add validate-config command (#4)

cmd/root/root.go

@@ -58,8 +58,8 @@ var app = &cli.App{
 			},
 		},
 		{
-			Name:    "validate",
-			Aliases: []string{"v", "lint", "l"},
+			Name:    "validate-rules",
+			Aliases: []string{"v", "lint", "l", "validate"},
 			Action: func(c *cli.Context) error {
 				args := c.Args()
 
@@ -75,12 +75,33 @@ var app = &cli.App{
 						return err
 					}
 
-					_, err = validator.Validate(data)
+					_, err = validator.ValidateRules(data)
 					if err != nil {
 						return cli.Exit(err, 1)
 					}
 				}
 
+				return nil
+			},
+		},
+		{
+			Name: "validate-config",
+			Action: func(c *cli.Context) error {
+				args := c.Args()
+
+				if args.Len() < 1 {
+					log.Fatal("Expected at least one rule file to validate.")
+				}
+
+				validator := c.Context.Value("impl").(tool.Checker)
+
+				for _, f := range args.Slice() {
+					err := validator.ValidateConfig(f)
+					if err != nil {
+						return err
+					}
+				}
+
 				return nil
 			},
 		},

go.mod

@@ -5,6 +5,7 @@ go 1.18
 require (
 	github.com/Masterminds/sprig/v3 v3.2.2
 	github.com/dustin/go-humanize v1.0.0
+	github.com/go-kit/log v0.2.1
 	github.com/grafana/regexp v0.0.0-20220304100321-149c8afcd6cb
 	github.com/json-iterator/go v1.1.12
 	github.com/pkg/errors v0.9.1
@@ -29,7 +30,6 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dennwc/varint v1.0.0 // indirect
 	github.com/edsrzf/mmap-go v1.1.0 // indirect
-	github.com/go-kit/log v0.2.1 // indirect
 	github.com/go-logfmt/logfmt v0.5.1 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect

pkg/tool/common.go

@@ -27,7 +27,8 @@ type LogQL struct {
 
 type Checker interface {
 	Transform(arg string, matchers *map[string]string) (string, error)
-	Validate(data []byte) (*rulefmt.RuleGroups, error)
+	ValidateRules(data []byte) (*rulefmt.RuleGroups, error)
+	ValidateConfig(filename string) (error)
 }
 
 func GetLabelMatchers(flags []string) (map[string]string, error) {

pkg/tool/logql_alert_test.go

@@ -9,7 +9,7 @@ import (
 
 func TestParseLokiAlertFileSuccess(t *testing.T) {
 	p := &tool.LogQL{}
-	_, errs := p.Validate(readFile(filepath.Join("testdata/loki_alerts", "basic.yaml")))
+	_, errs := p.ValidateRules(readFile(filepath.Join("testdata/loki_alerts", "basic.yaml")))
 	assert.Nil(t, errs, "unexpected errors parsing file")
 }
 
@@ -31,7 +31,7 @@ func TestParseLokiAlertFileFailure(t *testing.T) {
 	p := &tool.LogQL{}
 
 	for _, c := range table {
-		_, errs := p.Validate(readFile(filepath.Join("testdata/loki_alerts", c.filename)))
+		_, errs := p.ValidateRules(readFile(filepath.Join("testdata/loki_alerts", c.filename)))
 		assert.NotNil(t, errs, "Expected error parsing %s but got none", c.filename)
 		assert.Contains(t, errs.Error(), c.errMsg, "Expected error for %s.", c.filename)
 	}

pkg/tool/logql_transform.go

@@ -10,7 +10,7 @@ import (
 	"github.com/prometheus/prometheus/model/rulefmt"
 )
 
-func (p *LogQL) Validate(data []byte) (*rulefmt.RuleGroups, error) {
+func (p *LogQL) ValidateRules(data []byte) (*rulefmt.RuleGroups, error) {
 	// Expose the backend parser
 	rg, errs := lokiruler.Load(data)
 
@@ -21,6 +21,10 @@ func (p *LogQL) Validate(data []byte) (*rulefmt.RuleGroups, error) {
 	return rg, nil
 }
 
+func (p *LogQL) ValidateConfig(filename string) (error) {
+	return fmt.Errorf("Loki not supported for validate-config")
+}
+
 func (p *LogQL) Transform(arg string, matchers *map[string]string) (string, error) {
 	exp, err := parser.ParseExpr(arg)
 

pkg/tool/promql_alert_test.go

@@ -15,7 +15,7 @@ func readFile(filepath string) []byte {
 }
 func TestParsePromAlertFileSuccess(t *testing.T) {
 	p := &tool.PromQL{}
-	_, errs := p.Validate(readFile(filepath.Join("testdata/prom_alerts", "basic.yaml")))
+	_, errs := p.ValidateRules(readFile(filepath.Join("testdata/prom_alerts", "basic.yaml")))
 	assert.Nil(t, errs, "unexpected errors parsing file")
 }
 
@@ -37,7 +37,7 @@ func TestParsePromAlertFileFailure(t *testing.T) {
 	p := &tool.PromQL{}
 
 	for _, c := range table {
-		_, errs := p.Validate(readFile(filepath.Join("testdata/prom_alerts", c.filename)))
+		_, errs := p.ValidateRules(readFile(filepath.Join("testdata/prom_alerts", c.filename)))
 		assert.NotNil(t, errs, "Expected error parsing %s but got none", c.filename)
 		assert.Contains(t, errs.Error(), c.errMsg, "Expected error for %s.", c.filename)
 	}

pkg/tool/promql_config_check_test.go

@@ -0,0 +1,40 @@
+package tool_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/canonical/cos-tool/pkg/tool"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateConfig(t *testing.T) {
+	test_cases := []struct {
+		filename string
+		err bool
+	}{
+		{
+			filename: "good_config.yml",
+			err: false,
+		},
+		{
+			filename: "bad_yaml.yml",
+			err: true,
+		},
+		{
+			filename: "bad_key.yml",
+			err: true,
+		},
+	}
+
+	checker := &tool.PromQL{}
+
+	for _, test_case := range test_cases {
+		err := checker.ValidateConfig(fmt.Sprintf("testdata/prom_configs/%s", test_case.filename))
+		if test_case.err == true {
+			assert.NotNil(t, err, "ValidateConfig returned unexpected result")
+		} else {
+			assert.Nil(t, err, "ValidateConfig returned unexpected result")
+		}
+	}
+}

pkg/tool/promql_transform.go

@@ -2,12 +2,14 @@ package tool
 
 import (
 	"fmt"
+	"github.com/go-kit/log"
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/model/rulefmt"
 	"github.com/prometheus/prometheus/promql/parser"
+	"github.com/prometheus/prometheus/config"
 )
 
-func (p *PromQL) Validate(data []byte) (*rulefmt.RuleGroups, error) {
+func (p *PromQL) ValidateRules(data []byte) (*rulefmt.RuleGroups, error) {
 	// Expose the backend parser for alert rule validation
 	rg, errs := rulefmt.Parse(data)
 
@@ -17,6 +19,16 @@ func (p *PromQL) Validate(data []byte) (*rulefmt.RuleGroups, error) {
 	return rg, nil
 }
 
+// This function only checks syntax. If more in depth checking is needed, it must be expanded.
+func(p *PromQL) ValidateConfig(filename string) (error) {
+	// Assuming here that agent mode is false. If we support agent mode in the future, this needs to be revisited.
+	_, err := config.LoadFile(filename, false, false, log.NewNopLogger())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func (p *PromQL) Transform(arg string, matchers *map[string]string) (string, error) {
 	exp, err := parser.ParseExpr(arg)
 

pkg/tool/testdata/prom_configs/bad_key.yml

@@ -0,0 +1,28 @@
+global:
+  evaluation_interval: 1m
+  scrape_interval: 1m
+  scrape_timeout: 10s
+rule_files:
+- /etc/prometheus/rules/juju_*.rules
+scrape_configs:
+- honor_labels: true
+  job_name: my_scrape_job
+  metrics_path: /metrics
+  relabel_configs:
+  - regex: (.*)
+    separator: _
+    source_labels:
+    - juju_model
+    - juju_model_uuid
+    - juju_application
+    - juju_unit
+    target_label: instance
+  static_configs:
+  - labels:
+      juju_application: loki
+      juju_charm: loki-k8s
+      juju_model: lma
+      juju_model_uuid: 6e33e98f-61fe-4ced-85ec-6414252f6d30
+      juju_unit: loki/0
+    not_a_real_prometheus_key:
+    - 192.168.1.1:3100

pkg/tool/testdata/prom_configs/bad_yaml.yml

@@ -0,0 +1,28 @@
+global:
+  evaluation_interval: 1m
+  scrape_interval: 1m
+  scrape_timeout: 10s
+rule_files:
+- /etc/prometheus/rules/juju_*.rules
+scrape_configs:
+- honor_labels: true
+  job_name: my_scrape_job
+  metrics_path: /metrics
+  relabel_configs:
+  - regex: (.*)
+    separator: _
+    source_labels:
+    - juju_model
+    - juju_model_uuid
+    - juju_application
+    - juju_unit
+    target_label: instance
+  static_configs:
+  - labels:
+      juju_application: loki
+      juju_charm: loki-k8s
+      juju_model: lma
+      juju_model_uuid: 6e33e98f-61fe-4ced-85ec-6414252f6d30
+      juju_unit: loki/0
+    targets:
+    - *:3100

pkg/tool/testdata/prom_configs/good_config.yml

@@ -0,0 +1,28 @@
+global:
+  evaluation_interval: 1m
+  scrape_interval: 1m
+  scrape_timeout: 10s
+rule_files:
+- /etc/prometheus/rules/juju_*.rules
+scrape_configs:
+- honor_labels: true
+  job_name: my_scrape_job
+  metrics_path: /metrics
+  relabel_configs:
+  - regex: (.*)
+    separator: _
+    source_labels:
+    - juju_model
+    - juju_model_uuid
+    - juju_application
+    - juju_unit
+    target_label: instance
+  static_configs:
+  - labels:
+      juju_application: loki
+      juju_charm: loki-k8s
+      juju_model: lma
+      juju_model_uuid: 6e33e98f-61fe-4ced-85ec-6414252f6d30
+      juju_unit: loki/0
+    targets:
+    - 192.168.1.1:3100