Environment Variables

Mimic is configured entirely through environment variables. There are only two.

PORT

The TCP port Mimic listens on.

• Type: integer
• Default: 8080
• Example: PORT=9000

When you change PORT, you also need to update the Docker port mapping. For example, to run Mimic on port 9000:

docker run -d \
  --name mimic \
  -p 9000:9000 \
  -e PORT=9000 \
  -v $(pwd)/mocks:/app/mocks:ro \
  ragilhadi/mimic:latest

RUST_LOG

Controls log verbosity.

• Type: string
• Default: info
• Allowed values: trace, debug, info, warn, error

Level	When to use
error	Production. Logs only real errors.
warn	Production with a bit more context.
info	Default. Logs requests and major events.
debug	Local development and rule debugging. Shows match scoring and reload events.
trace	Deep debugging. Very verbose.

debug is particularly useful when figuring out why a specific mock is or isn’t being selected. See Match Priority for what those logs look like.

Setting variables

docker run

Pass each variable with -e:

docker run -d \
  --name mimic \
  -p 8080:8080 \
  -e PORT=8080 \
  -e RUST_LOG=info \
  -v $(pwd)/mocks:/app/mocks:ro \
  ragilhadi/mimic:latest

docker-compose.yml

Use the environment block:

services:
  mimic:
    image: ragilhadi/mimic:latest
    environment:
      PORT: 8080
      RUST_LOG: info

.env file

Docker Compose automatically reads a .env file in the same directory as the compose file:

.env

PORT=8080
RUST_LOG=info

Reference the variables in your compose file with ${VAR}:

services:
  mimic:
    environment:
      - PORT=${PORT}
      - RUST_LOG=${RUST_LOG}
    ports:
      - "${PORT}:${PORT}"

Running from source

If you’re running a locally built binary instead of the Docker image, export the variables in your shell:

export PORT=8080
export RUST_LOG=debug
cargo run --release