package main import ( "fmt" "os" "os/exec" "github.com/polydawn/meep" "github.com/tazjin/kontemplate/context" "github.com/tazjin/kontemplate/templater" "gopkg.in/alecthomas/kingpin.v2" ) const version string = "1.2.0" // This variable will be initialised by the Go linker during the builder var gitHash string type KubeCtlError struct { meep.AllTraits } var ( app = kingpin.New("kontemplate", "simple Kubernetes resource templating") // Global flags includes = app.Flag("include", "Resource sets to include explicitly").Short('i').Strings() excludes = app.Flag("exclude", "Resource sets to exclude explicitly").Short('e').Strings() // Commands template = app.Command("template", "Template resource sets and print them") templateFile = template.Arg("file", "Cluster configuration file to use").Required().String() apply = app.Command("apply", "Template resources and pass to 'kubectl apply'") applyFile = apply.Arg("file", "Cluster configuration file to use").Required().String() applyDryRun = apply.Flag("dry-run", "Print remote operations without executing them").Default("false").Bool() replace = app.Command("replace", "Template resources and pass to 'kubectl replace'") replaceFile = replace.Arg("file", "Cluster configuration file to use").Required().String() delete = app.Command("delete", "Template resources and pass to 'kubectl delete'") deleteFile = delete.Arg("file", "Cluster configuration file to use").Required().String() create = app.Command("create", "Template resources and pass to 'kubectl create'") createFile = create.Arg("file", "Cluster configuration file to use").Required().String() versionCmd = app.Command("version", "Show kontemplate version") ) func main() { app.HelpFlag.Short('h') switch kingpin.MustParse(app.Parse(os.Args[1:])) { case template.FullCommand(): templateCommand() case apply.FullCommand(): applyCommand() case replace.FullCommand(): replaceCommand() case delete.FullCommand(): deleteCommand() case create.FullCommand(): createCommand() case versionCmd.FullCommand(): versionCommand() } } func versionCommand() { if gitHash == "" { fmt.Printf("Kontemplate version %s (git commit unknown)\n", version) } else { fmt.Printf("Kontemplate version %s (git commit: %s)\n", version, gitHash) } } func templateCommand() { _, resourceSets := loadContextAndResources(templateFile) for _, rs := range *resourceSets { if len(rs.Resources) == 0 { fmt.Fprintf(os.Stderr, "Warning: Resource set '%s' does not exist or contains no valid templates\n", rs.Name) continue } for _, r := range rs.Resources { fmt.Fprintf(os.Stderr, "Rendered file %s/%s:\n", rs.Name, r.Filename) fmt.Println(r.Rendered) } } } func applyCommand() { ctx, resources := loadContextAndResources(applyFile) var kubectlArgs []string if *applyDryRun { kubectlArgs = []string{"apply", "-f", "-", "--dry-run"} } else { kubectlArgs = []string{"apply", "-f", "-"} } if err := runKubectlWithResources(ctx, &kubectlArgs, resources); err != nil { failWithKubectlError(err) } } func replaceCommand() { ctx, resources := loadContextAndResources(replaceFile) args := []string{"replace", "--save-config=true", "-f", "-"} if err := runKubectlWithResources(ctx, &args, resources); err != nil { failWithKubectlError(err) } } func deleteCommand() { ctx, resources := loadContextAndResources(deleteFile) args := []string{"delete", "-f", "-"} if err := runKubectlWithResources(ctx, &args, resources); err != nil { failWithKubectlError(err) } } func createCommand() { ctx, resources := loadContextAndResources(createFile) args := []string{"create", "--save-config=true", "-f", "-"} if err := runKubectlWithResources(ctx, &args, resources); err != nil { failWithKubectlError(err) } } func loadContextAndResources(file *string) (*context.Context, *[]templater.RenderedResourceSet) { ctx, err := context.LoadContextFromFile(*file) if err != nil { app.Fatalf("Error loading context: %v\n", err) } resources, err := templater.LoadAndApplyTemplates(includes, excludes, ctx) if err != nil { app.Fatalf("Error templating resource sets: %v\n", err) } return ctx, &resources } func runKubectlWithResources(c *context.Context, kubectlArgs *[]string, resourceSets *[]templater.RenderedResourceSet) error { args := append(*kubectlArgs, fmt.Sprintf("--context=%s", c.Name)) for _, rs := range *resourceSets { if len(rs.Resources) == 0 { fmt.Fprintf(os.Stderr, "Warning: Resource set '%s' contains no valid templates\n", rs.Name) continue } kubectl := exec.Command("kubectl", args...) stdin, err := kubectl.StdinPipe() if err != nil { return meep.New(&KubeCtlError{}, meep.Cause(err)) } kubectl.Stdout = os.Stdout kubectl.Stderr = os.Stderr if err = kubectl.Start(); err != nil { return meep.New(&KubeCtlError{}, meep.Cause(err)) } for _, r := range rs.Resources { fmt.Printf("Passing file %s/%s to kubectl\n", rs.Name, r.Filename) fmt.Fprintln(stdin, r.Rendered) } stdin.Close() if err = kubectl.Wait(); err != nil { return err } } return nil } func failWithKubectlError(err error) { fmt.Fprintf(os.Stderr, "Kubectl error: %v\n", err) os.Exit(1) }