Package org.apache.unomi.shell.migration.service

Class MigrationContext

java.lang.Object
org.apache.unomi.shell.migration.service.MigrationContext
public class MigrationContext extends Object
This class is instantiated for each migration process, it contains useful methods to handle the current migration lifecycle. This class allow for keeping track of the migration steps by persisting the steps and there state on the FileSystem, allowing for a migration to be able to restart from a failure in case it happens. This class allow also for logging the migration informations depending on the current context: - if executed in karaf shell using a karaf shell session, then the logging will be done in the shell console - if executed outside karaf shell using OSGI service direct, then the logging will be done using classical logger systems This class allow also to do a best effort on missing configuration information, by prompting questions in the karaf shell (not supported in case direct OSGI service usage)

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    MigrationContext.MigrationStep
    A simple migration step to be performed

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    MigrationContext(org.apache.karaf.shell.api.console.Session session, MigrationConfig migrationConfig)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    askUserWithAuthorizedAnswer(String msg, List<String> authorizedAnswer)
    This method allow you to ask a question to the user.
    String
    askUserWithDefaultAnswer(String msg, String defaultAnswer)
    This will ask a question to the user and return the default answer if the user does not answer.
    protected void
    cleanHistory()
    Clean history from FileSystem
    boolean
    getConfigBoolean(String name)
    Get config for property name, in case the property doesn't exist on file system config file Best effort will be made to prompt question in karaf shell to get the needed information
    String
    getConfigString(String name)
    Get config for property name, in case the property doesn't exist on file system config file Best effort will be made to prompt question in karaf shell to get the needed information
    org.apache.http.impl.client.CloseableHttpClient
    getHttpClient()
    This HTTP client is configured to be used for ElasticSearch requests to be able to perform migrations requests.
    void
    performMigrationStep(String stepKey, MigrationContext.MigrationStep step)
    this method allow for migration step execution: - in case the history already contains the given stepKey as COMPLETED, then the step won't be executed - in case the history doesn't contain the given stepKey, then the step will be executed Also this method is keeping track of the history by persisting it on the FileSystem.
    void
    printException(String msg)
    Same as above without stacktrace
    void
    printException(String msg, Throwable t)
    Print an exception along with a message in the console.
    void
    printMessage(String msg)
    Print a message in the console.
    String
    promptMessageToUser(String msg)
    This method allow you to prompt a message to the user.
    protected void
    setHttpClient(org.apache.http.impl.client.CloseableHttpClient httpClient)
     
    protected void
    tryRecoverFromHistory()
    Try to recover from a previous run I case we found an existing history we will ask if we want to recover or if we want to restart from the beginning (it is also configurable using the conf: recoverFromHistory)

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • MigrationContext

      protected MigrationContext(org.apache.karaf.shell.api.console.Session session, MigrationConfig migrationConfig)

  • Method Details

    • tryRecoverFromHistory

      protected void tryRecoverFromHistory() throws IOException
      Try to recover from a previous run I case we found an existing history we will ask if we want to recover or if we want to restart from the beginning (it is also configurable using the conf: recoverFromHistory)
      Throws:
      IOException

    • performMigrationStep

      public void performMigrationStep(String stepKey, MigrationContext.MigrationStep step) throws Exception
      this method allow for migration step execution: - in case the history already contains the given stepKey as COMPLETED, then the step won't be executed - in case the history doesn't contain the given stepKey, then the step will be executed Also this method is keeping track of the history by persisting it on the FileSystem.
      Parameters:
      stepKey - the key of the given step
      step - the step to be performed
      Throws:
      IOException
      Exception

    • cleanHistory

      protected void cleanHistory() throws IOException
      Clean history from FileSystem
      Throws:
      IOException

    • askUserWithDefaultAnswer

      public String askUserWithDefaultAnswer(String msg, String defaultAnswer) throws IOException
      This will ask a question to the user and return the default answer if the user does not answer.
      Parameters:
      msg - String message to ask
      defaultAnswer - String default answer
      Returns:
      the user's answer
      Throws:
      IOException - if there was a problem reading input from the console

    • askUserWithAuthorizedAnswer

      public String askUserWithAuthorizedAnswer(String msg, List<String> authorizedAnswer) throws IOException
      This method allow you to ask a question to the user. The answer is controlled before being return so the question will be ask until the user enter one the authorized answer
      Parameters:
      msg - String message to ask
      authorizedAnswer - Array of possible answer, all answer must be in lower case
      Returns:
      the user answer
      Throws:
      IOException - if there was an error retrieving an answer from the user on the console

    • promptMessageToUser

      public String promptMessageToUser(String msg)
      This method allow you to prompt a message to the user. No control is done on the answer provided by the user.
      Parameters:
      msg - String message to prompt
      Returns:
      the user answer

    • printMessage

      public void printMessage(String msg)
      Print a message in the console.
      Parameters:
      msg - the message to print out with a newline

    • printException

      public void printException(String msg, Throwable t)
      Print an exception along with a message in the console.
      Parameters:
      msg - the message to print out with a newline
      t - the exception to dump in the shell console after the message

    • printException

      public void printException(String msg)
      Same as above without stacktrace
      Parameters:
      msg - the message to print out with a newline

    • getConfigString

      public String getConfigString(String name) throws IOException
      Get config for property name, in case the property doesn't exist on file system config file Best effort will be made to prompt question in karaf shell to get the needed information
      Parameters:
      name - the name of the property
      Returns:
      the value of the property
      Throws:
      IOException

    • getConfigBoolean

      public boolean getConfigBoolean(String name) throws IOException
      Get config for property name, in case the property doesn't exist on file system config file Best effort will be made to prompt question in karaf shell to get the needed information
      Parameters:
      name - the name of the property
      Returns:
      the value of the property
      Throws:
      IOException

    • getHttpClient

      public org.apache.http.impl.client.CloseableHttpClient getHttpClient()
      This HTTP client is configured to be used for ElasticSearch requests to be able to perform migrations requests.
      Returns:
      the http client.

    • setHttpClient

      protected void setHttpClient(org.apache.http.impl.client.CloseableHttpClient httpClient)