Introduce option multi-dist to the publish commands

This change makes it possible to publish multiple distributions
with packages named the same but with different content by changing
structure of the generated pool hierarchy. The option not enabled
by default as this changes the structure of the output which could
break the expectations of other tools.

api/publish.go

@@ -101,6 +101,7 @@ func apiPublishRepoOrSnapshot(c *gin.Context) {
 		Architectures        []string
 		Signing              SigningOptions
 		AcquireByHash        *bool
+		MultiDist            bool
 	}
 
 	if c.Bind(&b) != nil {
@@ -226,7 +227,7 @@ func apiPublishRepoOrSnapshot(c *gin.Context) {
 			return &task.ProcessReturnValue{Code: http.StatusBadRequest, Value: nil}, fmt.Errorf("prefix/distribution already used by another published repo: %s", duplicate)
 		}
 
-		err := published.Publish(context.PackagePool(), context, collectionFactory, signer, publishOutput, b.ForceOverwrite)
+		err := published.Publish(context.PackagePool(), context, collectionFactory, signer, publishOutput, b.ForceOverwrite, b.MultiDist)
 		if err != nil {
 			return &task.ProcessReturnValue{Code: http.StatusInternalServerError, Value: nil}, fmt.Errorf("unable to publish: %s", err)
 		}
@@ -257,6 +258,7 @@ func apiPublishUpdateSwitch(c *gin.Context) {
 			Name      string `binding:"required"`
 		}
 		AcquireByHash *bool
+		MultiDist     bool
 	}
 
 	if c.Bind(&b) != nil {
@@ -341,7 +343,7 @@ func apiPublishUpdateSwitch(c *gin.Context) {
 	resources = append(resources, string(published.Key()))
 	taskName := fmt.Sprintf("Update published %s (%s): %s", published.SourceKind, strings.Join(updatedComponents, " "), strings.Join(updatedSnapshots, ", "))
 	maybeRunTaskInBackground(c, taskName, resources, func(out aptly.Progress, _ *task.Detail) (*task.ProcessReturnValue, error) {
-		err := published.Publish(context.PackagePool(), context, collectionFactory, signer, out, b.ForceOverwrite)
+		err := published.Publish(context.PackagePool(), context, collectionFactory, signer, out, b.ForceOverwrite, b.MultiDist)
 		if err != nil {
 			return &task.ProcessReturnValue{Code: http.StatusInternalServerError, Value: nil}, fmt.Errorf("unable to update: %s", err)
 		}