java/src/main/com/google/appengine/tools/development/EnvironmentVariableChecker.java

   1 package com.google.appengine.tools.development;
   2
   3 import com.google.apphosting.utils.config.AppEngineConfigException;
   4 import com.google.apphosting.utils.config.AppEngineWebXml;
   5 import com.google.common.annotations.VisibleForTesting;
   6 import com.google.common.collect.ImmutableList;
   7
   8 import java.io.File;
   9 import java.util.List;
  10 import java.util.Map;
  11 import java.util.logging.Logger;
  12
  13 /**
  14  * Checker for reporting differences between environment variables specified
  15  * in an application's appengine-web.xml files and values from
  16  * {@link System#getenv()}.
  17  * <p>
  18  * Users can specify values for environment variables in an application's
  19  * WEB-INF/appengine-web.xml file. It is not possible to set environment
  20  * variables after JVM startup so we report mismatches based on the current
  21  * reporting policy.
  22  *
  23  */
  24 class EnvironmentVariableChecker {
  25   @VisibleForTesting
  26   static final Logger LOGGER = Logger.getLogger(EnvironmentVariableChecker.class.getName());
  27
  28   /**
  29    * Enum for reporting policy.
  30    */
  31   static enum MismatchReportingPolicy {
  32     /** Report mismatches by logging. */
  33     LOG,
  34     /** Report mismatches by throwing an {@link AppEngineConfigException} */
  35     EXCEPTION,
  36     /** Don't report mismatches. */
  37     NONE
  38   }
  39
  40   private final MismatchReportingPolicy mismatchReportingPolicy;
  41   private final ImmutableList.Builder<Mismatch> mismatchListBuilder = ImmutableList.builder();
  42
  43   EnvironmentVariableChecker(MismatchReportingPolicy mismatchReportingPolicy) {
  44     this.mismatchReportingPolicy = mismatchReportingPolicy;
  45   }
  46
  47   void add(AppEngineWebXml appEngineWebXml, File appEngineWebXmlFile) {
  48     for (Map.Entry<String, String> entry : appEngineWebXml.getEnvironmentVariables().entrySet()) {
  49       if (!entry.getValue().equals(System.getenv(entry.getKey()))) {
  50         mismatchListBuilder.add(new Mismatch(entry.getKey(), System.getenv(entry.getKey()),
  51             entry.getValue(), appEngineWebXmlFile));
  52       }
  53     }
  54   }
  55
  56   void check() throws AppEngineConfigException {
  57     List<Mismatch> mismatches = mismatchListBuilder.build();
  58     if (!mismatches.isEmpty()) {
  59       String msg =
  60           "One or more environment variables have been configured in appengine-web.xml that have "
  61           + "missing or different values in your local environment. We recommend you use system "
  62           + "properties instead, but if you are interacting with legacy code that requires "
  63           + "specific environment variables to have specific values, please set these environment "
  64           + "variables in your environment before running.\n"
  65           + mismatches;
  66
  67       if (mismatchReportingPolicy == MismatchReportingPolicy.LOG) {
  68         LOGGER.warning(msg);
  69       } else if (mismatchReportingPolicy == MismatchReportingPolicy.EXCEPTION) {
  70         throw new IncorrectEnvironmentVariableException(msg, mismatches);
  71       }
  72     }
  73
  74   }
  75
  76   @VisibleForTesting
  77   static class Mismatch {
  78     private final String environmentVariableName;
  79     private final String environmentVariableValue;
  80     private final String appEngineWebXmlValue;
  81     private final File appEngineWebXmlFile;
  82
  83     Mismatch(String environmentVariableName, String environmentVariableValue,
  84         String appEngineWebXmlValue, File appEngineWebXmlFile) {
  85       this.environmentVariableName = environmentVariableName;
  86       this.environmentVariableValue = environmentVariableValue;
  87       this.appEngineWebXmlValue = appEngineWebXmlValue;
  88       this.appEngineWebXmlFile = appEngineWebXmlFile;
  89     }
  90
  91     /**
  92      * @return the environmentVariableName
  93      */
  94     public String getEnvironmentVariableName() {
  95       return environmentVariableName;
  96     }
  97
  98     /**
  99      * @return the environmentVariableValue
 100      */
 101     public String getEnvironmentVariableValue() {
 102       return environmentVariableValue;
 103     }
 104
 105     /**
 106      * @return the appEngineWebXmlValue
 107      */
 108     public String getAppEngineWebXmlValue() {
 109       return appEngineWebXmlValue;
 110     }
 111
 112     /**
 113      * @return the appEngineWebXmlFile
 114      */
 115     public File getAppEngineWebXmlFile() {
 116       return appEngineWebXmlFile;
 117     }
 118
 119     @Override
 120     public int hashCode() {
 121       final int prime = 31;
 122       int result = 1;
 123       result =
 124           prime * result + ((appEngineWebXmlFile == null) ? 0 : appEngineWebXmlFile.hashCode());
 125       result =
 126           prime * result + ((appEngineWebXmlValue == null) ? 0 : appEngineWebXmlValue.hashCode());
 127       result = prime * result
 128           + ((environmentVariableName == null) ? 0 : environmentVariableName.hashCode());
 129       result = prime * result
 130           + ((environmentVariableValue == null) ? 0 : environmentVariableValue.hashCode());
 131       return result;
 132     }
 133
 134     @Override
 135     public boolean equals(Object obj) {
 136       if (this == obj) {
 137         return true;
 138       }
 139       if (obj == null) {
 140         return false;
 141       }
 142       if (getClass() != obj.getClass()) {
 143         return false;
 144       }
 145       Mismatch other = (Mismatch) obj;
 146       if (appEngineWebXmlFile == null) {
 147         if (other.appEngineWebXmlFile != null) {
 148           return false;
 149         }
 150       } else if (!appEngineWebXmlFile.equals(other.appEngineWebXmlFile)) {
 151         return false;
 152       }
 153       if (appEngineWebXmlValue == null) {
 154         if (other.appEngineWebXmlValue != null) {
 155           return false;
 156         }
 157       } else if (!appEngineWebXmlValue.equals(other.appEngineWebXmlValue)) {
 158         return false;
 159       }
 160       if (environmentVariableName == null) {
 161         if (other.environmentVariableName != null) {
 162           return false;
 163         }
 164       } else if (!environmentVariableName.equals(other.environmentVariableName)) {
 165         return false;
 166       }
 167       if (environmentVariableValue == null) {
 168         if (other.environmentVariableValue != null) {
 169           return false;
 170         }
 171       } else if (!environmentVariableValue.equals(other.environmentVariableValue)) {
 172         return false;
 173       }
 174       return true;
 175     }
 176
 177     @Override
 178     public String toString() {
 179       return "Mismatch environmentVariableName=" + environmentVariableName
 180           + " environmentVariableValue=" + environmentVariableValue
 181           + " appEngineWebXmlValue=" + appEngineWebXmlValue
 182           + " appEngineWebXmlFile=" + appEngineWebXmlFile;
 183     }
 184   }
 185
 186   @VisibleForTesting
 187   static class IncorrectEnvironmentVariableException extends
 188       AppEngineConfigException {
 189
 190     private final List<Mismatch> mismatches;
 191     private IncorrectEnvironmentVariableException(String msg, List<Mismatch> mismatches) {
 192       super(msg);
 193       this.mismatches = mismatches;
 194     }
 195
 196     public List<Mismatch> getMismatches() {
 197       return mismatches;
 198     }
 199   }
 200 }