Merge pull request #4826 from TimeIncOSS/f-aws-lambda-permission

[WIP] provider/aws: Add aws_lambda_permission

builtin/providers/aws/provider.go

@@ -174,6 +174,7 @@ func Provider() terraform.ResourceProvider {
 			"aws_lambda_function":                  resourceAwsLambdaFunction(),
 			"aws_lambda_event_source_mapping":      resourceAwsLambdaEventSourceMapping(),
 			"aws_lambda_alias":                     resourceAwsLambdaAlias(),
+			"aws_lambda_permission":                resourceAwsLambdaPermission(),
 			"aws_launch_configuration":             resourceAwsLaunchConfiguration(),
 			"aws_lb_cookie_stickiness_policy":      resourceAwsLBCookieStickinessPolicy(),
 			"aws_main_route_table_association":     resourceAwsMainRouteTableAssociation(),

builtin/providers/aws/resource_aws_lambda_permission.go

@@ -0,0 +1,343 @@
+package aws
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/service/lambda"
+	"github.com/hashicorp/terraform/helper/resource"
+	"github.com/hashicorp/terraform/helper/schema"
+)
+
+var LambdaFunctionRegexp = `^(arn:aws:lambda:)?([a-z]{2}-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?$`
+
+func resourceAwsLambdaPermission() *schema.Resource {
+	return &schema.Resource{
+		Create: resourceAwsLambdaPermissionCreate,
+		Read:   resourceAwsLambdaPermissionRead,
+		Delete: resourceAwsLambdaPermissionDelete,
+
+		Schema: map[string]*schema.Schema{
+			"action": &schema.Schema{
+				Type:         schema.TypeString,
+				Required:     true,
+				ForceNew:     true,
+				ValidateFunc: validateLambdaPermissionAction,
+			},
+			"function_name": &schema.Schema{
+				Type:         schema.TypeString,
+				Required:     true,
+				ForceNew:     true,
+				ValidateFunc: validateLambdaFunctionName,
+			},
+			"principal": &schema.Schema{
+				Type:     schema.TypeString,
+				Required: true,
+				ForceNew: true,
+			},
+			"qualifier": &schema.Schema{
+				Type:         schema.TypeString,
+				Optional:     true,
+				ForceNew:     true,
+				ValidateFunc: validateLambdaQualifier,
+			},
+			"source_account": &schema.Schema{
+				Type:         schema.TypeString,
+				Optional:     true,
+				ForceNew:     true,
+				ValidateFunc: validateAwsAccountId,
+			},
+			"source_arn": &schema.Schema{
+				Type:         schema.TypeString,
+				Optional:     true,
+				ForceNew:     true,
+				ValidateFunc: validateArn,
+			},
+			"statement_id": &schema.Schema{
+				Type:         schema.TypeString,
+				Required:     true,
+				ForceNew:     true,
+				ValidateFunc: validatePolicyStatementId,
+			},
+		},
+	}
+}
+
+func resourceAwsLambdaPermissionCreate(d *schema.ResourceData, meta interface{}) error {
+	conn := meta.(*AWSClient).lambdaconn
+
+	functionName := d.Get("function_name").(string)
+
+	// There is a bug in the API (reported and acknowledged by AWS)
+	// which causes some permissions to be ignored when API calls are sent in parallel
+	// We work around this bug via mutex
+	awsMutexKV.Lock(functionName)
+	defer awsMutexKV.Unlock(functionName)
+
+	input := lambda.AddPermissionInput{
+		Action:       aws.String(d.Get("action").(string)),
+		FunctionName: aws.String(functionName),
+		Principal:    aws.String(d.Get("principal").(string)),
+		StatementId:  aws.String(d.Get("statement_id").(string)),
+	}
+
+	if v, ok := d.GetOk("qualifier"); ok {
+		input.Qualifier = aws.String(v.(string))
+	}
+	if v, ok := d.GetOk("source_account"); ok {
+		input.SourceAccount = aws.String(v.(string))
+	}
+	if v, ok := d.GetOk("source_arn"); ok {
+		input.SourceArn = aws.String(v.(string))
+	}
+
+	log.Printf("[DEBUG] Adding new Lambda permission: %s", input)
+	var out *lambda.AddPermissionOutput
+	err := resource.Retry(1*time.Minute, func() error {
+		var err error
+		out, err = conn.AddPermission(&input)
+
+		if err != nil {
+			if awsErr, ok := err.(awserr.Error); ok {
+				// IAM is eventually consistent :/
+				if awsErr.Code() == "ResourceConflictException" {
+					return fmt.Errorf("[WARN] Error adding new Lambda Permission for %s, retrying: %s",
+						*input.FunctionName, err)
+				}
+			}
+			return resource.RetryError{Err: err}
+		}
+		return nil
+	})
+
+	if err != nil {
+		return err
+	}
+
+	log.Printf("[DEBUG] Created new Lambda permission: %s", *out.Statement)
+
+	d.SetId(d.Get("statement_id").(string))
+
+	err = resource.Retry(5*time.Minute, func() error {
+		// IAM is eventually cosistent :/
+		err := resourceAwsLambdaPermissionRead(d, meta)
+		if err != nil {
+			if strings.HasPrefix(err.Error(), "Error reading Lambda policy: ResourceNotFoundException") {
+				return fmt.Errorf("[WARN] Error reading newly created Lambda Permission for %s, retrying: %s",
+					*input.FunctionName, err)
+			}
+			if strings.HasPrefix(err.Error(), "Failed to find statement \""+d.Id()) {
+				return fmt.Errorf("[WARN] Error reading newly created Lambda Permission statement for %s, retrying: %s",
+					*input.FunctionName, err)
+			}
+
+			log.Printf("[ERROR] An actual error occured when expecting Lambda policy to be there: %s", err)
+			return resource.RetryError{Err: err}
+		}
+		return nil
+	})
+
+	return err
+}
+
+func resourceAwsLambdaPermissionRead(d *schema.ResourceData, meta interface{}) error {
+	conn := meta.(*AWSClient).lambdaconn
+
+	input := lambda.GetPolicyInput{
+		FunctionName: aws.String(d.Get("function_name").(string)),
+	}
+	if v, ok := d.GetOk("qualifier"); ok {
+		input.Qualifier = aws.String(v.(string))
+	}
+
+	log.Printf("[DEBUG] Looking for Lambda permission: %s", input)
+	var out *lambda.GetPolicyOutput
+	var statement *LambdaPolicyStatement
+	err := resource.Retry(1*time.Minute, func() error {
+		// IAM is eventually cosistent :/
+		var err error
+		out, err = conn.GetPolicy(&input)
+		if err != nil {
+			if awsErr, ok := err.(awserr.Error); ok {
+				if awsErr.Code() == "ResourceNotFoundException" {
+					return err
+				}
+			}
+			return resource.RetryError{Err: err}
+		}
+
+		policyInBytes := []byte(*out.Policy)
+		policy := LambdaPolicy{}
+		err = json.Unmarshal(policyInBytes, &policy)
+		if err != nil {
+			return resource.RetryError{Err: fmt.Errorf("Error unmarshalling Lambda policy: %s", err)}
+		}
+
+		statement, err = findLambdaPolicyStatementById(&policy, d.Id())
+		return err
+	})
+	if err != nil {
+		return err
+	}
+
+	qualifier, err := getQualifierFromLambdaAliasOrVersionArn(statement.Resource)
+	if err == nil {
+		d.Set("qualifier", qualifier)
+	}
+
+	// Save Lambda function name in the same format
+	if strings.HasPrefix(d.Get("function_name").(string), "arn:aws:lambda:") {
+		// Strip qualifier off
+		trimmedArn := strings.TrimSuffix(statement.Resource, ":"+qualifier)
+		d.Set("function_name", trimmedArn)
+	} else {
+		functionName, err := getFunctionNameFromLambdaArn(statement.Resource)
+		if err != nil {
+			return err
+		}
+		d.Set("function_name", functionName)
+	}
+
+	d.Set("action", statement.Action)
+	d.Set("principal", statement.Principal["Service"])
+
+	if stringEquals, ok := statement.Condition["StringEquals"]; ok {
+		d.Set("source_account", stringEquals["AWS:SourceAccount"])
+	}
+
+	if arnLike, ok := statement.Condition["ArnLike"]; ok {
+		d.Set("source_arn", arnLike["AWS:SourceArn"])
+	}
+
+	return nil
+}
+
+func resourceAwsLambdaPermissionDelete(d *schema.ResourceData, meta interface{}) error {
+	conn := meta.(*AWSClient).lambdaconn
+
+	functionName := d.Get("function_name").(string)
+
+	// There is a bug in the API (reported and acknowledged by AWS)
+	// which causes some permissions to be ignored when API calls are sent in parallel
+	// We work around this bug via mutex
+	awsMutexKV.Lock(functionName)
+	defer awsMutexKV.Unlock(functionName)
+
+	input := lambda.RemovePermissionInput{
+		FunctionName: aws.String(functionName),
+		StatementId:  aws.String(d.Id()),
+	}
+
+	if v, ok := d.GetOk("qualifier"); ok {
+		input.Qualifier = aws.String(v.(string))
+	}
+
+	log.Printf("[DEBUG] Removing Lambda permission: %s", input)
+	_, err := conn.RemovePermission(&input)
+	if err != nil {
+		return err
+	}
+
+	err = resource.Retry(5*time.Minute, func() error {
+		log.Printf("[DEBUG] Checking if Lambda permission %q is deleted", d.Id())
+
+		params := &lambda.GetPolicyInput{
+			FunctionName: aws.String(d.Get("function_name").(string)),
+		}
+		if v, ok := d.GetOk("qualifier"); ok {
+			params.Qualifier = aws.String(v.(string))
+		}
+
+		log.Printf("[DEBUG] Looking for Lambda permission: %s", *params)
+		resp, err := conn.GetPolicy(params)
+		if err != nil {
+			if awsErr, ok := err.(awserr.Error); ok {
+				if awsErr.Code() == "ResourceNotFoundException" {
+					return nil
+				}
+			}
+			return resource.RetryError{Err: err}
+		}
+
+		if resp.Policy == nil {
+			return nil
+		}
+
+		policyInBytes := []byte(*resp.Policy)
+		policy := LambdaPolicy{}
+		err = json.Unmarshal(policyInBytes, &policy)
+		if err != nil {
+			return fmt.Errorf("Error unmarshalling Lambda policy: %s", err)
+		}
+
+		_, err = findLambdaPolicyStatementById(&policy, d.Id())
+		if err != nil {
+			return nil
+		}
+
+		log.Printf("[DEBUG] No error when checking if Lambda permission %s is deleted", d.Id())
+		return nil
+	})
+
+	if err != nil {
+		return fmt.Errorf("Failed removing Lambda permission: %s", err)
+	}
+
+	log.Printf("[DEBUG] Lambda permission with ID %q removed", d.Id())
+	d.SetId("")
+
+	return nil
+}
+
+func findLambdaPolicyStatementById(policy *LambdaPolicy, id string) (
+	*LambdaPolicyStatement, error) {
+
+	log.Printf("[DEBUG] Received %d statements in Lambda policy: %s", len(policy.Statement), policy.Statement)
+	for _, statement := range policy.Statement {
+		if statement.Sid == id {
+			return &statement, nil
+		}
+	}
+
+	return nil, fmt.Errorf("Failed to find statement %q in Lambda policy:\n%s", id, policy.Statement)
+}
+
+func getQualifierFromLambdaAliasOrVersionArn(arn string) (string, error) {
+	matches := regexp.MustCompile(LambdaFunctionRegexp).FindStringSubmatch(arn)
+	if len(matches) < 8 || matches[7] == "" {
+		return "", fmt.Errorf("Invalid ARN or otherwise unable to get qualifier from ARN (%q)",
+			arn)
+	}
+
+	return matches[7], nil
+}
+
+func getFunctionNameFromLambdaArn(arn string) (string, error) {
+	matches := regexp.MustCompile(LambdaFunctionRegexp).FindStringSubmatch(arn)
+	if len(matches) < 6 || matches[5] == "" {
+		return "", fmt.Errorf("Invalid ARN or otherwise unable to get qualifier from ARN (%q)",
+			arn)
+	}
+	return matches[5], nil
+}
+
+type LambdaPolicy struct {
+	Version   string
+	Statement []LambdaPolicyStatement
+	Id        string
+}
+
+type LambdaPolicyStatement struct {
+	Condition map[string]map[string]string
+	Action    string
+	Resource  string
+	Effect    string
+	Principal map[string]string
+	Sid       string
+}