Docker

Image ¶

Docker Hub contains a repository with images that can be used.

You can mount your print apps in /usr/local/tomcat/webapps/ROOT/print-apps.

You can mount additional font in core/docker/usr/share/fonts/truetype/[font-file], and verity that she is correctly installed by opening the view [base URL]/print/fonts.

Tunings ¶

The docker image can be tuned with several environment variables:

• CATALINA_OPTS: Java startup parameters.
• CONTEXT_PATH: Optional external URL prefix (sub path) when the service is exposed behind a reverse proxy under a sub path (for example /printservice). When set, the container entrypoint will:
  • Prefix all servlet mappings:
    • /metrics becomes /printservice/metrics
    • /print/* becomes /printservice/print/*
    • /sec/print/* becomes /printservice/sec/print/*
  • Copy the UI assets (index + icons) under the sub path (for example /printservice/index.html).
  • Inject a <base href="/printservice/"> tag into the copied UI page so relative links work.
  This mode is intended for proxies/ingresses that forward the prefixed path as-is (no path rewrite).
  The value must start with / and may contain only alphanumeric characters, dots (.), underscores (_), hyphens (-) and slashes (/) (for example /printservice or /api/v1/print). Invalid CONTEXT_PATH values will cause the container to exit with error code 2 during startup.
• DEFAULT_LOG_LEVEL: Set the default log level (defaults to INFO)
• TOMCAT_LOG_LEVEL: Set the tomcat log level (defaults to INFO)
• LOG_LEVEL: Set the mapfish print log level (defaults to INFO)
• SPRING_LOG_LEVEL: Set the Spring log level (defaults to WARN)
• JASPER_LOG_LEVEL: Set the JasperReports log level (defaults to WARN)
• APACHE_LOG_LEVEL: Set the Apache log level (defaults to WARN)
• SQL_LOG_LEVEL: Set the SQL (Hibernate) log level (defaults to WARN)
• SENTRY_LOG_LEVEL: Set the Sentry log level (defaults to ERROR)
• SENTRY_REPORTING_LOG_LEVEL: Starting from what log level to report to Sentry (defaults to WARN)
• TOMCAT_LOG_TYPE:
  • classic (default): The logs are human readable. Access logs are going to stdout and the other logs are going to stderr.
  • json: The logs will be formatted in a JSON suitable for logstash. Access logs are going to stdout and the other logs are going to stderr.
  • logstash: The logs will be formatted in a JSON suitable for logstash (@cee) and sent by syslog/UDP. The access logs are going to stdout in json format. More variables are available for this mode:
    • TOMCAT_LOG_HOST: the target host
    • TOMCAT_LOG_PORT: the target port
• EXTRA_JARS: If set, directory where extra JAR files are taken from. Can be used, for example, to add fonts.
• PRINT_YAML_MAX_ALIASES: Set the YAML max alias, see also (defaults to 50).

Filesystem writes ¶

The container expects to be able to write to some paths at runtime. If you run with a read-only root filesystem, ensure those locations are writable (for example by mounting an emptyDir or other volume), or use an init container to copy the webapp content to a writable volume.

• /usr/local/tomcat/webapps/ROOT/print-apps: created at startup (print apps directory).
• /usr/local/tomcat/temp/mapfish-print/ROOT: used by the graceful shutdown mechanism (docker-pre-stop-print creates stop/stopped files here).
• If CONTEXT_PATH is set:
  • /usr/local/tomcat/webapps/ROOT/WEB-INF/web.xml: rewritten at startup to prefix URL mappings.
  • /usr/local/tomcat/webapps/ROOT<CONTEXT_PATH>: created and populated with UI assets (for example /usr/local/tomcat/webapps/ROOT/printservice).

If you want to tune properties from mapfish-spring.properties You can override them by adding -D options to the CATALINA_OPTS environment variable.

Sentry integration ¶

You can enable Sentry crash reports by adding a parameter to the CATALINA_OPTS environment variable with the DSN provided by sentry: -Dsentry.dsn=https://public:private@host:port/project_id

Other parameters are documented here: https://docs.sentry.io/clients/java/config/

Graceful stop ¶

The container can be stopped gracefully by calling the docker-pre-stop-print script. This script will trigger a graceful stop, by stopping starting new jobs and waiting for the current jobs to finish.

In Kubernetes you can set it as a preStop hook

  lifecycle:
    preStop:
      exec:
        command:
          - /usr/local/tomcat/bin/docker-pre-stop-print
          - $(PRINT_TERMINATION_GRACE_PERIOD_SECONDS)