From a715dd84ecf1eec7fa562265465171be8ab2ff5d Mon Sep 17 00:00:00 2001 From: George Brighton Date: Mon, 2 Aug 2021 13:55:54 +0100 Subject: [PATCH] Describe EC2 availability zone IDs at most once per refresh (#9142) Signed-off-by: George Brighton --- discovery/aws/ec2.go | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/discovery/aws/ec2.go b/discovery/aws/ec2.go index d2ad9736a..351f8c7db 100644 --- a/discovery/aws/ec2.go +++ b/discovery/aws/ec2.go @@ -194,24 +194,35 @@ func (d *EC2Discovery) ec2Client(ctx context.Context) (*ec2.EC2, error) { return d.ec2, nil } -func (d *EC2Discovery) azID(ctx context.Context, az string) (string, error) { +func (d *EC2Discovery) azID(ctx context.Context, az string, azIDsRefreshAttempted *bool) (string, error) { if azID, ok := d.azToAZID[az]; ok { return azID, nil } + if !*azIDsRefreshAttempted { + *azIDsRefreshAttempted = true + if err := d.refreshAZIDs(ctx); err != nil { + return "", err + } + if azID, ok := d.azToAZID[az]; ok { + return azID, nil + } + } + + return "", fmt.Errorf("no availability zone ID mapping found for %s", az) +} + +func (d *EC2Discovery) refreshAZIDs(ctx context.Context) error { azs, err := d.ec2.DescribeAvailabilityZonesWithContext(ctx, &ec2.DescribeAvailabilityZonesInput{}) if err != nil { - return "", errors.Wrap(err, "could not describe availability zones") + // Likely due to missing ec2:DescribeAvailabilityZones. + return errors.Wrap(err, "could not describe availability zones") } d.azToAZID = make(map[string]string, len(azs.AvailabilityZones)) for _, az := range azs.AvailabilityZones { d.azToAZID[*az.ZoneName] = *az.ZoneId } - - if azID, ok := d.azToAZID[az]; ok { - return azID, nil - } - return "", fmt.Errorf("no availability zone ID mapping found for %s", az) + return nil } func (d *EC2Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) { @@ -233,14 +244,14 @@ func (d *EC2Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error } input := &ec2.DescribeInstancesInput{Filters: filters} - + azIDsRefreshAttempted := false if err := ec2Client.DescribeInstancesPagesWithContext(ctx, input, func(p *ec2.DescribeInstancesOutput, lastPage bool) bool { for _, r := range p.Reservations { for _, inst := range r.Instances { if inst.PrivateIpAddress == nil { continue } - azID, err := d.azID(ctx, *inst.Placement.AvailabilityZone) + azID, err := d.azID(ctx, *inst.Placement.AvailabilityZone, &azIDsRefreshAttempted) if err != nil { level.Warn(d.logger).Log( "msg", "Unable to determine availability zone ID",