CF app network loss

CF app network loss injects network loss into a Cloud Foundry app instance, causing it to lose network connectivity.

Use cases

CF app network loss:

• Checks resilience upon app network packet loss.
• Validates the effectiveness of disaster recovery and high availability of the app.

Mandatory tunables

Tunable	Description	Notes
deploymentModel	The deployment model being used for Linux Chaos Infrastructure + Cloud Foundry Fault Injector. For more information, refer here.	One of: model-1,model-2. No default value is assumed, if the tunable is not provided. For model-1, boshDeployment and faultInjectorLocation inputs are not required.
organization	Organization where the target app resides.	For example, dev-org
space	Space where the target app resides.	The space must reside within the given organization. For example, dev-space
app	The app to be stopped.	The app must reside within the given organization and space. For example, cf-app

Optional tunables

Tunable	Description	Notes
faultInjectorLocation	Fault injector placement with respect to where the LCI is hosted.	Default: local. Supports local and vSphere. For more information, go to Fault Injector location.
boshDeployment	The bosh deployment under which the CF components are being managed.	It can be obtained using the BOSH CLI command bosh deployments. For more information, go to BOSH deployment.
instanceAffectedPercentage	Percentage of total number of app instances that will be targeted.	Default: 0 (1 instance). For more information, go to instance affected percentage.
networkInterface	The network interface used by the container.	Default: eth0
destinationHosts	List of the target host names or keywords. For example, google.com,litmuschaos.io.	If neither destinationHosts nor destinationIPs is present, the fault injects chaos for all host names or domains.
destinationIPs	List of the target IPs. For example, 1.1.1.1,8.8.8.8	If neither destinationHosts nor destinationIPs is provided, all host names or domains are targeted.
packetLossPercentage	Percentage of packet loss. For example, 100	Default: 100%
sourcePorts	Source ports to be filtered for chaos. For example: 5000,8080 .	Alternatively, the ports can be whitelisted, that is, filtered to be exempt from chaos. Prepend a ! to the list of ports to be exempted. For example, !5000,8080 .
destinationPorts	Destination ports to be filtered for chaos. For example: 5000,8080	Alternatively, the ports can be whitelisted, that is, filtered to be exempt from chaos. Prepend a ! to the list of ports to be exempted. For example, !5000,8080 .
faultInjectorPort	Local server port used by the fault-injector utility.	Default: 50320. If the default port is unavailable, a random port in the range of 50320-51320 is selected. For more information, go to fault injector port.
duration	Duration through which chaos is injected into the target resource (in seconds).	Default: 30s. For more information, go to chaos duration.
skipSSLValidation	Skip SSL validation while invoking CF APIs.	Supports true and false. Default: false. For more information, go to skip SSL validation.
rampTime	Period to wait before and after injecting chaos (in seconds).	Defaults to 0.

CF secrets

The following Cloud Foundry secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/cf.env file in the following format:

CF_API_ENDPOINT=XXXXXXXXXXXXXXXXXXX
CF_USERNAME=XXXXXXXXXXXXXXXXXXXXXXX
CF_PASSWORD=XXXXXXXXXXXXXXXXXXXXXXX
UAA_SERVER_ENDPOINT=XXXXXXXXXXXXXXX
BOSH_CLIENT=XXXXXXXXXXXXXXXXXXXXXXX
BOSH_CLIENT_SECRET=XXXXXXXXXXXXXXXX
BOSH_CA_CERT=XXXXXXXXXXXXXXXXXXXXXX
BOSH_ENVIRONMENT=XXXXXXXXXXXXXXXXXX

info

If the secrets file is not provided, the secrets are attempted to be derived from environment variables and the config file by the fault-injector.

ENV name	Description	Example
CF_API_ENDPOINT	API endpoint for the CF setup	https://api.system.cf-setup.com
CF_USERNAME	Username for the CF user	username
CF_PASSWORD	Password for the CF user	password
UAA_SERVER_ENDPOINT	API endpoint for the UAA server for the CF setup	https://uaa.system.cf-setup.com
BOSH_CLIENT	Used by the bosh CLI, the BOSH client	admin
BOSH_CLIENT_SECRET	Used by the bosh CLI, the BOSH client secret	UBu9Fu3oW35sO6fw12auPH76gsRTy7
BOSH_CA_CERT	Used by the bosh CLI, the file path for BOSH CA certificate	/root/root_ca_certificate
BOSH_ENVIRONMENT	Used by the bosh CLI, the BOSH environment	bosh.corp.local

Fault injector ENVs and config file

If /etc/linux-chaos-infrastructure/cf.env file is not provided, fault-injector attempts to derive the secrets from environment variables or a configuration file. Any secret that is re-declared will be overridden in the following order of decreasing precedence:

1. /etc/linux-chaos-infrastructure/cf.env file
2. Environment variables
3. Configuration file

The configuration file should be provided at /etc/linux-chaos-infrastructure/cf-fault-injector.yaml:

cf-api-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
username: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
password: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
uaa-server-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client-secret: XXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-ca-cert: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-environment: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

A mapping between all the three formats for providing the secrets is as follows:

cf.env	ENV	cf-fault-injector.yaml
CF_API_ENDPOINT	CF_API_ENDPOINT	cf-api-endpoint
CF_USERNAME	USERNAME	username
CF_PASSWORD	PASSWORD	password
UAA_SERVER_ENDPOINT	UAA_SERVER_ENDPOINT	uaa-server-endpoint
BOSH_CLIENT	BOSH_CLIENT	bosh-client
BOSH_CLIENT_SECRET	BOSH_CLIENT_SECRET	bosh-client-secret
BOSH_CA_CERT	BOSH_CA_CERT	bosh-ca-cert
BOSH_ENVIRONMENT	BOSH_ENVIRONMENT	bosh-environment

vSphere secrets

These secrets are provided only if vSphere is used as the deployment platform for CF.

The following vSphere secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/vsphere.env file in the following format:

GOVC_URL=XXXXXXXXXXXXXXXXXXXXXX
GOVC_USERNAME=XXXXXXXXXXXXXXXXX
GOVC_PASSWORD=XXXXXXXXXXXXXXXXX
GOVC_INSECURE=XXXXXXXXXXXXXXXXX
VM_NAME=XXXXXXXXXXXXXXXXXXXXXXX
VM_USERNAME=XXXXXXXXXXXXXXXXXXX
VM_PASSWORD=XXXXXXXXXXXXXXXXXXX

ENV Name	Description	Notes
GOVC_URL	Endpoint for vSphere	For example, 192.168.214.244
GOVC_USERNAME	Username for the vSphere user	For example, username
GOVC_PASSWORD	Password for the vSphere user	For example, password
GOVC_INSECURE	Skip SSL validation for govc commands	For example, true
VM_NAME	Name of the vSphere VM where the fault-injector utility is installed	For example, cf-vm
VM_USERNAME	Username for the VM guest user	For example, root
VM_PASSWORD	Password for the VM guest user	For example, password

Fault Permissions

List all applications the user or client has access to

Required Roles (any one):

• SpaceDeveloper (in the app’s space)
• SpaceAuditor (read-only role in the app’s space)
• OrgManager or OrgAuditor (at the org level)

Required OAuth Scopes (for tokens):

• cloud_controller.read
• cloud_controller.admin
• cloud_controller.global_auditor

List all BOSH deployments (only for model-2)

Required Role:

• BOSH user with read permissions (typically admin or a user with read access to deployments)

Required Auth:

• Valid BOSH UAA token with bosh.read scope

Establish SSH session to a Diego Cell via BOSH SSH (only for model-2)

Required Role:

• BOSH user with SSH access permissions for the Diego Cell instance group

Required Auth:

• BOSH UAA token with bosh.ssh or bosh.admin scope

Use cfdot to list LRPs and locate app containers

Required Role:

• Operator with SSH access to a cell and executable access to cfdot

Required Auth:

• Requires diego.read scope in BOSH UAA or access to the Diego BBS with a trusted client certificate

Use ctr (containerd CLI) to get container-level metadata

Required Role:

• SSH-level access to the cell host and root access (or sudo) to interact with containerd

Required Auth:

• None via API; local root or elevated user access is required

Run nsenter and tc to inject or remove chaos in target container network namespaces

Required Role:

• Root access on the Diego Cell host (via BOSH SSH, for model-2)
• Ability to use Linux nsenter and tc tools within container network namespaces

Required Auth:

• None via API; requires local machine-level root privileges

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Deployment Model

The deploymentModel input specifies the LCI deployment model with respect to its placement in the host TAS VM.

• It accepts one of: model-1, model-2.
• No default value is assumed if the input is not provided, but the experiment execution fails with an error.

The following YAML snippet illustrates the use of this environment variable:

# deployment model for LCI
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    deploymentModel: model-1

Destination hosts

The destinationHosts input variable subjects the comma-separated names of the target hosts to chaos.

The following YAML snippet illustrates the use of this environment variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    destinationHosts: 'google.com'

Destination IPs

The destinationIPs input variable subjects the comma-separated names of the target IPs to chaos.

The following YAML snippet illustrates the use of this environment variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    destinationIPs: '1.1.1.1'

Source and destination ports

By default, the network experiments disrupt traffic for all the source and destination ports. Tune the interruption of specific port(s) using sourcePorts and destinationPorts inputs, respectively.

• sourcePorts: Ports of the target application whose accessibility is impacted.
• destinationPorts: Ports of the destination services or pods or the CIDR blocks(range of IPs) whose accessibility is impacted.

The following YAML snippet illustrates the use of this environment variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    destinationIPs: '1.1.1.1'
    sourcePorts: "8080,3000"
    destinationPorts: "5000,3000"

Ignore Source and Destination Ports

By default, the network experiments disrupt traffic for all the source and destination ports. Ignore the specific ports using sourcePorts and destinationPorts inputs, respectively.

• sourcePorts: Provide source ports that are not subject to chaos as comma-separated values preceded by !.
• destinationPorts: Provide destination ports that are not subject to chaos as comma-separated values preceded by !.

The following YAML snippet illustrates the use of this environment variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    destinationIPs: '1.1.1.1'
    sourcePorts: "!8080,3000"
    destinationPorts: "!5000,3000"

Packet loss percentage

The packetLossPercentage input variable loses a specific percentage of the data packets.

The following YAML snippet illustrates the use of this environment variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    packetLossPercentage: '50'

BOSH deployment

The boshDeployment input determines the BOSH deployment name under which all the CF resources are being managed. It can be obtained using the BOSH CLI command bosh deployments.

The following YAML snippet illustrates the use of this environment variable:

# bosh deployment
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    boshDeployment: cf

Instance affected percentage

The instanceAffectedPercentage input specifies the percentage of total number of app instances that will be targeted. It defaults to 0 (1 instance).

The following YAML snippet illustrates the use of this environment variable:

# instance affected percentage
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    boshDeployment: cf
    instanceAffectedPercentage: 50

Fault Injector location

The faultInjectorLocation input determines the fault injector placement with respect to where the LCI is hosted.

• It supports one of:
  • local: LCI and fault injector are placed in the same machine.
  • vSphere: Fault injector is placed in a remote vSphere managed VM.

The following YAML snippet illustrates the use of this environment variable:

# Fault Injector location
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space

Skip SSL validation

The skipSSLValidation input variable determines whether to skip SSL validation for calling the CF APIs.

The following YAML snippet illustrates the use of this environment variable:

# skip ssl validation for cf
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    skipSSLValidation: true

Fault injector port

The faultInjectorPort input variable determines the port used for the fault-injector local server.

The following YAML snippet illustrates the use of this environment variable:

# fault injector port
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-network-loss
  labels:
    name: app-network-loss
spec:
  cfAppNetworkChaos/inputs:
    duration: 30s
    faultInjectorLocation: local
    app: cf-app
    organization: dev-org
    space: dev-space
    faultInjectorPort: 50331