From 795a97466527a5f02e79e47b7fb316c78ffde667 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Fri, 20 Dec 2019 22:13:07 +0000 Subject: chore(kontemplate): Prepare kontemplate for depot-merge This merge will not yet include moving over to buildGo.nix, as support for testing and such is not present in that library yet. --- ops/kontemplate/templater/templater.go | 236 +++++++++++++++++++++++++++++++++ 1 file changed, 236 insertions(+) create mode 100644 ops/kontemplate/templater/templater.go (limited to 'ops/kontemplate/templater/templater.go') diff --git a/ops/kontemplate/templater/templater.go b/ops/kontemplate/templater/templater.go new file mode 100644 index 000000000000..a8f0c670a603 --- /dev/null +++ b/ops/kontemplate/templater/templater.go @@ -0,0 +1,236 @@ +// Copyright (C) 2016-2019 Vincent Ambo +// +// This file is part of Kontemplate. +// +// Kontemplate is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. + +package templater + +import ( + "bytes" + "encoding/json" + "fmt" + "io/ioutil" + "os" + "os/exec" + "path" + "strings" + "text/template" + + "github.com/Masterminds/sprig" + "github.com/tazjin/kontemplate/context" + "github.com/tazjin/kontemplate/util" +) + +const failOnMissingKeys string = "missingkey=error" + +type RenderedResource struct { + Filename string + Rendered string +} + +type RenderedResourceSet struct { + Name string + Resources []RenderedResource + Args []string +} + +func LoadAndApplyTemplates(include *[]string, exclude *[]string, c *context.Context) ([]RenderedResourceSet, error) { + limitedResourceSets := applyLimits(&c.ResourceSets, include, exclude) + renderedResourceSets := make([]RenderedResourceSet, 0) + + if len(*limitedResourceSets) == 0 { + return renderedResourceSets, fmt.Errorf("No valid resource sets included!") + } + + for _, rs := range *limitedResourceSets { + set, err := processResourceSet(c, &rs) + + if err != nil { + return nil, err + } + + renderedResourceSets = append(renderedResourceSets, *set) + } + + return renderedResourceSets, nil +} + +func processResourceSet(ctx *context.Context, rs *context.ResourceSet) (*RenderedResourceSet, error) { + fmt.Fprintf(os.Stderr, "Loading resources for %s\n", rs.Name) + + fileInfo, err := os.Stat(rs.Path) + if err != nil { + return nil, err + } + + var files []os.FileInfo + var resources []RenderedResource + + // Treat single-file resource paths separately from resource + // sets containing multiple templates + if fileInfo.IsDir() { + // Explicitly discard this error, which will give us an empty + // list of files instead. + // This will end up printing a warning to the user, but it + // won't stop the rest of the process. + files, _ = ioutil.ReadDir(rs.Path) + resources, err = processFiles(ctx, rs, files) + if err != nil { + return nil, err + } + } else { + resource, err := templateFile(ctx, rs, rs.Path) + if err != nil { + return nil, err + } + + resources = []RenderedResource{resource} + } + + return &RenderedResourceSet{ + Name: rs.Name, + Resources: resources, + Args: rs.Args, + }, nil +} + +func processFiles(ctx *context.Context, rs *context.ResourceSet, files []os.FileInfo) ([]RenderedResource, error) { + resources := make([]RenderedResource, 0) + + for _, file := range files { + if !file.IsDir() && isResourceFile(file) { + path := path.Join(rs.Path, file.Name()) + res, err := templateFile(ctx, rs, path) + + if err != nil { + return resources, err + } + + resources = append(resources, res) + } + } + + return resources, nil +} + +func templateFile(ctx *context.Context, rs *context.ResourceSet, filepath string) (RenderedResource, error) { + var resource RenderedResource + + tpl, err := template.New(path.Base(filepath)).Funcs(templateFuncs(ctx, rs)).Option(failOnMissingKeys).ParseFiles(filepath) + if err != nil { + return resource, fmt.Errorf("Could not load template %s: %v", filepath, err) + } + + var b bytes.Buffer + err = tpl.Execute(&b, rs.Values) + if err != nil { + return resource, fmt.Errorf("Error while templating %s: %v", filepath, err) + } + + resource = RenderedResource{ + Filename: path.Base(filepath), + Rendered: b.String(), + } + + return resource, nil +} + +// Applies the limits of explicitly included or excluded resources and returns the updated resource set. +// Exclude takes priority over include +func applyLimits(rs *[]context.ResourceSet, include *[]string, exclude *[]string) *[]context.ResourceSet { + if len(*include) == 0 && len(*exclude) == 0 { + return rs + } + + // Exclude excluded resource sets + excluded := make([]context.ResourceSet, 0) + for _, r := range *rs { + if !matchesResourceSet(exclude, &r) { + excluded = append(excluded, r) + } + } + + // Include included resource sets + if len(*include) == 0 { + return &excluded + } + included := make([]context.ResourceSet, 0) + for _, r := range excluded { + if matchesResourceSet(include, &r) { + included = append(included, r) + } + } + + return &included +} + +// Check whether an include/exclude string slice matches a resource set +func matchesResourceSet(s *[]string, rs *context.ResourceSet) bool { + for _, r := range *s { + r = strings.TrimSuffix(r, "/") + if r == rs.Name || r == rs.Parent { + return true + } + } + + return false +} + +func templateFuncs(c *context.Context, rs *context.ResourceSet) template.FuncMap { + m := sprig.TxtFuncMap() + m["json"] = func(data interface{}) string { + b, _ := json.Marshal(data) + return string(b) + } + m["passLookup"] = GetFromPass + m["gitHEAD"] = func() (string, error) { + out, err := exec.Command("git", "-C", c.BaseDir, "rev-parse", "HEAD").Output() + if err != nil { + return "", err + } + output := strings.TrimSpace(string(out)) + return output, nil + } + m["lookupIPAddr"] = GetIPsFromDNS + m["insertFile"] = func(file string) (string, error) { + data, err := ioutil.ReadFile(path.Join(rs.Path, file)) + if err != nil { + return "", err + } + + return string(data), nil + } + m["insertTemplate"] = func(file string) (string, error) { + data, err := templateFile(c, rs, path.Join(rs.Path, file)) + if err != nil { + return "", err + } + + return data.Rendered, nil + } + m["default"] = func(defaultVal interface{}, varName string) interface{} { + if val, ok := rs.Values[varName]; ok { + return val + } + + return defaultVal + } + return m +} + +// Checks whether a file is a resource file (i.e. is YAML or JSON) and not a default values file. +func isResourceFile(f os.FileInfo) bool { + for _, defaultFile := range util.DefaultFilenames { + if f.Name() == defaultFile { + return false + } + } + + return strings.HasSuffix(f.Name(), "yaml") || + strings.HasSuffix(f.Name(), "yml") || + strings.HasSuffix(f.Name(), "json") +} -- cgit 1.4.1