Consul

README.md

@@ -663,7 +663,7 @@ func main() {
 | providers/vault     | `vault.Provider(vault.Config{})`                              | Hashicorp Vault provider                                                                                                                           |
 | providers/appconfig     | `vault.AppConfig(appconfig.Config{})`                              | AWS AppConfig provider                                                                                                                           |
 | providers/etcd     | `etcd.Provider(etcd.Config{})`                              | CNCF etcd provider                                                                                                                           |
-|
+| providers/consul     | `consul.Provider(consul.Config{})`                              | Hashicorp Consul provider                                                                                                                           |
 
 ### Bundled parsers
 

examples/read-consul/data.json

@@ -0,0 +1,10 @@
+{
+	"parent1": "father",
+	"parent2": "mother",
+	"child1": "Alex",
+	"child2": "Julia",
+	"child3": "Michael",
+	"child4": "Natalie",
+	"child5": "Rosalind",
+	"child6": "Tim"
+}

examples/read-consul/koanfconsul.sh

@@ -0,0 +1,27 @@
+consul agent -dev &
+
+exitcode=1
+iterations=0
+
+while [ $exitcode -ne 0 ]
+do
+	consul members
+	exitcode=$?
+
+	sleep 1
+	((iterations++))
+
+	if [ $iterations -gt 5 ]; then
+		break
+	fi
+done
+
+if [ $exitcode -eq 0 ]; then
+	echo -e "\nTest program running..."
+	go run main.go
+	echo -e "\nShutdown..."
+	consul leave
+else
+	echo "Consul server is inavailable."
+	consul leave
+fi

examples/read-consul/main.go

@@ -0,0 +1,299 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+
+	"github.com/hashicorp/consul/api"
+	"github.com/knadh/koanf"
+	"github.com/knadh/koanf/parsers/json"
+	"github.com/knadh/koanf/providers/consul"
+	"github.com/knadh/koanf/providers/file"
+)
+
+var (
+	kData  = koanf.New(".")
+	kReq   = koanf.New(".")
+	kCheck = koanf.New(".")
+)
+
+func main() {
+	if err := kData.Load(file.Provider("data.json"), json.Parser()); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	cli, err := api.NewClient(api.DefaultConfig())
+	if err != nil {
+		log.Fatalf("error creating client: %v", err)
+	}
+
+	kv := cli.KV()
+
+	keysData := kData.Keys()
+	for _, key := range keysData {
+		newPair := &api.KVPair{Key: key, Value: []byte(kData.String(key))}
+		_, err = kv.Put(newPair, nil)
+
+		if err != nil {
+			log.Printf("Couldn't put key.")
+		}
+	}
+
+	// Single key/value.
+	var (
+		sKey string = "single_key"
+		sVal string = "single_val"
+	)
+
+	newPair := &api.KVPair{Key: sKey, Value: []byte(sVal)}
+	_, err = kv.Put(newPair, nil)
+
+	if err != nil {
+		log.Printf("Couldn't put key.")
+	}
+
+	provider := consul.Provider(consul.Config{
+		Key:      sKey,
+		Recurse:  false,
+		Detailed: false,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	if err := kCheck.Load(provider, nil); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	if len(kCheck.Keys()) != 1 {
+		fmt.Printf("Single key: FAILED\n")
+		return
+	}
+
+	if strings.Compare(sKey, kCheck.Keys()[0]) != 0 {
+		fmt.Printf("Single key: key comparison FAILED\n")
+		return
+	}
+
+	if strings.Compare(sVal, kCheck.String(kCheck.Keys()[0])) != 0 {
+		fmt.Printf("Single key: value comparison FAILED\n")
+		return
+	}
+
+	fmt.Printf("\nSingle key test passed.\n")
+	kCheck.Delete("")
+
+	// first request test
+	// analog of the command:
+	// consul kv get -recurse parent
+
+	if err := kReq.Load(file.Provider("req1.json"), json.Parser()); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	provider = consul.Provider(consul.Config{
+		Key:      "parent",
+		Recurse:  true,
+		Detailed: false,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	if err := kCheck.Load(provider, nil); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	keysReq := kReq.Keys()
+	keysCheck := kCheck.Keys()
+
+	if len(keysReq) != len(keysCheck) {
+		fmt.Printf("First request: keys FAILED\n")
+		return
+	}
+
+	for i := 0; i < len(keysReq); i++ {
+		if strings.Compare(keysReq[i], keysCheck[i]) != 0 {
+			fmt.Printf("First request: key comparison FAILED\n")
+			return
+		}
+
+		if strings.Compare(kReq.String(keysReq[i]), kCheck.String(keysCheck[i])) != 0 {
+			fmt.Printf("First request: value comparison FAILED\n")
+			return
+		}
+	}
+
+	fmt.Printf("First request test passed.\n")
+	kReq.Delete("")
+	kCheck.Delete("")
+
+	// second request test
+	// analog of the command:
+	// consul kv get -recurse child
+
+	if err := kReq.Load(file.Provider("req2.json"), json.Parser()); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	provider = consul.Provider(consul.Config{
+		Key:      "child",
+		Recurse:  true,
+		Detailed: false,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	if err := kCheck.Load(provider, nil); err != nil {
+		log.Fatalf("error loading config: %v", err)
+	}
+
+	keysReq = kReq.Keys()
+	keysCheck = kCheck.Keys()
+
+	if len(keysReq) != len(keysCheck) {
+		fmt.Printf("Second request: keys FAILED\n")
+		return
+	}
+
+	for i := 0; i < len(keysReq); i++ {
+		if strings.Compare(keysReq[i], keysCheck[i]) != 0 {
+		}
+
+		if strings.Compare(kReq.String(keysReq[i]), kCheck.String(keysCheck[i])) != 0 {
+			fmt.Printf("Second request: value comparison FAILED\n")
+			return
+		}
+	}
+
+	fmt.Printf("Second request test passed.\n")
+	kCheck.Delete("")
+
+	// adding metainformation: age (flags)
+	newPair = &api.KVPair{Key: "parent1", Flags: uint64(42), Value: []byte("father")}
+	_, err = kv.Put(newPair, nil)
+	if err != nil {
+		log.Printf("Couldn't put key with flags.")
+	}
+
+	// Single key detailed test.
+	// analog of the command:
+	// consul kv get -detailed parent1
+
+	sKey = "parent1"
+	sFlags := uint64(42)
+	sVal = "father"
+
+	provider = consul.Provider(consul.Config{
+		Key:      sKey,
+		Recurse:  false,
+		Detailed: true,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	if err := kCheck.Load(provider, nil); err != nil {
+		fmt.Printf("error loading config: %v", err)
+		return
+	}
+
+	if sFlags != uint64(kCheck.Int64("parent1.Flags")) {
+		fmt.Printf("Single detailed key: flags (metadata: age) comparison FAILED\n")
+		return
+	}
+
+	if strings.Compare(sVal, kCheck.String("parent1.Value")) != 0 {
+		fmt.Printf("Single detailed key: value comparison FAILED\n")
+		return
+	}
+
+	fmt.Printf("\nDetailed single key test passed.\n")
+
+	kCheck.Delete("")
+
+	// Detailed request (recurse) test.
+	// analog of the command:
+	// consul kv get -detailed -recurse parent
+
+	sKey = "parent"
+
+	provider = consul.Provider(consul.Config{
+		Key:      sKey,
+		Recurse:  true,
+		Detailed: true,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	if err := kCheck.Load(provider, nil); err != nil {
+		fmt.Printf("error loading config: %v", err)
+		return
+	}
+
+	if sFlags != uint64(kCheck.Int64("parent1.Flags")) {
+		fmt.Printf("Single detailed key: flags (metadata: age) comparison FAILED\n")
+		return
+	}
+
+	if strings.Compare(sVal, kCheck.String("parent1.Value")) != 0 {
+		fmt.Printf("Single key: value comparison FAILED\n")
+		return
+	}
+
+	sFlags = uint64(0)
+	sVal = "mother"
+
+	if sFlags != uint64(kCheck.Int64("parent2.Flags")) {
+		fmt.Printf("Single detailed key: flags (metadata: age) comparison FAILED\n")
+		return
+	}
+
+	if strings.Compare(sVal, kCheck.String("parent2.Value")) != 0 {
+		fmt.Printf("Single key: value comparison FAILED\n")
+		return
+	}
+
+	fmt.Printf("\nDetailed request (recurse) test passed.\n")
+
+	kCheck.Delete("")
+
+	// Watch test
+
+	sKey = "parent"
+	provider = consul.Provider(consul.Config{
+		Key:      sKey,
+		Recurse:  true,
+		Detailed: false,
+		Cfg:      api.DefaultConfig(),
+	})
+
+	// Getting the old value
+	kCheck.Load(provider, nil)
+	oldVal := kCheck.String("parent1")
+
+	changedC := make(chan string, 1)
+
+	provider.Watch(func(event interface{}, err error) {
+		if err != nil {
+			fmt.Printf("Unexpected error: %v", err)
+			return
+		}
+
+		kCheck.Load(provider, nil)
+		// skip the first call
+		if strings.Compare(oldVal, kCheck.String("parent1")) != 0 {
+			changedC <- kCheck.String("parent1")
+		}
+	})
+
+	// changing
+	var newVal string = "dad"
+	cmd := exec.Command("consul", "kv", "put", "parent1", newVal)
+	err = cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if strings.Compare(newVal, <-changedC) != 0 {
+		fmt.Printf("Watch failed: new value comparison FAILED\n")
+		return
+	}
+	fmt.Printf("Watch test passed.\n")
+
+	fmt.Printf("ALL TESTS PASSED\n")
+}

examples/read-consul/req1.json

@@ -0,0 +1,4 @@
+{
+	"parent1": "father",
+	"parent2": "mother"
+}

examples/read-consul/req2.json

@@ -0,0 +1,8 @@
+{
+	"child1": "Alex",
+	"child2": "Julia",
+	"child3": "Michael",
+	"child4": "Natalie",
+	"child5": "Rosalind",
+	"child6": "Tim"
+}

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/sts v1.7.2
 	github.com/fatih/structs v1.1.0
 	github.com/fsnotify/fsnotify v1.4.9
+	github.com/hashicorp/consul/api v1.13.0
 	github.com/hashicorp/hcl v1.0.0
 	github.com/hashicorp/vault/api v1.0.4
 	github.com/joho/godotenv v1.3.0