initial commit

.gitignore

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+requests.log

Dockerfile

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+FROM docker.io/golang:1.19-alpine AS builder
+
+WORKDIR /app
+
+COPY go.mod ./
+#COPY go.sum ./
+RUN go mod download
+
+COPY *.go ./
+
+RUN go build -o /reqlog
+
+FROM alpine:3.17.0
+WORKDIR /
+COPY --from=builder /reqlog .
+
+EXPOSE 3000
+CMD [ "/reqlog" ]

LICENSE

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+Copyright 2022 Jon Roeber
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

README.md

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+# Request Logger
+
+Serves an HTTP server on port 3000 and logs any requests to a file, stdout, and the response body.
+
+*This is not intended for production use. It is just a simple diagnostic tool for short-term testing.*
+
+## General use
+
+1. Install Docker: `sudo apt install docker.io`
+2. Create an empty log file: `touch requests.log`
+3. Run a container:
+
+```bash
+docker run \
+  --name reqlog \
+  --restart always \
+  -d \
+  -p 3000:3000 \
+  -v $(pwd)/requests.log:/requests.log \
+  git.roeber.dev/jon/reqlog:v0.0.1
+```
+
+4. Test:
+
+```bash
+curl \
+  -X POST \
+  http://localhost:3000/ \
+  -H "Content-Type: application/json" \
+  -d '{"temp": 98.6}'
+```
+
+The request gets logged to `requests.log`, printed to stdout (if running a container in daemon mode, check stdout with `docker logs reqlog`), and returned in the response body.

go.mod

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+module git.roeber.dev/jon/reqlog
+
+go 1.18

main.go

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+package main
+
+import (
+	"flag"
+	"fmt"
+	"net/http"
+	"net/http/httputil"
+	"os"
+	"strings"
+	"time"
+)
+
+var logFile *string
+
+func main() {
+	logFile = flag.String("logfile", "requests.log", "the file to log requests to")
+	flag.Parse()
+
+	http.HandleFunc("/", post)
+	err := http.ListenAndServe(":3000", nil)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func post(w http.ResponseWriter, r *http.Request) {
+	reqDump, err := httputil.DumpRequest(r, true)
+	if err != nil {
+		w.WriteHeader(500)
+		w.Write([]byte(err.Error()))
+		return
+	}
+	// log to stdout
+	fmt.Print(logString(reqDump))
+
+	// log to logfile
+	lf, err := os.OpenFile(*logFile, os.O_CREATE | os.O_APPEND | os.O_WRONLY, 0644)
+	if err != nil {
+		fmt.Printf("failed to open log file: %v", err)
+		w.WriteHeader(500)
+		w.Write([]byte(fmt.Sprintf("failed to open log file: %v", err)))
+	}
+	defer lf.Close()
+	lf.WriteString(logString(reqDump))
+
+	// echo log message as response
+	w.WriteHeader(200)
+	w.Write([]byte(logString(reqDump)))
+}
+
+func logString(reqDump []byte) string {
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("Received request at %v:\n\n", time.Now()))
+	sb.Write(reqDump)
+	sb.WriteString("\n\n")
+	return sb.String()
+}