diff --git a/builtin/providers/aws/provider.go b/builtin/providers/aws/provider.go index c9ea22e92..62623c8cc 100644 --- a/builtin/providers/aws/provider.go +++ b/builtin/providers/aws/provider.go @@ -1,7 +1,9 @@ package aws import ( + "net" "sync" + "time" "github.com/awslabs/aws-sdk-go/aws/credentials" "github.com/hashicorp/terraform/helper/hashcode" @@ -26,13 +28,48 @@ func Provider() terraform.ResourceProvider { var credErr error var once sync.Once getCreds := func() { - creds := credentials.NewChainCredentials([]credentials.Provider{ + // Build the list of providers to look for creds in + providers := []credentials.Provider{ &credentials.EnvProvider{}, &credentials.SharedCredentialsProvider{}, - &credentials.EC2RoleProvider{}, - }) + } - credVal, credErr = creds.Get() + // We only look in the EC2 metadata API if we can connect + // to the metadata service within a reasonable amount of time + conn, err := net.DialTimeout("tcp", "169.254.169.254:80", 100*time.Millisecond) + if err == nil { + conn.Close() + providers = append(providers, &credentials.EC2RoleProvider{}) + } + + credVal, credErr = credentials.NewChainCredentials(providers).Get() + + // If we didn't successfully find any credentials, just + // set the error to nil. + if credErr == credentials.ErrNoValidProvidersFoundInChain { + credErr = nil + } + } + + // getCredDefault is a function used by DefaultFunc below to + // get the default value for various parts of the credentials. + // This function properly handles loading the credentials, checking + // for errors, etc. + getCredDefault := func(def interface{}, f func() string) (interface{}, error) { + once.Do(getCreds) + + // If there was an error, that is always first + if credErr != nil { + return nil, credErr + } + + // If the value is empty string, return nil (not set) + val := f() + if val == "" { + return def, nil + } + + return val, nil } // The actual provider @@ -42,8 +79,9 @@ func Provider() terraform.ResourceProvider { Type: schema.TypeString, Required: true, DefaultFunc: func() (interface{}, error) { - once.Do(getCreds) - return credVal.AccessKeyID, credErr + return getCredDefault(nil, func() string { + return credVal.AccessKeyID + }) }, Description: descriptions["access_key"], }, @@ -52,8 +90,9 @@ func Provider() terraform.ResourceProvider { Type: schema.TypeString, Required: true, DefaultFunc: func() (interface{}, error) { - once.Do(getCreds) - return credVal.SecretAccessKey, credErr + return getCredDefault(nil, func() string { + return credVal.SecretAccessKey + }) }, Description: descriptions["secret_key"], }, @@ -62,8 +101,9 @@ func Provider() terraform.ResourceProvider { Type: schema.TypeString, Optional: true, DefaultFunc: func() (interface{}, error) { - once.Do(getCreds) - return credVal.SessionToken, credErr + return getCredDefault("", func() string { + return credVal.SessionToken + }) }, Description: descriptions["token"], },