opentofu/main.go
Martin Atkins 7bee77bdd3 command: Start of propagating OpenTelemetry context
Several times over the years we've considered adding tracing
instrumentation to Terraform, since even when running in isolation as a
CLI program it has a "distributed system-like" structure, with lots of
concurrent internal work and also some work delegated to provider plugins
that are essentially temporarily-running microservices.

However, it's always felt a bit overwhelming to do it because much of
Terraform predates the Go context.Context idiom and so it's tough to get
a clean chain of context.Context values all the way down the stack without
disturbing a lot of existing APIs.

This commit aims to just get that process started by establishing how a
context can propagate from "package main" into the command package,
focusing initially on "terraform init" and some other commands that share
some underlying functions with that command.

OpenTelemetry has emerged as a de-facto industry standard and so this uses
its API directly, without any attempt to hide it behind an abstraction.
The OpenTelemetry API is itself already an adapter layer, so we should be
able to swap in any backend that uses comparable concepts. For now we just
discard the tracing reports by default, and allow users to opt in to
delivering traces over OTLP by setting an environment variable when
running Terraform (the environment variable was established in an earlier
commit, so this commit builds on that.)

When tracing collection is enabled, every Terraform CLI run will generate
at least one overall span representing the command that was run. Some
commands might also create child spans, but most currently do not.
2023-07-14 10:24:10 -07:00

497 lines
16 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"net"
"os"
"path/filepath"
"runtime"
"strings"
"github.com/apparentlymart/go-shquot/shquot"
"github.com/hashicorp/go-plugin"
"github.com/hashicorp/terraform-svchost/disco"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/command/cliconfig"
"github.com/hashicorp/terraform/internal/command/format"
"github.com/hashicorp/terraform/internal/didyoumean"
"github.com/hashicorp/terraform/internal/httpclient"
"github.com/hashicorp/terraform/internal/logging"
"github.com/hashicorp/terraform/internal/terminal"
"github.com/hashicorp/terraform/version"
"github.com/mattn/go-shellwords"
"github.com/mitchellh/cli"
"github.com/mitchellh/colorstring"
"go.opentelemetry.io/otel/trace"
backendInit "github.com/hashicorp/terraform/internal/backend/init"
)
const (
// EnvCLI is the environment variable name to set additional CLI args.
EnvCLI = "TF_CLI_ARGS"
// The parent process will create a file to collect crash logs
envTmpLogPath = "TF_TEMP_LOG_PATH"
)
// ui wraps the primary output cli.Ui, and redirects Warn calls to Output
// calls. This ensures that warnings are sent to stdout, and are properly
// serialized within the stdout stream.
type ui struct {
cli.Ui
}
func (u *ui) Warn(msg string) {
u.Ui.Output(msg)
}
func init() {
Ui = &ui{&cli.BasicUi{
Writer: os.Stdout,
ErrorWriter: os.Stderr,
Reader: os.Stdin,
}}
}
func main() {
os.Exit(realMain())
}
func realMain() int {
defer logging.PanicHandler()
var err error
err = openTelemetryInit()
if err != nil {
// openTelemetryInit can only fail if Terraform was run with an
// explicit environment variable to enable telemetry collection,
// so in typical use we cannot get here.
Ui.Error(fmt.Sprintf("Could not initialize telemetry: %s", err))
Ui.Error(fmt.Sprintf("Unset environment variable %s if you don't intend to collect telemetry from Terraform.", openTelemetryExporterEnvVar))
return 1
}
var ctx context.Context
var otelSpan trace.Span
{
// At minimum we emit a span covering the entire command execution.
_, displayArgs := shquot.POSIXShellSplit(os.Args)
ctx, otelSpan = tracer.Start(context.Background(), fmt.Sprintf("terraform %s", displayArgs))
defer otelSpan.End()
}
tmpLogPath := os.Getenv(envTmpLogPath)
if tmpLogPath != "" {
f, err := os.OpenFile(tmpLogPath, os.O_RDWR|os.O_APPEND, 0666)
if err == nil {
defer f.Close()
log.Printf("[DEBUG] Adding temp file log sink: %s", f.Name())
logging.RegisterSink(f)
} else {
log.Printf("[ERROR] Could not open temp log file: %v", err)
}
}
log.Printf(
"[INFO] Terraform version: %s %s",
Version, VersionPrerelease)
for _, depMod := range version.InterestingDependencies() {
log.Printf("[DEBUG] using %s %s", depMod.Path, depMod.Version)
}
log.Printf("[INFO] Go runtime version: %s", runtime.Version())
log.Printf("[INFO] CLI args: %#v", os.Args)
if ExperimentsAllowed() {
log.Printf("[INFO] This build of Terraform allows using experimental features")
}
streams, err := terminal.Init()
if err != nil {
Ui.Error(fmt.Sprintf("Failed to configure the terminal: %s", err))
return 1
}
if streams.Stdout.IsTerminal() {
log.Printf("[TRACE] Stdout is a terminal of width %d", streams.Stdout.Columns())
} else {
log.Printf("[TRACE] Stdout is not a terminal")
}
if streams.Stderr.IsTerminal() {
log.Printf("[TRACE] Stderr is a terminal of width %d", streams.Stderr.Columns())
} else {
log.Printf("[TRACE] Stderr is not a terminal")
}
if streams.Stdin.IsTerminal() {
log.Printf("[TRACE] Stdin is a terminal")
} else {
log.Printf("[TRACE] Stdin is not a terminal")
}
// NOTE: We're intentionally calling LoadConfig _before_ handling a possible
// -chdir=... option on the command line, so that a possible relative
// path in the TERRAFORM_CONFIG_FILE environment variable (though probably
// ill-advised) will be resolved relative to the true working directory,
// not the overridden one.
config, diags := cliconfig.LoadConfig()
if len(diags) > 0 {
// Since we haven't instantiated a command.Meta yet, we need to do
// some things manually here and use some "safe" defaults for things
// that command.Meta could otherwise figure out in smarter ways.
Ui.Error("There are some problems with the CLI configuration:")
for _, diag := range diags {
earlyColor := &colorstring.Colorize{
Colors: colorstring.DefaultColors,
Disable: true, // Disable color to be conservative until we know better
Reset: true,
}
// We don't currently have access to the source code cache for
// the parser used to load the CLI config, so we can't show
// source code snippets in early diagnostics.
Ui.Error(format.Diagnostic(diag, nil, earlyColor, 78))
}
if diags.HasErrors() {
Ui.Error("As a result of the above problems, Terraform may not behave as intended.\n\n")
// We continue to run anyway, since Terraform has reasonable defaults.
}
}
// Get any configured credentials from the config and initialize
// a service discovery object. The slightly awkward predeclaration of
// disco is required to allow us to pass untyped nil as the creds source
// when creating the source fails. Otherwise we pass a typed nil which
// breaks the nil checks in the disco object
var services *disco.Disco
credsSrc, err := credentialsSource(config)
if err == nil {
services = disco.NewWithCredentialsSource(credsSrc)
} else {
// Most commands don't actually need credentials, and most situations
// that would get us here would already have been reported by the config
// loading above, so we'll just log this one as an aid to debugging
// in the unlikely event that it _does_ arise.
log.Printf("[WARN] Cannot initialize remote host credentials manager: %s", err)
// passing (untyped) nil as the creds source is okay because the disco
// object checks that and just acts as though no credentials are present.
services = disco.NewWithCredentialsSource(nil)
}
services.SetUserAgent(httpclient.TerraformUserAgent(version.String()))
providerSrc, diags := providerSource(config.ProviderInstallation, services)
if len(diags) > 0 {
Ui.Error("There are some problems with the provider_installation configuration:")
for _, diag := range diags {
earlyColor := &colorstring.Colorize{
Colors: colorstring.DefaultColors,
Disable: true, // Disable color to be conservative until we know better
Reset: true,
}
Ui.Error(format.Diagnostic(diag, nil, earlyColor, 78))
}
if diags.HasErrors() {
Ui.Error("As a result of the above problems, Terraform's provider installer may not behave as intended.\n\n")
// We continue to run anyway, because most commands don't do provider installation.
}
}
providerDevOverrides := providerDevOverrides(config.ProviderInstallation)
// The user can declare that certain providers are being managed on
// Terraform's behalf using this environment variable. This is used
// primarily by the SDK's acceptance testing framework.
unmanagedProviders, err := parseReattachProviders(os.Getenv("TF_REATTACH_PROVIDERS"))
if err != nil {
Ui.Error(err.Error())
return 1
}
// Initialize the backends.
backendInit.Init(services)
// Get the command line args.
binName := filepath.Base(os.Args[0])
args := os.Args[1:]
originalWd, err := os.Getwd()
if err != nil {
// It would be very strange to end up here
Ui.Error(fmt.Sprintf("Failed to determine current working directory: %s", err))
return 1
}
// The arguments can begin with a -chdir option to ask Terraform to switch
// to a different working directory for the rest of its work. If that
// option is present then extractChdirOption returns a trimmed args with that option removed.
overrideWd, args, err := extractChdirOption(args)
if err != nil {
Ui.Error(fmt.Sprintf("Invalid -chdir option: %s", err))
return 1
}
if overrideWd != "" {
err := os.Chdir(overrideWd)
if err != nil {
Ui.Error(fmt.Sprintf("Error handling -chdir option: %s", err))
return 1
}
}
// In tests, Commands may already be set to provide mock commands
if Commands == nil {
// Commands get to hold on to the original working directory here,
// in case they need to refer back to it for any special reason, though
// they should primarily be working with the override working directory
// that we've now switched to above.
initCommands(ctx, originalWd, streams, config, services, providerSrc, providerDevOverrides, unmanagedProviders)
}
// Run checkpoint
go runCheckpoint(ctx, config)
// Make sure we clean up any managed plugins at the end of this
defer plugin.CleanupClients()
// Build the CLI so far, we do this so we can query the subcommand.
cliRunner := &cli.CLI{
Args: args,
Commands: Commands,
HelpFunc: helpFunc,
HelpWriter: os.Stdout,
}
// Prefix the args with any args from the EnvCLI
args, err = mergeEnvArgs(EnvCLI, cliRunner.Subcommand(), args)
if err != nil {
Ui.Error(err.Error())
return 1
}
// Prefix the args with any args from the EnvCLI targeting this command
suffix := strings.Replace(strings.Replace(
cliRunner.Subcommand(), "-", "_", -1), " ", "_", -1)
args, err = mergeEnvArgs(
fmt.Sprintf("%s_%s", EnvCLI, suffix), cliRunner.Subcommand(), args)
if err != nil {
Ui.Error(err.Error())
return 1
}
// We shortcut "--version" and "-v" to just show the version
for _, arg := range args {
if arg == "-v" || arg == "-version" || arg == "--version" {
newArgs := make([]string, len(args)+1)
newArgs[0] = "version"
copy(newArgs[1:], args)
args = newArgs
break
}
}
// Rebuild the CLI with any modified args.
log.Printf("[INFO] CLI command args: %#v", args)
cliRunner = &cli.CLI{
Name: binName,
Args: args,
Commands: Commands,
HelpFunc: helpFunc,
HelpWriter: os.Stdout,
Autocomplete: true,
AutocompleteInstall: "install-autocomplete",
AutocompleteUninstall: "uninstall-autocomplete",
}
// Before we continue we'll check whether the requested command is
// actually known. If not, we might be able to suggest an alternative
// if it seems like the user made a typo.
// (This bypasses the built-in help handling in cli.CLI for the situation
// where a command isn't found, because it's likely more helpful to
// mention what specifically went wrong, rather than just printing out
// a big block of usage information.)
// Check if this is being run via shell auto-complete, which uses the
// binary name as the first argument and won't be listed as a subcommand.
autoComplete := os.Getenv("COMP_LINE") != ""
if cmd := cliRunner.Subcommand(); cmd != "" && !autoComplete {
// Due to the design of cli.CLI, this special error message only works
// for typos of top-level commands. For a subcommand typo, like
// "terraform state posh", cmd would be "state" here and thus would
// be considered to exist, and it would print out its own usage message.
if _, exists := Commands[cmd]; !exists {
suggestions := make([]string, 0, len(Commands))
for name := range Commands {
suggestions = append(suggestions, name)
}
suggestion := didyoumean.NameSuggestion(cmd, suggestions)
if suggestion != "" {
suggestion = fmt.Sprintf(" Did you mean %q?", suggestion)
}
fmt.Fprintf(os.Stderr, "Terraform has no command named %q.%s\n\nTo see all of Terraform's top-level commands, run:\n terraform -help\n\n", cmd, suggestion)
return 1
}
}
exitCode, err := cliRunner.Run()
if err != nil {
Ui.Error(fmt.Sprintf("Error executing CLI: %s", err.Error()))
return 1
}
// if we are exiting with a non-zero code, check if it was caused by any
// plugins crashing
if exitCode != 0 {
for _, panicLog := range logging.PluginPanics() {
Ui.Error(panicLog)
}
}
return exitCode
}
func mergeEnvArgs(envName string, cmd string, args []string) ([]string, error) {
v := os.Getenv(envName)
if v == "" {
return args, nil
}
log.Printf("[INFO] %s value: %q", envName, v)
extra, err := shellwords.Parse(v)
if err != nil {
return nil, fmt.Errorf(
"Error parsing extra CLI args from %s: %s",
envName, err)
}
// Find the command to look for in the args. If there is a space,
// we need to find the last part.
search := cmd
if idx := strings.LastIndex(search, " "); idx >= 0 {
search = cmd[idx+1:]
}
// Find the index to place the flags. We put them exactly
// after the first non-flag arg.
idx := -1
for i, v := range args {
if v == search {
idx = i
break
}
}
// idx points to the exact arg that isn't a flag. We increment
// by one so that all the copying below expects idx to be the
// insertion point.
idx++
// Copy the args
newArgs := make([]string, len(args)+len(extra))
copy(newArgs, args[:idx])
copy(newArgs[idx:], extra)
copy(newArgs[len(extra)+idx:], args[idx:])
return newArgs, nil
}
// parse information on reattaching to unmanaged providers out of a
// JSON-encoded environment variable.
func parseReattachProviders(in string) (map[addrs.Provider]*plugin.ReattachConfig, error) {
unmanagedProviders := map[addrs.Provider]*plugin.ReattachConfig{}
if in != "" {
type reattachConfig struct {
Protocol string
ProtocolVersion int
Addr struct {
Network string
String string
}
Pid int
Test bool
}
var m map[string]reattachConfig
err := json.Unmarshal([]byte(in), &m)
if err != nil {
return unmanagedProviders, fmt.Errorf("Invalid format for TF_REATTACH_PROVIDERS: %w", err)
}
for p, c := range m {
a, diags := addrs.ParseProviderSourceString(p)
if diags.HasErrors() {
return unmanagedProviders, fmt.Errorf("Error parsing %q as a provider address: %w", a, diags.Err())
}
var addr net.Addr
switch c.Addr.Network {
case "unix":
addr, err = net.ResolveUnixAddr("unix", c.Addr.String)
if err != nil {
return unmanagedProviders, fmt.Errorf("Invalid unix socket path %q for %q: %w", c.Addr.String, p, err)
}
case "tcp":
addr, err = net.ResolveTCPAddr("tcp", c.Addr.String)
if err != nil {
return unmanagedProviders, fmt.Errorf("Invalid TCP address %q for %q: %w", c.Addr.String, p, err)
}
default:
return unmanagedProviders, fmt.Errorf("Unknown address type %q for %q", c.Addr.Network, p)
}
unmanagedProviders[a] = &plugin.ReattachConfig{
Protocol: plugin.Protocol(c.Protocol),
ProtocolVersion: c.ProtocolVersion,
Pid: c.Pid,
Test: c.Test,
Addr: addr,
}
}
}
return unmanagedProviders, nil
}
func extractChdirOption(args []string) (string, []string, error) {
if len(args) == 0 {
return "", args, nil
}
const argName = "-chdir"
const argPrefix = argName + "="
var argValue string
var argPos int
for i, arg := range args {
if !strings.HasPrefix(arg, "-") {
// Because the chdir option is a subcommand-agnostic one, we require
// it to appear before any subcommand argument, so if we find a
// non-option before we find -chdir then we are finished.
break
}
if arg == argName || arg == argPrefix {
return "", args, fmt.Errorf("must include an equals sign followed by a directory path, like -chdir=example")
}
if strings.HasPrefix(arg, argPrefix) {
argPos = i
argValue = arg[len(argPrefix):]
}
}
// When we fall out here, we'll have populated argValue with a non-empty
// string if the -chdir=... option was present and valid, or left it
// empty if it wasn't present.
if argValue == "" {
return "", args, nil
}
// If we did find the option then we'll need to produce a new args that
// doesn't include it anymore.
if argPos == 0 {
// Easy case: we can just slice off the front
return argValue, args[1:], nil
}
// Otherwise we need to construct a new array and copy to it.
newArgs := make([]string, len(args)-1)
copy(newArgs, args[:argPos])
copy(newArgs[argPos:], args[argPos+1:])
return argValue, newArgs, nil
}