dropwizard-config-updater

Dropwizard command for config update

Should be used for updating configuration just after new application version installation (before startup).

Works with dropwizard 1.x and 2.x.

Arguments and behaviour are almost equivalent to cli module (full argument names works a bit differently).

For general workflow and update rules read root readme.

Setup

Maven:

<dependency>
  <groupId>ru.vyarus</groupId>
  <artifactId>dropwizard-config-updater</artifactId>
  <version>1.4.2</version>
</dependency>

Gradle:

implementation 'ru.vyarus:dropwizard-config-updater:1.4.2'

Register bundle:

bootstrap.addBundle(new UpdateConfigBundle());

Usage

java -jar yourApp.jar update-config config.yml update.yml

This will merge update.yml into config.yml file (creating backup of original file). Config.yml may not exist (initial installation case).

Update file may be a local file, path from classpath or any URL (e.g. to load new config from remote server).

NOTE: classpath case is useful if new configuration was packaged inside application jar. E.g.:

java -jar yourApp.jar update-config config.yml /config/default.yml

Options

usage: java -jar project.jar
       update-config [-b] [--backup-dir BACKUPDIR]
       [-d DELETE [DELETE ...]] [-e ENV [ENV ...]] [-v] [-s] [-i]
       [--dry-run] [-h] file update

Update configuration file from new file

positional arguments:
  file                   Path to  updating  configuration  file  (might not
                         exist)
  update                 Path to new configuration  file.  Could  also be a
                         classpath path or any URL.

named arguments:
  -b, --no-backup        Don't create  backup  before  configuration update
                         (default: true)
  --backup-dir BACKUPDIR
                         Directory to store backup in
  -d DELETE [DELETE ...], --delete-path DELETE [DELETE ...]
                         Delete properties from  the  current config before
                         update
  -e ENV [ENV ...], --env ENV [ENV ...]
                         Variables to replace  (name=value)  or  path(s) to
                         properties file with  variables  (could  also be a
                         classpath path or any URL)
  -v, --no-validate      Don't   validate   the    resulted   configuration
                         (default: true)
  -s, --non-strict       Don't fail if specified  properties  file does not
                         exists (default: true)
  -i, --verbose          Show debug logs (default: false)
  --dry-run              Test  run  without   file  modification  (default:
                         false)
  -h, --help             show this help message and exit

Dry run

You can run with --dry-run option to test migration: this is complete migration process, but without actual configuration updating (and no backup creation). Updated file would only be printed into console for consultation.

java -jar yourApp.jar update-config --dry-run config.yml /config/default.yml

Delete props

To delete deprecated property or replace property value use -d flag (or --delete-path=).

For example, to remove list sub-tree under prop1:

java -jar yourApp.jar update-config config.yml update.yml -d prop1.list

You can specify multiple properties:

java -jar yourApp.jar update-config config.yml update.yml -d prop1.list prop2

For full flag name:

java -jar yourApp.jar update-config config.yml update.yml --delete-path prop1.list prop2

NOTE: you can use both '.' and '/' as level separator ('/' is useful when property name contains dots)

Variables

To specify environment variables use -e (or --env=):

java -jar yourApp.jar update-config config.yml update.yml -e name=foo

If update.yaml contains:

prop: #{name}

then it would be replaced as:

prop: foo

NOTE: not specified variables are not replaced!

Multiple variables:

java -jar yourApp.jar update-config config.yml update.yml -e name=foo var2=other

Other syntax:

java -jar yourApp.jar update-config config.yml update.yml --env name=foo var2=other

Defaults

By default, all system environment variables (System.getenv()) are available, so if on target host variables already declared in environment, it would be replaced automatically.

Variables file

It is also possible to use properties files for variables definition:

vars.properties

name=foo
var2=other

java -jar yourApp.jar update-config config.yml update.yml -e vars.properties

Multiple files could be declared. Files and direct variable declaration could be mixed:

java -jar yourApp.jar update-config config.yml update.yml -e vars.properties custom=name

Variables file could be an url or classpath path (same as with update file):

java -jar yourApp.jar update-config config.yml update.yml -e http://mydomian.com/vars.properties

By default, error is thrown if specified variables file does not exist. But you can use -s (--non-strict) option to ignore not existing files.