[VOL-1386]  This commit add "dep" as the package management tool
for voltha-go.

Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/hashicorp/consul/api/kv.go b/vendor/github.com/hashicorp/consul/api/kv.go
new file mode 100644
index 0000000..97f5156
--- /dev/null
+++ b/vendor/github.com/hashicorp/consul/api/kv.go
@@ -0,0 +1,420 @@
+package api
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// KVPair is used to represent a single K/V entry
+type KVPair struct {
+	// Key is the name of the key. It is also part of the URL path when accessed
+	// via the API.
+	Key string
+
+	// CreateIndex holds the index corresponding the creation of this KVPair. This
+	// is a read-only field.
+	CreateIndex uint64
+
+	// ModifyIndex is used for the Check-And-Set operations and can also be fed
+	// back into the WaitIndex of the QueryOptions in order to perform blocking
+	// queries.
+	ModifyIndex uint64
+
+	// LockIndex holds the index corresponding to a lock on this key, if any. This
+	// is a read-only field.
+	LockIndex uint64
+
+	// Flags are any user-defined flags on the key. It is up to the implementer
+	// to check these values, since Consul does not treat them specially.
+	Flags uint64
+
+	// Value is the value for the key. This can be any value, but it will be
+	// base64 encoded upon transport.
+	Value []byte
+
+	// Session is a string representing the ID of the session. Any other
+	// interactions with this key over the same session must specify the same
+	// session ID.
+	Session string
+}
+
+// KVPairs is a list of KVPair objects
+type KVPairs []*KVPair
+
+// KVOp constants give possible operations available in a KVTxn.
+type KVOp string
+
+const (
+	KVSet            KVOp = "set"
+	KVDelete         KVOp = "delete"
+	KVDeleteCAS      KVOp = "delete-cas"
+	KVDeleteTree     KVOp = "delete-tree"
+	KVCAS            KVOp = "cas"
+	KVLock           KVOp = "lock"
+	KVUnlock         KVOp = "unlock"
+	KVGet            KVOp = "get"
+	KVGetTree        KVOp = "get-tree"
+	KVCheckSession   KVOp = "check-session"
+	KVCheckIndex     KVOp = "check-index"
+	KVCheckNotExists KVOp = "check-not-exists"
+)
+
+// KVTxnOp defines a single operation inside a transaction.
+type KVTxnOp struct {
+	Verb    KVOp
+	Key     string
+	Value   []byte
+	Flags   uint64
+	Index   uint64
+	Session string
+}
+
+// KVTxnOps defines a set of operations to be performed inside a single
+// transaction.
+type KVTxnOps []*KVTxnOp
+
+// KVTxnResponse has the outcome of a transaction.
+type KVTxnResponse struct {
+	Results []*KVPair
+	Errors  TxnErrors
+}
+
+// KV is used to manipulate the K/V API
+type KV struct {
+	c *Client
+}
+
+// KV is used to return a handle to the K/V apis
+func (c *Client) KV() *KV {
+	return &KV{c}
+}
+
+// Get is used to lookup a single key. The returned pointer
+// to the KVPair will be nil if the key does not exist.
+func (k *KV) Get(key string, q *QueryOptions) (*KVPair, *QueryMeta, error) {
+	resp, qm, err := k.getInternal(key, nil, q)
+	if err != nil {
+		return nil, nil, err
+	}
+	if resp == nil {
+		return nil, qm, nil
+	}
+	defer resp.Body.Close()
+
+	var entries []*KVPair
+	if err := decodeBody(resp, &entries); err != nil {
+		return nil, nil, err
+	}
+	if len(entries) > 0 {
+		return entries[0], qm, nil
+	}
+	return nil, qm, nil
+}
+
+// List is used to lookup all keys under a prefix
+func (k *KV) List(prefix string, q *QueryOptions) (KVPairs, *QueryMeta, error) {
+	resp, qm, err := k.getInternal(prefix, map[string]string{"recurse": ""}, q)
+	if err != nil {
+		return nil, nil, err
+	}
+	if resp == nil {
+		return nil, qm, nil
+	}
+	defer resp.Body.Close()
+
+	var entries []*KVPair
+	if err := decodeBody(resp, &entries); err != nil {
+		return nil, nil, err
+	}
+	return entries, qm, nil
+}
+
+// Keys is used to list all the keys under a prefix. Optionally,
+// a separator can be used to limit the responses.
+func (k *KV) Keys(prefix, separator string, q *QueryOptions) ([]string, *QueryMeta, error) {
+	params := map[string]string{"keys": ""}
+	if separator != "" {
+		params["separator"] = separator
+	}
+	resp, qm, err := k.getInternal(prefix, params, q)
+	if err != nil {
+		return nil, nil, err
+	}
+	if resp == nil {
+		return nil, qm, nil
+	}
+	defer resp.Body.Close()
+
+	var entries []string
+	if err := decodeBody(resp, &entries); err != nil {
+		return nil, nil, err
+	}
+	return entries, qm, nil
+}
+
+func (k *KV) getInternal(key string, params map[string]string, q *QueryOptions) (*http.Response, *QueryMeta, error) {
+	r := k.c.newRequest("GET", "/v1/kv/"+strings.TrimPrefix(key, "/"))
+	r.setQueryOptions(q)
+	for param, val := range params {
+		r.params.Set(param, val)
+	}
+	rtt, resp, err := k.c.doRequest(r)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	qm := &QueryMeta{}
+	parseQueryMeta(resp, qm)
+	qm.RequestTime = rtt
+
+	if resp.StatusCode == 404 {
+		resp.Body.Close()
+		return nil, qm, nil
+	} else if resp.StatusCode != 200 {
+		resp.Body.Close()
+		return nil, nil, fmt.Errorf("Unexpected response code: %d", resp.StatusCode)
+	}
+	return resp, qm, nil
+}
+
+// Put is used to write a new value. Only the
+// Key, Flags and Value is respected.
+func (k *KV) Put(p *KVPair, q *WriteOptions) (*WriteMeta, error) {
+	params := make(map[string]string, 1)
+	if p.Flags != 0 {
+		params["flags"] = strconv.FormatUint(p.Flags, 10)
+	}
+	_, wm, err := k.put(p.Key, params, p.Value, q)
+	return wm, err
+}
+
+// CAS is used for a Check-And-Set operation. The Key,
+// ModifyIndex, Flags and Value are respected. Returns true
+// on success or false on failures.
+func (k *KV) CAS(p *KVPair, q *WriteOptions) (bool, *WriteMeta, error) {
+	params := make(map[string]string, 2)
+	if p.Flags != 0 {
+		params["flags"] = strconv.FormatUint(p.Flags, 10)
+	}
+	params["cas"] = strconv.FormatUint(p.ModifyIndex, 10)
+	return k.put(p.Key, params, p.Value, q)
+}
+
+// Acquire is used for a lock acquisition operation. The Key,
+// Flags, Value and Session are respected. Returns true
+// on success or false on failures.
+func (k *KV) Acquire(p *KVPair, q *WriteOptions) (bool, *WriteMeta, error) {
+	params := make(map[string]string, 2)
+	if p.Flags != 0 {
+		params["flags"] = strconv.FormatUint(p.Flags, 10)
+	}
+	params["acquire"] = p.Session
+	return k.put(p.Key, params, p.Value, q)
+}
+
+// Release is used for a lock release operation. The Key,
+// Flags, Value and Session are respected. Returns true
+// on success or false on failures.
+func (k *KV) Release(p *KVPair, q *WriteOptions) (bool, *WriteMeta, error) {
+	params := make(map[string]string, 2)
+	if p.Flags != 0 {
+		params["flags"] = strconv.FormatUint(p.Flags, 10)
+	}
+	params["release"] = p.Session
+	return k.put(p.Key, params, p.Value, q)
+}
+
+func (k *KV) put(key string, params map[string]string, body []byte, q *WriteOptions) (bool, *WriteMeta, error) {
+	if len(key) > 0 && key[0] == '/' {
+		return false, nil, fmt.Errorf("Invalid key. Key must not begin with a '/': %s", key)
+	}
+
+	r := k.c.newRequest("PUT", "/v1/kv/"+key)
+	r.setWriteOptions(q)
+	for param, val := range params {
+		r.params.Set(param, val)
+	}
+	r.body = bytes.NewReader(body)
+	rtt, resp, err := requireOK(k.c.doRequest(r))
+	if err != nil {
+		return false, nil, err
+	}
+	defer resp.Body.Close()
+
+	qm := &WriteMeta{}
+	qm.RequestTime = rtt
+
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, resp.Body); err != nil {
+		return false, nil, fmt.Errorf("Failed to read response: %v", err)
+	}
+	res := strings.Contains(buf.String(), "true")
+	return res, qm, nil
+}
+
+// Delete is used to delete a single key
+func (k *KV) Delete(key string, w *WriteOptions) (*WriteMeta, error) {
+	_, qm, err := k.deleteInternal(key, nil, w)
+	return qm, err
+}
+
+// DeleteCAS is used for a Delete Check-And-Set operation. The Key
+// and ModifyIndex are respected. Returns true on success or false on failures.
+func (k *KV) DeleteCAS(p *KVPair, q *WriteOptions) (bool, *WriteMeta, error) {
+	params := map[string]string{
+		"cas": strconv.FormatUint(p.ModifyIndex, 10),
+	}
+	return k.deleteInternal(p.Key, params, q)
+}
+
+// DeleteTree is used to delete all keys under a prefix
+func (k *KV) DeleteTree(prefix string, w *WriteOptions) (*WriteMeta, error) {
+	_, qm, err := k.deleteInternal(prefix, map[string]string{"recurse": ""}, w)
+	return qm, err
+}
+
+func (k *KV) deleteInternal(key string, params map[string]string, q *WriteOptions) (bool, *WriteMeta, error) {
+	r := k.c.newRequest("DELETE", "/v1/kv/"+strings.TrimPrefix(key, "/"))
+	r.setWriteOptions(q)
+	for param, val := range params {
+		r.params.Set(param, val)
+	}
+	rtt, resp, err := requireOK(k.c.doRequest(r))
+	if err != nil {
+		return false, nil, err
+	}
+	defer resp.Body.Close()
+
+	qm := &WriteMeta{}
+	qm.RequestTime = rtt
+
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, resp.Body); err != nil {
+		return false, nil, fmt.Errorf("Failed to read response: %v", err)
+	}
+	res := strings.Contains(buf.String(), "true")
+	return res, qm, nil
+}
+
+// TxnOp is the internal format we send to Consul. It's not specific to KV,
+// though currently only KV operations are supported.
+type TxnOp struct {
+	KV *KVTxnOp
+}
+
+// TxnOps is a list of transaction operations.
+type TxnOps []*TxnOp
+
+// TxnResult is the internal format we receive from Consul.
+type TxnResult struct {
+	KV *KVPair
+}
+
+// TxnResults is a list of TxnResult objects.
+type TxnResults []*TxnResult
+
+// TxnError is used to return information about an operation in a transaction.
+type TxnError struct {
+	OpIndex int
+	What    string
+}
+
+// TxnErrors is a list of TxnError objects.
+type TxnErrors []*TxnError
+
+// TxnResponse is the internal format we receive from Consul.
+type TxnResponse struct {
+	Results TxnResults
+	Errors  TxnErrors
+}
+
+// Txn is used to apply multiple KV operations in a single, atomic transaction.
+//
+// Note that Go will perform the required base64 encoding on the values
+// automatically because the type is a byte slice. Transactions are defined as a
+// list of operations to perform, using the KVOp constants and KVTxnOp structure
+// to define operations. If any operation fails, none of the changes are applied
+// to the state store. Note that this hides the internal raw transaction interface
+// and munges the input and output types into KV-specific ones for ease of use.
+// If there are more non-KV operations in the future we may break out a new
+// transaction API client, but it will be easy to keep this KV-specific variant
+// supported.
+//
+// Even though this is generally a write operation, we take a QueryOptions input
+// and return a QueryMeta output. If the transaction contains only read ops, then
+// Consul will fast-path it to a different endpoint internally which supports
+// consistency controls, but not blocking. If there are write operations then
+// the request will always be routed through raft and any consistency settings
+// will be ignored.
+//
+// Here's an example:
+//
+//	   ops := KVTxnOps{
+//		   &KVTxnOp{
+//			   Verb:    KVLock,
+//			   Key:     "test/lock",
+//			   Session: "adf4238a-882b-9ddc-4a9d-5b6758e4159e",
+//			   Value:   []byte("hello"),
+//		   },
+//		   &KVTxnOp{
+//			   Verb:    KVGet,
+//			   Key:     "another/key",
+//		   },
+//	   }
+//	   ok, response, _, err := kv.Txn(&ops, nil)
+//
+// If there is a problem making the transaction request then an error will be
+// returned. Otherwise, the ok value will be true if the transaction succeeded
+// or false if it was rolled back. The response is a structured return value which
+// will have the outcome of the transaction. Its Results member will have entries
+// for each operation. Deleted keys will have a nil entry in the, and to save
+// space, the Value of each key in the Results will be nil unless the operation
+// is a KVGet. If the transaction was rolled back, the Errors member will have
+// entries referencing the index of the operation that failed along with an error
+// message.
+func (k *KV) Txn(txn KVTxnOps, q *QueryOptions) (bool, *KVTxnResponse, *QueryMeta, error) {
+	r := k.c.newRequest("PUT", "/v1/txn")
+	r.setQueryOptions(q)
+
+	// Convert into the internal format since this is an all-KV txn.
+	ops := make(TxnOps, 0, len(txn))
+	for _, kvOp := range txn {
+		ops = append(ops, &TxnOp{KV: kvOp})
+	}
+	r.obj = ops
+	rtt, resp, err := k.c.doRequest(r)
+	if err != nil {
+		return false, nil, nil, err
+	}
+	defer resp.Body.Close()
+
+	qm := &QueryMeta{}
+	parseQueryMeta(resp, qm)
+	qm.RequestTime = rtt
+
+	if resp.StatusCode == http.StatusOK || resp.StatusCode == http.StatusConflict {
+		var txnResp TxnResponse
+		if err := decodeBody(resp, &txnResp); err != nil {
+			return false, nil, nil, err
+		}
+
+		// Convert from the internal format.
+		kvResp := KVTxnResponse{
+			Errors: txnResp.Errors,
+		}
+		for _, result := range txnResp.Results {
+			kvResp.Results = append(kvResp.Results, result.KV)
+		}
+		return resp.StatusCode == http.StatusOK, &kvResp, qm, nil
+	}
+
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, resp.Body); err != nil {
+		return false, nil, nil, fmt.Errorf("Failed to read response: %v", err)
+	}
+	return false, nil, nil, fmt.Errorf("Failed request: %s", buf.String())
+}