Introduction
- The JS7 Agent comes preinstalled from a container image.
- The image includes a recent OpenJDK Java LTS release.
- Users who wish to run JS7 - JavaScript Jobs that require JS7 - Installing Oracle GraalVM should consider to build their own images, see JS7 - Agent Build of Container Image.
- Initial operation for JS7 Agents includes:
- registering the Controller instance(s) and Agents that are used in the job scheduling environment.
- optionally registering a JS7 - Agent Cluster.
As an alternative to the instructions from this article users can refer to the JS7 - Agent Installation using Docker Compose article.
Installation Video
This video explains how to install the JS7 Agent from a container image:
Pulling the Agent Image
Pull the version of the Agent container image that corresponds to the JS7 release in use, for example:
docker image pull sosberlin/js7:agent-2-5-0
Note: Current releases should be applied as available from https://hub.docker.com/r/sosberlin/js7
Alternatively, 'plus' container images are available that include a recent PowerShell environment and the JS7 - PowerShell Module:
docker image pull sosberlin/js7:agent-2-5-0-plus
Running the Agent Container
After pulling the Agent image you can run the container with a number of options such as:
#!/bin/sh docker run -dit --rm \ --hostname=js7-agent-primary \ --network=js7 \ --publish=16445:4445 \ --env="RUN_JS_JAVA_OPTIONS=-Xmx256m" \ --env="RUN_JS_USER_ID=$(id -u $USER):$(id -g $USER)" \ --mount="type=volume,src=js7-agent-primary-var,dst=/var/sos-berlin.com/js7/agent/var_4445" \ --name js7-agent-primary \ sosberlin/js7:agent-2-5-0
Explanation:
--network
The above example makes use of a container network - created, for example, using the commanddocker network create js7
- to allow network sharing between containers. Note that any inside ports used by containers are visible within a container network. Therefore an Agent running for the inside port4445
is accessible in conjunction with the container's hostname and the same port within the container network.--publish
The Agent is configured to listen to HTTP port4445
by default. An outside port of the container's host can be mapped to the Agent's inside HTTP port. This is not required for use with a container network, see--network
, however, it will allow direct access to the Agent from the container's host via its outside port .--env=RUN_JS_JAVA_OPTIONS
This allows Java options to be injected into the Agent's container. Preferably this is used to specify memory requirements for the Agent, e.g. with-Xmx256m
.--env=RUN_JS_USER_ID
Inside the container the Agent is operated with thejobscheduler
user account. In order to access files created by the Agent such as log files, and which are mounted to the container's host, it is recommended that you map the account that is starting the container to thejobscheduler
account inside the container. TheRUN_JS_USER_ID
environment variable accepts the User ID and Group ID of the account that will be mapped. The above example makes use of the current user, for details see JS7 - Running Containers for User Accounts.--mount
The following volume mounts are suggested:var
: This folder works as an entry point to the following sub-folders:config
: The configuration folder allows the specification of individual settings for the operation of the Agent - see the sections below and the JS7 - Agent Configuration Items article. Default settings are available on initial operation.logs
: In order to have persistent Agent log files they have to be written to a volume that is mounted for the container. Feel free to adjust the volume name from thesrc
attribute. However, the value of thedst
attribute should not be changed as it reflects the directory hierarchy inside the container.state
: The Agent requires a directory for journal information that should also be persistent. The journal is required to restore the state of orders when restarting the Agent.
Containers offer a number of methods for mounting volumes that include, for example, creating a local folder and mapping the folder to a volume before executing the
docker run
command listed above:Example how to create Docker volumes# example to map volumes to directories on the container's host prior to running the Agent container mkdir -p /home/sos/js7/js7-agent-primary/var docker volume create --driver local --opt o=bind --opt type=none --opt device="/home/sos/js7/js7-agent-primary/var" js7-agent-primary-var
sosberlin/js7:agent-2-5-0
: The name of the base image is the same as that which was previously used with thedocker pull
command. Alternatively this could besosberlin/js7:agent-2-5-0-plus
for use of a "plus" image.
Time Service
It is recommended that a time service is operated on the host which runs the Agent container in order to synchronize the system clock's time.
Log Files
Access to log files is essential to identify problems during installation and operation of containers.
When mounting a volume for log files as explained above you should have access to the files indicated with the JS7 - Log Files and Locations article.
- The
agent.log
file reports general information, warnings and errors. - The
watchdog.log
file includes information about automated restarts of the Agent.
Further Resources
Running the Agent Container from a "plus" Image
- See the JS7 - Agent Installation for Containers with 'plus' images article.
Manage Agents
Configure the Agent
Note that it is not necessary to configure the Agent - it runs out-of-the-box. The default configuration specifies that:
- deployment of objects such as workflows and jobs is not subject to compliance requirements such as non-repudiation.
- HTTP connections are used which expose unencrypted communication between Controller instances and Agent. Authentication is performed by hashed passwords.
Users who intend to operate a compliant and secure job scheduling environment are recommended to familiarize themselves with the JS7 - Agent Configuration for Containers article series.
Build the Agent Image
User who wish to create individual images of the Agent will find instructions in the JS7 - Agent Build of Container Image article.