Add PULUMI_BACKEND_URL env var (#5789)

The PULUMI_BACKEND_URL env var allows specifying the backend to use instead of deferring to the project or the ~/.pulumi/credentials.json file to decide on the "current" backend.  This allows for using Pulumi without a dependence on this piece of global filesystem state, so that each `pulumi` invocation can control the exact backend it want's to operate on, without having to do stateful `pulumi login`/`pulumi logout` operations.

This is especially useful for automation scenarios like Automation API generally (and effectively solves https://github.com/pulumi/pulumi/issues/5591), or https://github.com/pulumi/pulumi-kubernetes-operator/issues/83 specifically.

This also makes things like efe7a599e6/dist/actions/entrypoint.sh (L10) less necessary, and possible to accomplish for any containerized `pulumi` execution without the need for this logic to be embedded in bash scripts wrapping the CLI.

CHANGELOG.md

@@ -3,9 +3,12 @@ CHANGELOG
 
 ## HEAD (Unreleased)
 
-- Respect PULUMI_PYTHON_CMD in scripts.
+- Respect `PULUMI_PYTHON_CMD` in scripts.
   [#5782](https://github.com/pulumi/pulumi/pull/5782)
 
+- Add `PULUMI_BACKEND_URL` environment variable to configure the state backend.
+  [#5789](https://github.com/pulumi/pulumi/pull/5789)
+
 ## 2.14.0 (2020-11-18)
 
 - Propagate secretness of provider configuration through to the statefile. This ensures

sdk/go/common/testing/environment.go

@@ -44,6 +44,8 @@ type Environment struct {
 	RootPath string
 	// Current working directory.
 	CWD string
+	// Backend to use for commands
+	Backend string
 }
 
 // WriteYarnRCForTest writes a .yarnrc file which sets global configuration for every yarn inovcation. We use this
@@ -88,6 +90,11 @@ func NewEnvironment(t *testing.T) *Environment {
 	}
 }
 
+// SetBackend sets the backend to use for commands in this environment.
+func (e *Environment) SetBackend(backend string) {
+	e.Backend = backend
+}
+
 // ImportDirectory copies a folder into the test environment.
 func (e *Environment) ImportDirectory(path string) {
 	err := fsutil.CopyFile(e.RootPath, path, nil)
@@ -167,6 +174,9 @@ func (e *Environment) GetCommandResults(t *testing.T, command string, args ...st
 	cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%s", pulumiCredentialsPathEnvVar, e.RootPath))
 	cmd.Env = append(cmd.Env, "PULUMI_DEBUG_COMMANDS=true")
 	cmd.Env = append(cmd.Env, "PULUMI_CONFIG_PASSPHRASE=correct horse battery staple")
+	if e.Backend != "" {
+		cmd.Env = append(cmd.Env, fmt.Sprintf("PULUMI_BACKEND_URL=%s", e.Backend))
+	}
 
 	runErr := cmd.Run()
 	return outBuffer.String(), errBuffer.String(), runErr

sdk/go/common/workspace/creds.go

@@ -31,6 +31,10 @@ import (
 // credentials or tests interacting with one another
 const PulumiCredentialsPathEnvVar = "PULUMI_CREDENTIALS_PATH"
 
+// PulumiBackendURLEnvVar is an environment variable which can be used to set the backend that will be
+// used instead of the currently logged in backend or the current projects backend.
+const PulumiBackendURLEnvVar = "PULUMI_BACKEND_URL"
+
 // GetAccount returns an account underneath a given key.
 //
 // Note that the account may not be fully populated: it may only have a valid AccessToken. In that case, it is up to
@@ -129,6 +133,12 @@ func getCredsFilePath() (string, error) {
 // have not logged in.
 func GetCurrentCloudURL() (string, error) {
 	var url string
+
+	// Allow PULUMI_BACKEND_URL to override the current cloud URL selection
+	if backend := os.Getenv(PulumiBackendURLEnvVar); backend != "" {
+		url = backend
+	}
+
 	// Try detecting backend from config
 	projPath, err := DetectProjectPath()
 	if err == nil && projPath != "" {

tests/stack_test.go

@@ -50,7 +50,7 @@ func TestStackCommands(t *testing.T) {
 		}()
 
 		integration.CreateBasicPulumiRepo(e)
-		e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+		e.SetBackend(e.LocalURL())
 		e.RunCommand("pulumi", "stack", "init", "foo")
 
 		stacks, current := integration.GetStacks(e)
@@ -79,7 +79,7 @@ func TestStackCommands(t *testing.T) {
 		}()
 
 		integration.CreateBasicPulumiRepo(e)
-		e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+		e.SetBackend(e.LocalURL())
 		e.RunCommand("pulumi", "stack", "init", "blighttown")
 		e.RunCommand("pulumi", "stack", "init", "majula")
 		e.RunCommand("pulumi", "stack", "init", "lothric")
@@ -118,7 +118,7 @@ func TestStackCommands(t *testing.T) {
 
 		integration.CreateBasicPulumiRepo(e)
 
-		e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+		e.SetBackend(e.LocalURL())
 		e.RunCommand("pulumi", "stack", "init", "blighttown")
 		e.RunCommand("pulumi", "stack", "init", "majula")
 		e.RunCommand("pulumi", "stack", "init", "lothric")
@@ -166,7 +166,7 @@ func TestStackCommands(t *testing.T) {
 				}()
 
 				integration.CreateBasicPulumiRepo(e)
-				e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+				e.SetBackend(e.LocalURL())
 				e.RunCommand("pulumi", "stack", "init", "the-abyss")
 				stacks, _ := integration.GetStacks(e)
 				assert.Equal(t, 1, len(stacks))
@@ -214,7 +214,7 @@ func TestStackCommands(t *testing.T) {
 		stackName := addRandomSuffix("invalid-resources")
 		integration.CreateBasicPulumiRepo(e)
 		e.ImportDirectory("integration/stack_dependencies")
-		e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+		e.SetBackend(e.LocalURL())
 		e.RunCommand("pulumi", "stack", "init", stackName)
 		e.RunCommand("yarn", "install")
 		e.RunCommand("yarn", "link", "@pulumi/pulumi")
@@ -298,7 +298,7 @@ func TestStackBackups(t *testing.T) {
 			}
 		}()
 
-		e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+		e.SetBackend(e.LocalURL())
 		e.RunCommand("pulumi", "stack", "init", stackName)
 
 		// Build the project.
@@ -356,7 +356,7 @@ func TestStackRenameAfterCreate(t *testing.T) {
 	}()
 	stackName := addRandomSuffix("stack-rename")
 	integration.CreateBasicPulumiRepo(e)
-	e.RunCommand("pulumi", "login", "--cloud-url", e.LocalURL())
+	e.SetBackend(e.LocalURL())
 	e.RunCommand("pulumi", "stack", "init", stackName)
 
 	newName := addRandomSuffix("renamed-stack")