Ease usage with docker entrypoint and env vars

Dockerfile

@@ -1,13 +1,32 @@
-FROM golang as builder
-COPY . /go/src/github.com/vierbergenlars/bareos_exporter
+FROM golang:1.18.0 as builder
+
+RUN apt-get update \
+ && apt-get install -y upx
+
 WORKDIR /go/src/github.com/vierbergenlars/bareos_exporter
+COPY . .
+
 RUN go get -v .
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o bareos_exporter .
+RUN upx bareos_exporter
 
-FROM busybox:latest
-
+FROM busybox:1.34.1
 WORKDIR /bareos_exporter
 COPY --from=builder /go/src/github.com/vierbergenlars/bareos_exporter/bareos_exporter bareos_exporter
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod u+x /entrypoint.sh
+
+ENV PORT 9625
+ENV DB_TYPE postgres
+ENV DB_HOST localhost
+ENV DB_PORT 5432
+ENV DB_NAME bareos
+ENV DB_USER bareos
+ENV SSL_MODE disable
+ENV ENDPOINT /metrics
+ENV JOB_DAYS 7
+ENV WAIT_FOR_DB 0
 
-ENTRYPOINT ["./bareos_exporter"]
-EXPOSE $port
+EXPOSE $PORT
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["./bareos_exporter"]

README.md

@@ -6,12 +6,37 @@
 ## [`Dockerfile`](./Dockerfile)
 
 ## Usage with [docker](https://hub.docker.com/r/vierbergenlnars/bareos_exporter)
-1. Create a file containing your mysql password and mount it inside `/bareos_exporter/pw/auth`
-2. **(optional)** [Overwrite](https://docs.docker.com/engine/reference/run/#env-environment-variables) default args using ENV variables
-3. Run docker image as follows
+
+1. Create a .env file containing at least your database password using `DB_PASSWORD` variable.
+2. Run docker image as follows
+
+Using default variables (expected DB_PASSWORD)
+```bash
+docker run --name bareos_exporter -p 9625:9625 -d vierbergenlars/bareos_exporter:latest
+```
+
+Using custom variables
 ```bash
-docker run --name bareos_exporter -p 9625:9625 -d vierbergenlars/bareos_exporter:latest -dsn mysql://user:password@host/dbname
+docker run --name bareos_exporter -p 9625:9625 -e DB_TYPE=mysql -e DB_NAME=bareos-dir -d vierbergenlars/bareos_exporter:latest
 ```
+
+Using custom Docker CMD
+```bash
+docker run --name bareos_exporter -p 9625:9625 -d vierbergenlars/bareos_exporter:latest ./bareos_exporter -dsn 'mysql://login:password@tcp(host:port)/dbname?parseTime=true'
+```
+
+### Default variables
+
+* `DB_TYPE` postgres
+* `DB_HOST` localhost
+* `DB_PORT` 5432 (postgres)
+* `DB_USER` bareos
+* `DB_NAME` bareos
+* `SSL_MODE` disable
+* `ENDPOINT` /metrics
+* `JOB_DAYS` 7
+* `WAIT_FOR_DB` 0
+
 ## Metrics
 
 ### Aggregated metrics for all jobs

entrypoint.sh

@@ -0,0 +1,16 @@
+#!/bin/env sh
+#set -x
+
+# Wait for DB (default 0)
+sleep ${WAIT_FOR_DB}
+
+# Run Dockerfile CMD
+if [ "$#" -eq 1 -a "$1" == './bareos_exporter' ]; then
+  if [ "${DB_TYPE}" == 'postgres' ]; then
+    exec ./bareos_exporter -endpoint ${ENDPOINT} -job-discovery-days ${JOB_DAYS} -port ${PORT} -dsn "${DB_TYPE}://host=${DB_HOST} dbname=${DB_NAME} sslmode=${SSL_MODE} user=${DB_USER} password=${DB_PASSWORD} port=${DB_PORT} ${EXTRA_OPTS}"
+  else
+    exec ./bareos_exporter -endpoint ${ENDPOINT} -job-discovery-days ${JOB_DAYS} -port ${PORT} -dsn "${DB_TYPE}://${DB_USER}:${DB_PASSWORD}@tcp(${DB_HOST}:${DB_PORT})/${DB_NAME}?parseTime=true"
+  fi
+else
+  exec "$@"
+fi