONSE_BODY"
value: "true"
# modified status code for the http response
- name: STATUS_CODE
value: "500"
# 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-status-code
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"

Response body

It defines the body string that will overwrite the http response body. It can be tuned via RESPONSE_BODY and MODIFY_RESPONSE_BODY ENV. The MODIFY_RESPONSE_BODY ENV should be set to true to enable this feature.

Use the following example to tune this:

## provide the response body 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-status-code
spec:
components:
env:
# provide the body string to overwrite the response body. This will be used only if MODIFY_RESPONSE_BODY is set to true
- name: RESPONSE_BODY
value: "<h1>Hello World</h1>"
# whether to modify the body as per the status code provided
- name: "MODIFY_RESPONSE_BODY"
value: "true"
# modified status code for the http response
- name: STATUS_CODE
value: "500"
# provide the port of the targeted service
- name: TARGET_SERVICE_PORT
value: "80"

Content encoding and content type

It defines the content encoding and content type of the response body. It can be tuned via CONTENT_ENCODING and CONTENT_TYPE ENV.

Use the following example to tune this:

##  whether to modify the body as per the status code provided
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-status-code
spec:
components:
env:
# provide the encoding type for the response body
# currently supported value are gzip, deflate
# if empty no encoding will be applied
- name: CONTENT_ENCODING
value: "gzip"
# provide the content type for the response body
- name: CONTENT_TYPE
value: "text/html"
# whether to modify the body as per the status code provided
- name: "MODIFY_RESPONSE_BODY"
value: "true"
# modified status code for the http response
- name: STATUS_CODE
value: "500"
# 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-status-code
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"
# modified status code for the http response
- name: STATUS_CODE
value: "500"

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 docker.
  • SOCKET_PATH: It contains path of docker socket file by default(/var/run/docker.sock). For containerd, specify path as /var/containerd/containerd.sock. For crio, speecify 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-status-code
spec:
components:
env:
# runtime for the container
# supports docker, containerd, crio
- name: CONTAINER_RUNTIME
value: "docker"
# path of the socket file
- name: SOCKET_PATH
value: "/var/run/docker.sock"
# provide the port of the targeted service
- name: TARGET_SERVICE_PORT
value: "80"
# modified status code for the http response
- name: STATUS_CODE
value: "500"