Create docker file for docker-exporter

.github/workflows/docker-exporter.yaml

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+name: Build and Push Docker-Exporter Image
+
+on:
+  push:
+    branches: [ '*' ]
+    paths:
+      - 'docker-exporter/**'
+      - '.github/workflows/docker-exporter.yaml'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Generate container metadata
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: ghcr.io/obmondo/dockerfiles/docker-exporter
+          tags: |
+            type=semver,pattern={{version}},value=v0.3.0
+          flavor: |
+            latest=false
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build & push container image
+        id: docker_build
+        uses: docker/build-push-action@v2
+        with:
+          context: ./docker-exporter
+          labels: ${{ steps.meta.outputs.labels }}
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}

docker-exporter/Dockerfile

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+FROM golang:1.22-alpine3.21 AS base
+
+RUN adduser -D -H docker-exporter
+
+ENV GO111MODULE=on \
+    CGO_ENABLED=0 \
+    GOOS=linux \
+    GOARCH=amd64
+
+WORKDIR /build
+
+COPY . .
+
+RUN go mod download
+
+FROM base AS build
+
+RUN go build -o docker-exporter -tags prod main.go
+
+FROM scratch AS prod
+
+COPY --from=build /etc/passwd /etc/passwd
+COPY --from=build /etc/group /etc/group
+COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+
+COPY --from=build /build/docker-exporter /
+
+USER docker-exporter:docker-exporter
+
+CMD ["./docker-exporter"]

docker-exporter/LICENSE

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+MIT License
+
+Copyright (c) 2023 David Borzek
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

docker-exporter/README.md

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+# docker exporter
+
+[![Go Report Card](https://goreportcard.com/badge/github.com/davidborzek/docker-exporter)](https://goreportcard.com/report/github.com/davidborzek/docker-exporter)
+
+Simple and lightweight Prometheus exporter for docker container metrics.
+
+## Prerequisites
+
+- [Go](https://golang.org/doc/)
+
+## Installation
+
+### Using Docker
+
+The exporter is available as a Docker image.
+You can run it using the following example:
+
+```
+$ docker run \
+  -u root \
+  -v /var/run/docker.sock:/var/run/docker.sock \
+  -p 8080:8080 \
+  ghcr.io/davidborzek/docker-exporter:latest
+```
+
+> Note: To run Docker Exporter, you'll need to mount the Docker socket from your host system. This operation necessitates root privileges or the user running the command to be a member of the Docker group. It's important to note that mounting the Docker socket grants the container unrestricted access to Docker. For a more secure approach, consider utilizing the Docker Socket Proxy, which is further explained below for additional information.
+
+### Running with [docker-socket-proxy](https://github.com/Tecnativa/docker-socket-proxy)
+
+```
+$ docker run \
+  -e "DOCKER_HOST=tcp://localhost:2375" \
+  -p 8080:8080 \
+  ghcr.io/davidborzek/docker-exporter:latest
+```
+
+> Note: the [docker-socket-proxy](https://github.com/Tecnativa/docker-socket-proxy#not-always-needed) needs to have container access enabled. (`CONTAINERS=1`)
+
+### Prometheus config
+
+Once you have configured the exporter, update your `prometheus.yml` scrape config:
+
+```yaml
+scrape_configs:
+  - job_name: "docker_exporter"
+    static_configs:
+      - targets: ["localhost:8080"]
+```
+
+### Config
+
+| Flag             | Description                                                                                          | Default Value            | Environment Variable           |
+| ---------------- | ---------------------------------------------------------------------------------------------------- | ------------------------ | ------------------------------ |
+| `--port`         | The port of docker exporter server.                                                                  | `8080`                   | `DOCKER_EXPORTER_PORT`         |
+| `--host`         | The host of docker exporter server.                                                                  |                          | `DOCKER_EXPORTER_HOST`         |
+| `--auth-token`   | Optional auth token for the docker exporter server. If no token is set authentication is disabled.   |                          | `DOCKER_EXPORTER_AUTH_TOKEN`   |
+| `--log-level`    | Log level for the exporter.                                                                          | `info`                   | `DOCKER_EXPORTER_LOG_LEVEL`    |
+| `--ignore-label` | Set the label name for ignoring docker containers. (See [Ignoring Containers](#ignoring-containers)) | `docker-exporter.ignore` | `DOCKER_EXPORTER_IGNORE_LABEL` |
+
+### Exported Metrics
+
+| Metric Name                                 | Description                        | Labels                  |
+| ------------------------------------------- | ---------------------------------- | ----------------------- |
+| docker_container_block_io_read_bytes        | Block I/O read bytes total         | name                    |
+| docker_container_block_io_write_bytes       | Block I/O write bytes total        | name                    |
+| docker_container_cpu_usage_percentage       | CPU usage in percentage            | name                    |
+| docker_container_info                       | Infos about the container          | name, image_name, image |
+| docker_container_memory_total_bytes         | Total memory in bytes              | name                    |
+| docker_container_memory_usage_bytes         | Memory usage in bytes              | name                    |
+| docker_container_memory_usage_percentage    | Memory usage in percentage         | name                    |
+| docker_container_network_rx_bytes           | Network received bytes total       | name, network           |
+| docker_container_network_rx_dropped_packets | Network dropped packets total      | name, network           |
+| docker_container_network_rx_errors          | Network received errors            | name, network           |
+| docker_container_network_rx_packets         | Network received packets total     | name, network           |
+| docker_container_network_tx_bytes           | Network sent bytes total           | name, network           |
+| docker_container_network_tx_dropped_packets | Network dropped packets total      | name, network           |
+| docker_container_network_tx_errors          | Network sent errors                | name, network           |
+| docker_container_network_tx_packets         | Network sent packets total         | name, network           |
+| docker_container_pids_current               | Current number of pids             | name                    |
+| docker_container_state                      | State of the container             | name, state             |
+| docker_container_uptime                     | Uptime of the container in seconds | name                    |
+| docker_exporter_scrape_duration             | Duration of the scrape in seconds  |                         |
+| docker_exporter_scrape_errors               | Number of scrape errors            |                         |
+
+### Ignoring Containers
+
+You can ignore containers by setting the label `docker-exporter.ignore` on the container. The label name can be configured with the `--ignore-label` flag.
+
+```yaml
+services:
+  nginx:
+    image: nginx
+    labels:
+      docker-exporter.ignore: "true"
+```

docker-exporter/cmd/main.go

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+package cmd
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/davidborzek/docker-exporter/internal/clock"
+	"github.com/davidborzek/docker-exporter/internal/collector"
+	"github.com/davidborzek/docker-exporter/internal/handler"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/urfave/cli/v2"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	version = "v0.3.0"
+)
+
+var (
+	flags = []cli.Flag{
+		&cli.StringFlag{
+			Name:    "port",
+			Value:   "8080",
+			Usage:   "The port of docker exporter server",
+			EnvVars: []string{"DOCKER_EXPORTER_PORT"},
+		},
+		&cli.StringFlag{
+			Name:    "host",
+			Usage:   "The host of docker exporter server",
+			EnvVars: []string{"DOCKER_EXPORTER_HOST"},
+		},
+		&cli.StringFlag{
+			Name:    "auth-token",
+			Usage:   "Optional auth token for the docker exporter server. If no token is set authentication is disabled.",
+			EnvVars: []string{"DOCKER_EXPORTER_AUTH_TOKEN"},
+		},
+		&cli.StringFlag{
+			Name:    "log-level",
+			Usage:   "Log level",
+			Value:   "info",
+			EnvVars: []string{"DOCKER_EXPORTER_LOG_LEVEL"},
+		},
+		&cli.StringFlag{
+			Name:    "ignore-label",
+			Usage:   "Label to ignore containers",
+			Value:   "docker-exporter.ignore",
+			EnvVars: []string{"DOCKER_EXPORTER_IGNORE_LABEL"},
+		},
+	}
+)
+
+func parseLogLevel(level string) log.Level {
+	switch strings.ToLower(level) {
+	case "debug":
+		return log.DebugLevel
+	case "info":
+		return log.InfoLevel
+	case "warning":
+		return log.WarnLevel
+	case "error":
+		return log.ErrorLevel
+	case "fatal":
+		return log.FatalLevel
+	}
+
+	log.WithField("level", level).
+		Warn("invalid log level provided - falling back to 'info'")
+
+	return log.InfoLevel
+}
+
+func start(ctx *cli.Context) error {
+	log.SetFormatter(&log.TextFormatter{
+		FullTimestamp: true,
+	})
+
+	log.SetLevel(
+		parseLogLevel(ctx.String("log-level")),
+	)
+
+	log.WithField("pid", os.Getpid()).
+		Info("docker prometheus exporter started")
+
+	token := ctx.String("auth-token")
+	if len(token) > 0 {
+		log.Info("authentication is enabled")
+	}
+
+	dc, err := collector.NewDockerCollector(clock.NewClock(), ctx.String("ignore-label"))
+	if err != nil {
+		log.WithError(err).
+			Fatal("failed to create docker collector")
+	}
+
+	prometheus.MustRegister(dc)
+
+	h := handler.New(token)
+
+	addr := net.JoinHostPort(
+		ctx.String("host"), ctx.String("port"))
+	log.WithField("addr", addr).
+		Infof("starting the http server")
+
+	return http.ListenAndServe(addr, h)
+}
+
+func Main(args []string) {
+	app := cli.App{
+		Name:    "Docker Prometheus exporter",
+		Usage:   "Export Docker metrics to prometheus format",
+		Action:  start,
+		Flags:   flags,
+		Version: version,
+	}
+
+	if err := app.Run(args); err != nil {
+		fmt.Println(err.Error())
+	}
+}

docker-exporter/go.mod

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+module github.com/davidborzek/docker-exporter
+
+go 1.22
+
+toolchain go1.23.4
+
+require (
+	github.com/docker/docker v27.4.0+incompatible
+	github.com/prometheus/client_golang v1.20.5
+	github.com/sirupsen/logrus v1.9.3
+	github.com/stretchr/testify v1.10.0
+	github.com/urfave/cli/v2 v2.27.5
+	go.uber.org/mock v0.5.0
+)
+
+require (
+	github.com/Microsoft/go-winio v0.6.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.5 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/distribution/reference v0.5.0 // indirect
+	github.com/docker/distribution v2.8.2+incompatible // indirect
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/docker/go-units v0.5.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/kylelemons/godebug v1.1.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/matttproud/golang_protobuf_extensions/v2 v2.0.0 // indirect
+	github.com/moby/docker-image-spec v1.3.1 // indirect
+	github.com/moby/term v0.5.0 // indirect
+	github.com/morikuni/aec v1.0.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/opencontainers/image-spec v1.0.2 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.47.0 // indirect
+	go.opentelemetry.io/otel v1.22.0 // indirect
+	go.opentelemetry.io/otel/metric v1.22.0 // indirect
+	go.opentelemetry.io/otel/trace v1.22.0 // indirect
+	golang.org/x/mod v0.18.0 // indirect
+	golang.org/x/net v0.26.0 // indirect
+	golang.org/x/sync v0.7.0 // indirect
+	golang.org/x/sys v0.22.0 // indirect
+	golang.org/x/time v0.3.0 // indirect
+	golang.org/x/tools v0.22.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	gotest.tools/v3 v3.5.1 // indirect
+)