Add Dockerfile

Author: dbrgn

.dockerignore

@@ -0,0 +1,6 @@
+Dockerfile
+.dockerignore
+venv/
+.git/
+.mypy_cache/
+config.json

.gitignore

@@ -2,3 +2,4 @@
 *.pyc
 venv/
 config.json
+.mypy_cache/

Dockerfile

@@ -0,0 +1,27 @@
+FROM python:3.10-alpine3.14
+
+# Add user (UID 4333, chosen randomly)
+RUN addgroup -g 4333 -S spaceapi \
+ && adduser -u 4333 -S -G spaceapi spaceapi
+
+# Install system dependencies
+RUN apk update && apk add bash dumb-init
+
+# Install project dependencies
+COPY requirements.txt /code/requirements.txt
+RUN pip install -r /code/requirements.txt
+
+# Add code
+COPY . /code
+WORKDIR /code
+RUN chown -R spaceapi:spaceapi  /code/
+
+# Default config
+ENV RELAY_INTERVAL_SECONDS=60
+
+# Switch to non-privileged user
+USER spaceapi
+
+# Specify entrypoint
+ENTRYPOINT ["/usr/bin/dumb-init", "--"]
+CMD ["bash", "entrypoint.sh"]

README.md

@@ -26,6 +26,20 @@ After installing the requirements from `requirements.txt`, just run `python3
 relay.py <endpoint-url>` regularly :)
 
 
+## Docker
+
+The repository provides a `Dockerfile` that calls `relay.py` in a loop.
+Configure it using the following env vars:
+
+- `INFLUXDB_HOST`
+- `INFLUXDB_PORT`
+- `INFLUXDB_USER`
+- `INFLUXDB_PASS`
+- `INFLUXDB_DB`
+- `SPACEAPI_ENDPOINT`
+- `RELAY_INTERVAL_SECONDS`
+
+
 ## License
 
 Licensed under either of

entrypoint.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Ensure that the specified variable is defined and non-empty.
+# Otherwise, abort.
+function ensure_var() {
+    var=$1
+    if [[ ${!var:-} == "" ]]; then
+        1>&2 echo "Error: Variable $var not defined!"
+        exit 1
+    fi
+}
+
+# Required vars
+ensure_var "INFLUXDB_HOST"
+ensure_var "INFLUXDB_PORT"
+ensure_var "INFLUXDB_USER"
+ensure_var "INFLUXDB_PASS"
+ensure_var "INFLUXDB_DB"
+ensure_var "SPACEAPI_ENDPOINT"
+ensure_var "RELAY_INTERVAL_SECONDS"
+
+# Write config file
+{
+echo "{"
+echo "    \"influxdb_host\": \"$INFLUXDB_HOST\","
+echo "    \"influxdb_port\": $INFLUXDB_PORT,"
+echo "    \"influxdb_user\": \"$INFLUXDB_USER\","
+echo "    \"influxdb_pass\": \"$INFLUXDB_PASS\","
+echo "    \"influxdb_db\": \"$INFLUXDB_DB\""
+echo "}"
+} > config.json
+
+# Run every $RELAY_INTERVAL_SECONDS seconds
+while true; do
+    echo -n "$(date)    "
+    python3 relay.py "$SPACEAPI_ENDPOINT"
+    sleep "$RELAY_INTERVAL_SECONDS"
+done