import logging
import os
import sys

try:
    import psutil
except:
    psutil = None
import math
import re

import agent_util

DOCKER_SOCKET = "/var/run/docker.sock"
NANOSECONDS = 1000000000
CLOCK_TICKS = 100


class DockerPlugin(agent_util.Plugin):
    textkey = "docker"
    label = "Docker"

    #########################################################
    #                       Metadata                        #
    #########################################################

    @classmethod
    def is_cgroups_v2(self):
        return os.path.isfile("/sys/fs/cgroup/cgroup.controllers")
    
    @classmethod
    def map_cgroup_v2_io_textkey_to_metric(self, textkey):
        textkey_to_metric = {
            "io.bytes_read" : 'rbytes',
            "io.bytes_written" : 'wbytes',
            "io.read_ops" : 'rios',
            "io.write_ops" : 'wios'
        }
        return textkey_to_metric.get(textkey, None)

    @classmethod
    def get_metadata(self, config):
        status = agent_util.SUPPORTED

        if not agent_util.which("docker"):
            self.log.info("docker not present")
            status = agent_util.UNSUPPORTED
            msg = "Docker binary not found on instance"
            return {}

        return {
            "containers.num_running": {
                "label": "Number of containers running",
                "options": None,
                "status": status,
                "error_message": "",
                "unit": "count",
            },
            "containers.num_running_img": {
                "label": "Number of containers running image",
                "options": None,
                "option_string": True,
                "status": status,
                "error_message": "",
                "unit": "count",
            },
            "containers.num_running_name": {
                "label": "Number of containers running by name",
                "options": None,
                "option_string": True,
                "status": status,
                "error_message": "",
                "unit": "count",
            },
        }

    @classmethod
    def get_metadata_docker(self, container, config):
        status = agent_util.SUPPORTED
        msg = None

        metadata = {}
        metadata.update(self.get_cpu_metadata(container, config))
        metadata.update(self.get_memory_metadata(container, config))
        metadata.update(self.get_network_metadata(container, config))
        metadata.update(self.get_io_metadata(container, config))

        metadata.update(
            {
                # Container is running
                "status.running": {
                    "label": "Container is Running",
                    "options": None,
                    "status": agent_util.SUPPORTED,
                    "error_message": "",
                    "unit": "boolean",
                },
                # Disk metrics are always available
                "disk.size_rw": {
                    "label": "Size RW",
                    "options": None,
                    "status": agent_util.SUPPORTED,
                    "error_message": "",
                    "unit": "bytes",
                },
                "disk.size_root_fs": {
                    "label": "Size Root FS",
                    "options": None,
                    "status": agent_util.SUPPORTED,
                    "error_message": "",
                    "unit": "bytes",
                },
            }
        )

        return metadata

    @classmethod
    def get_cpu_metadata(self, container, config):
        container_id = container["Id"]

        cpu_metadata = {
            "cpu.usage_percentage": {
                "label": "CPU Usage Percentage",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "%",
            },
            "cpu.user_usage": {
                "label": "CPU Percent Used [User]",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "%",
            },
            "cpu.sys_usage": {
                "label": "CPU Percent Used [System]",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "%",
            },
        }

        if self.is_cgroups_v2():
            stat_file = (
                '/sys/fs/cgroup/system.slice/docker-{}.scope/cpu.stat'.format(container_id)
            )
            stats = DockerPlugin.read_stats_from_file(stat_file)
            textkey_map = {
                "cpu.usage_percentage": "usage_usec",
                "cpu.user_usage": "user_usec",
                "cpu.sys_usage": "system_usec",
            }
            for key in cpu_metadata.keys():
                if stats.get(textkey_map[key], None) is None:
                    cpu_metadata[key][
                        "error_message"
                    ] = "Cannot access docker stats file"
                    cpu_metadata[key]["status"] = agent_util.UNSUPPORTED

        else:
            # map textkey to docker interface file used for metrics
            textkey_map = {
                "cpu.usage_percentage": "cpuacct.usage",
                "cpu.user_usage": "cpuacct.usage_user",
                "cpu.sys_usage": "cpuacct.usage_sys",
            }

            for textkey in cpu_metadata.keys():
                file_name = textkey_map.get(textkey, None)
                if file_name is None:
                    self.log.warning('Docker CPU metadata: missing map key {}'.format(textkey))
                    continue
                fpath = "/sys/fs/cgroup/cpuacct/docker/{}/{}".format(container_id, file_name)
                metric = DockerPlugin.read_single_stat_file(fpath)
                if metric is None:
                    cpu_metadata[textkey]["status"] = agent_util.UNSUPPORTED
                    cpu_metadata[textkey]["error_msg"] = "Can't access '{}'".format(
                        file_name
                    )

        return cpu_metadata

    @classmethod
    def read_single_stat_file(self, file_name):
        try:
            with open(file_name, "r") as f:
                metric = f.read()
                return float(metric)
        except Exception:
            self.log.exception("Read stat file {} failure".format(file_name))
            return None

    @classmethod
    def read_stats_from_file(self, file_name):
        try:
            with open(file_name, "r") as f:
                output = f.readlines()
                stats = {}
                for line in output:
                    stat_type, num = line.split(" ")
                    stats[stat_type] = float(num)
                return stats
        except Exception:
            self.log.exception("Read stats from {} failure".format(file_name))
            return {}

    @classmethod
    def read_io_stats_v2(self, container):
        result = {}
        try:
            successes = 0
            identifier = None
            container_stats = '/sys/fs/cgroup/system.slice/docker-{}.scope/io.stat'.format(container) 
            with open(container_stats, 'r') as cf:
                line = cf.read()
                identifier = line.split()[0]

            metric_line_split = None
            with open('/sys/fs/cgroup/io.stat', 'r') as sf:
                lines = sf.readlines()
                for line in lines:
                    items = line.split(' ')
                    if items[0] == identifier:
                        result['identifier'] = items[0]
                        metric_line_split = items
                        break

            if metric_line_split is None:
                raise Exception('No identifier for container')
            else:
                for item in metric_line_split[1:]:
                    metric_and_value = item.strip('\n').split('=')
                    if 2 == len(metric_and_value):
                        try:
                            result[metric_and_value[0]] = int(metric_and_value[1])
                        except:
                            pass
        except Exception:
            _, e = sys.exc_info()[:2]
            result['error_msg'] = str(e)
        return result

    @classmethod
    def get_memory_metadata(self, container, config):
        container_id = container["Id"]
        if self.is_cgroups_v2():
            memory_metadata = {
                "memory.usage": {
                    "label": "Memory Used",
                    "options": None,
                    "status": agent_util.SUPPORTED,
                    "error_message": "",
                    "unit": "bytes",
                },
                "memory.mapped_file": {
                    "label": "Memory Mapped File",
                    "options": None,
                    "status": agent_util.SUPPORTED,
                    "error_message": "",
                    "unit": "bytes",
                },
            }

            stats_file = (
                '/sys/fs/cgroup/system.slice/docker-{}.scope/memory.stat'.format(container_id)
            )
            metrics = DockerPlugin.read_stats_from_file(stats_file)
            if metrics.get('file_mapped', None) is None:
                memory_metadata['memory.mapped_file']['error_message'] = 'Cannot read {}'.format(stats_file)
                memory_metadata['memory.mapped_file']['status'] = agent_util.UNSUPPORTED

            memory_current = '/sys/fs/cgroup/system.slice/docker-{}.scope/memory.current'.format(container_id)
            metric = DockerPlugin.read_single_stat_file(memory_current)
            if metric is None:
                memory_metadata['memory.usage']['error_message'] = 'Cannot read {}'.format(stats_file)
                memory_metadata['memory.usage']['status'] = agent_util.UNSUPPORTEDev
            return memory_metadata

        memory_metadata = {
            "memory.usage": {
                "label": "Memory Used",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "bytes",
            },
            "memory.cache": {
                "label": "Memory Cached",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "bytes",
            },
            "memory.rss": {
                "label": "Memory RSS",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "bytes",
            },
            "memory.mapped_file": {
                "label": "Memory Mapped File",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "bytes",
            },
            "memory.swap": {
                "label": "Swap Used",
                "options": None,
                "status": agent_util.SUPPORTED,
                "error_message": "",
                "unit": "bytes",
            },
        }

        total_metric = self.read_single_stat_file(
            "/sys/fs/cgroup/memory/docker/%s/memory.usage_in_bytes" % container_id
        )
        if total_metric is None:
            memory_metadata["memory.usage"]["status"] = agent_util.UNSUPPORTED
            memory_metadata["memory.usage"][
                "error_message"
            ] = "Can't access 'memory.usage_in_bytes'"

        stats = self.read_stats_from_file(
            "/sys/fs/cgroup/memory/docker/%s/memory.stat" % container_id
        )
        for key in memory_metadata.keys():
            if "memory.usage" == key:
                continue
            metric_key = key.split(".")[1]
            if metric_key not in stats:
                memory_metadata[key]["status"] = agent_util.UNSUPPORTED
                memory_metadata[key]["error_msg"] = "Unable to read stats file"
        return memory_metadata

    @classmethod
    def find_physical_ethernet_interface(self):
        try:
            cmd = """ find /sys/class/net -type l -not -lname '*virtual*' -printf '%f\n' """
            rc, out = agent_util.execute_command(cmd)
            if 0 != rc:
                raise Exception('Non-zero rc')
            return out.strip('\n')
        except:
            return 'eth0'

    @classmethod
    def get_network_metadata(self, container, config):
        container_id = container["Id"]

        status = agent_util.UNSUPPORTED
        msg = ""

        # Get the PID
        try:
            conn = agent_util.UnixHTTPConnection(DOCKER_SOCKET)
            conn.request(
                "GET",
                "/containers/%s/json" % container_id,
                headers={"Host": "localhost"},
            )
            r = conn.getresponse().read()
            j = agent_util.json_loads(r)
            container_pid = j["State"]["Pid"]
        except Exception:
            container_pid = None
            msg = "Can't get container's PID"

        if container_pid:
            phys_eth = '{}:'.format(self.find_physical_ethernet_interface())
            try:
                with open("/proc/%s/net/dev" % container_pid, "r") as f:
                    output = f.readlines()
                    eth0 = False
                    for line in output:
                        if line.lstrip().startswith(phys_eth):
                            eth0 = True
                            split = line.split()
                            if len(split) == 17:
                                status = agent_util.SUPPORTED
                            else:
                                msg = "Unexpected # of columns in /proc/<pid>/net/dev"
                            break
                    if not eth0:
                        msg = "Can't find {} device on container".format(phys_eth)
            except Exception:
                msg = "Can't access /proc/<pid>/net/dev"

        return {
            "net.rx_bytes": {
                "label": "Bytes In Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "bytes/sec",
            },
            "net.rx_packets": {
                "label": "Packets In Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "packets/sec",
            },
            "net.rx_errs": {
                "label": "RX Errors Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "errors/sec",
            },
            "net.tx_bytes": {
                "label": "Bytes Out Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "bytes/sec",
            },
            "net.tx_packets": {
                "label": "Packets Out Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "packets/sec",
            },
            "net.tx_errs": {
                "label": "TX Errors Per Second",
                "options": None,
                "status": status,
                "error_message": msg,
                "unit": "errors/sec",
            },
        }

    @classmethod
    def get_io_metadata(self, container, config):
        io_metadata = {
            "io.bytes_written": {
                "label": "Bytes Written Per Second",
                "options": None,
                "status": agent_util.UNSUPPORTED,
                "error_message": None,
                "unit": "bytes/s",
            },
            "io.bytes_read": {
                "label": "Bytes Read Per Second",
                "options": None,
                "status": agent_util.UNSUPPORTED,
                "error_message": None,
                "unit": "bytes/s",
            },
            "io.write_ops": {
                "label": "Writes Per Second",
                "options": None,
                "status": agent_util.UNSUPPORTED,
                "error_message": None,
                "unit": "w/s",
            },
            "io.read_ops": {
                "label": "Reads Per Second",
                "options": None,
                "status": agent_util.UNSUPPORTED,
                "error_message": None,
                "unit": "r/s",
            },
        }
        container_id = container["Id"]
        if self.is_cgroups_v2():
            cgv2_status = agent_util.UNSUPPORTED
            cgv2_msg = ''
            io_stats_data = self.read_io_stats_v2(container_id)
            cgv2_msg = io_stats_data.get('eror_msg', None) 
            if cgv2_msg is not None:
                for  v in io_metadata.values():
                    v['status'] = cgv2_status
                    v['error_message'] = cgv2_msg
                return io_metadata
             
            for textkey in io_metadata.keys():
                metric_key = self.map_cgroup_v2_io_textkey_to_metric(textkey)
                if metric_key is None:
                    io_metadata[textkey]['error_message'] = 'Unknown metric from {}'.format(textkey)
                    continue
                if io_stats_data.get(metric_key, None) is not None:
                    io_metadata[textkey]['status'] = agent_util.SUPPORTED
                else:
                    io_metadata[textkey]['error_message'] = 'Unable to read i/o stats'
                
            return io_metadata

        service_bytes = agent_util.UNSUPPORTED
        service_bytes_message = ""
        try:
            fpath = (
                "/sys/fs/cgroup/blkio/docker/%s/blkio.throttle.io_service_bytes"
                % container_id
            )
            with open(fpath, "r") as f:
                f.read()
            service_bytes = agent_util.SUPPORTED
        except Exception:
            service_bytes_message = "Can't access 'blkio.throttle.io_service_bytes'"

        for tk in ['io.bytes_written', 'io.bytes_read']:
            io_metadata[tk]['status'] = service_bytes
            io_metadata[tk]['error_message'] = service_bytes_message

        operations = agent_util.UNSUPPORTED
        operations_message = ""
        try:
            fpath = (
                "/sys/fs/cgroup/blkio/docker/%s/blkio.throttle.io_serviced"
                % container_id
            )
            with open(fpath, "r") as f:
                f.read()
            operations = agent_util.SUPPORTED
        except Exception:
            operations_message = "Can't access 'blkio.throttle.io_serviced'"

        for tk in ['io.write_ops', 'io.read_ops']:
            io_metadata[tk]['status'] = operations
            io_metadata[tk]['error_message'] = operations_message

        return io_metadata

    #########################################################
    #                       Checks                          #
    #########################################################

    def check(self, textkey, data, config):
        if textkey.startswith("containers."):
            return self.get_containers_metric(textkey, data, config)

    def get_containers_metric(self, textkey, data, config):
        def get_running_containers():
            try:
                conn = agent_util.UnixHTTPConnection(DOCKER_SOCKET)
                conn.request("GET", "/containers/json", headers={"Host": "localhost"})
                r = conn.getresponse().read()
                j = agent_util.json_loads(r)
                return j
            except Exception:
                self.log.exception("Get running containers error")
                return None

        if textkey == "containers.num_running":
            running = get_running_containers()
            return len(running)
        elif textkey == "containers.num_running_img":
            running = get_running_containers()

            search = data or "*"
            search = search.replace("*", ".*")
            search = search.replace('""', ".*")

            count = 0
            for container in running:
                image = container.get("Image", "")
                if re.search(search, image):
                    count += 1
            return count
        elif textkey == "containers.num_running_name":
            running = get_running_containers()

            search = data or "*"
            search = search.replace("*", ".*")
            search = search.replace('""', ".*")

            count = 0
            for container in running:
                names = container.get("Names", [])
                for name in names:
                    if re.search(search, name):
                        count += 1

            return count

    def check_docker(self, container, textkey, data, config):
        if textkey.startswith("cpu."):
            return self.get_cpu_metric(container, textkey, data, config)
        elif textkey.startswith("memory."):
            return self.get_memory_metric(container, textkey, data, config)
        elif textkey.startswith("net."):
            return self.get_network_metric(container, textkey, data, config)
        elif textkey.startswith("disk."):
            return self.get_disk_metric(container, textkey, data, config)
        elif textkey.startswith("io."):
            return self.get_io_metric(container, textkey, data, config)
        elif textkey.startswith("status."):
            return self.get_status_metric(container, textkey, data, config)

        return None

    def _read_cpu_metric(self, textkey, container_id):
        if self.is_cgroups_v2():
            stat_file = '/sys/fs/cgroup/system.slice/docker-{}.scope/cpu.stat'.format(container_id)

            stats = DockerPlugin.read_stats_from_file(stat_file)
            if "cpu.usage_percentage" == textkey:
                return stats.get("usage_usec", None)
            elif "cpu.user_usage" == textkey:
                return stats.get("user_usec", None)
            elif "cpu.sys_usage" == textkey:
                return stats.get("system_usec", None)
            self.log.warning('Unrecognized textkey {} in _read_cpu_metric'.format(textkey))
            return None

        stat_file = None
        base_path = '/sys/fs/cgroup/cpuacct/docker/{}'.format(container_id)
        if "cpu.usage_percentage" == textkey:
            stat_file = os.path.join(base_path, "cpuacct.usage")
        elif "cpu.user_usage" == textkey:
            stat_file = os.path.join(base_path, "cpuacct.usage_user")
        elif "cpu.sys_usage" == textkey:
            stat_file = os.path.join(base_path, "cpuacct.usage_sys")
        if stat_file is None:
            self.log.error('Unrecognized textkey {} in _read_cpu_metric'.format(textkey))
            return None
        return DockerPlugin.read_single_stat_file(stat_file)

    def get_cpu_metric(self, container, textkey, data, config):
        container_id = container["Id"]

        def get_total_system():
            cpu_times = psutil.cpu_times()
            total_system = 0
            for key in ["user", "nice", "system", "idle", "iowait", "irq", "softirq"]:
                total_system += getattr(cpu_times, key) * 100
            total_system = (total_system * NANOSECONDS) / CLOCK_TICKS
            if self.is_cgroups_v2():
                total_system = total_system / 1000
            return total_system

        if textkey == "cpu.usage_percentage":
            last_system = self.get_cache_results(
                "docker.cpu.usage_percentage", "total_system"
            )
            if last_system:
                last_system = last_system[0][1]
            else:
                last_system = None
            last_container = self.get_cache_results(
                "docker.cpu.usage_percentage", container_id
            )
            if last_container:
                last_container = last_container[0][1]
            else:
                last_container = None

            total_system = get_total_system()
            self.cache_result(
                "docker.cpu.usage_percentage",
                "total_system",
                total_system,
                replace=True,
            )

            total_container = self._read_cpu_metric(textkey, container_id)
            if total_container is None:
                return None
            self.cache_result(
                "docker.cpu.usage_percentage",
                container_id,
                total_container,
                replace=True,
            )

            if last_system is None or last_container is None:
                return None

            container_delta = total_container - last_container
            system_delta = total_system - last_system

            num_cpus = psutil.cpu_count()

            return (float(container_delta) / system_delta) * num_cpus * 100.0
        elif textkey == "cpu.user_usage":
            last_system = self.get_cache_results(
                "docker.cpu.user_usage", "total_system"
            )
            if last_system:
                last_system = last_system[0][1]
            else:
                last_system = None
            last_container = self.get_cache_results(
                "docker.cpu.user_usage", container_id
            )
            if last_container:
                last_container = last_container[0][1]
            else:
                last_container = None

            total_system = get_total_system()
            self.cache_result(
                "docker.cpu.user_usage", "total_system", total_system, replace=True
            )

            container_val = self._read_cpu_metric(textkey, container_id)
            if container_val is None:
                return None
            self.cache_result(
                "docker.cpu.user_usage", container_id, container_val, replace=True
            )

            if last_system is None or last_container is None:
                return None

            container_delta = container_val - last_container
            system_delta = total_system - last_system

            num_cpus = psutil.cpu_count()

            return (float(container_delta) / system_delta) * num_cpus * 100.0
        elif textkey == "cpu.sys_usage":
            last_system = self.get_cache_results("docker.cpu.sys_usage", "total_system")
            if last_system:
                last_system = last_system[0][1]
            else:
                last_system = None
            last_container = self.get_cache_results(
                "docker.cpu.sys_usage", container_id
            )
            if last_container:
                last_container = last_container[0][1]
            else:
                last_container = None

            total_system = get_total_system()
            self.cache_result(
                "docker.cpu.sys_usage", "total_system", total_system, replace=True
            )

            container_val = self._read_cpu_metric(textkey, container_id)
            if container_val is None:
                return None

            self.cache_result(
                "docker.cpu.sys_usage", container_id, container_val, replace=True
            )

            if last_system is None or last_container is None:
                return None

            container_delta = container_val - last_container
            system_delta = total_system - last_system

            num_cpus = psutil.cpu_count()

            return (float(container_delta) / system_delta) * num_cpus * 100.0

    def get_memory_metric(self, container, textkey, data, config):
        container_id = container["Id"]

        def get_total_bytes():
            fname = (
                "/sys/fs/cgroup/memory/docker/%s/memory.usage_in_bytes" % container_id
            )
            if self.is_cgroups_v2():
                fname = '/sys/fs/cgroup/system.slice/docker-{}.scope/memory.current'.format(container_id)
            return DockerPlugin.read_single_stat_file(fname)

        def get_memory_stats():
            fname = "/sys/fs/cgroup/memory/docker/%s/memory.stat" % container_id
            if self.is_cgroups_v2():
                fname = '/sys/fs/cgroup/system.slice/docker-{}.scope/memory.stat'.format(container_id)
            return DockerPlugin.read_stats_from_file(fname)

        if textkey == "memory.usage":
            try:
                total_bytes = get_total_bytes()
                if self.is_cgroups_v2():
                    return total_bytes
                memory_stats = get_memory_stats()
                return total_bytes - memory_stats["cache"]
            except Exception:
                self.log.exception("Docker get memory.usage error")
                return None
        elif textkey in [
            "memory.cache",
            "memory.rss",
            "memory.mapped_file",
            "memory.swap",
        ]:
            try:
                memory_stats = get_memory_stats()
                if not self.is_cgroups_v2():
                    stat_type = textkey.split(".")[1]
                    return memory_stats[stat_type]
                if 'memory.mapped_file' == textkey:
                    return memory_stats['file_mapped']
                raise Exception('Unrecognized textkey {}'.format(textkey))
            except Exception:
                self.log.exception("Docker get {} error".format(textkey))
                return None

    def get_container_pid(self, container):
        conn = None
        try:
            container_id = container["Id"]
            conn = agent_util.UnixHTTPConnection(DOCKER_SOCKET)
            conn.request(
                "GET",
                "/containers/%s/json" % container_id,
                headers={"Host": "localhost"},
            )
            r = conn.getresponse().read()
            j = agent_util.json_loads(r)
            return j["State"]["Pid"]
        except Exception:
            self.log.exception("Get container pid error")
            return None
        finally:
            try:
                conn.close()
            except:
                pass

    def get_network_metric(self, container, textkey, data, config):
        container_id = container["Id"]

        # Find the container's PID
        container_pid = self.get_container_pid(container)
        if container_pid is None:
            return None

        phys_eth = '{}:'.format(DockerPlugin.find_physical_ethernet_interface())
        def get_proc_stats(pid):
            proc_file = "/proc/%s/net/dev" % pid
            with open(proc_file, "r") as f:
                content = f.readlines()
                eth0_line = None
                for line in content:
                    if line.lstrip().startswith(phys_eth):
                        eth0_line = line
                        break
                if not eth0_line:
                    raise Exception("No line for {} in {}".format(phys_eth, proc_file))

                eth0_line = eth0_line.split()
                keys = [
                    "",
                    "rx_bytes",
                    "rx_packets",
                    "rx_errs",
                    "",
                    "",
                    "",
                    "",
                    "",
                    "",
                    "tx_bytes",
                    "tx_packets",
                    "tx_errs",
                    "",
                    "",
                    "",
                    "",
                    "",
                ]
                stats = {}
                for col, text in enumerate(eth0_line):
                    key = keys[col]
                    if key:
                        stats[key] = int(text)
                return stats

        if textkey in [
            "net.rx_bytes",
            "net.rx_packets",
            "net.rx_errs",
            "net.tx_bytes",
            "net.tx_packets",
            "net.tx_errs",
        ]:
            key = textkey.split(".")[1]
            last = self.get_cache_results("docker.net", key)
            if last:
                last_val = last[0][1]
                seconds = last[0][0]
            else:
                last_val = None
                seconds = None

            try:
                stats = get_proc_stats(container_pid)
                stat = stats[key]
            except Exception:
                self.log.exception(
                    "Error accessing /proc/%s/net/dev: %s", container_pid, e
                )
                return None

            self.cache_result("docker.net", key, stat, replace=True)

            if last_val is None:
                return None

            return (stat - last_val) / seconds

    def get_disk_metric(self, container, textkey, data, config):
        container_id = container["Id"]

        try:
            conn = agent_util.UnixHTTPConnection(DOCKER_SOCKET)
            conn.request(
                "GET",
                "/containers/%s/json?size=true" % container_id,
                headers={"Host": "localhost"},
            )
            r = conn.getresponse().read()
            j = agent_util.json_loads(r)
        except Exception:
            self.log.exception("Docker get disk metric error")
            return None

        if textkey == "disk.size_rw":
            return j.get("SizeRw", None)
        elif textkey == "disk.size_root_fs":
            return j.get("SizeRootFs", None)

    def get_metric_as_bytes(self, metric_string):
        try:
            index = 0
            while True:
                if metric_string[index].isdigit() or '.' == metric_string[index]:
                    index += 1
                    continue
                break
            metric_value = float(metric_string[0:index])
            units = metric_string[index:].lower()
            self.log.info(
                "metric_string {} ->  {} {}".format(metric_string, metric_value, units)
            )
            conversion = 1
            if "kib" == units:
                conversion = 1000
            elif "mib" == units:
                conversion = math.pow(1024, 2)
            elif "gib" == units:
                conversion = math.pow(1024, 3)
            elif "kb" == units:
                conversion = 1000
            elif "mb" == units:
                conversion = math.pow(1000, 2)
            elif "gb" == units:
                conversion = math.pow(1000, 3)
            return metric_value * conversion
        except Exception:
            self.log.exception("get_metric_as_bytes error")
            return None

    def _get_docker_block_stats(self, container, textkey):
        """
        Read the I/O metrics from docker stats, because the /proc io file is
        read-only to root.
        """
        import json

        def parse_multi_metric_entry(metric_line):
            items = metric_line.split('/')
            items = metric_line.split("/")
            metrics = [item.strip() for item in items]
            rv = []
            for metric in metrics:
                rv.append(self.get_metric_as_bytes(metric))
            return rv

        try:
            container_id = container["Id"]
            rc, output = agent_util.execute_command(
                "docker stats {} --no-stream --format json".format(container_id),
                cache_timeout=agent_util.DEFAULT_CACHE_TIMEOUT,
            )
            if 0 != rc:
                self.log.error("Docker stats failure: {}".format(rc))
                return None

            data = agent_util.json_loads(output)
            self.log.debug("Docker Stats result: {}".format(json.dumps(data, indent=1)))
            mld = parse_multi_metric_entry(data["BlockIO"])
            if 2 != len(mld):
                self.log.error("get_docker_block_stats error: Unexpected metric count")
                self.log.info(output)
                return None

            if "io.bytes_out" == textkey:
                return mld[1]
            elif "io.bytes_in" == textkey:
                return mld[0]
            else:
                return None
        except Exception:
            self.log.exception("get_docker_block_stats error")
            return None

    def get_io_metric(self, container, textkey, data, config):
        container_id = container["Id"]

        def get_total(fname, operation_type):
            with open(fname, "r") as f:
                lines = f.readlines()
                total = 0
                for line in lines:
                    if line.startswith("Total"):
                        continue
                    device, op_type, num = line.split(" ")
                    if op_type == operation_type:
                        total += int(num)
                return total

        key = textkey.split(".")[1]
        last = self.get_cache_results("docker.io", key)
        if last:
            last_val = last[0][1]
            seconds = last[0][0]
        else:
            last_val = None
            seconds = None

        new_val = None

       
        if self.is_cgroups_v2():
            io_metrics = DockerPlugin.read_io_stats_v2(container_id)
            if io_metrics.get('error_msg', None) is not None:
                self.log.error('I/O stats error {}'.format(io_metrics['error_msg']))
                return None
            mtk = DockerPlugin.map_cgroup_v2_io_textkey_to_metric(textkey)
            if io_metrics.get(mtk, None) is None:
                self.log.error('No metric found for {}'.format(textkey))
                return None
            new_val = io_metrics[mtk]
        
        else:
            if textkey in ["io.bytes_written", "io.bytes_read"]:
                try:
                    fname = (
                        "/sys/fs/cgroup/blkio/docker/%s/blkio.throttle.io_service_bytes"
                        % container_id
                    )
                    if "written" in textkey:
                        new_val = get_total(fname, "Write")
                    elif "read" in textkey:
                        new_val = get_total(fname, "Read")
                except Exception:
                    self.log.error("Error accessing %s", fname)
                    return None
            elif textkey in ["io.write_os", "io.read_ops"]:
                try:
                    fname = (
                        "/sys/fs/cgroup/blkio/docker/%s/blkio.throttle.io_serviced"
                        % container_id
                    )
                    if "write" in textkey:
                        new_val = get_total(fname, "Write")
                    elif "read" in textkey:
                        new_val = get_total(fname, "Read")
                except Exception:
                    self.log.error("Error accessing %s", fname)
                    return None

        if new_val is None:
            return None

        self.cache_result("docker.io", key, new_val, replace=True)

        if last_val is None:
            return None
        
        if new_val < last_val:
            return None

        return (new_val - last_val) / seconds

    def get_status_metric(self, container, textkey, data, config):
        if textkey == "status.running":
            if container.get("State") != "running":
                return 0
            return 1