AWSTemplateFormatVersion: '2010-09-09'
Description: Gerrit primary launch configuration and autoscaling group
Parameters:
  TemplateBucketName:
    Description: S3 bucket containing cloudformation templates
    Type: String
  EC2AMI:
    Description: AMI ID for the EC2 instance hosting gerrit primaries
    Type: String
  InstanceType:
    Description: EC2 instance type
    Type: String
    AllowedValues: [t2.micro, t2.small, t2.medium, t2.large, m3.medium, m3.large,
                    m3.xlarge, m3.2xlarge, m4.large, m4.xlarge, m4.2xlarge, m4.4xlarge, m4.10xlarge,
                    c4.large, c4.xlarge, c4.2xlarge, c4.4xlarge, c4.8xlarge, c3.large, c3.xlarge,
                    c3.2xlarge, c3.4xlarge, c3.8xlarge, r3.large, r3.xlarge, r3.2xlarge, r3.4xlarge,
                    r3.8xlarge, i2.xlarge, i2.2xlarge, i2.4xlarge, i2.8xlarge]
    ConstraintDescription: Please choose a valid instance type.
  ECSKeyName:
    Type: String
    Description: EC2 key pair name the cluter's instances
  EnvironmentName:
    Description: An environment name used to build the log stream names
    Type: String
  ECSCluster:
    Description: The ECSCluster reference name to register gerrit primaries to
    Type: String
  EC2SecurityGroup:
    Description: security groups to assign to the instances in the Auto Scaling group hosting gerrit primaries
    Type: String
  EC2InstanceProfile:
    Description: The Amazon Resource Name (ARN) of the instance profile associated with the IAM role for the EC2 instances running gerrit primaries
    Type: String
  GerritInstanceNumber:
    Description: Whether this is primary1 or primary2
    Type: Number
    AllowedValues: [1,2]
  FileSystem:
    Description: The ID of the filesystem to share git data between gerrit primary instances
    Type: String
  SubnetId:
    Description: The subnet ID where gerrit primary in the Auto Scaling group can be created
    Type: String
  AvailabilityZone:
    Description: The Availability Zone in which to create the volume from a snapshot
    Type: String
  LogGroupName:
    Description: The log group name
    Type: String
  PrimaryMaxCount:
    Description: The maximum number of EC2 instances in the primary autoscaling group
    Type: Number
  GerritVolumeSnapshotId:
    Description: Id of the EBS snapshot for Gerrit volume
    Type: String
  GerritVolumeAttachMaxRetries:
    Description: Maximum number of retries when attaching Gerrit Volume
    Type: Number
  GerritVolumeAttachRetryDelay:
    Description: The delay in seconds between Gerrit Volume attach attempts
    Type: Number
  GerritVolumeSizeInGiB:
    Description: Gerrit volume size in GiB
    Type: Number

Resources:
  PrimaryECSAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      VPCZoneIdentifier:
        - !Ref SubnetId
      LaunchTemplate:
        LaunchTemplateId: !Ref 'PrimaryLaunchTemplate'
        Version: !GetAtt PrimaryLaunchTemplate.DefaultVersionNumber
      MinSize: '1'
      MaxSize: !Ref PrimaryMaxCount
      DesiredCapacity: '1'
    CreationPolicy:
      ResourceSignal:
        Timeout: PT15M
    UpdatePolicy:
      AutoScalingReplacingUpdate:
        WillReplace: 'true'

  PrimaryLaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Properties:
      LaunchTemplateName: !Sub ${AWS::StackName}-lt-primary${GerritInstanceNumber}
      LaunchTemplateData:
        ImageId: !Ref 'EC2AMI'
        SecurityGroupIds:
          - !Ref EC2SecurityGroup
        InstanceType: !Ref 'InstanceType'
        IamInstanceProfile:
          Arn: !Ref 'EC2InstanceProfile'
        KeyName: !Ref ECSKeyName
        UserData:
          Fn::Base64: !Sub |
            #!/bin/bash -xe
            export PRIMARY_ID=primary-${GerritInstanceNumber}
            echo ECS_CLUSTER=${ECSCluster} >> /etc/ecs/ecs.config
            echo ECS_INSTANCE_ATTRIBUTES={\"target_group\":\"$PRIMARY_ID\"} >> /etc/ecs/ecs.config

            yum install -y aws-cfn-bootstrap nfs-utils wget aws-cli xfsprogs

            EC2_INSTANCE_ID=`curl -s http://169.254.169.254/latest/meta-data/instance-id`
            VOLUME_ID=${GerritVolumeStack.Outputs.GerritVolumeRef}
            echo "Volume Id: $VOLUME_ID"

            aws ec2 attach-volume --region ${AWS::Region} --volume-id $VOLUME_ID --instance-id $EC2_INSTANCE_ID --device /dev/xvdg

            for i in $(seq 1 ${GerritVolumeAttachMaxRetries}); do
              echo "Waiting for volume $VOLUME_ID to be attached to the instace $EC2_INSTANCE_ID ($i/${GerritVolumeAttachMaxRetries})"
              volumeStatus=`aws ec2 describe-volumes --region ${AWS::Region} --volume-ids $VOLUME_ID`
              if [[ $volumeStatus =~ "\"State\": \"attached\"" ]]; then
                echo "Volume $VOLUME_ID attached to the instace $EC2_INSTANCE_ID"
                break
              elif [[ "$i" -eq "${GerritVolumeAttachMaxRetries}" ]]; then
                echo "Could not attach the volume $VOLUME_ID to the instace $EC2_INSTANCE_ID after ${GerritVolumeAttachMaxRetries} attempts"
                exit 1
              fi
              sleep ${GerritVolumeAttachRetryDelay}
            done

            if [[ "${GerritVolumeSnapshotId}" = "" ]]; then
              echo "Create file system for Gerrit volume"
              mkfs -t xfs /dev/xvdg
            fi

            mkdir /gerrit-mount-point
            mount /dev/xvdg /gerrit-mount-point

            if [[ "${GerritVolumeSnapshotId}" = "" ]]; then
              echo "Create Gerrit directories"
              mkdir -p /gerrit-mount-point/gerrit-logs \
               /gerrit-mount-point/gerrit-cache \
               /gerrit-mount-point/gerrit-data \
               /gerrit-mount-point/gerrit-git \
               /gerrit-mount-point/gerrit-index \
               /gerrit-mount-point/gerrit-db
            fi

            chown 1000:1000 -R /gerrit-mount-point

            # EFS setting
            DIR_TGT=/mnt/efs/gerrit-shared
            mkdir -p $DIR_TGT
            EC2_REGION=${AWS::Region}
            # 169.254.169.254 link-local address, valid only from the instance, to retrieve meta-data information.
            EC2_AVAIL_ZONE=`curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone`
            EFS_FILE_SYSTEM_ID=${FileSystem}
            DIR_SRC=$EC2_AVAIL_ZONE.$EFS_FILE_SYSTEM_ID.efs.$EC2_REGION.amazonaws.com

            touch /home/ec2-user/echo.res
            echo $PRIMARY_ID >> /home/ec2-user/echo.res
            echo $EFS_FILE_SYSTEM_ID >> /home/ec2-user/echo.res
            echo $EC2_AVAIL_ZONE >> /home/ec2-user/echo.res
            echo $EC2_REGION >> /home/ec2-user/echo.res
            echo $DIR_SRC >> /home/ec2-user/echo.res
            echo $DIR_TGT >> /home/ec2-user/echo.res
            MAX_RETRIES=20
            for i in $(seq 1 $MAX_RETRIES); do
              echo "Mounting EFS volume ($i/$MAX_RETRIES)..."
              `mount -t nfs4 -o nfsvers=4.1,hard,timeo=600,retrans=2 $DIR_SRC:/ $DIR_TGT >> /home/ec2-user/echo.res` \
                && s=0 && break || s=$? && sleep 5;
            done; (exit $s)
            mkdir -p $DIR_TGT/git
            mkdir -p $DIR_TGT/high-availability
            chown -R 1000:1000 $DIR_TGT
            cp -p /etc/fstab /etc/fstab.back-$(date +%F)
            echo -e "$DIR_SRC:/ \t\t $DIR_TGT \t\t nfs \t\t defaults \t\t 0 \t\t 0" | tee -a /etc/fstab
            # Get the CloudWatch Logs agent
            echo -e "
              {\"logs\":
                {\"logs_collected\":
                  {\"files\":
                    {\"collect_list\":
                      [
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/replication_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/replication_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/httpd_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/httpd_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/error_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/error_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/sshd_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/sshd_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/gc_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/gc_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/sharedref_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/sharedref_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/message_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/message_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/websession_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/websession_log\",
                        \"timezone\": \"UTC\"
                        },
                        {\"file_path\": \"/gerrit-mount-point/gerrit-logs/audit_log\",
                        \"log_group_name\": \"${LogGroupName}\",
                        \"log_stream_name\": \"${EnvironmentName}/{instance_id}/$PRIMARY_ID/audit_log\",
                        \"timezone\": \"UTC\"
                        }
                      ]
                    }
                  }
                }
              }" >> /home/ec2-user/gerritlogsaccess.json

            # Install the CloudWatch Logs agent
            wget https://s3.amazonaws.com/amazoncloudwatch-agent/centos/amd64/latest/amazon-cloudwatch-agent.rpm
            rpm -U ./amazon-cloudwatch-agent.rpm
            /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -c file:/home/ec2-user/gerritlogsaccess.json -s

            # Signal to CloudFormation aws-cfn-bootstrap has been correctly updated
            /opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource PrimaryECSAutoScalingGroup --region ${AWS::Region}

  GerritVolumeStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: !Join [ '', ['https://', !Ref TemplateBucketName, '.s3.amazonaws.com/cf-gerrit-volume.yml'] ]
      TimeoutInMinutes: '25'
      Parameters:
        GerritVolumeId: ""
        GerritVolumeSnapshotId: !Ref GerritVolumeSnapshotId
        GerritVolumeSizeInGiB: !Ref GerritVolumeSizeInGiB
        AvailabilityZone: !Ref AvailabilityZone

Outputs:
  PrimaryLaunchTemplate:
    Value: !Ref PrimaryLaunchTemplate
    Export:
      Name: !Join [ '-', [ !Ref 'AWS::StackName', 'PrimaryLaunchTemplate', !Ref GerritInstanceNumber ] ]

  PrimaryECSAutoScalingGroup:
    Value: !Ref PrimaryECSAutoScalingGroup
    Export:
      Name: !Join [ '-', [ !Ref 'AWS::StackName', 'PrimaryECSAutoScalingGroup', !Ref GerritInstanceNumber ] ]