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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  of the Agent container image that corresponds to the JS7 release in use, for example:

docker image pull sosberlin/jobschedulerjs7: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

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the Agent Container

After pulling the Agent image you can run the container with a number of options like thissuch as:

#!/bin/sh

docker run -dit --rm \
      --user="$(id -u $USER):$(id -g $USER)" \
      --hostname=js7-agent-2-0-primary \
      --network=js7 \
      --publish=1444516445:4445 \
      --env="RUN_JS_HTTPJAVA_PORTOPTIONS=14445-Xmx256m" \
      --env="RUN_JS_JAVAUSER_OPTIONSID=-Xmx256m" \
      --mount="type=volume,src=js7-agent-2-0-primary-config,dst=/var/sos-berlin.com/js7/agent/var_4445/config$(id -u $USER):$(id -g $USER)" \
      --mount="type=volume,src=js7-agent-2-0-primary-logs,dst=/var/sos-berlin.com/js7/agent/var_4445/logs" \
      --mount="type=volume,src=js7-agent-2-0-primary-state,dst=/var/sos-berlin.com/js7/agent/var_4445/state" \
      --name js7-agent-2-0-0-primary \
      sosberlin/jobschedulerjs7:agent-2-05-0

Explanations:

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Explanation:

• --network The above example makes use of a Docker container network - created e.g. with , for example, using the command docker network create js7  - to allow network sharing between containers. Consider Note that any inside ports used by Docker containers are visible within a Docker networkcontainer network. Therefore an Agent running for the inside port 4445 is accessible in conjunction with the container's hostname and the same port within the Docker container network.
• --publish The Agent is prepared configured to listen to the HTTP port 4445 by default. An outside port of the Docker container's host can be mapped to the Agent's inside HTTP port. This is not required for use with a Docker container network, see --network, however, it will allow direct access to the Agent from the Docker container's host by via its outside port .
• --env=RUN_JS_HTTP_PORT Consider to specify the same outside port that is used with the --publish option to map an outside port to the inside HTTP port.--env=JAVA_OPTIONS This allows to inject any Java options to be injected into the Agent's container. Preferably this is used to specify memory requirements of an for the Agent, e.g. with -Xmx256m.
• --mountenv=RUN_JS_USER_ID Inside the container the Agent is operated with the jobscheduler 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 the jobscheduler account inside the container. The RUN_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 The following volume mounts are suggested:
  • var: This folder works as an entry point to the following sub-folders:
    • config: The
    optional
    • configuration folder allows
    to specify
    • the specification of individual settings for
    Agent operation, see below chapters
    • the operation of the Agent - see the sections below and the JS7 - Agent Configuration Items article.
    Without this folder the default
    • Default settings are
    used
    • available on initial operation.
    • logs: In order to have persistent Agent log files
    persisted
    • they have to be written to a volume that is mounted for the container. Feel free to adjust the volume name from the src attribute
    , however
    • . However, the value of the dst 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
    persisted
    • persistent. The journal is required to restore the state of orders when restarting the Agent.

Configuring an Agent

Consider that it is not required to configure an Agent - it runs out-of-the-box. Zero configuration includes that

• deployment of objects, e.g. workflows and jobs, is not subject to compliance requirements such as non-repudiation.
• HTTP connections are used that expose unencrypted communication between Controller and Agent and that are secured by hashed passwords.

Users who intend to operate a compliant and secure job scheduling environment should consider the explanations for

• deployment of objects with digital signatures that can be used to restrict and to verify who deploys a given object such as a workflow.
• HTTPS connections that encrypt communication and that include mutual authentication by certificates without use of passwords.

Compliance: Use of Signing Certificates

Agents accept deployments for a number of objects such as workflows from a Controller only if such objects are digitally signed.

• If JOC Cockpit is operated for Security Level Low then a single X.509 private key assigned to the JOC Cockpit root account is used to sign any objects by any JOC Cockpit accounts.
• If JOC Cockpit is operated for Security Level Medium or High then each account that deploys objects has to own an individual X.509 private key or PGP private key.

To verify the signature of an object the Agent has to apply the public key or certificate that matches the private key used for signing with JOC Cockpit.

• If X.509 private keys are used for signing of objects then the Root CA Certificate or Intermediate CA Certificate that was used to sign the respective private key has to be in place with the Agent.
• If PGP private keys are used for signing of objects then the public key matching the signing key has to be in place with the Agent.
• The Agent expects certificates/public keys from the following locations:
  • X.509 Certificates
    • Location
      • Windows: C:\ProgramData\sos-berlin.com\js7\agent\var_4445\config\private\trusted-x509-keys
      • Unix: /var/sos-berlin.com/js7/agent/var_4445/config/private/trusted-x509-keys
    • The expected X.509 certificate format is PEM. Certificates can be added from any file names with the extension .pem.
    • Consider that instead of individual certificates per signing key the Root CA Certificate or Intermediate CA Certificate that was used to sign the private keys is sufficient.
  • PGP Public Keys
    • Location
      • Windows: C:\ProgramData\sos-berlin.com\js7\agent\var_4445\config\private\trusted-pgp-keys
      • Unix: /var/sos-berlin.com/js7/agent/var_4445/config/private/trusted-pgp-keys
    • PGP public keys are expected in ASCII armored format. They can be added from any file names with the extension .asc.
    • Consider that for each PGP private key that is used for signing the corresponding public key has to be available with the Agent.
  • By default the Agent ships with an X.509 certificate of SOS that matches the default signing key available with the JOC Cockpit root account.
• In order to add individual certificates/public keys add the respective files to the above location corresponding the key type. To revoke certificates/public keys accordingly remove the respective files from the above location matching the key type.
• The above locations for certificates/public keys can be accessed from the Docker volume specified with the --mount option for the Agent's container directory /var/sos-berlin.com/js7/agent/var_4445/config. The locations for X.509 certificates and PGP public keys are available from sub-directories.

Security: Use with HTTPS Connections

The Agent by default is prepared for connections by Controllers using the HTTP and the HTTPS protocols. 

In order to activate HTTPS consider the following prerequisites.

Provide Keystore, Truststore and Configuration for Mutual Authentication

Connections to Agents are established from a Controller. If the HTTPS protocol is used then in addition to securing the communication channel the Agent requires mutual authentication.

Agent Keystore and Truststore

• The Controller's private key has to be created for Server Authentication and Client Authentication extended key usages.
• The Agent is provided
  • a keystore that holds its private key, certificate, Root CA Certificate and optionally Intermediate CA Certificate.
  • a truststore that holds the certificate chain - consisting of Root CA Certificate and optionally Intermediate CA Certificate - required to verify the Controller's certificate.
• Keystores and truststores are files in PKCS12 format, usually with a .p12 extension. They should be added to the following locations:
  • Keystore
    • Windows: C:\ProgramData\sos-berlin.com\js7\agent\var_4445\config\private\https-keystore.p12
    • Unix: /var/sos-berlin.com/js7/agent/var_4445/config/private/https-keystore.p12
  • Truststore
    • Windows: C:\ProgramData\sos-berlin.com\js7\agent\var_4445\config\private\https-truststore.p12
    • Unix: /var/sos-berlin.com/js7/agent/var_4445/config/private/https-truststore.p12

Agent Configuration

• The Agent's private.conf configuration file has to be added the following configuration items. For details see JS7 - Agent Configuration
  • Mutual Authentication

    • Code Block
      language bash title Agent Configuration for Mutual Authentication linenumbers true
      js7 { auth { # User accounts for https connections users { # Controller account for connections by primary/secondary Controller instance Controller { distinguished-names=[ "DNQ=SOS CA, CN=js7-controller-primary, OU=IT, O=SOS, L=Berlin, ST=Berlin, C=DE", "DNQ=SOS CA, CN=js7-controller-secondary, OU=IT, O=SOS, L=Berlin, ST=Berlin, C=DE" ] } } }

    • This setting specifies the distinguished names that are available from the subjects of Controller certificates. Consider that the common name (CN) attribute specifies the hostname of a Controller. The configuration authenticates a given Controller as the distinguished name is unique for a server certificate and therefore replaces use of passwords.
  • Keystore and truststore locations:

    • Code Block
      language bash title Agent Configuration for Keystore and Truststore Locations linenumbers true
      js7 { web { # Locations of keystore and truststore files for HTTPS connections https { keystore { # Default: ${js7.config-directory}"/private/https-keystore.p12" file=${js7.config-directory}"/private/https-keystore.p12" key-password=jobscheduler store-password=jobscheduler } truststores=[ { # Default: ${js7.config-directory}"/private/https-truststore.p12" file=${js7.config-directory}"/private/https-truststore.p12" store-password=jobscheduler } ] } } }

    • The above configuration items specify the locations of keystore and truststore.
    • Consider optional use of a key password and store password for keystores and of a store password for truststores.

Run Agent Container for HTTPS Connections

The following additional arguments are required for HTTPS connections:

#!/bin/sh

docker run -dit --rm \
      ...
      --publish=14443:4443 \
      --env="RUN_JS_HTTPS_PORT=14443" \
      ...

Explanations:

• --publish The Agent image is prepared to accept HTTPS requests on port 4443. If the Agent is not operated in a Docker network then an outside port of the Docker host has to be mapped to the inside HTTPS port 4443. The same port has to be assigned the RUN_JS_HTTPS_PORT environment variable.
• --env=RUN_JS_HTTPS_PORT The port assigned this environment variable is the same as the outside HTTP port specified with the --publish option.

Note:

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• • 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:
    
    

    Code Block
    language bash title Example how to create Docker volumes linenumbers true
    # 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 the docker pull command. Alternatively this could be sosberlin/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

• JS7 - Management of Standalone Agents
• JS7 - Management of Agent Clusters

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

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