open-nomad/helper/pluginutils/hclutils/util.go
2019-07-19 10:04:39 -07:00

93 lines
2.9 KiB
Go

package hclutils
import (
"bytes"
"errors"
"fmt"
"github.com/hashicorp/hcl2/hcl"
hjson "github.com/hashicorp/hcl2/hcl/json"
"github.com/hashicorp/hcl2/hcldec"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/ugorji/go/codec"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/function"
"github.com/zclconf/go-cty/cty/function/stdlib"
)
// ParseHclInterface is used to convert an interface value representing a hcl2
// body and return the interpolated value. Vars may be nil if there are no
// variables to interpolate.
func ParseHclInterface(val interface{}, spec hcldec.Spec, vars map[string]cty.Value) (cty.Value, hcl.Diagnostics, []error) {
evalCtx := &hcl.EvalContext{
Variables: vars,
Functions: GetStdlibFuncs(),
}
// Encode to json
var buf bytes.Buffer
enc := codec.NewEncoder(&buf, structs.JsonHandle)
err := enc.Encode(val)
if err != nil {
// Convert to a hcl diagnostics message
errorMessage := fmt.Sprintf("Label encoding failed: %v", err)
return cty.NilVal,
hcl.Diagnostics([]*hcl.Diagnostic{{
Severity: hcl.DiagError,
Summary: "Failed to encode label value",
Detail: errorMessage,
}}),
[]error{errors.New(errorMessage)}
}
// Parse the json as hcl2
hclFile, diag := hjson.Parse(buf.Bytes(), "")
if diag.HasErrors() {
return cty.NilVal, diag, formattedDiagnosticErrors(diag)
}
value, decDiag := hcldec.Decode(hclFile.Body, spec, evalCtx)
diag = diag.Extend(decDiag)
if diag.HasErrors() {
return cty.NilVal, diag, formattedDiagnosticErrors(diag)
}
return value, diag, nil
}
// GetStdlibFuncs returns the set of stdlib functions.
func GetStdlibFuncs() map[string]function.Function {
return map[string]function.Function{
"abs": stdlib.AbsoluteFunc,
"coalesce": stdlib.CoalesceFunc,
"concat": stdlib.ConcatFunc,
"hasindex": stdlib.HasIndexFunc,
"int": stdlib.IntFunc,
"jsondecode": stdlib.JSONDecodeFunc,
"jsonencode": stdlib.JSONEncodeFunc,
"length": stdlib.LengthFunc,
"lower": stdlib.LowerFunc,
"max": stdlib.MaxFunc,
"min": stdlib.MinFunc,
"reverse": stdlib.ReverseFunc,
"strlen": stdlib.StrlenFunc,
"substr": stdlib.SubstrFunc,
"upper": stdlib.UpperFunc,
}
}
// TODO: update hcl2 library with better diagnostics formatting for streamed configs
// - should be arbitrary labels not JSON https://github.com/hashicorp/hcl2/blob/4fba5e1a75e382aed7f7a7993f2c4836a5e1cd52/hcl/json/structure.go#L66
// - should not print diagnostic subject https://github.com/hashicorp/hcl2/blob/4fba5e1a75e382aed7f7a7993f2c4836a5e1cd52/hcl/diagnostic.go#L77
func formattedDiagnosticErrors(diag hcl.Diagnostics) []error {
var errs []error
for _, d := range diag {
if d.Summary == "Extraneous JSON object property" {
d.Summary = "Invalid label"
}
err := errors.New(fmt.Sprintf("%s: %s", d.Summary, d.Detail))
errs = append(errs, err)
}
return errs
}