From c5277224c74c64f2083592e429ac607eb5da005f Mon Sep 17 00:00:00 2001
From: James Rasell <jrasell@hashicorp.com>
Date: Tue, 11 Aug 2020 17:43:12 +0100
Subject: [PATCH] api: add node purge SDK function.

---
 api/nodes.go      | 34 +++++++++++++++++++++++++++++++++-
 api/nodes_test.go | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/api/nodes.go b/api/nodes.go
index 8ec6f8d0ab9..55c335ae771 100644
--- a/api/nodes.go
+++ b/api/nodes.go
@@ -14,7 +14,7 @@ const (
 	NodeStatusDown  = "down"
 
 	// NodeSchedulingEligible and Ineligible marks the node as eligible or not,
-	// respectively, for receiving allocations. This is orthoginal to the node
+	// respectively, for receiving allocations. This is orthogonal to the node
 	// status being ready.
 	NodeSchedulingEligible   = "eligible"
 	NodeSchedulingIneligible = "ineligible"
@@ -435,6 +435,38 @@ func (n *Nodes) GcAlloc(allocID string, q *QueryOptions) error {
 	return err
 }
 
+// Purge removes a node from the system. Nodes can still re-join the cluster if
+// they are alive.
+func (n *Nodes) Purge(nodeID string, q *QueryOptions) (*NodePurgeResponse, *QueryMeta, error) {
+	var resp NodePurgeResponse
+	path := fmt.Sprintf("/v1/node/%s/purge", nodeID)
+	qm, err := n.client.putQuery(path, nil, &resp, q)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &resp, qm, nil
+}
+
+// NodePurgeResponse is used to deserialize a Purge response.
+type NodePurgeResponse struct {
+	HeartbeatTTL    time.Duration
+	EvalIDs         []string
+	EvalCreateIndex uint64
+	NodeModifyIndex uint64
+	LeaderRPCAddr   string
+	NumNodes        int32
+	Servers         []*NodeServerInfo
+}
+
+// NodeServerInfo is used within NodePurgeResponse to deserialize a Purge
+// response.
+type NodeServerInfo struct {
+	Datacenter       string
+	RPCAdvertiseAddr string
+	RPCMajorVersion  int32
+	RPCMinorVersion  int32
+}
+
 // DriverInfo is used to deserialize a DriverInfo entry
 type DriverInfo struct {
 	Attributes        map[string]string
diff --git a/api/nodes_test.go b/api/nodes_test.go
index 4bf8c41b2ea..49b9c1e956f 100644
--- a/api/nodes_test.go
+++ b/api/nodes_test.go
@@ -506,6 +506,47 @@ func TestNodes_DrainStrategy_Equal(t *testing.T) {
 	require.True(d.Equal(o))
 }
 
+func TestNodes_Purge(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+	c, s := makeClient(t, nil, func(c *testutil.TestServerConfig) {
+		c.DevMode = true
+	})
+	defer s.Stop()
+
+	// Purge on a nonexistent node fails.
+	_, _, err := c.Nodes().Purge("12345678-abcd-efab-cdef-123456789abc", nil)
+	if err == nil || !strings.Contains(err.Error(), "not found") {
+		t.Fatalf("expected not found error, got: %#v", err)
+	}
+
+	// Wait for node registration and get the ID so we can attempt to purge a
+	// node that exists.
+	var nodeID string
+	testutil.WaitForResult(func() (bool, error) {
+		out, _, err := c.Nodes().List(nil)
+		if err != nil {
+			return false, err
+		}
+		if n := len(out); n != 1 {
+			return false, fmt.Errorf("expected 1 node, got: %d", n)
+		}
+		nodeID = out[0].ID
+		return true, nil
+	}, func(err error) {
+		t.Fatalf("err: %s", err)
+	})
+
+	// Perform the node purge and check the response objects.
+	out, meta, err := c.Nodes().Purge(nodeID, nil)
+	require.Nil(err)
+	require.NotNil(out)
+
+	// We can't use assertQueryMeta here, as the RPC response does not populate
+	// the known leader field.
+	require.Greater(meta.LastIndex, uint64(0))
+}
+
 func TestNodeStatValueFormatting(t *testing.T) {
 	t.Parallel()