/
config.go
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/
config.go
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// Copyright 2020 Erik Agsjö
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"fmt"
"os"
"text/tabwriter"
"github.com/erkkah/letarette"
"github.com/kelseyhightower/envconfig"
)
// Config holds the main configuration
type Config struct {
Nats struct {
URLS []string `default:"nats://localhost:4222"`
SeedFile string
RootCAs []string
Topic string `default:"leta"`
}
Host string `default:""`
Port uint16 `default:"8080"`
}
const prefix = "LRMON"
// LoadConfig loads configuration variables from the environment
// and returns a fully populated Config instance.
func LoadConfig() (cfg Config, err error) {
err = envconfig.CheckDisallowed(prefix, &cfg)
if err != nil {
return
}
err = envconfig.Process(prefix, &cfg)
if err != nil {
return
}
return
}
var usageFormat = fmt.Sprintf("{{$t:=\"\t\"}}Letarette monitor\n%s (%s)\n", letarette.Tag, letarette.Revision) + `
Configuration environment variables:
VARIABLE{{$t}}TYPE{{$t}}DEFAULT
========{{$t}}===={{$t}}=======
LOG_LEVEL{{$t}}String{{$t}}INFO
{{range .}}{{if usage_description . | eq "internal" | not}}{{usage_key .}}{{$t}}{{usage_type .}}{{$t}}{{usage_default .}}
{{end}}{{end}}
`
// Usage prints usage help to stdout
func Usage() {
var cfg Config
tabs := tabwriter.NewWriter(os.Stdout, 1, 0, 4, ' ', 0)
_ = envconfig.Usagef(prefix, &cfg, tabs, usageFormat)
}