Change query to use gojq (#5)

* Transition from path using gojsonq to query using gojq
* Update CHANGELOG

Signed-off-by: Todd Campbell <todd@sensu.io>

CHANGELOG.md

@@ -7,6 +7,9 @@ Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
 
+### BREAKING CHANGE
+- Changed from --path using gojsonq to --query using gojq
+
 ## [0.2.0] - 2021-01-13
 
 ### Changed

README.md

@@ -173,42 +173,50 @@ Available Commands:
 
 Flags:
   -u, --url string               URL to test (default "http://localhost:80/")
-  -T, --timeout int              Request timeout in seconds (default 15)
-  -p, --path string              Path to query in JSON
-  -e, --expression string        Expression to query in JSON
+  -q, --query string             Query written in jq format
+  -e, --expression string        Expression for comparing result of query
   -H, --header strings           Additional header(s) to send in check request
-  -t, --trusted-ca-file string   TLS CA certificate bundle in PEM format
   -i, --insecure-skip-verify     Skip TLS certificate verification (not recommended!)
+  -t, --trusted-ca-file string   TLS CA certificate bundle in PEM format
+  -T, --timeout int              Request timeout in seconds (default 15)
   -h, --help                     help for http-json
 
 Use "http-json [command] --help" for more information about a command.
 ```
 
+#### Writing queries and expressions
+
+Queries are written in [jq][6] format as implemented by the [gojq][7] library.
+The query is used to obtain a value in the JSON requested from the URL
+specified by `--url`. This value is then evaluated against the expression
+provided by `--expression`.
+
 #### Example(s)
 
 ```
 # Boolean example - checking Sensu cluster health
-http-json --url http://backend:8080/health --path ClusterHealth.[0].Healthy --expression "== true"
-http-json OK:  The value true found at ClusterHealth.[0].Healthy matched with expression "== true" and returned true
+http-json --url http://backend:8080/health --query ".ClusterHealth.[0].Healthy" --expression "== true"
+http-json OK:  The value true found at .ClusterHealth.[0].Healthy matched with expression "== true" and returned true
 
 # String comparison expressions
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path id --expression "== \"HeaFdiyIJe\""
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .id --expression "== \"HeaFdiyIJe\""
 http-json OK:  The value HeaFdiyIJe found at id matched with expression "== \"HeaFdiyIJe\"" and returned true
 
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path id --expression "== \"BadText\""
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .id --expression "== \"BadText\""
 http-json CRITICAL: The value HeaFdiyIJe found at id did not match with expression "== \"BadText\"" and returned false
 
 # Numeric comparison expressions
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "== 200"
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .status --expression "== 200"
 http-json OK:  The value 200 found at status matched with expression "== 200" and returned true
 
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "< 300"
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .status --expression "< 300"
 http-json OK:  The value 200 found at status matched with expression "< 300" and returned true
 
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "> 300"
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .status --expression "> 300"
 http-json CRITICAL: The value 200 found at status did not match with expression "> 300" and returned false
 
-http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "< 300" --header "Custom-Header: Custom header value"
+# With a custom header
+http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --query .status --expression "< 300" --header "Custom-Header: Custom header value"
 http-json OK:  The value 200 found at status matched with expression "< 300" and returned true
 
 ```
@@ -311,3 +319,5 @@ For more information about contributing to this plugin, see [Contributing][4].
 [3]: https://bonsai.sensu.io/assets/nixwiz/http-checks
 [4]: https://github.com/sensu/sensu-go/blob/master/CONTRIBUTING.md
 [5]: https://github.com/ncr-devops-platform/nagiosfoundation
+[6]: https://github.com/stedolan/jq
+[7]: https://github.com/itchyny/gojq

cmd/http-json/main.go

@@ -6,6 +6,7 @@ package main
 
 import (
 	"crypto/tls"
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -14,10 +15,9 @@ import (
 	"time"
 
 	"github.com/PaesslerAG/gval"
+	"github.com/itchyny/gojq"
 	"github.com/sensu-community/sensu-plugin-sdk/sensu"
 	corev2 "github.com/sensu/sensu-go/api/core/v2"
-	"github.com/sensu/sensu-go/types"
-	"github.com/thedevsaddam/gojsonq"
 )
 
 // Config represents the check plugin config.
@@ -27,7 +27,7 @@ type Config struct {
 	TrustedCAFile      string
 	InsecureSkipVerify bool
 	Timeout            int
-	Path               string
+	Query              string
 	Expression         string
 	Headers            []string
 }
@@ -81,21 +81,21 @@ var (
 			Value:     &plugin.Timeout,
 		},
 		{
-			Path:      "path",
+			Path:      "query",
 			Env:       "",
-			Argument:  "path",
-			Shorthand: "p",
+			Argument:  "query",
+			Shorthand: "q",
 			Default:   "",
-			Usage:     "Path to query in JSON",
-			Value:     &plugin.Path,
+			Usage:     "Query written in jq format",
+			Value:     &plugin.Query,
 		},
 		{
 			Path:      "expression",
 			Env:       "",
 			Argument:  "expression",
 			Shorthand: "e",
 			Default:   "",
-			Usage:     "Expression to query in JSON",
+			Usage:     "Expression for comparing result of query",
 			Value:     &plugin.Expression,
 		},
 		{
@@ -115,7 +115,7 @@ func main() {
 	check.Execute()
 }
 
-func checkArgs(event *types.Event) (int, error) {
+func checkArgs(event *corev2.Event) (int, error) {
 	if len(plugin.URL) == 0 {
 		return sensu.CheckStateWarning, fmt.Errorf("--url or CHECK_URL environment variable is required")
 	}
@@ -138,16 +138,16 @@ func checkArgs(event *types.Event) (int, error) {
 
 	tlsConfig.CipherSuites = corev2.DefaultCipherSuites
 
-	if len(plugin.Path) == 0 {
-		return sensu.CheckStateWarning, fmt.Errorf("--path is required")
+	if len(plugin.Query) == 0 {
+		return sensu.CheckStateWarning, fmt.Errorf("--query is required")
 	}
 	if len(plugin.Expression) == 0 {
 		return sensu.CheckStateWarning, fmt.Errorf("--expression is required")
 	}
 	return sensu.CheckStateOK, nil
 }
 
-func executeCheck(event *types.Event) (int, error) {
+func executeCheck(event *corev2.Event) (int, error) {
 
 	client := http.DefaultClient
 	client.Transport = http.DefaultTransport
@@ -190,21 +190,58 @@ func executeCheck(event *types.Event) (int, error) {
 		return sensu.CheckStateCritical, err
 	}
 
-	value := gojsonq.New().JSONString(string(body)).Find(plugin.Path)
+	query, err := gojq.Parse(plugin.Query)
+	if err != nil {
+		return sensu.CheckStateCritical, fmt.Errorf("Failed to parse query %q, error: %v", plugin.Query, err)
+	}
+	code, err := gojq.Compile(query)
+	if err != nil {
+		return sensu.CheckStateCritical, fmt.Errorf("Failed to compile query %q, error: %v", plugin.Query, err)
+	}
+
+	var jsonBody interface{}
+
+	err = json.Unmarshal(body, &jsonBody)
+	if err != nil {
+		return sensu.CheckStateCritical, fmt.Errorf("Could not unmarshal response body into JSON: %v", err)
+	}
+
+	iter := code.Run(jsonBody)
+
+	var value interface{}
+
+	for {
+		var ok bool
+		v, ok := iter.Next()
+		if !ok {
+			// no more iterations
+			break
+		}
+		if _, ok := v.(error); ok {
+			// should we output anything here?
+			continue
+		}
+		value = v
+	}
+
+	if value == nil {
+		fmt.Printf("%s CRITICAL: No value was returned for query %q\n", plugin.PluginConfig.Name, plugin.Query)
+		return sensu.CheckStateCritical, nil
+	}
 
-	found, err := evaluateExpression(value, plugin.Expression, plugin.Path)
+	found, err := evaluateExpression(value, plugin.Expression)
 	if err != nil {
 		return sensu.CheckStateCritical, fmt.Errorf("Error evaluating expression: %v", err)
 	}
 	if found {
-		fmt.Printf("%s OK:  The value %v found at %s matched with expression %q and returned true\n", plugin.PluginConfig.Name, value, plugin.Path, plugin.Expression)
+		fmt.Printf("%s OK:  The value %v found at %s matched with expression %q and returned true\n", plugin.PluginConfig.Name, value, plugin.Query, plugin.Expression)
 		return sensu.CheckStateOK, nil
 	}
 
-	fmt.Printf("%s CRITICAL: The value %v found at %s did not match with expression %q and returned false\n", plugin.PluginConfig.Name, value, plugin.Path, plugin.Expression)
+	fmt.Printf("%s CRITICAL: The value %v found at %s did not match with expression %q and returned false\n", plugin.PluginConfig.Name, value, plugin.Query, plugin.Expression)
 	return sensu.CheckStateCritical, nil
 }
-func evaluateExpression(actualValue interface{}, expression, path string) (bool, error) {
+func evaluateExpression(actualValue interface{}, expression string) (bool, error) {
 	evalResult, err := gval.Evaluate("value "+expression, map[string]interface{}{"value": actualValue})
 	if err != nil {
 		return false, err

cmd/http-json/main_test.go

@@ -33,21 +33,21 @@ func TestExecuteCheck(t *testing.T) {
 
 	testCases := []struct {
 		status     int
-		path       string
+		query      string
 		expression string
 	}{
-		{sensu.CheckStateOK, "text", "== \"testing\""},
-		{sensu.CheckStateCritical, "text", "== \"notfound\""},
-		{sensu.CheckStateOK, "number", "== 10"},
-		{sensu.CheckStateCritical, "number", "== 11"},
-		{sensu.CheckStateOK, "number", ">= 10"},
-		{sensu.CheckStateOK, "number", "> 9"},
-		{sensu.CheckStateCritical, "number", ">= 11"},
-		{sensu.CheckStateCritical, "number", "> 12"},
-		{sensu.CheckStateOK, "number", "<= 10"},
-		{sensu.CheckStateOK, "number", "< 11"},
-		{sensu.CheckStateCritical, "number", "<= 9"},
-		{sensu.CheckStateCritical, "number", "< 8"},
+		{sensu.CheckStateOK, ".text", "== \"testing\""},
+		{sensu.CheckStateCritical, ".text", "== \"notfound\""},
+		{sensu.CheckStateOK, ".number", "== 10"},
+		{sensu.CheckStateCritical, ".number", "== 11"},
+		{sensu.CheckStateOK, ".number", ">= 10"},
+		{sensu.CheckStateOK, ".number", "> 9"},
+		{sensu.CheckStateCritical, ".number", ">= 11"},
+		{sensu.CheckStateCritical, ".number", "> 12"},
+		{sensu.CheckStateOK, ".number", "<= 10"},
+		{sensu.CheckStateOK, ".number", "< 11"},
+		{sensu.CheckStateCritical, ".number", "<= 9"},
+		{sensu.CheckStateCritical, ".number", "< 8"},
 	}
 
 	for _, tc := range testCases {
@@ -65,7 +65,7 @@ func TestExecuteCheck(t *testing.T) {
 		require.NoError(t, err)
 		plugin.URL = test.URL
 		plugin.Expression = tc.expression
-		plugin.Path = tc.path
+		plugin.Query = tc.query
 		status, err := executeCheck(event)
 		assert.NoError(err)
 		assert.Equal(tc.status, status)
@@ -82,7 +82,7 @@ func TestExecuteCheck(t *testing.T) {
 	_, err := url.ParseRequestURI(test.URL)
 	require.NoError(t, err)
 	plugin.URL = test.URL
-	plugin.Path = "number"
+	plugin.Query = ".number"
 	plugin.Expression = "== 10"
 	plugin.Headers = []string{"Test-Header-1: Test Header 1 Value", "Test-Header-2: Test Header 2 Value"}
 	status, err := executeCheck(event)

go.mod

@@ -3,9 +3,33 @@ module github.com/nixwiz/http-checks
 go 1.13
 
 require (
-	github.com/PaesslerAG/gval v1.0.1
-	github.com/sensu-community/sensu-plugin-sdk v0.6.0
-	github.com/sensu/sensu-go v0.0.0-20200131164840-40b1d5938251
-	github.com/stretchr/testify v1.4.0
-	github.com/thedevsaddam/gojsonq v2.3.0+incompatible
+	github.com/PaesslerAG/gval v1.1.0
+	github.com/coreos/etcd v3.3.25+incompatible // indirect
+	github.com/fsnotify/fsnotify v1.4.9 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.4.3 // indirect
+	github.com/google/uuid v1.1.5 // indirect
+	github.com/itchyny/gojq v0.12.1
+	github.com/json-iterator/go v1.1.10 // indirect
+	github.com/magiconair/properties v1.8.4 // indirect
+	github.com/mitchellh/mapstructure v1.4.1 // indirect
+	github.com/pelletier/go-toml v1.8.1 // indirect
+	github.com/robertkrimen/otto v0.0.0-20200922221731-ef014fd054ac // indirect
+	github.com/sensu-community/sensu-plugin-sdk v0.11.0
+	github.com/sensu/sensu-go/api/core/v2 v2.6.0
+	github.com/sensu/sensu-go/types v0.4.0
+	github.com/sirupsen/logrus v1.7.0 // indirect
+	github.com/spf13/afero v1.5.1 // indirect
+	github.com/spf13/cast v1.3.1 // indirect
+	github.com/spf13/cobra v1.1.1 // indirect
+	github.com/spf13/jwalterweatherman v1.1.0 // indirect
+	github.com/spf13/viper v1.7.1 // indirect
+	github.com/stretchr/testify v1.6.1
+	golang.org/x/net v0.0.0-20210119194325-5f4716e94777 // indirect
+	golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 // indirect
+	golang.org/x/text v0.3.5 // indirect
+	google.golang.org/genproto v0.0.0-20210120162456-f5e8c5e2aaf2 // indirect
+	google.golang.org/grpc v1.35.0 // indirect
+	gopkg.in/ini.v1 v1.62.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
 )