Revert "client/driver/env: interpolate empty optional meta params as …

…empty strings"

This reverts commit 84926f7.

CHANGELOG.md

@@ -32,8 +32,6 @@ IMPROVEMENTS:
    image pulls [[GH-4192](https://github.com/hashicorp/nomad/issues/4192)]
  * driver/raw_exec: Use cgroups to manage process tree for precise cleanup of
    launched processes [[GH-4350](https://github.com/hashicorp/nomad/issues/4350)]
- * env: Default interpolation of optional meta fields of parameterized jobs to
-   an empty string rather than the field key. [[GH-3720](https://github.com/hashicorp/nomad/issues/3720)]
  * ui: Show node drain, node eligibility, and node drain strategy information in the Client list and Client detail pages [[GH-4353](https://github.com/hashicorp/nomad/issues/4353)]
  * ui: Show reschedule-event information for allocations that were server-side rescheduled [[GH-4254](https://github.com/hashicorp/nomad/issues/4254)]
  * ui: Show the running deployment Progress Deadlines on the Job Detail Page [[GH-4388](https://github.com/hashicorp/nomad/issues/4388)]

client/driver/env/env.go

@@ -397,23 +397,7 @@ func (b *Builder) setAlloc(alloc *structs.Allocation) *Builder {
 
 	// Set meta
 	combined := alloc.Job.CombinedTaskMeta(alloc.TaskGroup, b.taskName)
-	// taskMetaSize is double to total meta keys to account for given and upper
-	// cased values
-	taskMetaSize := len(combined) * 2
-
-	// if job is parameterized initialize optional meta to empty strings
-	if alloc.Job.IsParameterized() {
-		b.taskMeta = make(map[string]string,
-			taskMetaSize+(len(alloc.Job.ParameterizedJob.MetaOptional)*2))
-
-		for _, k := range alloc.Job.ParameterizedJob.MetaOptional {
-			b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, strings.ToUpper(k))] = ""
-			b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, k)] = ""
-		}
-	} else {
-		b.taskMeta = make(map[string]string, taskMetaSize)
-	}
-
+	b.taskMeta = make(map[string]string, len(combined)*2)
 	for k, v := range combined {
 		b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, strings.ToUpper(k))] = v
 		b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, k)] = v

client/driver/env/env_test.go

@@ -11,7 +11,6 @@ import (
 	cstructs "github.com/hashicorp/nomad/client/structs"
 	"github.com/hashicorp/nomad/nomad/mock"
 	"github.com/hashicorp/nomad/nomad/structs"
-	"github.com/stretchr/testify/require"
 )
 
 const (
@@ -373,18 +372,3 @@ func TestEnvironment_UpdateTask(t *testing.T) {
 		t.Errorf("Expected NOMAD_META_taskmeta to be unset but found: %q", v)
 	}
 }
-
-// TestEnvironment_InterpolateEmptyOptionalMeta asserts that in a parameterized
-// job, if an optional meta field is not set, it will get interpolated as an
-// empty string.
-func TestEnvironment_InterpolateEmptyOptionalMeta(t *testing.T) {
-	a := mock.Alloc()
-	a.Job.ParameterizedJob = &structs.ParameterizedJobConfig{
-		MetaOptional: []string{"metaopt1", "metaopt2"},
-	}
-	task := a.Job.TaskGroups[0].Tasks[0]
-	task.Meta = map[string]string{"metaopt1": "metaopt1val"}
-	env := NewBuilder(mock.Node(), a, task, "global").Build()
-	require.Equal(t, "metaopt1val", env.ReplaceEnv("${NOMAD_META_metaopt1}"))
-	require.Empty(t, env.ReplaceEnv("${NOMAD_META_metaopt2}"))
-}