Checking if string from golang file exists in yaml file - go

Question

I am rather new to working with yaml and golang. Currently, I am creating a golang program that parses an rpm package to check for subsystem dependencies. It extends the go-rpmutils library.
So far this is the code I have within my main function to handle conditions:
func main() {
// Parse the rpm
rpm, err := rpmutils.ReadRpm("file.rpm")
if err != nil {
panic(err)
}
// Get RPM Deps
dependencies, err := rpm.Header.GetStrings(rpmutils.REQUIRENAME)
if err != nil {
panic(err)
}
// Check for specific dep condition
for _, p := range dependencies {
if strings.HasPrefix(p, "prefix1") && p != "string-including-prefix1" {
fmt.Printf("\t%s\n", p)
defer os.Exit(1)
}
}
}
I am able to output the dependencies but want to set up several if else conditions for when specific subsystem dependencies exist.
In a separate yaml file, I have:
allowed-deps:
-dep1
-dep2
-dep3
third-party-deps:
-dep4
-dep5
-dep6
internal-deps:
-dep7
-dep8
-dep9
I'd like to compare the value of var p from the for loop with the values in the yaml file. So for example:
if p only equals values from allowed-deps, print "successfully built rpm" and do not prompt os.Exit(1)
if p equals any of the third-party-deps, print "err msg for third-party deps" and os.Exit(1)
if p equals any internal-deps, print "another err mssg" and os.Exit(1)
How can I go about doing this?

Answer 1

You can use a YAML package (like https://github.com/go-yaml/yaml), load your file into a variable and check it on every step in the ifs that you propose. I would use maps as it seems that you will be checking very frequently the sets.
Here you have a simple example that I made using that package so you can see how to unmarshal your file, convert into maps, and check the maps: https://play.golang.org/p/t1GhUPvAQNQ
package main
import (
"fmt"
"github.com/go-yaml/yaml"
)
const str = `
allowed-deps:
- dep1
- dep2
- dep3
third-party-deps:
- dep4
- dep5
- dep6
internal-deps:
- dep7
- dep8
- dep9
`
type MyYAML struct {
AllowedDeps []string `yaml:"allowed-deps"`
ThirdPartyDeps []string `yaml:"third-party-deps"`
InternalDeps []string `yaml:"internal-deps"`
}
func main() {
var a MyYAML
err := yaml.Unmarshal([]byte(str), &a)
if err != nil {
panic(err)
}
// Build a map for every section.
allowedDeps := map[string]struct{}{}
thirdPartyDeps := map[string]struct{}{}
internalDeps := map[string]struct{}{}
for _, dep := range a.AllowedDeps {
allowedDeps[dep] = struct{}{}
}
for _, dep := range a.ThirdPartyDeps {
thirdPartyDeps[dep] = struct{}{}
}
for _, dep := range a.InternalDeps {
internalDeps[dep] = struct{}{}
}
// Some checking examples.
if _, ok := allowedDeps["dep1"]; ok {
fmt.Println("dep1 found")
}
if _, ok := thirdPartyDeps["dep1"]; ok {
fmt.Println("dep1 found")
}
if _, ok := internalDeps["dep8"]; ok {
fmt.Println("dep8 found")
}
}