feat(clients): parses and uses additional HTTP headers

The additional http headers set via `MONACO_ADDITIONAL_HTTP_HEADERS` are parsed and used in all places where a client factory is used to create REST clients. Additionally, it is parsed once in the runner in order to log the keys of the additional HTTP headers right at the start of Monaco.

Author: d0weinberger

cmd/monaco/account/delete.go

@@ -27,6 +27,7 @@ import (
 	"github.com/dynatrace/dynatrace-configuration-as-code-core/clients"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/cmdutils"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/completion"
+	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/environment"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/errutils"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/files"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/log"
@@ -160,10 +161,12 @@ func createAccountDeleteClient(ctx context.Context, a manifest.Account) (delete.
 		apiUrl = a.ApiUrl.Value
 	}
 
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
 	c, err := clients.Factory().
 		WithAccountURL(apiUrl).
 		WithOAuthCredentials(oauthCreds).
 		WithUserAgent(client.DefaultMonacoUserAgent).
+		WithCustomHeaders(additionalHeaders).
 		AccountClient(ctx)
 	if err != nil {
 		return delete.Account{}, err

cmd/monaco/dynatrace/dynatrace.go

@@ -75,11 +75,13 @@ func isValidEnvironment(ctx context.Context, env manifest.EnvironmentDefinition)
 // canEstablishClassicConnection checks if a classic connection (via token) can be established. Scopes are not validated.
 func canEstablishClassicConnection(ctx context.Context, env manifest.EnvironmentDefinition) bool {
 	token := env.Auth.Token.Value.Value()
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
 	client, err := clients.Factory().
 		WithClassicURL(env.URL.Value).
 		WithAccessToken(token).
 		WithRateLimiter(true).
 		WithRetryOptions(&client.DefaultRetryOptions).
+		WithCustomHeaders(additionalHeaders).
 		CreateClassicClient()
 	if err != nil {
 		report.GetReporterFromContextOrDiscard(ctx).ReportLoading(report.StateError, fmt.Errorf("could not create client %q (%s): %w", env.Name, env.URL.Value, err), "", nil)
@@ -124,6 +126,7 @@ func handleAuthError(ctx context.Context, env manifest.EnvironmentDefinition, er
 // CreateAccountClients gives back clients to use for specific accounts
 func CreateAccountClients(ctx context.Context, manifestAccounts map[string]manifest.Account) (map[account.AccountInfo]*accounts.Client, error) {
 	concurrentRequestLimit := environment.GetEnvValueIntLog(environment.ConcurrentRequestsEnvKey)
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
 	accClients := make(map[account.AccountInfo]*accounts.Client, len(manifestAccounts))
 	for _, acc := range manifestAccounts {
 		oauthCreds := clientcredentials.Config{
@@ -138,7 +141,8 @@ func CreateAccountClients(ctx context.Context, manifestAccounts map[string]manif
 			WithUserAgent(client.DefaultMonacoUserAgent).
 			WithRateLimiter(true).
 			WithRetryOptions(&client.DefaultRetryOptions).
-			WithAccountURL(accountApiUrlOrDefault(acc.ApiUrl))
+			WithAccountURL(accountApiUrlOrDefault(acc.ApiUrl)).
+			WithCustomHeaders(additionalHeaders)
 
 		if supportarchive.IsEnabled(ctx) {
 			factory = factory.WithHTTPListener(&corerest.HTTPListener{Callback: trafficlogs.GetInstance().LogToFiles})
@@ -218,7 +222,13 @@ func getDynatraceClassicURL(ctx context.Context, platformURL string, oauthCreds
 		}
 	}
 
-	client, err := clients.Factory().WithPlatformURL(platformURL).WithOAuthCredentials(oauthCreds).CreatePlatformClient(ctx)
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
+	client, err := clients.Factory().
+		WithPlatformURL(platformURL).
+		WithOAuthCredentials(oauthCreds).
+		WithCustomHeaders(additionalHeaders).
+		CreatePlatformClient(ctx)
+
 	if err != nil {
 		return "", err
 	}
@@ -231,9 +241,10 @@ func findSimpleClassicURL(ctx context.Context, platformURL string) (classicUrl s
 		return "", false
 	}
 
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
 	classicUrl = strings.Replace(platformURL, ".apps.", ".live.", 1)
 
-	client, err := clients.Factory().WithClassicURL(classicUrl).CreateClassicClient()
+	client, err := clients.Factory().WithClassicURL(classicUrl).WithCustomHeaders(additionalHeaders).CreateClassicClient()
 	if err != nil {
 		return "", false
 	}

cmd/monaco/runner/runner.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
+	"golang.org/x/exp/maps"
 
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/account"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/delete"
@@ -29,6 +30,7 @@ import (
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/purge"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/supportarchive"
 	versionCommand "github.com/dynatrace/dynatrace-configuration-as-code/v2/cmd/monaco/version"
+	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/environment"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/featureflags"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/log"
 	"github.com/dynatrace/dynatrace-configuration-as-code/v2/internal/log/field"
@@ -96,6 +98,11 @@ Examples:
 			}
 
 			memory.SetDefaultLimit()
+
+			additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
+			if len(additionalHeaders) > 0 {
+				log.Info("Additional custom HTTP headers: %q, from '%s' environment variable", maps.Keys(additionalHeaders), environment.AdditionalHttpHeaders)
+			}
 		},
 		Run: func(cmd *cobra.Command, args []string) {
 			_ = cmd.Help()

pkg/client/clientset.go

@@ -264,16 +264,18 @@ func CreateClientSetWithOptions(ctx context.Context, url string, auth manifest.A
 		serviceLevelObjectiveClient ServiceLevelObjectiveClient
 		err                         error
 	)
-	concurrentReqLimit := environment.GetEnvValueIntLog(environment.ConcurrentRequestsEnvKey)
 	if err = validateURL(url); err != nil {
 		return nil, err
 	}
 
+	concurrentReqLimit := environment.GetEnvValueIntLog(environment.ConcurrentRequestsEnvKey)
+	additionalHeaders := environment.GetAdditionalHttpHeadersFromEnv()
 	cFactory := clients.Factory().
 		WithConcurrentRequestLimit(concurrentReqLimit).
 		WithUserAgent(opts.getUserAgentString()).
 		WithRetryOptions(&DefaultRetryOptions).
-		WithRateLimiter(true)
+		WithRateLimiter(true).
+		WithCustomHeaders(additionalHeaders)
 
 	if supportarchive.IsEnabled(ctx) {
 		cFactory = cFactory.WithHTTPListener(&rest.HTTPListener{Callback: trafficlogs.GetInstance().LogToFiles})