feat: handle no config viper

docs/2022-07-10-bootstrap-go.html

@@ -71,7 +71,7 @@ import (
 )
 </code></pre><p>And then in <code>Makefile</code>:<pre><code class=language-Makefile>build:
     go install github.com/golang/protobuf/protoc-gen-go
-</code></pre><p>We always get the version of build tools in <code>go.mod</code> each time we install it.<br>Future contributors will not cry anymore.<h3>Don't use cli libs (<a href=https://github.com/spf13/cobra>spf13/cobra</a>, <a href=https://github.com/urfave/cli>urfave/cli</a>) just for Go service</h3><p>What is the point to pass many params (<code>do-it</code>, <code>--abc</code>, <code>--xyz</code>) when what we only need is start service?<p>In my case, service starts with only config, and config should be read from file or environment like <a href=https://12factor.net/>The Twelve Factors</a> guide.<h3>Don't use <a href=https://github.com/grpc-ecosystem/grpc-gateway>grpc-ecosystem/grpc-gateway</a></h3><p>Just don't.<p>Use <a href=https://github.com/protocolbuffers/protobuf-go>protocolbuffers/protobuf-go</a>, <a href=https://github.com/grpc/grpc-go>grpc/grpc-go</a> for gRPC.<p>Write 1 for both gRPC, REST sounds good, but in the end, it is not worth it.<h3>Don't use <a href=https://github.com/uber/prototool>uber/prototool</a>, use <a href=https://github.com/bufbuild/buf>bufbuild/buf</a></h3><p>prototool is deprecated, and buf can generate, lint, format as good as prototool.<h3>Use <a href=https://github.com/gin-gonic/gin>gin-gonic/gin</a> for REST.</h3><p>Don't use <code>gin.Context</code> when pass context from handler layer to service layer, use <code>gin.Context.Request.Context()</code> instead.<h3>If you want log, just use <a href=https://github.com/uber-go/zap>uber-go/zap</a></h3><p>It is fast!<ul><li><p>Don't overuse <code>func (*Logger) With</code>. Because if log line is too long, there is a possibility that we can lost it.<li><p>Use <code>MarshalLogObject</code> when we need to hide some field of object when log (field is long or has sensitive value)<li><p>Don't use <code>Panic</code>. Use <code>Fatal</code> for errors when start service to check dependencies. If you really need panic level, use <code>DPanic</code>.<li><p>If doubt, use <code>zap.Any</code>.<li><p>Use <code>contextID</code> or <code>traceID</code> in every log lines for easily debug.</ul><h3>To read config, use <a href=https://github.com/spf13/viper>spf13/viper</a></h3><p>Only init config in main or cmd layer.<br>Do not use <code>viper.Get...</code> in business layer or inside business layer.<p>Why?<ul><li>Hard to mock and test<li>Put all config in single place for easily tracking</ul><h3>Don't overuse ORM libs, no need to handle another layer above SQL.</h3><p>Each ORM libs has each different syntax.<br>To learn and use those libs correctly is time consuming.<br>So just stick to plain SQL.<br>It is easier to debug when something is wrong.<p>But <code>database/sql</code> has its own limit.<br>For example, it is hard to get primary key after insert/update.<br>So may be you want to use ORM for those cases.<br>I hear that <a href=https://github.com/go-gorm/gorm>go-gorm/gorm</a>, <a href=https://github.com/ent/ent>ent/ent</a> is good.<h3>If you want test, just use <a href=https://github.com/stretchr/testify>stretchr/testify</a>.</h3><p>It is easy to write a suite test, thanks to testify.<br>Also, for mocking, there are many options out there.<br>Pick 1 then sleep peacefully.<h3>If need to mock, choose <a href=https://github.com/matryer/moq>matryer/moq</a> or <a href=https://github.com/golang/mock>golang/mock</a></h3><p>The first is easy to use but not powerful as the later.<br>If you want to make sure mock func is called with correct times, use the later.<p>Example with <code>matryer/moq</code>:<pre><code class=language-go>// Only gen mock if source code file is newer than mock file
+</code></pre><p>We always get the version of build tools in <code>go.mod</code> each time we install it.<br>Future contributors will not cry anymore.<h3>Don't use cli libs (<a href=https://github.com/spf13/cobra>spf13/cobra</a>, <a href=https://github.com/urfave/cli>urfave/cli</a>) just for Go service</h3><p>What is the point to pass many params (<code>do-it</code>, <code>--abc</code>, <code>--xyz</code>) when what we only need is start service?<p>In my case, service starts with only config, and config should be read from file or environment like <a href=https://12factor.net/>The Twelve Factors</a> guide.<h3>Don't use <a href=https://github.com/grpc-ecosystem/grpc-gateway>grpc-ecosystem/grpc-gateway</a></h3><p>Just don't.<p>Use <a href=https://github.com/protocolbuffers/protobuf-go>protocolbuffers/protobuf-go</a>, <a href=https://github.com/grpc/grpc-go>grpc/grpc-go</a> for gRPC.<p>Write 1 for both gRPC, REST sounds good, but in the end, it is not worth it.<h3>Don't use <a href=https://github.com/uber/prototool>uber/prototool</a>, use <a href=https://github.com/bufbuild/buf>bufbuild/buf</a></h3><p>prototool is deprecated, and buf can generate, lint, format as good as prototool.<h3>Use <a href=https://github.com/gin-gonic/gin>gin-gonic/gin</a> for REST.</h3><p>Don't use <code>gin.Context</code> when pass context from handler layer to service layer, use <code>gin.Context.Request.Context()</code> instead.<h3>If you want log, just use <a href=https://github.com/uber-go/zap>uber-go/zap</a></h3><p>It is fast!<ul><li>Don't overuse <code>func (*Logger) With</code>. Because if log line is too long, there is a possibility that we can lost it.<li>Use <code>MarshalLogObject</code> when we need to hide some field of object when log (field is long or has sensitive value)<li>Don't use <code>Panic</code>. Use <code>Fatal</code> for errors when start service to check dependencies. If you really need panic level, use <code>DPanic</code>.<li>If doubt, use <code>zap.Any</code>.<li>Use <code>contextID</code> or <code>traceID</code> in every log lines for easily debug.</ul><h3>To read config, use <a href=https://github.com/spf13/viper>spf13/viper</a></h3><p>Only init config in main or cmd layer.<br>Do not use <code>viper.Get...</code> in business layer or inside business layer.<p>Why?<ul><li>Hard to mock and test<li>Put all config in single place for easily tracking</ul><p>Also, be careful if config value is empty.<br>You should decide to continue or stop the service if there is no config.<h3>Don't overuse ORM libs, no need to handle another layer above SQL.</h3><p>Each ORM libs has each different syntax.<br>To learn and use those libs correctly is time consuming.<br>So just stick to plain SQL.<br>It is easier to debug when something is wrong.<p>But <code>database/sql</code> has its own limit.<br>For example, it is hard to get primary key after insert/update.<br>So may be you want to use ORM for those cases.<br>I hear that <a href=https://github.com/go-gorm/gorm>go-gorm/gorm</a>, <a href=https://github.com/ent/ent>ent/ent</a> is good.<h3>If you want test, just use <a href=https://github.com/stretchr/testify>stretchr/testify</a>.</h3><p>It is easy to write a suite test, thanks to testify.<br>Also, for mocking, there are many options out there.<br>Pick 1 then sleep peacefully.<h3>If need to mock, choose <a href=https://github.com/matryer/moq>matryer/moq</a> or <a href=https://github.com/golang/mock>golang/mock</a></h3><p>The first is easy to use but not powerful as the later.<br>If you want to make sure mock func is called with correct times, use the later.<p>Example with <code>matryer/moq</code>:<pre><code class=language-go>// Only gen mock if source code file is newer than mock file
 // https://jonwillia.ms/2019/12/22/conditional-gomock-mockgen
 //go:generate sh -c &quot;test service_mock_generated.go -nt $GOFILE &amp;&amp; exit 0; moq -rm -out service_mock_generated.go . Service&quot;
 </code></pre><h3>Be careful with <a href=https://github.com/spf13/cast>spf13/cast</a></h3><p>Don't cast proto enum:<pre><code class=language-go>// Bad

posts/2022-07-10-bootstrap-go.md

@@ -206,13 +206,9 @@ Don't use `gin.Context` when pass context from handler layer to service layer, u
 It is fast!
 
 - Don't overuse `func (*Logger) With`. Because if log line is too long, there is a possibility that we can lost it.
-
 - Use `MarshalLogObject` when we need to hide some field of object when log (field is long or has sensitive value)
-
 - Don't use `Panic`. Use `Fatal` for errors when start service to check dependencies. If you really need panic level, use `DPanic`.
-
 - If doubt, use `zap.Any`.
-
 - Use `contextID` or `traceID` in every log lines for easily debug.
 
 ### To read config, use [spf13/viper](https://github.com/spf13/viper)
@@ -225,6 +221,9 @@ Why?
 - Hard to mock and test
 - Put all config in single place for easily tracking
 
+Also, be careful if config value is empty.
+You should decide to continue or stop the service if there is no config.
+
 ### Don't overuse ORM libs, no need to handle another layer above SQL.
 
 Each ORM libs has each different syntax.