Environment Variables
fault is configured through its CLI arguments. However, in some cases, it may be simpler to populate these options via environment variables.
Common Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_LOG_FILE |
(none) | Path to a file where to write fault logs |
fault_WITH_STDOUT_LOGGING |
false |
Whether to enable logging to stdout |
fault_LOG_LEVEL |
info,tower_http=debug |
Level respecting tracing subscriber env filter directives |
Observability Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_WITH_OTEL |
false |
Whether to enable Open Telemetry tracing and metrics |
run Command Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_PROXY_NO_UI |
(none) | Disables the terminal UI and make the output fully silent. |
fault_PROXY_ADDRESS |
127.0.0.1:3180 |
The address on which the proxy server listens. |
fault_ENABLE_STEALTH |
false |
Whether stealth mode (using eBPF) is enabled. |
fault_EBPF_PROCESS_NAME |
(none) | The name of a process to intercept traffic from (used when stealth mode is enabled). |
fault_EBPF_PROGRAMS_DIR |
"$HOME/cargo/bin" |
The directory where eBPF programs for fault can be found (used when stealth mode is enabled). |
fault_EBPF_PROXY_IP |
(none) | The address to use by the eBPF proxy. If unset, uses the same as the default proxy address. |
fault_EBPF_PROXY_PORT |
(none) | The port the eBPF proxy is bound to. By default uses a random port. |
fault_EBPF_PROXY_IFACE |
(none) | The interface to attach the eBPF programs to. Uses the interface of the proxy IP by default. |
fault_GRPC_PLUGINS |
(none) | Comma-separated list of gRPC plugin addresses. |
fault_UPSTREAMS |
(none) | Comma-separated list of upstream hostnames to proxy. |
fault_WITH_LATENCY |
false |
Whether a latency fault is enabled. |
fault_LATENCY_PER_READ_WRITE |
false |
Whether latency should be applied on a per read/write operation or once. |
fault_LATENCY_DISTRIBUTION |
normal |
The statistical distribution used. |
fault_LATENCY_SIDE |
server |
The side which will be impacted by the fault. |
fault_LATENCY_DIRECTION |
ingress |
The direction which will be impacted by the fault. |
fault_LATENCY_MEAN |
(none) | Mean latency in milliseconds for latency fault injection. |
fault_LATENCY_STANDARD_DEVIATION |
(none) | Standard deviation of latency in milliseconds. |
fault_LATENCY_SHAPE |
(none) | Distribution shape when using pareto or pareto normal. |
fault_LATENCY_SCALE |
(none) | Distribution scale when using pareto or pareto normal. |
fault_LATENCY_MIN |
(none) | Minimum latency when using a uniform distribution. |
fault_LATENCY_MAX |
(none) | Maximum latency when using a uniform distribution. |
fault_WITH_BANDWIDTH |
false |
Whether a bandwidth fault is enabled. |
fault_BANDWIDTH_DIRECTION |
ingress |
The direction which will be impacted by the fault. |
fault_BANDWIDTH_RATE |
1000 |
Rate to impose on traffic. |
fault_BANDWIDTH_UNIT |
bps |
Unit of the rate. |
fault_WITH_JITTER |
false |
Whether a jitter fault is enabled. |
fault_JITTER_AMPLITUDE |
20.0 |
Maximum jitter delay in milliseconds for jitter fault injection. |
fault_JITTER_FREQ |
5.0 |
Frequency (in Hertz) of jitter application. |
fault_WITH_PACKET_LOSS |
false |
Whether a packet-loss fault is enabled. |
fault_PACKET_LOSS_SIDE |
server |
The side which will be impacted by the fault. |
fault_PACKET_LOSS_DIRECTION |
ingress |
The direction which will be impacted by the fault. |
fault_WITH_HTTP_FAULT |
false |
Whether a http fault fault is enabled. |
fault_HTTP_FAULT_STATUS |
500 |
HTTP status code to return when the HTTP response fault is triggered. |
fault_HTTP_FAULT_PROBABILITY |
1.0 |
Probability to apply the fault on a given HTTP exchange. |
fault_WITH_DNS |
false |
Whether a dns fault is enabled. |
fault_DNS_PROBABILITY |
0.5 |
Probability (0–100) to trigger a DNS fault. |
scenario Command Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_SCENARIO_REPORT_PATH |
(none) | The file path to a scenario file or a directory path to a folder containing scenario files. |
fault_SCENARIO_PROXY_ADDR |
127.0.0.1:3180 |
Address of the proxy the secanrio command will run during the tests |
agent Command Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_AGENT_CLIENT |
open-ai |
The LLM client to use (amongst open-ai, open-router or ollama). |
LLM_PROMPT_REASONING_MODEL |
o4-mini |
The LLM reasoning model to use. |
LLM_PROMPT_CHAT_MODEL |
gpt-4.1-mini |
The LLM chat model to use. |
fault_AGENT_EMBED_MODEL |
text-embedding-3-small |
The LLM embedding model to use. |
scenario-review Subcommand Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_SCENARIO_RESULTS_PATH |
(none) | Path to the results file from the scenario run command. |
fault_AGENT_SCENARIO_REVIEW_REPORT_FILE |
scenario-analysis-report.md |
Path to the file where to save the generated report. |
fault_AGENT_ADVICE_ROLE |
developer |
Role to generate the report from, one of developer or sre. |
code-review Subcommand Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_SCENARIO_RESULTS_PATH |
(none) | Path to the results file from the scenario run command. |
fault_AGENT_CODE_REVIEW_REPORT_FILE |
code-review-report.md |
Path to the file where to save the generated report. |
fault_AGENT_CODE_REVIEW_SOURCE_DIR |
(none) | Directory where the source code is located |
fault_AGENT_CODE_REVIEW_SOURCE_LANGUAGE |
(none) | Language of the source code: python, go, rust, java, typescript, javascript, elixir |
fault_AGENT_CODE_REVIEW_SOURCE_INDEX_PATH |
/tmp/index.db |
Path of the DuckDB vector database where storing the index |
fault_AGENT_SCENARIO_REVIEW_REPORT_FILE |
scenario-analysis-report.md |
Path of the report generated by agent scenario-review |
demo Command Variables
| Name | Default Value | Explanation |
|---|---|---|
fault_DEMO_ADDR |
127.0.0.1 |
IP address to bind the server to. |
fault_DEMO_PORT |
7070 |
Port to bind the server to. |