# pmdadocker

## NAME



           **pmdadocker** - docker performance metrics domain agent (PMDA)
    


## SYNOPSIS



           **$PCP_PMDAS_DIR/docker/pmdadocker**[**-D** _debug_] [**-d** _domain_] [**-l**
           _logfile_]
    


## DESCRIPTION



           **pmdadocker** is a docker Performance Metrics Domain Agent (PMDA)
           which exposes performance metrics as reported from the Docker
           Remote API.
    
           A brief description of the **pmdadocker** command line options
           follows:
    
           **-d** It is absolutely crucial that the performance metrics _domain_
                number specified here is unique and consistent.  That is,
                _domain_ should be different for every PMDA on the one host,
                and the same _domain_ number should be used for the same PMDA
                on all hosts.
    
           **-l** Location of the log file.  By default, a log file named
                _docker.log_ is written in the current directory of pmcd(1)
                when **pmdadocker** is started, i.e.  **$PCP_LOG_DIR/pmcd**.  If the
                log file cannot be created or is not writable, output is
                written to the standard error instead.
    
           Remote API metric requests are activated automatically and are
           fetched on a timer.  This timer is represented as a by **pmdadocker**
           via the **docker.control.timing.** By default, **pmdadocker** will be set
           to fetch on a 1 second interval.
    
           **pmdadocker** will iterate over three different **docker** remote API
           calls:
    
           **/containers/$ID/json**
                  Container metrics regarding the current state of the
                  container. Such as PID, name or if the container is
                  running.
    
           **/version**
                  Basic version metrics about the current docker daemon in
                  use.
    
           **/containers/$ID/stats?stream=0**
                  More in depth memory and cpu metrics of the container.
    


## INSTALLATION



           If you want access to the names, help text and values for the
           docker performance metrics, do the following as root:
    
                # cd $PCP_PMDAS_DIR/docker
                # ./Install
    
           If you want to undo the installation (and remove both PMDAs), do
           the following as root:
    
                # cd $PCP_PMDAS_DIR/docker
                # ./Remove
    
           **pmdadocker** is launched by pmcd(1) and should never be executed
           directly.  The Install and Remove scripts notify pmcd(1) when the
           agent is installed or removed.
    


## FILES



           **$PCP_PMCDCONF_PATH**
                  command line options used to launch **pmdadocker**
           **$PCP_PMDAS_DIR/docker/help**
                  default help text file for the docker metrics
           **$PCP_PMDAS_DIR/docker/Install**
                  installation script for the **pmdadocker** agent
           **$PCP_PMDAS_DIR/docker/Remove**
                  undo installation script for the **pmdadocker** agent
           **$PCP_LOG_DIR/pmcd/docker.log**
                  default log file for error messages and other information
                  from **pmdadocker**
    


## PCP ENVIRONMENT



           Environment variables with the prefix **PCP_** are used to
           parameterize the file and directory names used by PCP.  On each
           installation, the file **/etc/pcp.conf** contains the local values for
           these variables.  The **$PCP_CONF** variable may be used to specify an
           alternative configuration file, as described in pcp.conf(5).  In
           particular, the **$PCP_DOCKER_DIR** may be set to change the default
           directory from **/var/lib/docker**.
    


## DEBUGGING OPTIONS



           The **-D** or **--debug** option enables the output of additional
           diagnostics on _stderr_ to help triage problems, although the
           information is sometimes cryptic and primarily intended to provide
           guidance for developers rather end-users.  _debug_ is a comma
           separated list of debugging options; use pmdbg(1) with the **-l**
           option to obtain a list of the available debugging options and
           their meaning.
    
           Debugging options specific to **pmdadocker** are as follows:
           ┌────────┬────────────────────────────────────────┐
           │ **Option** │ **Description** │
           ├────────┼────────────────────────────────────────┤
           │ **appl1** │ report failure to fetch stats via http │
           └────────┴────────────────────────────────────────┘
    


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