helmfile/pkg/app/two_pass_renderer.go

100 lines
3.7 KiB
Go

package app
import (
"bytes"
"fmt"
"github.com/imdario/mergo"
"github.com/roboll/helmfile/environment"
"github.com/roboll/helmfile/state"
"github.com/roboll/helmfile/tmpl"
"strings"
)
func prependLineNumbers(text string) string {
buf := bytes.NewBufferString("")
lines := strings.Split(text, "\n")
for i, line := range lines {
buf.WriteString(fmt.Sprintf("%2d: %s\n", i, line))
}
return buf.String()
}
func (r *desiredStateLoader) renderEnvironment(firstPassEnv environment.Environment, baseDir, filename string, content []byte) environment.Environment {
tmplData := state.EnvironmentTemplateData{Environment: firstPassEnv, Namespace: r.namespace}
firstPassRenderer := tmpl.NewFirstPassRenderer(baseDir, tmplData)
// parse as much as we can, tolerate errors, this is a preparse
yamlBuf, err := firstPassRenderer.RenderTemplateContentToBuffer(content)
if err != nil && r.logger != nil {
r.logger.Debugf("first-pass rendering input of \"%s\":\n%s", filename, prependLineNumbers(string(content)))
if yamlBuf == nil { // we have a template syntax error, let the second parse report
r.logger.Debugf("template syntax error: %v", err)
return firstPassEnv
}
}
c := state.NewCreator(r.logger, r.readFile, r.abs)
c.Strict = false
// create preliminary state, as we may have an environment. Tolerate errors.
prestate, err := c.ParseAndLoadEnv(yamlBuf.Bytes(), baseDir, filename, r.env)
if err != nil && r.logger != nil {
switch err.(type) {
case *state.StateLoadError:
r.logger.Infof("could not deduce `environment:` block, configuring only .Environment.Name. error: %v", err)
}
r.logger.Debugf("error in first-pass rendering: result of \"%s\":\n%s", filename, prependLineNumbers(yamlBuf.String()))
}
if prestate != nil {
intEnv := environment.Environment{Name: firstPassEnv.Name}
if err := mergo.Merge(&intEnv, &firstPassEnv, mergo.WithAppendSlice); err != nil {
r.logger.Debugf("error in first-pass rendering: result of \"%s\": %v", filename, err)
return firstPassEnv
}
if err := mergo.Merge(&intEnv, &prestate.Env, mergo.WithAppendSlice); err != nil {
r.logger.Debugf("error in first-pass rendering: result of \"%s\": %v", filename, err)
return firstPassEnv
}
firstPassEnv = intEnv
}
return firstPassEnv
}
func (r *desiredStateLoader) renderTemplatesToYaml(baseDir, filename string, content []byte, context ...environment.Environment) (*bytes.Buffer, error) {
var env environment.Environment
if len(context) > 0 {
env = context[0]
} else {
env = environment.Environment{Name: r.env, Values: map[string]interface{}(nil)}
}
return r.twoPassRenderTemplateToYaml(env, baseDir, filename, content)
}
func (r *desiredStateLoader) twoPassRenderTemplateToYaml(initEnv environment.Environment, baseDir, filename string, content []byte) (*bytes.Buffer, error) {
// try a first pass render. This will always succeed, but can produce a limited env
if r.logger != nil {
r.logger.Debugf("first-pass rendering input of \"%s\": %v", filename, initEnv)
}
firstPassEnv := r.renderEnvironment(initEnv, baseDir, filename, content)
if r.logger != nil {
r.logger.Debugf("first-pass rendering result of \"%s\": %v", filename, firstPassEnv)
}
tmplData := state.EnvironmentTemplateData{Environment: firstPassEnv, Namespace: r.namespace}
secondPassRenderer := tmpl.NewFileRenderer(r.readFile, baseDir, tmplData)
yamlBuf, err := secondPassRenderer.RenderTemplateContentToBuffer(content)
if err != nil {
if r.logger != nil {
r.logger.Debugf("second-pass rendering failed, input of \"%s\":\n%s", filename, prependLineNumbers(string(content)))
}
return nil, err
}
if r.logger != nil {
r.logger.Debugf("second-pass rendering result of \"%s\":\n%s", filename, prependLineNumbers(yamlBuf.String()))
}
return yamlBuf, nil
}