Merge branch 'master' into next-major

Reviewed-on: https://git.iamthefij.com/iamthefij/minitor-go/pulls/13

.drone.yml

@@ -4,7 +4,7 @@ name: test
 
 steps:
   - name: test
-    image: golang:1.20
+    image: golang:1.21
     environment:
       VERSION: ${DRONE_TAG:-${DRONE_COMMIT}}
     commands:
@@ -30,7 +30,7 @@ trigger:
 
 steps:
   - name: build all binaries
-    image: golang:1.20
+    image: golang:1.21
     environment:
       VERSION: ${DRONE_TAG:-${DRONE_COMMIT}}
     commands:

.gitea/workflows/build.yml

@@ -0,0 +1,111 @@
+name: ci
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "v*"
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go.mod
+
+      - name: Run tests
+        run: make test
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go.mod
+
+      - name: Set up Python
+        uses: actions/setup-python@v6
+
+      - name: Run pre-commit
+        uses: https://git.iamthefij.com/iamthefij/pre-commit-action@v3.0.2
+
+  release:
+    runs-on: ubuntu-latest
+    needs: test
+    if: "${{ github.event_name != 'pull_request' }}"
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go.mod
+
+      - name: Build binaries
+        env:
+          VERSION: "${{ github.REF_NAME }}"
+        run: make all
+
+      # Package binaries and create release if this is a tagged build
+      - name: Compress binaries
+        if: "${{ github.ref_type == 'tag' }}"
+        run: find ./dist -type f -executable -execdir tar -czvf {}.tar.gz {} \;
+
+      - name: Upload release
+        uses: https://gitea.com/actions/gitea-release-action@v1
+        if: "${{ github.ref_type == 'tag' }}"
+        with:
+          files: |-
+            dist/*.tar.gz
+          md5sum: true
+          sha256sum: true
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            ${{ github.REPOSITORY }}
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        if: "${{ github.event_name != 'pull_request' }}"
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          # Use path context so we can access pre-compiled binaries
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          platforms: |
+            linux/amd64
+            linux/arm64
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.gitignore

@@ -14,6 +14,7 @@
 
 # User configuration
 config.yml
+config.hcl
 
 # Output binary
 minitor

.golangci.yml

@@ -1,16 +1,13 @@
----
+version: "2"
 linters:
   enable:
     - errname
     - errorlint
     - exhaustive
-    - gofumpt
-    - goimports
-    - gomnd
     - goprintffuncname
     - misspell
+    - mnd
     - tagliatelle
-    - tenv
     - testpackage
     - thelper
     - tparallel
@@ -19,18 +16,37 @@ linters:
     - wsl
   disable:
     - gochecknoglobals
-
+  settings:
-linters-settings:
     gosec:
       excludes:
         - G204
     tagliatelle:
       case:
         rules:
+          json: snake
           yaml: snake
-
+  exclusions:
-issues:
+    generated: lax
-  exclude-rules:
+    presets:
-    - path: _test\.go
+      - comments
-      linters:
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    rules:
+      - linters:
           - gosec
+        path: _test\.go
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - gofumpt
+    - goimports
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 ---
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v6.0.0
     hooks:
       - id: check-added-large-files
       - id: check-yaml
@@ -11,10 +11,10 @@ repos:
       - id: end-of-file-fixer
       - id: check-merge-conflict
   - repo: https://github.com/golangci/golangci-lint
-    rev: v1.52.2
+    rev: v2.7.2
     hooks:
       - id: golangci-lint
   - repo: https://github.com/hadolint/hadolint
-    rev: v2.12.1-beta
+    rev: refs/pull/1152/head
     hooks:
-      - id: hadolint
+      - id: hadolint-github

Dockerfile

@@ -1,10 +1,11 @@
-FROM alpine:3.18
+FROM alpine:3.23
 
 RUN mkdir /app
 WORKDIR /app/
 
 # Add common checking tools
-RUN apk --no-cache add bash=~5 curl=~8 jq=~1 bind-tools=~9 tzdata~=2024a
+# hadolint ignore=DL3018
+RUN apk --no-cache add bash=~5 curl=~8 jq=~1 bind-tools=~9 tzdata
 
 # Add minitor user for running as non-root
 RUN addgroup -S minitor && adduser -S minitor -G minitor

Dockerfile.multi-stage

@@ -1,4 +1,4 @@
-FROM golang:1.20 AS builder
+FROM golang:1.25 AS builder
 
 WORKDIR /app
 
@@ -13,7 +13,7 @@ ARG VERSION=dev
 ENV CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=${TARGETARCH}
 RUN go build -ldflags "-X main.version=${VERSION}" -a -installsuffix nocgo -o minitor .
 
-FROM alpine:3.18
+FROM alpine:3.23
 RUN mkdir /app
 WORKDIR /app/
 
@@ -21,7 +21,8 @@ WORKDIR /app/
 COPY --from=builder /app/minitor .
 
 # Add common checking tools
-RUN apk --no-cache add bash=~5 curl=~8 jq=~1 bind-tools=~9 tzdata~=2024a
+# hadolint ignore=DL3018
+RUN apk --no-cache add bash=~5 curl=~8 jq=~1 bind-tools=~9 tzdata
 
 # Add minitor user for running as non-root
 RUN addgroup -S minitor && adduser -S minitor -G minitor

README.md

@@ -17,7 +17,7 @@ I'm running a few small services and found Sensu, Consul, Nagios, etc. to all be
 Install and execute with:
 
 ```bash
-go install github.com/iamthefij/minitor-go@latest
+go install github.com/iamthefij/minitor-go/v2@latest
 minitor
 ```
 
@@ -50,15 +50,17 @@ You can configure the timezone for the container by passing a `TZ` env variable.
 
 ## Configuring
 
-In this repo, you can explore the `sample-config.hcl` file for an example, but the general structure is as follows. It should be noted that environment variable interpolation happens on load of the HCL file.
+In this repo, you can explore the `sample-config.hcl` file for an example, but the general structure is as follows. If you are passing environment variables to your commands or alerts, you should be aware that `${VAR}` syntax is reserved for HCL variable interpolation. To avoid issues, you can use `$${VAR}` syntax to escape the `$` character, simply use `$VAR`.
+
+```hcl
 
 The global configurations are:
 
 |key|value|
 |---|---|
 |`check_interval`|Maximum frequency to run checks for each monitor as duration, eg. 1m2s.|
-|`default_alert_after`|A default value used as an `alert_after` value for a monitor if not specified or 0.|
+|`default_alert_after`|A default value used as an `alert_after` value for a monitor if not specified. Defaults 1, which will alert immediately.|
-|`default_alert_every`|A default value used as an `alert_every` value for a monitor if not specified.|
+|`default_alert_every`|A default value used as an `alert_every` value for a monitor if not specified. Defaults to -1, which will re-alert exponentially.|
 |`default_alert_down`|Default down alerts to used by a monitor in case none are provided.|
 |`default_alert_up`|Default up alerts to used by a monitor in case none are provided.|
 |`monitor`|block listing monitors. Detailed description below|
@@ -75,7 +77,7 @@ monitor "example" {
   alert_up = ["log"]
   check_interval = "1m"
   alert_after = 1
-  alert_every = 0
+  alert_every = -1
 }
 ```
 
@@ -167,6 +169,48 @@ minitor -metrics
 minitor -metrics -metrics-port 3000
 ```
 
+## Migrating from v1 to v2
+
+Minitor v2 introduces some breaking changes from v1. The most notable changes are:
+  - The configuration file is now in HCL format instead of YAML.
+  - The the Python formatting backwards compatability is removed.
+  - The Command and ShellCommand fields are now mutually exclusive.
+  - The check_interval is now strictly a duration string value. Eg. "30s" rather than `30`.
+  - Default alert_every is now -1 (exponential backoff) rather than 0 (no re-alerting).
+
+For the configuration, a confic that looked like this in v1:
+
+```yaml
+check_interval: 60
+
+monitors:
+  - name: example
+    command: "false"
+    alert_down: ["log"]
+
+alerts:
+  log:
+    command: ["echo", "Minitor up={{.IsUp}} for {{.MonitorName}}"]
+```
+
+Would now look like this in v2:
+
+```hcl
+check_interval = "1m"
+
+monitor "example" {
+  # example showing string to shell command migration
+  shell_command = "false"
+  alert_down = ["log"]
+  check_interval = "1m"
+}
+
+alert "log" {
+  # example showing list to exec command migration
+  command = ["echo", "Minitor up={{.IsUp}} for {{.MonitorName}}"]
+}
+```
+
 ## Contributing
 
 Whether you're looking to submit a patch or tell me I broke something, you can contribute through the Github mirror and I can merge PRs back to the source repository.
@@ -174,11 +218,3 @@ Whether you're looking to submit a patch or tell me I broke something, you can c
 Primary Repo: https://git.iamthefij.com/iamthefij/minitor.git
 
 Github Mirror: https://github.com/IamTheFij/minitor.git
-
-## Original Minitor
-
-This is a reimplementation of [Minitor](https://git.iamthefij.com/iamthefij/minitor) in Go
-
-Minitor is already a minimal monitoring tool. Python 3 was a quick way to get something live, but Python itself comes with a large footprint. Thus Go feels like a better fit for the project, longer term.
-
-Initial target is meant to be roughly compatible requiring only minor changes to configuration. Future iterations may diverge to take advantage of Go specific features.

alert.go

@@ -37,13 +37,32 @@ type AlertNotice struct {
 	LastCheckOutput string
 }
 
-// IsValid returns a boolean indicating if the Alert has been correctly
+// Validate checks that the Alert is properly configured and returns errors if not
-// configured
+func (alert Alert) Validate() error {
-func (alert Alert) IsValid() bool {
+	hasCommand := len(alert.Command) > 0
-	hasAtLeastOneCommand := alert.Command != nil || alert.ShellCommand != ""
+	hasShellCommand := alert.ShellCommand != ""
-	hasAtMostOneCommand := alert.Command == nil || alert.ShellCommand == ""
 
-	return hasAtLeastOneCommand && hasAtMostOneCommand
+	var err error
+
+	hasAtLeastOneCommand := hasCommand || hasShellCommand
+	if !hasAtLeastOneCommand {
+		err = errors.Join(err, fmt.Errorf(
+			"%w: alert %s has no command or shell_command configured",
+			ErrInvalidAlert,
+			alert.Name,
+		))
+	}
+
+	hasAtMostOneCommand := !(hasCommand && hasShellCommand)
+	if !hasAtMostOneCommand {
+		err = errors.Join(err, fmt.Errorf(
+			"%w: alert %s has both command and shell_command configured",
+			ErrInvalidAlert,
+			alert.Name,
+		))
+	}
+
+	return err
 }
 
 // BuildTemplates compiles command templates for the Alert
@@ -82,14 +101,14 @@ func (alert *Alert) BuildTemplates() error {
 	}
 
 	switch {
-	case alert.commandTemplate == nil && alert.Command != nil:
+	case alert.Command != nil:
 		alert.commandTemplate = []*template.Template{}
 		for i, cmdPart := range alert.Command {
 			alert.commandTemplate = append(alert.commandTemplate, template.Must(
 				template.New(alert.Name+fmt.Sprint(i)).Funcs(timeFormatFuncs).Parse(cmdPart),
 			))
 		}
-	case alert.commandShellTemplate == nil && alert.ShellCommand != "":
+	case alert.ShellCommand != "":
 		shellCmd := alert.ShellCommand
 
 		alert.commandShellTemplate = template.Must(

alert_test.go

@@ -1,20 +1,24 @@
 package main_test
 
 import (
+	"errors"
 	"testing"
 
-	m "git.iamthefij.com/iamthefij/minitor-go"
+	m "git.iamthefij.com/iamthefij/minitor-go/v2"
 )
 
-func TestAlertIsValid(t *testing.T) {
+func TestAlertValidate(t *testing.T) {
+	t.Parallel()
+
 	cases := []struct {
 		alert    m.Alert
-		expected bool
+		expected error
 		name     string
 	}{
-		{m.Alert{Command: []string{"echo", "test"}}, true, "Command only"},
+		{m.Alert{Command: []string{"echo", "test"}}, nil, "Command only"},
-		{m.Alert{ShellCommand: "echo test"}, true, "CommandShell only"},
+		{m.Alert{ShellCommand: "echo test"}, nil, "CommandShell only"},
-		{m.Alert{}, false, "No commands"},
+		{m.Alert{Command: []string{"echo", "test"}, ShellCommand: "echo test"}, m.ErrInvalidAlert, "Both commands"},
+		{m.Alert{}, m.ErrInvalidAlert, "No commands"},
 	}
 
 	for _, c := range cases {
@@ -23,8 +27,11 @@ func TestAlertIsValid(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			t.Parallel()
 
-			actual := c.alert.IsValid()
+			actual := c.alert.Validate()
-			if actual != c.expected {
+			hasErr := (actual != nil)
+			expectErr := (c.expected != nil)
+
+			if hasErr != expectErr || !errors.Is(actual, c.expected) {
 				t.Errorf("expected=%t actual=%t", c.expected, actual)
 			}
 		})

config.go

@@ -6,21 +6,26 @@ import (
 	"time"
 
 	"git.iamthefij.com/iamthefij/slog"
-	/*
-	 * "github.com/hashicorp/hcl/v2"
-	 * "github.com/hashicorp/hcl/v2/gohcl"
-	 */
 	"github.com/hashicorp/hcl/v2/hclsimple"
 )
 
-var errInvalidConfig = errors.New("Invalid configuration")
+var (
+	ErrLoadingConfig  = errors.New("Failed to load or parse configuration")
+	ErrConfigInit     = errors.New("Failed to initialize configuration")
+	ErrInvalidConfig  = errors.New("Invalid configuration")
+	ErrNoAlerts       = errors.New("No alerts provided")
+	ErrInvalidAlert   = errors.New("Invalid alert configuration")
+	ErrNoMonitors     = errors.New("No monitors provided")
+	ErrInvalidMonitor = errors.New("Invalid monitor configuration")
+	ErrUnknownAlert   = errors.New("Unknown alert")
+)
 
 // Config type is contains all provided user configuration
 type Config struct {
 	CheckIntervalStr string `hcl:"check_interval"`
 	CheckInterval    time.Duration
 
-	DefaultAlertAfter *int       `hcl:"default_alert_after,optional"`
+	DefaultAlertAfter int        `hcl:"default_alert_after,optional"`
 	DefaultAlertEvery *int       `hcl:"default_alert_every,optional"`
 	DefaultAlertDown  []string   `hcl:"default_alert_down,optional"`
 	DefaultAlertUp    []string   `hcl:"default_alert_up,optional"`
@@ -30,6 +35,77 @@ type Config struct {
 	alertLookup map[string]*Alert
 }
 
+// Init performs extra initialization on top of loading the config from file
+func (config *Config) Init() (err error) {
+	config.CheckInterval, err = time.ParseDuration(config.CheckIntervalStr)
+	if err != nil {
+		return fmt.Errorf("failed to parse top level check_interval duration: %w", err)
+	}
+
+	if config.DefaultAlertAfter == 0 {
+		minAlertAfter := 1
+		config.DefaultAlertAfter = minAlertAfter
+	}
+
+	if config.DefaultAlertEvery == nil {
+		defaultDefaultAlertEvery := -1
+		config.DefaultAlertEvery = &defaultDefaultAlertEvery
+	}
+
+	for _, monitor := range config.Monitors {
+		if err = monitor.Init(
+			config.DefaultAlertAfter,
+			config.DefaultAlertEvery,
+			config.DefaultAlertDown,
+			config.DefaultAlertUp,
+		); err != nil {
+			return
+		}
+	}
+
+	err = config.BuildAllTemplates()
+
+	return
+}
+
+// IsValid checks config validity and returns true if valid
+func (config Config) IsValid() error {
+	var err error
+
+	// Validate alerts
+	if len(config.Alerts) == 0 {
+		err = errors.Join(err, ErrNoAlerts)
+	}
+
+	for _, alert := range config.Alerts {
+		err = errors.Join(err, alert.Validate())
+	}
+
+	// Validate monitors
+	if len(config.Monitors) == 0 {
+		err = errors.Join(err, ErrNoMonitors)
+	}
+
+	for _, monitor := range config.Monitors {
+		err = errors.Join(err, monitor.Validate())
+
+		// Check that all Monitor alerts actually exist
+		for _, isUp := range []bool{true, false} {
+			for _, alertName := range monitor.GetAlertNames(isUp) {
+				if _, ok := config.GetAlert(alertName); !ok {
+					err = errors.Join(
+						err,
+						fmt.Errorf("%w: %s. %w: %s", ErrInvalidMonitor, monitor.Name, ErrUnknownAlert, alertName),
+					)
+				}
+			}
+		}
+	}
+
+	return err
+}
+
+// GetAlert returns an alert by name
 func (c Config) GetAlert(name string) (*Alert, bool) {
 	if c.alertLookup == nil {
 		c.alertLookup = map[string]*Alert{}
@@ -54,119 +130,24 @@ func (c *Config) BuildAllTemplates() (err error) {
 	return
 }
 
-// IsValid checks config validity and returns true if valid
-func (config Config) IsValid() (isValid bool) {
-	isValid = true
-
-	// Validate alerts
-	if len(config.Alerts) == 0 {
-		// This should never happen because there is a default alert named 'log' for now
-		slog.Errorf("Invalid alert configuration: Must provide at least one alert")
-
-		isValid = false
-	}
-
-	for _, alert := range config.Alerts {
-		if !alert.IsValid() {
-			slog.Errorf("Invalid alert configuration: %+v", alert.Name)
-
-			isValid = false
-		}
-	}
-
-	// Validate monitors
-	if len(config.Monitors) == 0 {
-		slog.Errorf("Invalid monitor configuration: Must provide at least one monitor")
-
-		isValid = false
-	}
-
-	for _, monitor := range config.Monitors {
-		if !monitor.IsValid() {
-			slog.Errorf("Invalid monitor configuration: %s", monitor.Name)
-
-			isValid = false
-		}
-		// Check that all Monitor alerts actually exist
-		for _, isUp := range []bool{true, false} {
-			for _, alertName := range monitor.GetAlertNames(isUp) {
-				if _, ok := config.GetAlert(alertName); !ok {
-					slog.Errorf(
-						"Invalid monitor configuration: %s. Unknown alert %s",
-						monitor.Name, alertName,
-					)
-
-					isValid = false
-				}
-			}
-		}
-	}
-
-	return isValid
-}
-
-// Init performs extra initialization on top of loading the config from file
-func (config *Config) Init() (err error) {
-	config.CheckInterval, err = time.ParseDuration(config.CheckIntervalStr)
-	if err != nil {
-		return fmt.Errorf("failed to parse top level check_interval duration: %w", err)
-	}
-
-	for _, monitor := range config.Monitors {
-		// TODO: Move this to a Monitor.Init() method
-
-		// Parse the check_interval string into a time.Duration
-		if monitor.CheckIntervalStr != nil {
-			monitor.CheckInterval, err = time.ParseDuration(*monitor.CheckIntervalStr)
-			if err != nil {
-				return fmt.Errorf("failed to parse check_interval duration for monitor %s: %w", monitor.Name, err)
-			}
-		}
-
-		// Set default values for monitor alerts
-		if monitor.AlertAfter == 0 && config.DefaultAlertAfter != nil {
-			monitor.AlertAfter = *config.DefaultAlertAfter
-		} else if monitor.AlertAfter == 0 {
-			monitor.AlertAfter = 1
-		}
-
-		if monitor.AlertEvery == nil {
-			monitor.AlertEvery = config.DefaultAlertEvery
-		}
-
-		if monitor.AlertDown == nil {
-			monitor.AlertDown = config.DefaultAlertDown
-		}
-
-		if monitor.AlertUp == nil {
-			monitor.AlertUp = config.DefaultAlertUp
-		}
-	}
-
-	err = config.BuildAllTemplates()
-
-	return
-}
-
 // LoadConfig will read config from the given path and parse it
-func LoadConfig(filePath string) (config Config, err error) {
+func LoadConfig(filePath string) (Config, error) {
-	err = hclsimple.DecodeFile(filePath, nil, &config)
+	var config Config
-	if err != nil {
+
-		return
+	if err := hclsimple.DecodeFile(filePath, nil, &config); err != nil {
+		return config, errors.Join(ErrLoadingConfig, err)
 	}
 
 	slog.Debugf("Config values:\n%v\n", config)
 
 	// Finish initializing configuration
-	if err = config.Init(); err != nil {
+	if err := config.Init(); err != nil {
-		return
+		return config, errors.Join(ErrConfigInit, err)
 	}
 
-	if !config.IsValid() {
+	if err := config.IsValid(); err != nil {
-		err = errInvalidConfig
+		return config, errors.Join(ErrInvalidConfig, err)
-
-		return
 	}
 
-	return config, err
+	return config, nil
 }

config_test.go

@@ -1,23 +1,27 @@
 package main_test
 
 import (
+	"errors"
 	"testing"
+	"time"
 
-	m "git.iamthefij.com/iamthefij/minitor-go"
+	m "git.iamthefij.com/iamthefij/minitor-go/v2"
 )
 
 func TestLoadConfig(t *testing.T) {
 	cases := []struct {
 		configPath  string
-		expectErr  bool
+		expectedErr error
 		name        string
 	}{
-		{"./test/does-not-exist", true, "Invalid config path"},
+		{"./test/does-not-exist", m.ErrLoadingConfig, "Invalid config path"},
-		{"./test/invalid-config-missing-alerts.hcl", true, "Invalid config missing alerts"},
+		{"./test/invalid-config-wrong-hcl-type.hcl", m.ErrLoadingConfig, "Incorrect HCL type"},
-		{"./test/invalid-config-type.hcl", true, "Invalid config type for key"},
+		{"./test/invalid-config-missing-alerts.hcl", m.ErrNoAlerts, "Invalid config missing alerts"},
-		{"./test/invalid-config-unknown-alert.hcl", true, "Invalid config unknown alert"},
+		{"./test/invalid-config-missing-alerts.hcl", m.ErrInvalidConfig, "Invalid config general"},
-		{"./test/valid-config-default-values.hcl", false, "Valid config file with default values"},
+		{"./test/invalid-config-invalid-duration.hcl", m.ErrConfigInit, "Invalid config type for key"},
-		{"./test/valid-config.hcl", false, "Valid config file"},
+		{"./test/invalid-config-unknown-alert.hcl", m.ErrUnknownAlert, "Invalid config unknown alert"},
+		{"./test/valid-config-default-values.hcl", nil, "Valid config file with default values"},
+		{"./test/valid-config.hcl", nil, "Valid config file"},
 	}
 	for _, c := range cases {
 		c := c
@@ -27,14 +31,100 @@ func TestLoadConfig(t *testing.T) {
 
 			_, err := m.LoadConfig(c.configPath)
 			hasErr := (err != nil)
+			expectErr := (c.expectedErr != nil)
 
-			if hasErr != c.expectErr {
+			if hasErr != expectErr || !errors.Is(err, c.expectedErr) {
-				t.Errorf("LoadConfig(%v), expected_error=%v actual=%v", c.name, c.expectErr, err)
+				t.Errorf("LoadConfig(%v), expected_error=%v actual=%v", c.name, c.expectedErr, err)
 			}
 		})
 	}
 }
 
+func TestDefaultConfig(t *testing.T) {
+	cases := []struct {
+		configPath     string
+		expectedResult m.Config
+		name           string
+	}{
+		{
+			"./test/valid-config-default-values.hcl",
+			m.Config{
+				CheckInterval:     1 * time.Second,
+				DefaultAlertAfter: 2,
+				DefaultAlertEvery: Ptr(0),
+				DefaultAlertDown:  []string{"log_command"},
+			},
+			"override defaults",
+		},
+		{
+			"./test/valid-config.hcl",
+			m.Config{
+				CheckInterval:     30 * time.Second,
+				DefaultAlertAfter: 1,
+				DefaultAlertEvery: Ptr(-1),
+				DefaultAlertDown:  []string{},
+			},
+			"default defaults",
+		},
+	}
+
+	for _, c := range cases {
+		c := c
+
+		t.Run(c.name, func(t *testing.T) {
+			t.Parallel()
+
+			config, err := m.LoadConfig(c.configPath)
+			if err != nil {
+				t.Errorf("Got error when loading config file %q: %s", c.configPath, err)
+			}
+
+			// Test Config has default values
+			if config.DefaultAlertAfter != c.expectedResult.DefaultAlertAfter {
+				t.Errorf("Got unexpected DefaultAlertAfter from file %q: expected=%v actual=%v", c.configPath, c.expectedResult.DefaultAlertAfter, config.DefaultAlertAfter)
+			}
+
+			if *config.DefaultAlertEvery != *c.expectedResult.DefaultAlertEvery {
+				t.Errorf("Got unexpected DefaultAlertEvery from file %q: expected=%v actual=%v", c.configPath, *c.expectedResult.DefaultAlertEvery, *config.DefaultAlertEvery)
+			}
+
+			if !m.EqualSliceString(config.DefaultAlertUp, c.expectedResult.DefaultAlertUp) {
+				t.Errorf("Got unexpected DefaultAlertUp from file %q: expected=%v actual=%v", c.configPath, c.expectedResult.DefaultAlertUp, config.DefaultAlertUp)
+			}
+
+			if !m.EqualSliceString(config.DefaultAlertDown, c.expectedResult.DefaultAlertDown) {
+				t.Errorf("Got unexpected DefaultAlertDown from file %q: expected=%v actual=%v", c.configPath, c.expectedResult.DefaultAlertDown, config.DefaultAlertDown)
+			}
+
+			// Check that monitor defaults propagate
+			var defaultMonitor *m.Monitor
+			for _, monitor := range config.Monitors {
+				if monitor.Name == "Default" {
+					defaultMonitor = monitor
+				}
+			}
+
+			if defaultMonitor == nil {
+				t.Errorf("failed to find default monitor in %q", c.configPath)
+			}
+
+			if defaultMonitor.AlertAfter != c.expectedResult.DefaultAlertAfter {
+				t.Errorf("Got unexpected AlertAfter from file %q: expected=%v actual=%v", c.configPath, c.expectedResult.DefaultAlertAfter, defaultMonitor.AlertAfter)
+			}
+
+			if *defaultMonitor.AlertEvery != *c.expectedResult.DefaultAlertEvery {
+				t.Errorf("Got unexpected AlertEvery from file %q: expected=%v actual=%v", c.configPath, *c.expectedResult.DefaultAlertEvery, *defaultMonitor.AlertEvery)
+			}
+
+			if !m.EqualSliceString(defaultMonitor.AlertUp, c.expectedResult.DefaultAlertUp) {
+				t.Errorf("Got unexpected AlertUp from file %q: expected=%v actual=%v", c.configPath, c.expectedResult.DefaultAlertUp, defaultMonitor.AlertUp)
+			}
+
+			// NOTE: Can't compare AlertDown because default is empty and that is invalid
+		})
+	}
+}
+
 // TestMultiLineConfig is a more complicated test stepping through the parsing
 // and execution of mutli-line strings presented in YAML
 func TestMultiLineConfig(t *testing.T) {

go.mod

@@ -1,25 +1,27 @@
-module git.iamthefij.com/iamthefij/minitor-go
+module git.iamthefij.com/iamthefij/minitor-go/v2
 
-go 1.20
+go 1.25.0
 
 require (
 	git.iamthefij.com/iamthefij/slog v1.3.0
 	github.com/hashicorp/hcl/v2 v2.11.1
-	github.com/prometheus/client_golang v1.19.0
+	github.com/prometheus/client_golang v1.23.2
 )
 
 require (
 	github.com/agext/levenshtein v1.2.1 // indirect
 	github.com/apparentlymart/go-textseg/v13 v13.0.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
-	github.com/google/go-cmp v0.6.0 // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
 	github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7 // indirect
-	github.com/prometheus/client_model v0.5.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
-	github.com/prometheus/common v0.48.0 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
-	github.com/prometheus/procfs v0.12.0 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/procfs v0.16.1 // indirect
 	github.com/zclconf/go-cty v1.8.0 // indirect
-	golang.org/x/sys v0.16.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
-	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/sys v0.35.0 // indirect
-	google.golang.org/protobuf v1.32.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+	google.golang.org/protobuf v1.36.8 // indirect
 )

go.sum

@@ -8,8 +8,8 @@ github.com/apparentlymart/go-textseg/v13 v13.0.0 h1:Y+KvPE1NYz0xl601PVImeQfFyEy6
 github.com/apparentlymart/go-textseg/v13 v13.0.0/go.mod h1:ZK2fH7c4NqDTLtiYLvIkEghdlcqw7yxLeM89kiTRPUo=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
-github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
-github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-test/deep v1.0.3 h1:ZrJSEWsXzPOxaZnFteGEfooLba+ju3FYIbOrS+rQd68=
@@ -18,33 +18,43 @@ github.com/golang/protobuf v1.1.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.4/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
-github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/hashicorp/hcl/v2 v2.11.1 h1:yTyWcXcm9XB0TEkyU/JCRU6rYy4K+mgLtzn2wlrJbcc=
 github.com/hashicorp/hcl/v2 v2.11.1/go.mod h1:FwWsfWEjyV/CMj8s/gqAuiviY72rJ1/oayI9WftqcKg=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348 h1:MtvEpTB6LX3vkb4ax0b5D2DHbNAUsen0Gx5wZoq3lV4=
 github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348/go.mod h1:B69LEHPfb2qLo0BaaOLcbitczOKLWTsrBG9LczfCD4k=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7 h1:DpOJ2HYzCv8LZP15IdmG+YdwD2luVPHITV96TkirNBM=
 github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7/go.mod h1:ZXFpozHsX6DPmq2I0TCekCxypsnAUbP2oI0UX1GXzOo=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v1.19.0 h1:ygXvpU1AoN1MhdzckN+PyD9QJOSD4x7kmXYlnfbA6JU=
+github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
-github.com/prometheus/client_golang v1.19.0/go.mod h1:ZRM9uEAypZakd+q/x7+gmsvXdURP+DABIEIjnmDdp+k=
+github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
-github.com/prometheus/client_model v0.5.0 h1:VQw1hfvPvk3Uv6Qf29VrPF32JB6rtbgI6cYPYQjL0Qw=
+github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
-github.com/prometheus/client_model v0.5.0/go.mod h1:dTiFglRmd66nLR9Pv9f0mZi7B7fk5Pm3gvsjB5tr+kI=
+github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
-github.com/prometheus/common v0.48.0 h1:QO8U2CdOzSn1BBsmXJXduaaW+dY/5QLjfB8svtSzKKE=
+github.com/prometheus/common v0.66.1 h1:h5E0h5/Y8niHc5DlaLlWLArTQI7tMrsfQjHV+d9ZoGs=
-github.com/prometheus/common v0.48.0/go.mod h1:0/KsvlIEfPQCQ5I2iNSAWKPZziNCvRs5EC6ILDTlAPc=
+github.com/prometheus/common v0.66.1/go.mod h1:gcaUsgf3KfRSwHY4dIMXLPV0K/Wg1oZ8+SbZk/HH/dA=
-github.com/prometheus/procfs v0.12.0 h1:jluTpSng7V9hY0O2R9DzzJHYb2xULk9VTR1V1R/k6Bo=
+github.com/prometheus/procfs v0.16.1 h1:hZ15bTNuirocR6u0JZ6BAHHmwS1p8B4P6MRqxtzMyRg=
-github.com/prometheus/procfs v0.12.0/go.mod h1:pcuDEFsWDnvcgNzo4EEweacyhjeA9Zk3cnaOZAZEfOo=
+github.com/prometheus/procfs v0.16.1/go.mod h1:teAbpZRB1iIAJYREa1LsoWUXykVXA1KlTmWl8x/U+Is=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
+github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/vmihailenco/msgpack v3.3.3+incompatible/go.mod h1:fy3FlTQTDXWkZ7Bh6AcGMlsjHatGryHQYUTf1ShIgkk=
 github.com/vmihailenco/msgpack/v4 v4.3.12/go.mod h1:gborTTJjAo/GWTqqRjrLCn9pgNN+NXzzngzBKDPIqw4=
 github.com/vmihailenco/tagparser v0.1.1/go.mod h1:OeAg3pn3UbLjkWt+rN9oFYB6u/cQgqMEUPoW2WPyhdI=
@@ -52,6 +62,10 @@ github.com/zclconf/go-cty v1.2.0/go.mod h1:hOPWgoHbaTUnI5k4D2ld+GRpFJSCe6bCM7m1q
 github.com/zclconf/go-cty v1.8.0 h1:s4AvqaeQzJIu3ndv4gVIhplVD0krU+bgrcLSVUnaWuA=
 github.com/zclconf/go-cty v1.8.0/go.mod h1:vVKLxnk3puL4qRAv72AO+W99LUD4da90g3uUAzyuvAk=
 github.com/zclconf/go-cty-debug v0.0.0-20191215020915-b22d67c1ba0b/go.mod h1:ZRKQfBXbGkpdV6QMzT3rU1kSTAnfu1dO8dPKjYprgj8=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
+go.yaml.in/yaml/v2 v2.4.2 h1:DzmwEr2rDGHl7lsFgAHxmNz/1NlQ7xLIrlN2h5d1eGI=
+go.yaml.in/yaml/v2 v2.4.2/go.mod h1:081UH+NErpNdqlCXm3TtEran0rJZGxAYx9hb/ELlsPU=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20180811021610-c39426892332/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -62,16 +76,21 @@ golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.16.0 h1:xWw16ngr6ZMtmxDyKyIgsE93KNKz5HKmMa3b8ALHidU=
+golang.org/x/sys v0.35.0 h1:vz1N37gP5bs89s7He8XuIYXpyY0+QlsKmzipCbUtyxI=
-golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.35.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.6.5/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
-google.golang.org/protobuf v1.32.0 h1:pPC6BG5ex8PDFnkbrGU3EixyhKcQ2aDuBS36lqK/C7I=
+google.golang.org/protobuf v1.36.8 h1:xHScyCOEuuwZEc6UtSOvPbAT4zRh0xcNRYekJwfqyMc=
-google.golang.org/protobuf v1.32.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -119,7 +119,7 @@ func SendStartupAlerts(config *Config, alertNames []string) error {
 
 func main() {
 	showVersion := flag.Bool("version", false, "Display the version of minitor and exit")
-	configPath := flag.String("config", "config.yml", "Alternate configuration path (default: config.yml)")
+	configPath := flag.String("config", "config.hcl", "Alternate configuration path (default: config.hcl)")
 	startupAlerts := flag.String("startup-alerts", "", "List of alerts to run on startup. This can help determine unhealthy alerts early on. (default \"\")")
 
 	flag.BoolVar(&slog.DebugLevel, "debug", false, "Enables debug logs (default: false)")
@@ -136,7 +136,7 @@ func main() {
 
 	// Load configuration
 	config, err := LoadConfig(*configPath)
-	slog.OnErrFatalf(err, "Error loading config: %v", err)
+	slog.OnErrFatalf(err, "Error loading config")
 
 	// Serve metrics exporter, if specified
 	if ExportMetrics {

main_test.go

@@ -3,7 +3,7 @@ package main_test
 import (
 	"testing"
 
-	m "git.iamthefij.com/iamthefij/minitor-go"
+	m "git.iamthefij.com/iamthefij/minitor-go/v2"
 )
 
 func Ptr[T any](v T) *T {

monitor.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"errors"
+	"fmt"
 	"math"
 	"os/exec"
 	"time"
@@ -15,6 +17,7 @@ type Monitor struct { //nolint:maligned
 	CheckInterval    time.Duration
 
 	Name         string `hcl:"name,label"`
+	AlertCount   int
 	AlertAfter   int      `hcl:"alert_after,optional"`
 	AlertEvery   *int     `hcl:"alert_every,optional"`
 	AlertDown    []string `hcl:"alert_down,optional"`
@@ -23,7 +26,6 @@ type Monitor struct { //nolint:maligned
 	ShellCommand string   `hcl:"shell_command,optional"`
 
 	// Other values
-	alertCount        int
 	failureCount      int
 	lastCheck         time.Time
 	lastSuccess       time.Time
@@ -31,30 +33,91 @@ type Monitor struct { //nolint:maligned
 	lastCheckDuration time.Duration
 }
 
-// IsValid returns a boolean indicating if the Monitor has been correctly
+// Init initializes the Monitor with default values
-// configured
+func (monitor *Monitor) Init(defaultAlertAfter int, defaultAlertEvery *int, defaultAlertDown []string, defaultAlertUp []string) error {
-func (monitor Monitor) IsValid() bool {
+	// Parse the check_interval string into a time.Duration
-	// TODO: Refactor and return an error containing more information on what was invalid
+	if monitor.CheckIntervalStr != nil {
+		var err error
+
+		monitor.CheckInterval, err = time.ParseDuration(*monitor.CheckIntervalStr)
+		if err != nil {
+			return fmt.Errorf("failed to parse check_interval duration for monitor %s: %w", monitor.Name, err)
+		}
+	}
+
+	// Set default values for monitor alerts
+	if monitor.AlertAfter == 0 {
+		minAlertAfter := 1
+		monitor.AlertAfter = max(defaultAlertAfter, minAlertAfter)
+	}
+
+	if monitor.AlertEvery == nil {
+		monitor.AlertEvery = defaultAlertEvery
+	}
+
+	if len(monitor.AlertDown) == 0 {
+		monitor.AlertDown = defaultAlertDown
+	}
+
+	if len(monitor.AlertUp) == 0 {
+		monitor.AlertUp = defaultAlertUp
+	}
+
+	return nil
+}
+
+// Validate checks that the Monitor is properly configured and returns errors if not
+func (monitor Monitor) Validate() error {
 	hasCommand := len(monitor.Command) > 0
 	hasShellCommand := monitor.ShellCommand != ""
 	hasValidAlertAfter := monitor.AlertAfter > 0
 	hasAlertDown := len(monitor.AlertDown) > 0
 
-	hasAtLeastOneCommand := hasCommand || hasShellCommand
+	var err error
-	hasAtMostOneCommand := !(hasCommand && hasShellCommand)
 
-	return hasAtLeastOneCommand &&
+	hasAtLeastOneCommand := hasCommand || hasShellCommand
-		hasAtMostOneCommand &&
+	if !hasAtLeastOneCommand {
-		hasValidAlertAfter &&
+		err = errors.Join(err, fmt.Errorf(
-		hasAlertDown
+			"%w: monitor %s has no command or shell_command configured",
+			ErrInvalidMonitor,
+			monitor.Name,
+		))
+	}
+
+	hasAtMostOneCommand := !(hasCommand && hasShellCommand)
+	if !hasAtMostOneCommand {
+		err = errors.Join(err, fmt.Errorf(
+			"%w: monitor %s has both command and shell_command configured",
+			ErrInvalidMonitor,
+			monitor.Name,
+		))
+	}
+
+	if !hasValidAlertAfter {
+		err = errors.Join(err, fmt.Errorf(
+			"%w: monitor %s has invalid alert_after value %d. Must be greater than 0",
+			ErrInvalidMonitor,
+			monitor.Name,
+			monitor.AlertAfter,
+		))
+	}
+
+	if !hasAlertDown {
+		err = errors.Join(err, fmt.Errorf(
+			"%w: monitor %s has no alert_down configured. Configure one here or add a default_alert_down",
+			ErrInvalidMonitor,
+			monitor.Name,
+		))
+	}
+
+	return err
 }
 
 func (monitor Monitor) LastOutput() string {
 	return monitor.lastOutput
 }
 
-// ShouldCheck returns a boolean indicating if the Monitor is ready to be
+// ShouldCheck returns a boolean indicating if the Monitor is ready to be be checked again
-// be checked again
 func (monitor Monitor) ShouldCheck() bool {
 	if monitor.lastCheck.IsZero() || monitor.CheckInterval == 0 {
 		return true
@@ -65,8 +128,7 @@ func (monitor Monitor) ShouldCheck() bool {
 	return sinceLastCheck >= monitor.CheckInterval
 }
 
-// Check will run the command configured by the Monitor and return a status
+// Check will run the command configured by the Monitor and return a status and a possible AlertNotice
-// and a possible AlertNotice
 func (monitor *Monitor) Check() (bool, *AlertNotice) {
 	var cmd *exec.Cmd
 	if len(monitor.Command) > 0 {
@@ -87,9 +149,9 @@ func (monitor *Monitor) Check() (bool, *AlertNotice) {
 
 	isSuccess := (err == nil)
 	if isSuccess {
-		alertNotice = monitor.success()
+		alertNotice = monitor.Success()
 	} else {
-		alertNotice = monitor.failure()
+		alertNotice = monitor.Failure()
 	}
 
 	slog.Debugf("Command output: %s", monitor.lastOutput)
@@ -105,9 +167,18 @@ func (monitor *Monitor) Check() (bool, *AlertNotice) {
 	return isSuccess, alertNotice
 }
 
+// GetAlertNames gives a list of alert names for a given monitor status
+func (monitor Monitor) GetAlertNames(up bool) []string {
+	if up {
+		return monitor.AlertUp
+	}
+
+	return monitor.AlertDown
+}
+
 // IsUp returns the status of the current monitor
 func (monitor Monitor) IsUp() bool {
-	return monitor.alertCount == 0
+	return monitor.AlertCount == 0
 }
 
 // LastCheckMilliseconds gives number of miliseconds the last check ran for
@@ -115,20 +186,20 @@ func (monitor Monitor) LastCheckMilliseconds() int64 {
 	return monitor.lastCheckDuration.Milliseconds()
 }
 
-func (monitor *Monitor) success() (notice *AlertNotice) {
+func (monitor *Monitor) Success() (notice *AlertNotice) {
 	if !monitor.IsUp() {
 		// Alert that we have recovered
 		notice = monitor.createAlertNotice(true)
 	}
 
 	monitor.failureCount = 0
-	monitor.alertCount = 0
+	monitor.AlertCount = 0
 	monitor.lastSuccess = time.Now()
 
 	return
 }
 
-func (monitor *Monitor) failure() (notice *AlertNotice) {
+func (monitor *Monitor) Failure() (notice *AlertNotice) {
 	monitor.failureCount++
 	// If we haven't hit the minimum failures, we can exit
 	if monitor.failureCount < monitor.AlertAfter {
@@ -160,33 +231,25 @@ func (monitor *Monitor) failure() (notice *AlertNotice) {
 		}
 	default:
 		// Handle negative numbers indicating an exponential backoff
-		if failureCount >= int(math.Pow(2, float64(monitor.alertCount))-1) { //nolint:gomnd
+		if failureCount >= int(math.Pow(2, float64(monitor.AlertCount))-1) { //nolint:mnd
 			notice = monitor.createAlertNotice(false)
 		}
 	}
 
 	// If we're going to alert, increment count
 	if notice != nil {
-		monitor.alertCount++
+		monitor.AlertCount++
+		notice.AlertCount = monitor.AlertCount
 	}
 
 	return notice
 }
 
-// GetAlertNames gives a list of alert names for a given monitor status
-func (monitor Monitor) GetAlertNames(up bool) []string {
-	if up {
-		return monitor.AlertUp
-	}
-
-	return monitor.AlertDown
-}
-
 func (monitor Monitor) createAlertNotice(isUp bool) *AlertNotice {
 	// TODO: Maybe add something about recovery status here
 	return &AlertNotice{
 		MonitorName:     monitor.Name,
-		AlertCount:      monitor.alertCount,
+		AlertCount:      monitor.AlertCount,
 		FailureCount:    monitor.failureCount,
 		LastCheckOutput: monitor.lastOutput,
 		LastSuccess:     monitor.lastSuccess,

monitor_test.go

@@ -1,25 +1,27 @@
 package main_test
 
 import (
+	"errors"
 	"reflect"
 	"testing"
 	"time"
 
-	m "git.iamthefij.com/iamthefij/minitor-go"
+	m "git.iamthefij.com/iamthefij/minitor-go/v2"
 )
 
-// TestMonitorIsValid tests the Monitor.IsValid()
+func TestMonitorValidate(t *testing.T) {
-func TestMonitorIsValid(t *testing.T) {
+	t.Parallel()
+
 	cases := []struct {
 		monitor  m.Monitor
-		expected bool
+		expected error
 		name     string
 	}{
-		{m.Monitor{AlertAfter: 1, Command: []string{"echo", "test"}, AlertDown: []string{"log"}}, true, "Command only"},
+		{m.Monitor{AlertAfter: 1, Command: []string{"echo", "test"}, AlertDown: []string{"log"}}, nil, "Command only"},
-		{m.Monitor{AlertAfter: 1, ShellCommand: "echo test", AlertDown: []string{"log"}}, true, "CommandShell only"},
+		{m.Monitor{AlertAfter: 1, ShellCommand: "echo test", AlertDown: []string{"log"}}, nil, "CommandShell only"},
-		{m.Monitor{AlertAfter: 1, Command: []string{"echo", "test"}}, false, "No AlertDown"},
+		{m.Monitor{AlertAfter: 1, Command: []string{"echo", "test"}}, m.ErrInvalidMonitor, "No AlertDown"},
-		{m.Monitor{AlertAfter: 1, AlertDown: []string{"log"}}, false, "No commands"},
+		{m.Monitor{AlertAfter: 1, AlertDown: []string{"log"}}, m.ErrInvalidMonitor, "No commands"},
-		{m.Monitor{AlertAfter: -1, Command: []string{"echo", "test"}, AlertDown: []string{"log"}}, false, "Invalid alert threshold, -1"},
+		{m.Monitor{AlertAfter: -1, Command: []string{"echo", "test"}, AlertDown: []string{"log"}}, m.ErrInvalidMonitor, "Invalid alert threshold, -1"},
 	}
 
 	for _, c := range cases {
@@ -28,8 +30,11 @@ func TestMonitorIsValid(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			t.Parallel()
 
-			actual := c.monitor.IsValid()
+			actual := c.monitor.Validate()
-			if actual != c.expected {
+			hasErr := (actual != nil)
+			expectErr := (c.expected != nil)
+
+			if hasErr != expectErr || !errors.Is(actual, c.expected) {
 				t.Errorf("IsValid(%v), expected=%t actual=%t", c.name, c.expected, actual)
 			}
 		})
@@ -111,6 +116,45 @@ func TestMonitorGetAlertNames(t *testing.T) {
 	}
 }
 
+func TestMonitorAlertCount(t *testing.T) {
+	alertEvery := 1
+
+	cases := []struct {
+		checkSuccess bool
+		alertCount   int
+		name         string
+	}{
+		{false, 1, "First failure and first alert"},
+		{false, 2, "Second failure and first alert"},
+		{true, 2, "Success should preserve past alert count"},
+		{false, 1, "First failure and first alert after success"},
+	}
+
+	// Unlike previous tests, this one requires a static Monitor with repeated
+	// calls to the failure method
+	monitor := m.Monitor{AlertAfter: 1, AlertEvery: &alertEvery}
+
+	for _, c := range cases {
+		t.Logf("Testing case %s", c.name)
+
+		var notice *m.AlertNotice
+		if c.checkSuccess {
+			notice = monitor.Success()
+		} else {
+			notice = monitor.Failure()
+		}
+
+		if notice == nil {
+			t.Fatalf("failure(%v) expected notice, got nil", c.name)
+		}
+
+		if notice.AlertCount != c.alertCount {
+			t.Errorf("failure(%v), expected=%v actual=%v", c.name, c.alertCount, notice.AlertCount)
+			t.Logf("Case failed: %s", c.name)
+		}
+	}
+}
+
 // TestMonitorFailureAlertAfter tests that alerts will not trigger until
 // hitting the threshold provided by AlertAfter
 func TestMonitorFailureAlertAfter(t *testing.T) {

renovate.json

@@ -0,0 +1,3 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json"
+}

sample-config.hcl

@@ -38,15 +38,15 @@ alert "mailgun_down" {
     -F to=me@minitor.mon \
     -F text="Our monitor failed" \
     https://api.mailgun.net/v3/minitor.mon/messages \
-    -u "api:${MAILGUN_API_KEY}"
+    -u "api:$${MAILGUN_API_KEY}"
   EOF
 }
 
 alert "sms_down" {
   shell_command = <<-EOF
   curl -s -X POST -F "Body=Failure! {{.MonitorName}} has failed" \
-    -F "From=${AVAILABLE_NUMBER}" -F "To=${MY_PHONE}" \
+    -F "From=$${AVAILABLE_NUMBER}" -F "To=$${MY_PHONE}" \
-    "https://api.twilio.com/2010-04-01/Accounts/${ACCOUNT_SID}/Messages" \
+    "https://api.twilio.com/2010-04-01/Accounts/$${ACCOUNT_SID}/Messages" \
-    -u "${ACCOUNT_SID}:${AUTH_TOKEN}"
+    -u "$${ACCOUNT_SID}:$${AUTH_TOKEN}"
   EOF
 }

test/invalid-config-wrong-hcl-type.hcl

@@ -0,0 +1,12 @@
+check_interval = "1s"
+
+alert "log_command" {
+  command = "should be a list"
+}
+
+monitor "Command" {
+  command =  ["echo", "$PATH"]
+  alert_down =  ["log_command"]
+  alert_every =  2
+  check_interval =  "10s"
+}

test/valid-config-default-values.hcl

@@ -1,6 +1,11 @@
 check_interval = "1s"
 default_alert_down = ["log_command"]
-default_alert_after = 1
+default_alert_every = 0
+default_alert_after = 2
+
+monitor "Default" {
+  command = ["echo"]
+}
 
 monitor "Command" {
   command = ["echo", "$PATH"]

test/valid-config.hcl

@@ -8,6 +8,11 @@ alert "log_shell" {
   shell_command = "echo \"Failure on {{.MonitorName}} User is $USER\""
 }
 
+monitor "Default" {
+  command = ["echo"]
+  alert_down = ["log_command"]
+}
+
 monitor "Command" {
   command =  ["echo", "$PATH"]
   alert_down =  ["log_command", "log_shell"]

test/valid-config.yml

@@ -1,25 +0,0 @@
----
-check_interval: 1s
-
-monitors:
-  - name: Command
-    command: ["echo", "$PATH"]
-    alert_down: ["log_command", "log_shell"]
-    alert_every: 0
-    check_interval: 10s
-  - name: Shell
-    command: >
-      echo 'Some string with stuff';
-      echo 'another line';
-      echo $PATH;
-      exit 1
-    alert_down: ["log_command", "log_shell"]
-    alert_after: 5
-    alert_every: 0
-    check_interval: 1m
-
-alerts:
-  log_command:
-    command: ["echo", "regular", '"command!!!"', "{{.MonitorName}}"]
-  log_shell:
-    command: echo "Failure on {{.MonitorName}} User is $USER"