Installation and Upgrade

Requirements

The resource availability monitor is delivered as a self-contained docker image using the Docker Content Trust (DCT) system to ensure the integrity and publisher of all the data downloaded. Installation of the image can be undertaken on any host running docker¹.

In this document the host running the monitor container is referred to as the docker host. This host must have network access to any cluster resources to be monitored so it in turn can make those resources available to the container running the monitor itself.

For example, to monitor a clustered NFS share then the docker host must be able to mount and access that share, as the docker container will require access to successfully monitor that resources availability. Also note, the process running the monitor docker image must belong to the docker group on the host OS (this is a requirement of docker).

Running under docker, the monitor tool requires a persistent location to store its data, logs and ancillary files. This location is provided by the host OS and mapped to the directory /tmp/hamonitor when the container is started (see section 3 Starting the Monitor). This way existing configurations, logs and other components are preserved during upgrades, migrations etc.

Installation

The monitor is distributed from our docker server and is installed as follows:

1. Download and install the docker application package from www.docker.com onto the docker host machine. Start the docker daemon on the host machine.

2. In order to use the docker server, it is necessary to have a username, password combination - this should be requested using the email address docker-trust@high-availability.com.

3. In your browser, navigate to Our Docker Repo and the Harbor Login page:

4. Login using the username/password provided in step 2. Next select the hamonitor project:

5. Then hamonitor/hamonitor:

6. Here you'll see the list of hamonitor images available:

7. Select which version you want from the list, then click "COPY PULL COMMAND" and then Docker:

8. Next on the CLI, using the same user/password combination retrieved in step 2, login to the docker repo:

   # docker login docker.high-availability.com
   

   The docker login subcommand will prompt for a username and password. Note that once you have successfully logged into the server, docker saves a login token locally in the users’ home directory in the file .docker/config.json thereby avoiding the need for this user to login again. The token can be cleared using the docker logout subcommand.

9. Paste the command copied from the browser:

   # docker pull docker.high-availability.com/hamonitor/hamonitor@sha256:ac3ef8d04823562ff287a3f3a7ce83cdc07bc211586eae642ca70bc57e4819e8 
   

   The output from the docker pull should look similar to the following:

    docker.high-availability.com/hamonitor/hamonitor@sha256:ac3ef8d04823562ff287a3f3a7ce83cdc07bc211586eae642ca70bc57e4819e8: Pulling from hamonitor/hamonitor
    7264a8db6415: Pull complete 
    4434401d211c: Pull complete 
    41cf4a3cd624: Pull complete 
    6437156e3886: Pull complete 
    53e4d6276f5e: Pull complete 
    c66b89b79141: Pull complete 
    bb7dcefc7457: Pull complete 
    3ad7fad29bbf: Pull complete 
    1e737d0e46f2: Pull complete 
    bf26a55235e4: Pull complete 
    16f1e4fb340b: Pull complete 
    f37fa5fc1191: Pull complete 
    d1749efd36e2: Pull complete 
    752b2f20cdbf: Pull complete 
    d4fd976e8482: Pull complete 
    9280bcb05597: Pull complete 
    eed64a99ae98: Pull complete 
    71cc6336270d: Pull complete 
    ae79a4b91b9f: Pull complete 
    a81de1a64b7e: Pull complete 
    7b97bc2e0f1b: Pull complete 
    fc9b201d2868: Pull complete 
    f4403c979d35: Pull complete 
    5f5c8731b162: Pull complete 
    ecabd7645b77: Pull complete 
    3be67a56aa00: Pull complete 
    Digest: sha256:ac3ef8d04823562ff287a3f3a7ce83cdc07bc211586eae642ca70bc57e4819e8
    Status: Downloaded newer image for docker.high-availability.com/hamonitor/hamonitor@sha256:ac3ef8d04823562ff287a3f3a7ce83cdc07bc211586eae642ca70bc57e4819e8
    docker.high-availability.com/hamonitor/hamonitor@sha256:ac3ef8d04823562ff287a3f3a7ce83cdc07bc211586eae642ca70bc57e4819e8
   

Installation and upgrade on dark sites

To install the monitor on hosts that have no external internet connection (and thus cannot make a connection to the docker trust server) necessitates a two-step approach, the result of which creates an offline image which can then be used to install the monitor on any hosts, regardless of whether they have external connectivity or not.

The first step in creating the image is to designate a download host (with internet connectivity) to download the monitor as described in the previous section. The next step is to create an image which can be shipped to the non-connected hosts and installed locally. Creating an image is accomplished as follows:

1. On the host where the monitor has been downloaded create an image of the monitor:

   # docker image save -o hamonitor_v1.0.tar dkr.high-availability.com/hamonitor:v2.2.6
   

2. The newly created tar file (in this example hamonitor_v2.2.6.tar) can then be copied to any host and installed using the following command:

   # docker load -i hamonitor_v2.2.6.tar
   

3. Finally, on the host where the image was loaded, check the image ID is the same, output will be similar to the following:

   # docker images 
   REPOSITORY                          TAG  IMAGE ID     CREATED  SIZE
   docker.high-availability.com/hamonitor v2.2.6 fc254100c107 3 months 768MB
   

The monitor is now installed and ready to run. To upgrade a dark site installation simply create a new image using docker image save from the updated local image and add it to the dark site host using docker load.

Upgrading the monitor image

You can check for updated versions via Our Docker Repo and repeat the installation steps above to pull the latest image.

As the configuration data, logs etc. for the hamonitor are kept in a shared directory on the host machine (specified with the --volume parameter when creating the container), upgrading to a newer version is simply a matter of stopping the monitor, deleting the container with the older version, then restarting with the updated version.

# docker rm hamonitor
# docker run \
    --detach \
    --name hamonitor \
    --net host \
    --privileged \
    --restart unless-stopped \
    --volume <host directory>:/tmp/hamonitor \
    dkr.high-availability.com/hamonitor:v2.2.7 \
    --publish 13514

Finally, check the running monitor:

# docker ps
CONTAINER ID   IMAGE                                 COMMAND                  CREATED         STATUS         PORTS     NAMES
c41d6c875459   dkr.high-availability.com/hamonitor   "python3 /root/api/h…"   5 minutes ago   Up 5 minutes             hamonitor