From 152290db7ed25d3d5caa1519bc18722e3508f50c Mon Sep 17 00:00:00 2001
From: Constantine <ckryvomaz@gmail.com>
Date: Mon, 19 Mar 2018 18:39:37 +0200
Subject: [PATCH] Add `\health` rpc endpoint (#1306)

* Init `\health` rpc endpoint

* remove additional info from `\health` rpc endpoint

* Cleanup imports

* Added time threshold for health check

* Update rpc doc

* Remove unnecessary checks for blocktime creation lag

* Clean up of unnecessary config usage
---
 .gitignore                  |  3 +++
 docs/specification/rpc.rst  |  1 +
 rpc/core/doc.go             |  1 +
 rpc/core/health.go          | 30 ++++++++++++++++++++++++++++++
 rpc/core/pipe.go            |  4 ++--
 rpc/core/routes.go          |  1 +
 rpc/core/types/responses.go |  2 ++
 types/heartbeat.go          |  2 +-
 8 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 rpc/core/health.go

diff --git a/.gitignore b/.gitignore
index b031ce185..7b7b746fb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,6 @@ docs/tools
 
 scripts/wal2json/wal2json
 scripts/cutWALUntil/cutWALUntil
+
+.idea/
+*.iml
diff --git a/docs/specification/rpc.rst b/docs/specification/rpc.rst
index 7df394d77..386791aa7 100644
--- a/docs/specification/rpc.rst
+++ b/docs/specification/rpc.rst
@@ -97,6 +97,7 @@ An HTTP Get request to the root RPC endpoint (e.g.
     http://localhost:46657/genesis
     http://localhost:46657/net_info
     http://localhost:46657/num_unconfirmed_txs
+    http://localhost:46657/health
     http://localhost:46657/status
     http://localhost:46657/unconfirmed_txs
     http://localhost:46657/unsafe_flush_mempool
diff --git a/rpc/core/doc.go b/rpc/core/doc.go
index 5f3e2dced..b479482c4 100644
--- a/rpc/core/doc.go
+++ b/rpc/core/doc.go
@@ -81,6 +81,7 @@ Available endpoints:
 /net_info
 /num_unconfirmed_txs
 /status
+/health
 /unconfirmed_txs
 /unsafe_flush_mempool
 /unsafe_stop_cpu_profiler
diff --git a/rpc/core/health.go b/rpc/core/health.go
new file mode 100644
index 000000000..dd71b4a91
--- /dev/null
+++ b/rpc/core/health.go
@@ -0,0 +1,30 @@
+package core
+
+import (
+	ctypes "github.com/tendermint/tendermint/rpc/core/types"
+)
+
+// Get node health. Checks whether new blocks are created.
+//
+// ```shell
+// curl 'localhost:46657/health'
+// ```
+//
+// ```go
+// client := client.NewHTTP("tcp://0.0.0.0:46657", "/websocket")
+// result, err := client.Health()
+// ```
+//
+// > The above command returns JSON structured like this:
+//
+// ```json
+// {
+// 	"error": "",
+// 	"result": {},
+// 	"id": "",
+// 	"jsonrpc": "2.0"
+// }
+// ```
+func Health() (*ctypes.ResultHealth, error) {
+	return &ctypes.ResultHealth{}, nil
+}
diff --git a/rpc/core/pipe.go b/rpc/core/pipe.go
index 2edb3f3d1..1eb00ceeb 100644
--- a/rpc/core/pipe.go
+++ b/rpc/core/pipe.go
@@ -3,10 +3,10 @@ package core
 import (
 	"time"
 
-	crypto "github.com/tendermint/go-crypto"
+	"github.com/tendermint/go-crypto"
 	"github.com/tendermint/tendermint/consensus"
 	cstypes "github.com/tendermint/tendermint/consensus/types"
-	p2p "github.com/tendermint/tendermint/p2p"
+	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/proxy"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/state/txindex"
diff --git a/rpc/core/routes.go b/rpc/core/routes.go
index 3ea7aa08c..0e10cefee 100644
--- a/rpc/core/routes.go
+++ b/rpc/core/routes.go
@@ -12,6 +12,7 @@ var Routes = map[string]*rpc.RPCFunc{
 	"unsubscribe_all": rpc.NewWSRPCFunc(UnsubscribeAll, ""),
 
 	// info API
+	"health":               rpc.NewRPCFunc(Health, ""),
 	"status":               rpc.NewRPCFunc(Status, ""),
 	"net_info":             rpc.NewRPCFunc(NetInfo, ""),
 	"blockchain":           rpc.NewRPCFunc(BlockchainInfo, "minHeight,maxHeight"),
diff --git a/rpc/core/types/responses.go b/rpc/core/types/responses.go
index e13edc843..7567fe650 100644
--- a/rpc/core/types/responses.go
+++ b/rpc/core/types/responses.go
@@ -155,3 +155,5 @@ type ResultEvent struct {
 	Query string            `json:"query"`
 	Data  types.TMEventData `json:"data"`
 }
+
+type ResultHealth struct{}
diff --git a/types/heartbeat.go b/types/heartbeat.go
index fc5f8ad7f..8b86a15ba 100644
--- a/types/heartbeat.go
+++ b/types/heartbeat.go
@@ -14,7 +14,7 @@ import (
 // json field tags because we always want the JSON
 // representation to be in its canonical form.
 type Heartbeat struct {
-	ValidatorAddress Address   `json:"validator_address"`
+	ValidatorAddress Address          `json:"validator_address"`
 	ValidatorIndex   int              `json:"validator_index"`
 	Height           int64            `json:"height"`
 	Round            int              `json:"round"`