terraform/command/plugins.go

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package command
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"runtime"
"strings"
plugin "github.com/hashicorp/go-plugin"
"github.com/kardianos/osext"
"github.com/hashicorp/terraform/addrs"
terraformProvider "github.com/hashicorp/terraform/builtin/providers/terraform"
tfplugin "github.com/hashicorp/terraform/plugin"
"github.com/hashicorp/terraform/plugin/discovery"
"github.com/hashicorp/terraform/providers"
"github.com/hashicorp/terraform/provisioners"
"github.com/hashicorp/terraform/terraform"
)
// multiVersionProviderResolver is an implementation of
// terraform.ResourceProviderResolver that matches the given version constraints
// against a set of versioned provider plugins to find the newest version of
// each that satisfies the given constraints.
type multiVersionProviderResolver struct {
Available discovery.PluginMetaSet
// Internal is a map that overrides the usual plugin selection process
// for internal plugins. These plugins do not support version constraints
// (will produce an error if one is set). This should be used only in
// exceptional circumstances since it forces the provider's release
// schedule to be tied to that of Terraform Core.
Internal map[addrs.Provider]providers.Factory
}
func chooseProviders(avail discovery.PluginMetaSet, internal map[addrs.Provider]providers.Factory, reqd discovery.PluginRequirements) map[string]discovery.PluginMeta {
candidates := avail.ConstrainVersions(reqd)
ret := map[string]discovery.PluginMeta{}
for name, metas := range candidates {
// If the provider is in our internal map then we ignore any
// discovered plugins for it since these are dealt with separately.
if _, isInternal := internal[addrs.NewLegacyProvider(name)]; isInternal {
continue
}
if len(metas) == 0 {
continue
}
ret[name] = metas.Newest()
}
return ret
}
func (r *multiVersionProviderResolver) ResolveProviders(
reqd discovery.PluginRequirements,
) (map[addrs.Provider]providers.Factory, []error) {
factories := make(map[addrs.Provider]providers.Factory, len(reqd))
var errs []error
chosen := chooseProviders(r.Available, r.Internal, reqd)
for name, req := range reqd {
if factory, isInternal := r.Internal[addrs.NewLegacyProvider(name)]; isInternal {
if !req.Versions.Unconstrained() {
errs = append(errs, fmt.Errorf("provider.%s: this provider is built in to Terraform and so it does not support version constraints", name))
continue
}
factories[addrs.NewLegacyProvider(name)] = factory
continue
}
if newest, available := chosen[name]; available {
digest, err := newest.SHA256()
if err != nil {
errs = append(errs, fmt.Errorf("provider.%s: failed to load plugin to verify its signature: %s", name, err))
continue
}
if !reqd[name].AcceptsSHA256(digest) {
errs = append(errs, fmt.Errorf("provider.%s: new or changed plugin executable", name))
continue
}
factories[addrs.NewLegacyProvider(name)] = providerFactory(newest)
} else {
msg := fmt.Sprintf("provider.%s: no suitable version installed", name)
required := req.Versions.String()
// no version is unconstrained
if required == "" {
required = "(any version)"
}
foundVersions := []string{}
for meta := range r.Available.WithName(name) {
foundVersions = append(foundVersions, fmt.Sprintf("%q", meta.Version))
}
found := "none"
if len(foundVersions) > 0 {
found = strings.Join(foundVersions, ", ")
}
msg += fmt.Sprintf("\n version requirements: %q\n versions installed: %s", required, found)
errs = append(errs, errors.New(msg))
}
}
return factories, errs
}
// store the user-supplied path for plugin discovery
func (m *Meta) storePluginPath(pluginPath []string) error {
if len(pluginPath) == 0 {
return nil
}
path := filepath.Join(m.DataDir(), PluginPathFile)
// remove the plugin dir record if the path was set to an empty string
if len(pluginPath) == 1 && (pluginPath[0] == "") {
err := os.Remove(path)
if !os.IsNotExist(err) {
return err
}
return nil
}
js, err := json.MarshalIndent(pluginPath, "", " ")
if err != nil {
return err
}
// if this fails, so will WriteFile
os.MkdirAll(m.DataDir(), 0755)
return ioutil.WriteFile(path, js, 0644)
}
// Load the user-defined plugin search path into Meta.pluginPath if the file
// exists.
func (m *Meta) loadPluginPath() ([]string, error) {
js, err := ioutil.ReadFile(filepath.Join(m.DataDir(), PluginPathFile))
if os.IsNotExist(err) {
return nil, nil
}
if err != nil {
return nil, err
}
var pluginPath []string
if err := json.Unmarshal(js, &pluginPath); err != nil {
return nil, err
}
return pluginPath, nil
}
// the default location for automatically installed plugins
func (m *Meta) pluginDir() string {
return filepath.Join(m.DataDir(), "plugins", fmt.Sprintf("%s_%s", runtime.GOOS, runtime.GOARCH))
}
// pluginDirs return a list of directories to search for plugins.
//
// Earlier entries in this slice get priority over later when multiple copies
// of the same plugin version are found, but newer versions always override
// older versions where both satisfy the provider version constraints.
func (m *Meta) pluginDirs(includeAutoInstalled bool) []string {
// user defined paths take precedence
if len(m.pluginPath) > 0 {
return m.pluginPath
}
// When searching the following directories, earlier entries get precedence
// if the same plugin version is found twice, but newer versions will
// always get preference below regardless of where they are coming from.
// TODO: Add auto-install dir, default vendor dir and optional override
// vendor dir(s).
dirs := []string{"."}
// Look in the same directory as the Terraform executable.
// If found, this replaces what we found in the config path.
exePath, err := osext.Executable()
if err != nil {
log.Printf("[ERROR] Error discovering exe directory: %s", err)
} else {
dirs = append(dirs, filepath.Dir(exePath))
}
// add the user vendor directory
dirs = append(dirs, DefaultPluginVendorDir)
if includeAutoInstalled {
dirs = append(dirs, m.pluginDir())
}
dirs = append(dirs, m.GlobalPluginDirs...)
return dirs
}
func (m *Meta) pluginCache() discovery.PluginCache {
dir := m.PluginCacheDir
if dir == "" {
return nil // cache disabled
}
dir = filepath.Join(dir, pluginMachineName)
return discovery.NewLocalPluginCache(dir)
}
// providerPluginSet returns the set of valid providers that were discovered in
// the defined search paths.
func (m *Meta) providerPluginSet() discovery.PluginMetaSet {
plugins := discovery.FindPlugins("provider", m.pluginDirs(true))
// Add providers defined in the legacy .terraformrc,
if m.PluginOverrides != nil {
for k, v := range m.PluginOverrides.Providers {
log.Printf("[DEBUG] found plugin override in .terraformrc: %q, %q", k, v)
}
plugins = plugins.OverridePaths(m.PluginOverrides.Providers)
}
plugins, _ = plugins.ValidateVersions()
for p := range plugins {
log.Printf("[DEBUG] found valid plugin: %q, %q, %q", p.Name, p.Version, p.Path)
}
return plugins
}
// providerPluginAutoInstalledSet returns the set of providers that exist
// within the auto-install directory.
func (m *Meta) providerPluginAutoInstalledSet() discovery.PluginMetaSet {
plugins := discovery.FindPlugins("provider", []string{m.pluginDir()})
plugins, _ = plugins.ValidateVersions()
for p := range plugins {
log.Printf("[DEBUG] found valid plugin: %q", p.Name)
}
return plugins
}
// providerPluginManuallyInstalledSet returns the set of providers that exist
// in all locations *except* the auto-install directory.
func (m *Meta) providerPluginManuallyInstalledSet() discovery.PluginMetaSet {
plugins := discovery.FindPlugins("provider", m.pluginDirs(false))
// Add providers defined in the legacy .terraformrc,
if m.PluginOverrides != nil {
for k, v := range m.PluginOverrides.Providers {
log.Printf("[DEBUG] found plugin override in .terraformrc: %q, %q", k, v)
}
plugins = plugins.OverridePaths(m.PluginOverrides.Providers)
}
plugins, _ = plugins.ValidateVersions()
for p := range plugins {
log.Printf("[DEBUG] found valid plugin: %q, %q, %q", p.Name, p.Version, p.Path)
}
return plugins
}
func (m *Meta) providerResolver() providers.Resolver {
return &multiVersionProviderResolver{
Available: m.providerPluginSet(),
Internal: m.internalProviders(),
}
}
func (m *Meta) internalProviders() map[addrs.Provider]providers.Factory {
return map[addrs.Provider]providers.Factory{
addrs.NewLegacyProvider("terraform"): func() (providers.Interface, error) {
return terraformProvider.NewProvider(), nil
},
}
}
// filter the requirements returning only the providers that we can't resolve
func (m *Meta) missingProviders(avail discovery.PluginMetaSet, reqd discovery.PluginRequirements) discovery.PluginRequirements {
missing := make(discovery.PluginRequirements)
candidates := avail.ConstrainVersions(reqd)
internal := m.internalProviders()
for name, versionSet := range reqd {
// internal providers can't be missing
if _, ok := internal[addrs.NewLegacyProvider(name)]; ok {
continue
}
log.Printf("[DEBUG] plugin requirements: %q=%q", name, versionSet.Versions)
if metas := candidates[name]; metas.Count() == 0 {
missing[name] = versionSet
}
}
return missing
}
func (m *Meta) provisionerFactories() map[string]terraform.ProvisionerFactory {
dirs := m.pluginDirs(true)
plugins := discovery.FindPlugins("provisioner", dirs)
plugins, _ = plugins.ValidateVersions()
// For now our goal is to just find the latest version of each plugin
// we have on the system. All provisioners should be at version 0.0.0
// currently, so there should actually only be one instance of each plugin
// name here, even though the discovery interface forces us to pretend
// that might not be true.
factories := make(map[string]terraform.ProvisionerFactory)
// Wire up the internal provisioners first. These might be overridden
// by discovered provisioners below.
for name := range InternalProvisioners {
factories[name] = internalProvisionerFactory(discovery.PluginMeta{Name: name})
}
byName := plugins.ByName()
for name, metas := range byName {
// Since we validated versions above and we partitioned the sets
// by name, we're guaranteed that the metas in our set all have
// valid versions and that there's at least one meta.
newest := metas.Newest()
factories[name] = provisionerFactory(newest)
}
return factories
}
func internalPluginClient(kind, name string) (*plugin.Client, error) {
cmdLine, err := BuildPluginCommandString(kind, name)
if err != nil {
return nil, err
}
// See the docstring for BuildPluginCommandString for why we need to do
// this split here.
cmdArgv := strings.Split(cmdLine, TFSPACE)
cfg := &plugin.ClientConfig{
Cmd: exec.Command(cmdArgv[0], cmdArgv[1:]...),
HandshakeConfig: tfplugin.Handshake,
Managed: true,
VersionedPlugins: tfplugin.VersionedPlugins,
AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
}
return plugin.NewClient(cfg), nil
}
func providerFactory(meta discovery.PluginMeta) providers.Factory {
return func() (providers.Interface, error) {
client := tfplugin.Client(meta)
// Request the RPC client so we can get the provider
// so we can build the actual RPC-implemented provider.
rpcClient, err := client.Client()
if err != nil {
return nil, err
}
raw, err := rpcClient.Dispense(tfplugin.ProviderPluginName)
if err != nil {
return nil, err
}
// store the client so that the plugin can kill the child process
p := raw.(*tfplugin.GRPCProvider)
p.PluginClient = client
return p, nil
}
}
func provisionerFactory(meta discovery.PluginMeta) terraform.ProvisionerFactory {
return func() (provisioners.Interface, error) {
client := tfplugin.Client(meta)
return newProvisionerClient(client)
}
}
func internalProvisionerFactory(meta discovery.PluginMeta) terraform.ProvisionerFactory {
return func() (provisioners.Interface, error) {
client, err := internalPluginClient("provisioner", meta.Name)
if err != nil {
return nil, fmt.Errorf("[WARN] failed to build command line for internal plugin %q: %s", meta.Name, err)
}
return newProvisionerClient(client)
}
}
func newProvisionerClient(client *plugin.Client) (provisioners.Interface, error) {
// Request the RPC client so we can get the provisioner
// so we can build the actual RPC-implemented provisioner.
rpcClient, err := client.Client()
if err != nil {
return nil, err
}
raw, err := rpcClient.Dispense(tfplugin.ProvisionerPluginName)
if err != nil {
return nil, err
}
// store the client so that the plugin can kill the child process
p := raw.(*tfplugin.GRPCProvisioner)
p.PluginClient = client
return p, nil
}