// ExpandChart passes the given configuration to the expander and returns the
// expanded configuration as a string on success.
func (e *expander) ExpandChart(request *expansion.ServiceRequest) (*expansion.ServiceResponse, error) {
if err := expansion.ValidateRequest(request); err != nil {
return nil, err
}
request, err := expansion.ValidateProperties(request)
if err != nil {
return nil, err
}
chartInv := request.ChartInvocation
chartFile := request.Chart.Chartfile
chartMembers := request.Chart.Members
if e.ExpansionBinary == "" {
message := fmt.Sprintf("expansion binary cannot be empty")
return nil, fmt.Errorf("%s: %s", chartInv.Name, message)
}
entrypointIndex := -1
for i, f := range chartMembers {
if f.Path == chartFile.Expander.Entrypoint {
entrypointIndex = i
}
}
if entrypointIndex == -1 {
message := fmt.Sprintf("The entrypoint in the chart.yaml cannot be found: %s", chartFile.Expander.Entrypoint)
return nil, fmt.Errorf("%s: %s", chartInv.Name, message)
}
// Those are automatically increasing buffers, so writing arbitrary large
// data here won't block the child process.
var stdout bytes.Buffer
var stderr bytes.Buffer
// Now we convert the new chart representation into the form that classic ExpandyBird takes.
chartInvJSON, err := json.Marshal(chartInv)
if err != nil {
return nil, fmt.Errorf("error marshalling chart invocation %s: %s", chartInv.Name, err)
}
content := "{ \"resources\": [" + string(chartInvJSON) + "] }"
cmd := &exec.Cmd{
Path: e.ExpansionBinary,
// Note, that binary name still has to be passed argv[0].
Args: []string{e.ExpansionBinary, content},
Stdout: &stdout,
Stderr: &stderr,
}
for i, f := range chartMembers {
name := f.Path
path := f.Path
if i == entrypointIndex {
// This is how expandyBird identifies the entrypoint.
name = chartInv.Type
}
cmd.Args = append(cmd.Args, name, path, string(f.Content))
}
if err := cmd.Start(); err != nil {
log.Printf("error starting expansion process: %s", err)
return nil, err
}
cmd.Wait()
log.Printf("Expansion process: pid: %d SysTime: %v UserTime: %v", cmd.ProcessState.Pid(),
cmd.ProcessState.SystemTime(), cmd.ProcessState.UserTime())
if stderr.String() != "" {
return nil, fmt.Errorf("%s: %s", chartInv.Name, stderr.String())
}
output := &expandyBirdOutput{}
if err := yaml.Unmarshal(stdout.Bytes(), output); err != nil {
return nil, fmt.Errorf("cannot unmarshal expansion result (%s):\n%s", err, output)
}
return &expansion.ServiceResponse{Resources: output.Config.Resources}, nil
}
// ExpandChart resolves the given files to a sequence of JSON-marshalable values.
func (e *expander) ExpandChart(request *expansion.ServiceRequest) (*expansion.ServiceResponse, error) {
err := expansion.ValidateRequest(request)
if err != nil {
return nil, err
}
request, err = expansion.ValidateProperties(request)
if err != nil {
return nil, err
}
chartInv := request.ChartInvocation
chartMembers := request.Chart.Members
resources := []interface{}{}
for _, file := range chartMembers {
name := file.Path
content := file.Content
tmpl := template.New(name).Funcs(sprig.HermeticTxtFuncMap())
for _, otherFile := range chartMembers {
otherName := otherFile.Path
otherContent := otherFile.Content
if name == otherName {
continue
}
_, err := tmpl.Parse(string(otherContent))
if err != nil {
return nil, err
}
}
// Have to put something in that resolves non-empty or Go templates get confused.
_, err := tmpl.Parse("# Content begins now")
if err != nil {
return nil, err
}
tmpl, err = tmpl.Parse(string(content))
if err != nil {
return nil, err
}
generated := bytes.NewBuffer(nil)
if err := tmpl.ExecuteTemplate(generated, name, chartInv.Properties); err != nil {
return nil, err
}
stream, err := parseYAMLStream(generated)
if err != nil {
return nil, fmt.Errorf("%s\nContent:\n%s", err.Error(), generated)
}
for _, doc := range stream {
resources = append(resources, doc)
}
}
return &expansion.ServiceResponse{Resources: resources}, nil
}