From d26995a1e45267e395dee319bb043fd4e303bc47 Mon Sep 17 00:00:00 2001
From: Martin Boehm <martin.boehm@1mbsoftware.net>
Date: Wed, 5 Jun 2019 13:29:06 +0200
Subject: [PATCH] Show blockbook status in case of backend error

---
 api/types.go                | 23 ++++++++++++-----------
 api/worker.go               | 16 +++++++++++-----
 static/templates/index.html |  6 ++++++
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/api/types.go b/api/types.go
index c839093e..111e6c55 100644
--- a/api/types.go
+++ b/api/types.go
@@ -341,17 +341,18 @@ type BlockbookInfo struct {
 
 // BackendInfo is used to get information about blockchain
 type BackendInfo struct {
-	Chain           string  `json:"chain"`
-	Blocks          int     `json:"blocks"`
-	Headers         int     `json:"headers"`
-	Bestblockhash   string  `json:"bestBlockHash"`
-	Difficulty      string  `json:"difficulty"`
-	SizeOnDisk      int64   `json:"sizeOnDisk"`
-	Version         string  `json:"version"`
-	Subversion      string  `json:"subversion"`
-	ProtocolVersion string  `json:"protocolVersion"`
-	Timeoffset      float64 `json:"timeOffset"`
-	Warnings        string  `json:"warnings"`
+	BackendError    string  `json:"error,omitempty"`
+	Chain           string  `json:"chain,omitempty"`
+	Blocks          int     `json:"blocks,omitempty"`
+	Headers         int     `json:"headers,omitempty"`
+	BestBlockHash   string  `json:"bestBlockHash,omitempty"`
+	Difficulty      string  `json:"difficulty,omitempty"`
+	SizeOnDisk      int64   `json:"sizeOnDisk,omitempty"`
+	Version         string  `json:"version,omitempty"`
+	Subversion      string  `json:"subversion,omitempty"`
+	ProtocolVersion string  `json:"protocolVersion,omitempty"`
+	Timeoffset      float64 `json:"timeOffset,omitempty"`
+	Warnings        string  `json:"warnings,omitempty"`
 }
 
 // SystemInfo contains information about the running blockbook and backend instance
diff --git a/api/worker.go b/api/worker.go
index e305ae45..b2a47795 100644
--- a/api/worker.go
+++ b/api/worker.go
@@ -1091,13 +1091,18 @@ func (w *Worker) ComputeFeeStats(blockFrom, blockTo int, stopCompute chan os.Sig
 // GetSystemInfo returns information about system
 func (w *Worker) GetSystemInfo(internal bool) (*SystemInfo, error) {
 	start := time.Now()
-	ci, err := w.chain.GetChainInfo()
-	if err != nil {
-		return nil, errors.Annotatef(err, "GetChainInfo")
-	}
 	vi := common.GetVersionInfo()
 	inSync, bestHeight, lastBlockTime := w.is.GetSyncState()
 	inSyncMempool, lastMempoolTime, mempoolSize := w.is.GetMempoolSyncState()
+	ci, err := w.chain.GetChainInfo()
+	var backendError string
+	if err != nil {
+		backendError = errors.Annotatef(err, "GetChainInfo").Error()
+		ci = &bchain.ChainInfo{}
+		// set not in sync in case of backend error
+		inSync = false
+		inSyncMempool = false
+	}
 	var columnStats []common.InternalStateColumn
 	var internalDBSize int64
 	if internal {
@@ -1125,7 +1130,8 @@ func (w *Worker) GetSystemInfo(internal bool) (*SystemInfo, error) {
 		About:             Text.BlockbookAbout,
 	}
 	backendInfo := &BackendInfo{
-		Bestblockhash:   ci.Bestblockhash,
+		BackendError:    backendError,
+		BestBlockHash:   ci.Bestblockhash,
 		Blocks:          ci.Blocks,
 		Chain:           ci.Chain,
 		Difficulty:      ci.Difficulty,
diff --git a/static/templates/index.html b/static/templates/index.html
index 5e275fc3..ff36faa8 100644
--- a/static/templates/index.html
+++ b/static/templates/index.html
@@ -58,6 +58,12 @@
         <h3>Backend</h3>
         <table class="table data-table">
             <tbody>
+                {{- if $be.BackendError -}}
+                <tr>
+                    <td style="width: 30%;">Backend Error</td>
+                    <td class="data text-danger">{{$be.BackendError}}</td>
+                </tr>
+                {{- end -}}
                 <tr>
                     <td style="width: 30%;">Chain</td>
                     <td class="data">{{$be.Chain}}</td>