add comments

be/src/util/s3_util.cpp

@@ -370,6 +370,7 @@ Status S3ClientFactory::convert_properties_to_s3_conf(
  }
  }
  if (auto it = properties.find(S3_PROVIDER); it != properties.end()) {
+ // S3 Provider properties should be case insensitive.
  if (0 == strcasecmp(it->second.c_str(), AZURE_PROVIDER_STRING)) {
  s3_conf->client_conf.provider = io::ObjStorageType::AZURE;
  }

fe/fe-core/src/main/java/org/apache/doris/analysis/CopyStmt.java

@@ -205,6 +205,7 @@ private void analyzeStagePB(StagePB stagePB) throws AnalysisException {
  }
  brokerProperties.put(S3_BUCKET, objInfo.getBucket());
  brokerProperties.put(S3_PREFIX, objInfo.getPrefix());
+ // S3 Provider properties should be case insensitive.
  brokerProperties.put(S3Properties.PROVIDER, objInfo.getProvider().toString().toUpperCase());
  StageProperties stageProperties = new StageProperties(stagePB.getPropertiesMap());
  this.copyIntoProperties.mergeProperties(stageProperties);

fe/fe-core/src/main/java/org/apache/doris/analysis/LoadStmt.java

@@ -527,6 +527,7 @@ private String getProviderFromEndpoint() {
  Map<String, String> properties = brokerDesc.getProperties();
  for (Map.Entry<String, String> entry : properties.entrySet()) {
  if (entry.getKey().equalsIgnoreCase(S3Properties.PROVIDER)) {
+ // S3 Provider properties should be case insensitive.
  return entry.getValue().toUpperCase();
  }
  }

fe/fe-core/src/main/java/org/apache/doris/analysis/StageProperties.java

@@ -135,6 +135,7 @@ private void analyzeStorageProperties() throws AnalysisException {
  }
  properties.put(PREFIX, prefix);
  // analyze provider
+ // S3 Provider properties should be case insensitive.
  String provider = properties.get(PROVIDER).toUpperCase();
  if (!EnumUtils.isValidEnumIgnoreCase(ObjectStoreInfoPB.Provider.class, provider)) {
  throw new AnalysisException("Property " + PROVIDER + " with invalid value " + provider);

fe/fe-core/src/main/java/org/apache/doris/datasource/property/constants/S3Properties.java

@@ -197,6 +197,7 @@ public static Map<String, String> requiredS3TVFProperties(Map<String, String> pr
  private static void checkProvider(Map<String, String> properties) throws DdlException {
  if (properties.containsKey(PROVIDER)) {
  properties.put(PROVIDER, properties.get(PROVIDER).toUpperCase());
+ // S3 Provider properties should be case insensitive.
  if (!PROVIDERS.stream().anyMatch(s -> s.equals(properties.get(PROVIDER).toUpperCase()))) {
  throw new DdlException("Provider must be one of OSS, OBS, AZURE, BOS, COS, S3, GCP");
  }
@@ -330,6 +331,7 @@ public static Cloud.ObjectStoreInfoPB.Builder getObjStoreInfoPB(Map<String, Stri
  builder.setExternalEndpoint(properties.get(S3Properties.EXTERNAL_ENDPOINT));
  }
  if (properties.containsKey(S3Properties.PROVIDER)) {
+ // S3 Provider properties should be case insensitive.
  builder.setProvider(Provider.valueOf(properties.get(S3Properties.PROVIDER).toUpperCase()));
  }
  return builder;

fe/fe-core/src/test/java/org/apache/doris/analysis/StageTest.java

@@ -103,6 +103,7 @@ public void testAnalyzeStorageProperties() throws Exception {
  + "'prefix' = 'tmp_prefix', "
  + "'provider' = 'abc', "
  + "'ak'='tmp_ak', 'sk'='tmp_sk', 'access_type'='aksk');";
+ // S3 Provider will be converted to upper case.
  parseAndAnalyzeWithException(sql, "Property provider with invalid value ABC");
 
  // test getObjectInfoPB

regression-test/framework/src/main/groovy/org/apache/doris/regression/Config.groovy

@@ -630,7 +630,7 @@ class Config {
  } else if (config.s3Source == "huawei") {
  s3Provider = "OBS"
  } else if (config.s3Source == "azure") {
- s3Provider = "Azure"
+ s3Provider = "Azure" // case insensitive test
  } else if (config.s3Source == "gcp") {
  s3Provider = "GCP"
  }