Installation

Docker Compose (recommended)

This is the easiest way to get UpSlim running. You only need Docker installed.

Step 1 — Create your project folder

mkdir my-upslim && cd my-upslim

Step 2 — Create your config file

Create a config/ folder and add a YAML file inside it:

mkdir config

# config/monitors.yaml
alerting:
  - name: slack-ops
    type: slack
    token: ${SLACK_BOT_TOKEN}
    channel: "#ops-alerts"

monitors:
  - name: my-website
    type: http
    url: "https://example.com"
    conditions:
      - "[STATUS] == 200"
      - "[RESPONSE_TIME] < 2000"
    alerts:
      - name: slack-ops

Where does this file go?

Put it anywhere on your machine — just make sure to mount the folder into Docker in the next step. The example above puts it in ./config/monitors.yaml relative to where your docker-compose.yml will live.

What is :ro?

The :ro at the end of the volume mount stands for read-only. It means the container can read your config files but cannot modify them. This is a security best practice — UpSlim only needs to read your config, never write to it.

Step 3 — Create docker-compose.yml

In your project folder (next to config/), create this file:

# docker-compose.yml
services:
  upslim:
    image: abians7/upslim-server:latest
    volumes:
      - ./config:/config:ro   # :ro = read-only, the container cannot modify your files
      - upslim-state:/data    # stores alert state across restarts
    environment:
      UPSLIM_STATE_DIR: /data
      SLACK_BOT_TOKEN: ${SLACK_BOT_TOKEN}   # read from your shell or .env file
      RUST_LOG: info
    restart: unless-stopped

volumes:
  upslim-state:

Your folder structure should now look like this:

my-upslim/
├── docker-compose.yml
└── config/
    └── monitors.yaml

Step 4 — Start UpSlim

# Set your Slack token (or add it to a .env file)
export SLACK_BOT_TOKEN=xoxb-...

# Start in the background
docker compose up -d

# Follow the logs
docker compose logs -f

You should see:

INFO  Configuration loaded monitors=1 providers=1
INFO  Starting 1 monitors
INFO  Monitor started monitor=my-website interval_secs=60

That's it — UpSlim is running.

---

Using multiple config files

UpSlim can load a whole folder of YAML files and merge them. This is useful for splitting config by team or service. Files are merged in alphabetical order.

config/
├── 01-alerting.yaml    ← alert providers
├── 02-platform.yaml    ← infra monitors
└── 03-apps.yaml        ← application monitors

The volume mount in docker-compose.yml stays the same — UpSlim reads everything in ./config/ automatically.

---

docker run (without Compose)

If you prefer a single command:

docker run -d \
  --name upslim \
  -v /absolute/path/to/config:/config:ro \
  -v upslim-state:/data \
  -e UPSLIM_STATE_DIR=/data \
  -e SLACK_BOT_TOKEN=xoxb-... \
  -e RUST_LOG=info \
  --restart unless-stopped \
  abians7/upslim-server:latest

Use an absolute path

-v /absolute/path/to/config:/config:ro — Docker requires an absolute path on the left side when using docker run. With Docker Compose you can use ./config (relative).

---

Build from source

You need Rust 1.86+ and Cargo.

git clone https://github.com/AbianS/upslim
cd upslim
cargo build --release -p upslim-server

The binary is at target/release/upslim-server.

# Point it at a single file
./target/release/upslim-server --config ./config/monitors.yaml

# Or a whole directory
./target/release/upslim-server --config ./config/

---

Environment variables

Variable	Default	Description
UPSLIM_STATE_DIR	./state	Directory for persisting alert state
UPSLIM_MAX_CONCURRENT	10	Maximum parallel checks at any point
RUST_LOG	info	Log level: trace, debug, info, warn, error

---

Verifying it works

Checks passing:

INFO  Configuration loaded monitors=2 providers=1
INFO  Monitor started monitor=my-website interval_secs=60
INFO  Monitor started monitor=my-db interval_secs=60

A check fails — alert fired:

WARN  Check FAILED monitor=my-website response_time_ms=5012 reason=Some("[STATUS] == 200: got '503'")
INFO  Alert sent monitor=my-website provider=slack-ops action=Fire

Service recovers — recovery alert sent:

INFO  Check passed monitor=my-website response_time_ms=112
INFO  Alert sent monitor=my-website provider=slack-ops action=Resolve