terraform/command/plugins.go

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package command
import (
"fmt"
"log"
"os/exec"
"path/filepath"
"runtime"
"strings"
plugin "github.com/hashicorp/go-plugin"
tfplugin "github.com/hashicorp/terraform/plugin"
"github.com/hashicorp/terraform/plugin/discovery"
"github.com/hashicorp/terraform/terraform"
"github.com/kardianos/osext"
)
// 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
}
func choosePlugins(avail discovery.PluginMetaSet, reqd discovery.PluginRequirements) map[string]discovery.PluginMeta {
candidates := avail.ConstrainVersions(reqd)
ret := map[string]discovery.PluginMeta{}
for name, metas := range candidates {
if len(metas) == 0 {
continue
}
ret[name] = metas.Newest()
}
return ret
}
func (r *multiVersionProviderResolver) ResolveProviders(
reqd discovery.PluginRequirements,
) (map[string]terraform.ResourceProviderFactory, []error) {
factories := make(map[string]terraform.ResourceProviderFactory, len(reqd))
var errs []error
chosen := choosePlugins(r.Available, reqd)
for name := range reqd {
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) {
// This generic error message is intended to avoid troubling
// users with implementation details. The main useful point
// here is that they need to run "terraform init" to
// fix this, which is covered by the UI code reporting these
// error messages.
errs = append(errs, fmt.Errorf("provider.%s: installed but not yet initialized", name))
continue
}
client := tfplugin.Client(newest)
factories[name] = providerFactory(client)
} else {
errs = append(errs, fmt.Errorf("provider.%s: no suitable version installed", name))
}
}
return factories, errs
}
// 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 {
// 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))
}
if includeAutoInstalled {
dirs = append(dirs, m.pluginDir())
}
dirs = append(dirs, m.GlobalPluginDirs...)
return dirs
}
// 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))
plugins, _ = plugins.ValidateVersions()
for p := range plugins {
log.Printf("[DEBUG] found valid plugin: %q", p.Name)
}
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))
plugins, _ = plugins.ValidateVersions()
for p := range plugins {
log.Printf("[DEBUG] found valid plugin: %q", p.Name)
}
return plugins
}
func (m *Meta) providerResolver() terraform.ResourceProviderResolver {
return &multiVersionProviderResolver{
Available: m.providerPluginSet(),
}
}
// filter the requirements returning only the providers that we can't resolve
func (m *Meta) missingPlugins(avail discovery.PluginMetaSet, reqd discovery.PluginRequirements) discovery.PluginRequirements {
missing := make(discovery.PluginRequirements)
for n, r := range reqd {
log.Printf("[DEBUG] plugin requirements: %q=%q", n, r.Versions)
}
candidates := avail.ConstrainVersions(reqd)
for name, versionSet := range reqd {
if metas := candidates[name]; metas.Count() == 0 {
missing[name] = versionSet
}
}
return missing
}
func (m *Meta) provisionerFactories() map[string]terraform.ResourceProvisionerFactory {
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.ResourceProvisionerFactory)
// Wire up the internal provisioners first. These might be overridden
// by discovered provisioners below.
for name := range InternalProvisioners {
client, err := internalPluginClient("provisioner", name)
if err != nil {
log.Printf("[WARN] failed to build command line for internal plugin %q: %s", name, err)
continue
}
factories[name] = provisionerFactory(client)
}
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()
client := tfplugin.Client(newest)
factories[name] = provisionerFactory(client)
}
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,
Plugins: tfplugin.PluginMap,
}
return plugin.NewClient(cfg), nil
}
func providerFactory(client *plugin.Client) terraform.ResourceProviderFactory {
return func() (terraform.ResourceProvider, error) {
// 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
}
return raw.(terraform.ResourceProvider), nil
}
}
func provisionerFactory(client *plugin.Client) terraform.ResourceProvisionerFactory {
return func() (terraform.ResourceProvisioner, 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
}
return raw.(terraform.ResourceProvisioner), nil
}
}