golang

.gitignore

@@ -0,0 +1 @@
+.idea

README.md

@@ -1,7 +1,93 @@
 # inventor
+
 Prometheus HTTP SD implementation
 
-## helm chart
+## Description
+
+The Inventor is a Prometheus HTTP SD Server allows users to dynamcially add or remove prometheus targets and labels and expose it to a [Prometheus HTTP SD](https://prometheus.io/docs/prometheus/latest/http_sd/) job.
+
+## Usage
+
+Running the server:
+```
+cd src
+go run main.go
+```
+
+Installing with Helm
 ```bash
 helm repo add inventor https://code-tool.github.io/inventor/
 ```
+
+Registering new target:
+```bash
+curl -X PUT -H "x-api-token: secret" http://127.0.0.1:9101/target \
+-d '{"static_config": {"targets": ["10.0.10.2:9100",], "labels": {"__meta_datacenter": "dc-01", "__meta_prometheus_job": "node"}, "target_group": "mygroup"}}'
+```
+
+More examples: `./test/end-to-end`
+
+Prometheus SD config example
+```yaml
+scrape_configs:
+  - job_name: http_sd
+    http_sd_configs:
+      - url: http://127.0.0.1:9101/discover
+        # if SD_TOKEN env variable is set
+        headers:
+          - "x-sd-token: REDACTED"
+
+```
+
+Prometheus SD config with groups example
+```yaml
+scrape_configs:
+  - job_name: http_sd_mygroup
+    http_sd_configs:
+      - url: http://127.0.0.1:9101/group?name=mygroup
+        # if SD_TOKEN env variable is set
+        headers:
+          - "x-sd-token: REDACTED"
+
+```
+
+
+## Configuration Environmet Valiables
+
+  * `REDIS_ADDR`: redis server addres to store metrics and targets
+  * `REDIS_PORT`: redis server port
+  * `REDIS_DBNO`: redis server keyspace
+  * `TTL_SECONDS`: ttl for storing target, default is 6h (21600 seconds)
+  * `API_TOKEN`: API token for manipulating targets
+  * `SD_TOKEN`: Options token for Prometheus HTTP SD, is empty by default and not validating (header `x-sd-token`)
+
+## API Methods
+
+* **GET /discover**
+    * Returning the list of targets in Prometheus HTTP SD format
+* **GET /group**
+    * Returning targets by group name `/group?name=mygroup`
+* **PUT /target**
+    * Adds the new target
+* **GET /target**
+    * Returning target by ID
+* **DELETE /target**
+    * Removing target by ID
+* **GET /metrics**
+    * Metrics in prometheus format
+* **GET /healthcheck**
+    * Health Check for kubernetes deployments
+
+
+## Build Docker image
+```bash
+docker build -t ghcr.io/code-tool/inventor/inventor:$(cat VERSION.txt) --build-arg BUILD_VERSION=$(cat VERSION.txt) -f docker/Dockerfile .
+```
+pulling image:
+```bash
+ghcr.io/code-tool/inventor/inventor:0.0.3
+```
+
+## License
+
+Covered under the [MIT license](LICENSE.md).

docker/Dockerfile

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+FROM golang:1.21.11-bullseye AS builder
+ARG BUILD_VERSION='1.2.3'
+ENV LISTEN_PORT=9101
+WORKDIR /opt/inventor/
+COPY go.mod ./
+COPY go.sum .
+COPY src ./src
+RUN go mod download
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags "-X main.buildVersion=${BUILD_VERSION}" -a -installsuffix cgo -o inventor src/main.go
+
+FROM debian:bullseye
+WORKDIR /opt/inventor/
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends \
+    curl \
+  && rm -rf /var/cache/apt/archives/*
+COPY --from=builder /opt/inventor/inventor .
+
+EXPOSE ${LISTEN_PORT}
+CMD ["/opt/inventor/inventor"]

go.mod

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+module inventor
+
+go 1.21
+
+require (
+	github.com/go-redis/redis/v9 v9.0.0-beta.2
+	github.com/google/uuid v1.0.0
+	github.com/joho/godotenv v1.4.0
+	github.com/prometheus/client_golang v1.13.0
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/gorilla/mux v1.8.1
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+)

src/.env

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+APP_ENV="dev"
+API_TOKEN="secret"
+SD_TOKEN=""
+LISTEN_PORT="9101"
+REDIS_ADDR="127.0.0.1"
+REDIS_PORT="6379"
+REDIS_DBNO="7"
+TTL_SECONDS="300"

src/config/config.go

@@ -0,0 +1,60 @@
+package config
+
+import (
+	"log"
+	"os"
+	"reflect"
+
+	"github.com/joho/godotenv"
+)
+
+type Config struct {
+	APP_ENV     string
+	API_TOKEN   string
+	SD_TOKEN    string
+	LISTEN_PORT string
+	REDIS_ADDR  string
+	REDIS_PORT  string
+	REDIS_DBNO  string
+	TTL_SECONDS string
+}
+
+var config *Config
+
+func GetConfig() Config {
+	return *config
+}
+
+func loadEnvFile() {
+	log.Println("Loading .env file.")
+	err := godotenv.Load(".env")
+	if err != nil {
+		panic("Error loading .env file.")
+	}
+}
+
+func init() {
+	config = &Config{}
+	_, found := os.LookupEnv("APP_ENV")
+	if !found {
+		loadEnvFile()
+	}
+	_, found = os.LookupEnv("LISTEN_PORT")
+	if !found {
+		os.Setenv("LISTEN_PORT", "80")
+	}
+	_, found = os.LookupEnv("SD_TOKEN")
+	if !found {
+		os.Setenv("SD_TOKEN", "")
+	}
+	refl := reflect.ValueOf(config).Elem()
+	numFields := refl.NumField()
+	for i := 0; i < numFields; i++ {
+		envName := refl.Type().Field(i).Name
+		envVal, foud := os.LookupEnv(envName)
+		if !foud {
+			panic("Environment [" + envName + "] not found.")
+		}
+		refl.Field(i).SetString(envVal)
+	}
+}