github.com/erda-project/erda-infra@v1.0.9/base/servicehub/usage.go (about)

     1  // Copyright (c) 2021 Terminus, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package servicehub
    16  
    17  import (
    18  	"bytes"
    19  	"reflect"
    20  )
    21  
    22  // Usage .
    23  func Usage(names ...string) string {
    24  	buf := &bytes.Buffer{}
    25  	buf.WriteString("Service Providers:\n")
    26  	if len(names) <= 0 {
    27  		for name, define := range serviceProviders {
    28  			providerUsage(name, define, buf)
    29  		}
    30  	} else {
    31  		for _, name := range names {
    32  			if define, ok := serviceProviders[name]; ok {
    33  				providerUsage(name, define, buf)
    34  			}
    35  		}
    36  	}
    37  	return buf.String()
    38  }
    39  
    40  func providerUsage(name string, define ProviderDefine, buf *bytes.Buffer) {
    41  	buf.WriteString(name)
    42  	var usage string
    43  	if s, ok := define.(ProviderUsageSummary); ok {
    44  		usage = s.Summary()
    45  	}
    46  	if len(usage) <= 0 {
    47  		if u, ok := define.(ProviderUsage); ok {
    48  			usage = u.Description()
    49  		}
    50  	}
    51  	if len(usage) > 0 {
    52  		buf.WriteString("\n    ")
    53  		buf.WriteString(usage)
    54  	}
    55  	if creator, ok := define.(ConfigCreator); ok {
    56  		cfg := creator.Config()
    57  		typ := reflect.TypeOf(cfg)
    58  		for typ.Kind() == reflect.Ptr {
    59  			typ = typ.Elem()
    60  		}
    61  		num := typ.NumField()
    62  		for i := 0; i < num; i++ {
    63  			field := typ.Field(i)
    64  			file := field.Tag.Get("file")
    65  			flag := field.Tag.Get("flag")
    66  			env := field.Tag.Get("env")
    67  			defval := field.Tag.Get("default")
    68  			desc := field.Tag.Get("desc")
    69  			var tags []string
    70  			if len(file) > 0 {
    71  				tags = append(tags, "file:\""+file+"\"")
    72  			}
    73  			if len(flag) > 0 {
    74  				tags = append(tags, "flag:\""+flag+"\"")
    75  			}
    76  			if len(env) > 0 {
    77  				tags = append(tags, "env:\""+env+"\"")
    78  			}
    79  			if len(defval) > 0 {
    80  				tags = append(tags, "default:\""+defval+"\"")
    81  			}
    82  			if len(desc) > 0 {
    83  				tags = append(tags, ", "+desc)
    84  			}
    85  			buf.WriteString("\n    ")
    86  			for _, tag := range tags {
    87  				buf.WriteString(tag)
    88  				buf.WriteRune(' ')
    89  			}
    90  		}
    91  	}
    92  	buf.WriteRune('\n')
    93  }