Hello world 👋

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/provider/azure/cli.go

@@ -0,0 +1,123 @@
+package azure
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
+)
+
+// cliCredential gets tokens from the az CLI for one signed-in account.
+//
+// az can hold several accounts, but `az account get-access-token` can't be
+// told which user to use: it picks the account a subscription belongs to.
+// So each account is pinned with --subscription. az refuses --subscription
+// together with --tenant, which the SDK's AzureCLICredential would pass for
+// every Key Vault request (the vault's auth challenge names a tenant), so
+// this sends --tenant only for vaults in another tenant.
+//
+// Tokens are cached in memory until shortly before they expire, so the
+// many SDK clients don't each start an az process.
+type cliCredential struct {
+	subscription string // pins the account; "" for az's default account
+	tenant       string // the account's tenant, if known
+	run          func(ctx context.Context, args ...string) ([]byte, error)
+
+	mu    sync.Mutex
+	cache map[string]azcore.AccessToken // by resource and tenant argument
+}
+
+func newCLICredential(subscription, tenant string) *cliCredential {
+	return &cliCredential{subscription: subscription, tenant: tenant, run: runAz, cache: map[string]azcore.AccessToken{}}
+}
+
+// refreshMargin renews tokens this long before they expire.
+const refreshMargin = 5 * time.Minute
+
+func (c *cliCredential) GetToken(ctx context.Context, opts policy.TokenRequestOptions) (azcore.AccessToken, error) {
+	if len(opts.Scopes) != 1 {
+		return azcore.AccessToken{}, errors.New("az: exactly one scope is supported")
+	}
+	if opts.Claims != "" {
+		return azcore.AccessToken{}, errors.New("az: this request needs multifactor authentication; run az login again")
+	}
+	resource := strings.TrimSuffix(opts.Scopes[0], "/.default")
+	args := []string{"account", "get-access-token", "--output", "json", "--resource", resource}
+	switch {
+	case opts.TenantID != "" && opts.TenantID != c.tenant:
+		// Another tenant: az picks the account itself.
+		args = append(args, "--tenant", opts.TenantID)
+	case c.subscription != "":
+		args = append(args, "--subscription", c.subscription)
+	}
+	key := strings.Join(args[5:], " ")
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if tok, ok := c.cache[key]; ok && time.Until(tok.ExpiresOn) > refreshMargin {
+		return tok, nil
+	}
+	out, err := c.run(ctx, args...)
+	if err != nil {
+		return azcore.AccessToken{}, err
+	}
+	tok, err := parseCLIToken(out)
+	if err != nil {
+		return azcore.AccessToken{}, err
+	}
+	c.cache[key] = tok
+	return tok, nil
+}
+
+func parseCLIToken(b []byte) (azcore.AccessToken, error) {
+	var t struct {
+		AccessToken string `json:"accessToken"`
+		ExpiresOn   int64  `json:"expires_on"` // az 2.54+
+		ExpiresOnS  string `json:"expiresOn"`  // older az: local time
+	}
+	if err := json.Unmarshal(b, &t); err != nil {
+		return azcore.AccessToken{}, fmt.Errorf("az: unexpected output: %w", err)
+	}
+	if t.AccessToken == "" {
+		return azcore.AccessToken{}, errors.New("az: no access token in output")
+	}
+	exp := time.Unix(t.ExpiresOn, 0)
+	if t.ExpiresOn == 0 {
+		var err error
+		exp, err = time.ParseInLocation("2006-01-02 15:04:05.999999", t.ExpiresOnS, time.Local)
+		if err != nil {
+			return azcore.AccessToken{}, fmt.Errorf("az: unexpected expiry %q", t.ExpiresOnS)
+		}
+	}
+	return azcore.AccessToken{Token: t.AccessToken, ExpiresOn: exp}, nil
+}
+
+// azTimeout bounds one az call; a hung az would otherwise block a pane.
+const azTimeout = 30 * time.Second
+
+func runAz(ctx context.Context, args ...string) ([]byte, error) {
+	ctx, cancel := context.WithTimeout(ctx, azTimeout)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "az", args...)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	out, err := cmd.Output()
+	if errors.Is(err, exec.ErrNotFound) {
+		return nil, errors.New("az CLI not found; install it or set AZURE_* for a service principal")
+	}
+	if err != nil {
+		if msg := strings.TrimSpace(stderr.String()); msg != "" {
+			return nil, errors.New(msg)
+		}
+		return nil, err
+	}
+	return out, nil
+}