Initial commit

Author: joecorall

.github/workflows/build-push.yml

@@ -0,0 +1,55 @@
+name: build-push
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  lint-test:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
+
+      - name: Set up Go
+        uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6
+        with:
+          go-version-file: "go.mod"
+
+      - name: go mod tidy
+        run: |
+          go mod tidy
+          if ! git diff --exit-code go.mod go.sum; then
+            echo "Error: go.mod or go.sum is not tidy. Run 'go mod tidy' locally and commit the changes."
+            exit 1
+          fi
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@e7fa5ac41e1cf5b7d48e45e42232ce7ada589601 # v9
+        with:
+          version: latest
+
+      - name: Install dependencies
+        run: go get .
+
+      - run: go build
+
+      - name: unit test
+        run: go test -race -v ./...
+
+      - name: coverage
+        run: go test -v -coverprofile=coverage.out -covermode=atomic ./...
+
+      - name: upload coverage to codecov
+        uses: codecov/codecov-action@5a1091511ad55cbe89839c7260b706298ca349f7 # v5
+        with:
+          files: ./coverage.out
+          fail_ci_if_error: false
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+
+  run:
+    needs: [lint-test]
+    uses: libops/.github/.github/workflows/build-push-ghcr.yaml@main
+    permissions:
+      contents: read
+      packages: write
+    secrets: inherit

.gitignore

@@ -0,0 +1 @@
+cap

.golangci.yaml

@@ -0,0 +1,26 @@
+version: "2"
+linters:
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - ../../go
+      - ../../../../opt
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - gofmt
+  exclusions:
+    generated: lax
+    paths:
+      - ../../go
+      - ../../../../opt
+      - third_party$
+      - builtin$
+      - examples$

Dockerfile

@@ -0,0 +1,20 @@
+FROM ghcr.io/libops/go1.25:main@sha256:f43c9b34f888d2ac53e87c8e061554f826b8eb580863d7b21fd787b6f0378f8f AS builder
+
+SHELL ["/bin/ash", "-o", "pipefail", "-ex", "-c"]
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN --mount=type=cache,target=/go/pkg/mod \
+  go mod download
+
+COPY *.go ./
+COPY config ./config
+COPY scraper ./scraper
+
+RUN --mount=type=cache,target=/root/.cache/go-build \
+  CGO_ENABLED=0 go build -ldflags="-s -w" -o /app/binary .
+
+FROM ghcr.io/libops/go1.25:main@sha256:f43c9b34f888d2ac53e87c8e061554f826b8eb580863d7b21fd787b6f0378f8f
+
+COPY --from=builder /app/binary /app/binary

README.md

@@ -0,0 +1,9 @@
+# cAdvisor Plus (cap)
+
+[ops-agent](https://docs.cloud.google.com/stackdriver/docs/solutions/agents/ops-agent) metrics for Google Compute Engine instances running Google Container Optimized OS.
+
+This service scrapes cadvisor every 30s, filters out metrics, and sends the filtered metrics to Google Cloud Monitoring
+
+## Attribution
+
+Code essentially forked from https://github.com/GoogleCloudPlatform/prometheus-engine/blob/7ca3c5c4e2a43cad2e79edbf724bc58cf064e423/pkg/export/gcm/promtest/local_export.go

config/config.go

@@ -0,0 +1,57 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"time"
+)
+
+// Config holds all necessary configuration loaded from environment variables.
+type Config struct {
+	ProjectID      string
+	Location       string
+	Cluster        string
+	CADVISORHost   string
+	ScrapeInterval time.Duration
+	FilterPattern  string
+	FilterRegex    *regexp.Regexp
+}
+
+const (
+	defaultCAdvisorHost   = "localhost:8080"
+	defaultScrapeInterval = 30 * time.Second
+	envVarName            = "SERVICE_PATTERN"
+)
+
+// LoadFromEnv reads configuration from environment variables.
+func LoadFromEnv() (Config, error) {
+	cfg := Config{
+		ProjectID:      os.Getenv("GCP_PROJECT"),
+		Location:       os.Getenv("GCP_ZONE"),
+		Cluster:        os.Getenv("GCP_INSTANCE_NAME"),
+		CADVISORHost:   os.Getenv("CADVISOR_HOST"),
+		ScrapeInterval: defaultScrapeInterval,
+	}
+
+	if cfg.CADVISORHost == "" {
+		cfg.CADVISORHost = defaultCAdvisorHost
+	}
+
+	cfg.FilterPattern = os.Getenv(envVarName)
+	if cfg.FilterPattern == "" {
+		cfg.FilterPattern = `.*`
+	}
+
+	var err error
+	cfg.FilterRegex, err = regexp.Compile(cfg.FilterPattern)
+	if err != nil {
+		return cfg, fmt.Errorf("failed to compile regex pattern %q: %w", cfg.FilterPattern, err)
+	}
+
+	if cfg.ProjectID == "" || cfg.Location == "" || cfg.Cluster == "" {
+		return cfg, fmt.Errorf("GCP environment variables (GCP_PROJECT, GCP_ZONE, GCP_INSTANCE_NAME) must be set")
+	}
+
+	return cfg, nil
+}

config/config_test.go

@@ -0,0 +1,76 @@
+package config_test
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/libops/cap/config"
+)
+
+// Helper function to reset environment variables after each test
+func resetEnv() {
+	_ = os.Unsetenv("GCP_PROJECT")
+	_ = os.Unsetenv("GCP_ZONE")
+	_ = os.Unsetenv("GCP_INSTANCE_NAME")
+	_ = os.Unsetenv("CADVISOR_HOST")
+	_ = os.Unsetenv("SERVICE_PATTERN")
+}
+
+func TestLoadFromEnv_Success(t *testing.T) {
+	resetEnv()
+	_ = os.Setenv("GCP_PROJECT", "test-project")
+	_ = os.Setenv("GCP_ZONE", "us-central1-a")
+	_ = os.Setenv("GCP_INSTANCE_NAME", "test-cluster")
+	_ = os.Setenv("SERVICE_PATTERN", `(test-service|other-service)`)
+
+	cfg, err := config.LoadFromEnv()
+
+	if err != nil {
+		t.Fatalf("LoadFromEnv failed unexpectedly: %v", err)
+	}
+
+	if cfg.ProjectID != "test-project" {
+		t.Errorf("Expected ProjectID 'test-project', got %s", cfg.ProjectID)
+	}
+	if cfg.CADVISORHost != "localhost:8080" {
+		t.Errorf("Expected default CADVISORHost 'localhost:8080', got %s", cfg.CADVISORHost)
+	}
+	if cfg.FilterRegex.String() != `(test-service|other-service)` {
+		t.Errorf("Expected regex to match pattern, got %s", cfg.FilterRegex.String())
+	}
+}
+
+func TestLoadFromEnv_MissingGCPVars(t *testing.T) {
+	resetEnv()
+	// Intentionally omit GCP_PROJECT
+
+	_, err := config.LoadFromEnv()
+
+	if err == nil {
+		t.Fatal("LoadFromEnv unexpectedly succeeded when required GCP vars were missing")
+	}
+	expectedError := "GCP environment variables (GCP_PROJECT, GCP_ZONE, GCP_INSTANCE_NAME) must be set"
+	if !strings.Contains(err.Error(), expectedError) {
+		t.Errorf("Expected error containing '%s', got: %v", expectedError, err)
+	}
+}
+
+func TestLoadFromEnv_InvalidRegex(t *testing.T) {
+	resetEnv()
+	_ = os.Setenv("GCP_PROJECT", "p")
+	_ = os.Setenv("GCP_ZONE", "z")
+	_ = os.Setenv("GCP_INSTANCE_NAME", "c")
+	// Invalid regex: trailing backslash
+	_ = os.Setenv("SERVICE_PATTERN", `\`)
+
+	_, err := config.LoadFromEnv()
+
+	if err == nil {
+		t.Fatal("LoadFromEnv unexpectedly succeeded with invalid regex")
+	}
+	expectedError := "failed to compile regex pattern"
+	if !strings.Contains(err.Error(), expectedError) {
+		t.Errorf("Expected error containing '%s', got: %v", expectedError, err)
+	}
+}

go.mod

@@ -0,0 +1,73 @@
+module github.com/libops/cap
+
+go 1.25.3
+
+require (
+	github.com/GoogleCloudPlatform/prometheus-engine v0.8.0
+	github.com/go-kit/log v0.2.1
+	github.com/prometheus/client_golang v1.23.2
+	github.com/prometheus/prometheus v1.99.0
+)
+
+require (
+	cloud.google.com/go/auth v0.17.0 // indirect
+	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
+	cloud.google.com/go/compute/metadata v0.9.0 // indirect
+	cloud.google.com/go/monitoring v1.24.3 // indirect
+	github.com/alecthomas/units v0.0.0-20240927000941-0f3dac36c52b // indirect
+	github.com/aws/aws-sdk-go v1.55.8 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dennwc/varint v1.0.0 // indirect
+	github.com/go-logfmt/logfmt v0.6.1 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang-jwt/jwt/v5 v5.3.0 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/google/s2a-go v0.1.9 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
+	github.com/googleapis/gax-go/v2 v2.15.0 // indirect
+	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 // indirect
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
+	github.com/jmespath/go-jmespath v0.4.0 // indirect
+	github.com/jpillora/backoff v1.0.0 // indirect
+	github.com/kylelemons/godebug v1.1.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.67.4 // indirect
+	github.com/prometheus/common/sigv4 v0.1.0 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.63.0 // indirect
+	go.opentelemetry.io/otel v1.38.0 // indirect
+	go.opentelemetry.io/otel/metric v1.38.0 // indirect
+	go.opentelemetry.io/otel/trace v1.38.0 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
+	go.uber.org/goleak v1.3.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.3 // indirect
+	golang.org/x/crypto v0.45.0 // indirect
+	golang.org/x/exp v0.0.0-20251113190631-e25ba8c21ef6 // indirect
+	golang.org/x/net v0.47.0 // indirect
+	golang.org/x/oauth2 v0.33.0 // indirect
+	golang.org/x/sync v0.18.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/text v0.31.0 // indirect
+	golang.org/x/time v0.14.0 // indirect
+	google.golang.org/api v0.256.0 // indirect
+	google.golang.org/genproto v0.0.0-20251111163417-95abcf5c77ba // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20251111163417-95abcf5c77ba // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251111163417-95abcf5c77ba // indirect
+	google.golang.org/grpc v1.77.0 // indirect
+	google.golang.org/protobuf v1.36.10 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/prometheus/prometheus => github.com/prometheus/prometheus v0.41.0