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tailscale/cmd/gitops-pusher/gitops-pusher.go

224 lines
4.8 KiB
Go

// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Command gitops-pusher allows users to use a GitOps flow for managing Tailscale ACLs.
//
// See README.md for more details.
package main
import (
"context"
"crypto/sha256"
"encoding/json"
"flag"
"fmt"
"io"
"log"
"net/http"
"os"
"strings"
"time"
)
var (
policyFname = flag.String("policy-file", "./policy.hujson", "filename for policy file")
timeout = flag.Duration("timeout", 5*time.Minute, "timeout for the entire CI run")
)
func main() {
flag.Parse()
ctx, cancel := context.WithTimeout(context.Background(), *timeout)
defer cancel()
tailnet, ok := os.LookupEnv("TS_TAILNET")
if !ok {
log.Fatal("set envvar TS_TAILNET to your tailnet's name")
}
apiKey, ok := os.LookupEnv("TS_API_KEY")
if !ok {
log.Fatal("set envvar TS_API_KEY to your Tailscale API key")
}
switch flag.Arg(0) {
case "apply":
controlEtag, err := getACLETag(ctx, tailnet, apiKey)
if err != nil {
log.Fatal(err)
}
localEtag, err := sumFile(*policyFname)
if err != nil {
log.Fatal(err)
}
log.Printf("control: %s", controlEtag)
log.Printf("local: %s", localEtag)
if controlEtag == localEtag {
log.Println("no update needed, doing nothing")
os.Exit(0)
}
if err := applyNewACL(ctx, tailnet, apiKey, *policyFname, controlEtag); err != nil {
log.Fatal(err)
}
case "test":
controlEtag, err := getACLETag(ctx, tailnet, apiKey)
if err != nil {
log.Fatal(err)
}
localEtag, err := sumFile(*policyFname)
if err != nil {
log.Fatal(err)
}
log.Printf("control: %s", controlEtag)
log.Printf("local: %s", localEtag)
if controlEtag == localEtag {
log.Println("no updates found, doing nothing")
os.Exit(0)
}
if err := testNewACLs(ctx, tailnet, apiKey, *policyFname); err != nil {
log.Fatal(err)
}
default:
log.Fatalf("usage: %s [options] <test|apply>", os.Args[0])
}
}
func sumFile(fname string) (string, error) {
fin, err := os.Open(fname)
if err != nil {
return "", err
}
defer fin.Close()
h := sha256.New()
_, err = io.Copy(h, fin)
if err != nil {
return "", err
}
return fmt.Sprintf("\"%x\"", h.Sum(nil)), nil
}
func applyNewACL(ctx context.Context, tailnet, apiKey, policyFname, oldEtag string) error {
fin, err := os.Open(policyFname)
if err != nil {
return err
}
defer fin.Close()
req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl", tailnet), fin)
if err != nil {
return err
}
req.SetBasicAuth(apiKey, "")
req.Header.Set("Content-Type", "application/hujson")
req.Header.Set("If-Match", oldEtag)
resp, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
got := resp.StatusCode
want := http.StatusOK
if got != want {
return fmt.Errorf("wanted HTTP status code %d but got %d", want, got)
}
return nil
}
func testNewACLs(ctx context.Context, tailnet, apiKey, policyFname string) error {
fin, err := os.Open(policyFname)
if err != nil {
return err
}
defer fin.Close()
req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl/validate", tailnet), fin)
if err != nil {
return err
}
req.SetBasicAuth(apiKey, "")
req.Header.Set("Content-Type", "application/hujson")
resp, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
var ate ACLTestError
err := json.NewDecoder(resp.Body).Decode(&ate)
if err != nil {
return err
}
return ate
}
return nil
}
type ACLTestError struct {
Message string `json:"message"`
Data []ACLTestErrorDetail `json:"data"`
}
func (ate ACLTestError) Error() string {
var sb strings.Builder
fmt.Fprintln(&sb, ate.Message)
fmt.Fprintln(&sb)
for _, data := range ate.Data {
fmt.Fprintf(&sb, "For user %s:\n", data.User)
for _, err := range data.Errors {
fmt.Fprintf(&sb, "- %s\n", err)
}
}
return sb.String()
}
type ACLTestErrorDetail struct {
User string `json:"user"`
Errors []string `json:"errors"`
}
func getACLETag(ctx context.Context, tailnet, apiKey string) (string, error) {
req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl", tailnet), nil)
if err != nil {
return "", err
}
req.SetBasicAuth(apiKey, "")
req.Header.Set("Accept", "application/hujson")
resp, err := http.DefaultClient.Do(req)
if err != nil {
return "", err
}
defer resp.Body.Close()
got := resp.StatusCode
want := http.StatusOK
if got != want {
return "", fmt.Errorf("wanted HTTP status code %d but got %d", want, got)
}
return resp.Header.Get("ETag"), nil
}