Getting "ambari.properties" details using APIs intead of doing ssh to Ambari Host ?

[#1]

- Many times while working on some issues we want to take a quick look at the "/etc/ambari-server/conf/ambari.properties" without actually doing a SSH to the ambari host.

- In order to access the Ambari Service using the following URL: (here "erie1.example.com" is ambari hostname)

http://erie1.example.com:8080/api/v1/services/AMBARI/components/AMBARI_SERVER

.

- We will find that "ambari.properties" values are being returned as part of the JSON response something like following:

{
  "href" : "http://erie1.example.com:8080/api/v1/services/AMBARI/components/AMBARI_SERVER",
  "RootServiceComponents" : {
    "component_name" : "AMBARI_SERVER",
    "component_version" : "2.4.1.0",
    "server_clock" : 1482322132,
    "service_name" : "AMBARI",
    "properties" : {
      "AAA" : "BBB",
      "agent.package.install.task.timeout" : "1800",
      "agent.stack.retry.on_repo_unavailability" : "false",
      "agent.stack.retry.tries" : "5",
      "agent.task.timeout" : "900",
      "agent.threadpool.size.max" : "25",
      "ambari-server.user" : "root",
      "ambari.python.wrap" : "ambari-python-wrap",
      "bootstrap.dir" : "/var/run/ambari-server/bootstrap",
      "bootstrap.script" : "/usr/lib/python2.6/site-packages/ambari_server/bootstrap.py",
      "bootstrap.setup_agent.script" : "/usr/lib/python2.6/site-packages/ambari_server/setupAgent.py",
      "check_database_skipped" : "false",
      "client.threadpool.size.max" : "25",
      "common.services.path" : "/var/lib/ambari-server/resources/common-services",
      "custom.action.definitions" : "/var/lib/ambari-server/resources/custom_action_definitions",
      "extensions.path" : "/var/lib/ambari-server/resources/extensions",
      "http.strict-transport-security" : "max-age=31536000",
      "http.x-frame-options" : "DENY",
      "http.x-xss-protection" : "1; mode=block",
      "java.home" : "/usr/jdk64/jdk1.8.0_60",
      "java.releases" : "jdk1.8,jdk1.7",
      "java.version" : "1.8",
      "jce.download.supported" : "true",
      "jce.name" : "jce_policy-8.zip",
      "jdk.download.supported" : "true",
      "jdk.name" : "jdk-8u60-linux-x64.tar.gz",
      "jdk1.7.desc" : "Oracle JDK 1.7 + Java Cryptography Extension (JCE) Policy Files 7",
      "jdk1.7.dest-file" : "jdk-7u67-linux-x64.tar.gz",
      "jdk1.7.home" : "/usr/jdk64/",
      "jdk1.7.jcpol-file" : "UnlimitedJCEPolicyJDK7.zip",
      "jdk1.7.jcpol-url" : "http://public-repo-1.hortonworks.com/ARTIFACTS/UnlimitedJCEPolicyJDK7.zip",
      "jdk1.7.re" : "(jdk.*)/jre",
      "jdk1.7.url" : "http://public-repo-1.hortonworks.com/ARTIFACTS/jdk-7u67-linux-x64.tar.gz",
      "jdk1.8.desc" : "Oracle JDK 1.8 + Java Cryptography Extension (JCE) Policy Files 8",
      "jdk1.8.dest-file" : "jdk-8u60-linux-x64.tar.gz",
      "jdk1.8.home" : "/usr/jdk64/",
      "jdk1.8.jcpol-file" : "jce_policy-8.zip",
      "jdk1.8.jcpol-url" : "http://public-repo-1.hortonworks.com/ARTIFACTS/jce_policy-8.zip",
      "jdk1.8.re" : "(jdk.*)/jre",
      "jdk1.8.url" : "http://public-repo-1.hortonworks.com/ARTIFACTS/jdk-8u60-linux-x64.tar.gz",
      "jdk_location" : "http://erie1.example.com:8080/resources/",
      "kerberos.keytab.cache.dir" : "/var/lib/ambari-server/data/cache",
      "metadata.path" : "/var/lib/ambari-server/resources/stacks",
      "mpacks.staging.path" : "/var/lib/ambari-server/resources/mpacks",
      "org.apache.ambari.contrib.snmp.script" : "/root/SNMP_Demo/snmp_mib_script.sh",
      "pid.dir" : "/var/run/ambari-server",
      "recommendations.artifacts.lifetime" : "1w",
      "recommendations.dir" : "/var/run/ambari-server/stack-recommendations",
      "resources.dir" : "/var/lib/ambari-server/resources",
      "rolling.upgrade.skip.packages.prefixes" : "",
      "security.server.disabled.ciphers" : "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384|TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384|TLS_RSA_WITH_AES_256_CBC_SHA256|TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384|TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384|TLS_DHE_RSA_WITH_AES_256_CBC_SHA256|TLS_DHE_DSS_WITH_AES_256_CBC_SHA256|TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA|TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA|TLS_RSA_WITH_AES_256_CBC_SHA|TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA|TLS_ECDH_RSA_WITH_AES_256_CBC_SHA|TLS_DHE_RSA_WITH_AES_256_CBC_SHA|TLS_DHE_DSS_WITH_AES_256_CBC_SHA|TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256|TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256|TLS_RSA_WITH_AES_128_CBC_SHA256|TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256|TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256|TLS_DHE_RSA_WITH_AES_128_CBC_SHA256|TLS_DHE_DSS_WITH_AES_128_CBC_SHA256|TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA|TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA|TLS_RSA_WITH_AES_128_CBC_SHA|TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA|TLS_ECDH_RSA_WITH_AES_128_CBC_SHA|TLS_DHE_RSA_WITH_AES_128_CBC_SHA|TLS_DHE_DSS_WITH_AES_128_CBC_SHA|TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA|TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA|TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA|TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA|SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA|SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA|TLS_EMPTY_RENEGOTIATION_INFO_SCSV|TLS_DH_anon_WITH_AES_256_CBC_SHA256|TLS_ECDH_anon_WITH_AES_256_CBC_SHA|TLS_DH_anon_WITH_AES_256_CBC_SHA|TLS_DH_anon_WITH_AES_128_CBC_SHA256|TLS_ECDH_anon_WITH_AES_128_CBC_SHA|TLS_DH_anon_WITH_AES_128_CBC_SHA|TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA|SSL_DH_anon_WITH_3DES_EDE_CBC_SHA|SSL_RSA_WITH_DES_CBC_SHA|SSL_DHE_RSA_WITH_DES_CBC_SHA|SSL_DHE_DSS_WITH_DES_CBC_SHA|SSL_DH_anon_WITH_DES_CBC_SHA|SSL_RSA_EXPORT_WITH_DES40_CBC_SHA|SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA|SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA|SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA|TLS_RSA_WITH_NULL_SHA256|TLS_ECDHE_ECDSA_WITH_NULL_SHA|TLS_ECDHE_RSA_WITH_NULL_SHA|SSL_RSA_WITH_NULL_SHA|TLS_ECDH_ECDSA_WITH_NULL_SHA|TLS_ECDH_RSA_WITH_NULL_SHA|TLS_ECDH_anon_WITH_NULL_SHA|SSL_RSA_WITH_NULL_MD5|TLS_KRB5_WITH_3DES_EDE_CBC_SHA|TLS_KRB5_WITH_3DES_EDE_CBC_MD5|TLS_KRB5_WITH_DES_CBC_SHA|TLS_KRB5_WITH_DES_CBC_MD5|TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA|TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5",
      "security.server.disabled.protocols" : "SSL|SSLv2|SSLv2Hello|SSLv3|TLSv1.0|TLSv1.1",
      "security.server.keys_dir" : "/var/lib/ambari-server/keys",
      "server.connection.max.idle.millis" : "900000",
      "server.execution.scheduler.isClustered" : "false",
      "server.execution.scheduler.maxDbConnections" : "5",
      "server.execution.scheduler.maxThreads" : "5",
      "server.execution.scheduler.misfire.toleration.minutes" : "480",
      "server.fqdn.service.url" : "http://169.254.169.254/latest/meta-data/public-hostname",
      "server.http.session.inactive_timeout" : "1800",
      "server.jdbc.connection-pool" : "internal",
      "server.jdbc.database" : "postgres",
      "server.jdbc.database_name" : "ambari",
      "server.jdbc.postgres.schema" : "ambari",
      "server.jdbc.user.name" : "ambari",
      "server.jdbc.user.passwd" : "/etc/ambari-server/conf/password.dat",
      "server.os_family" : "redhat6",
      "server.os_type" : "redhat6",
      "server.persistence.type" : "local",
      "server.stages.parallel" : "true",
      "server.task.timeout" : "1200",
      "server.tmp.dir" : "/var/lib/ambari-server/data/tmp",
      "server.version.file" : "/var/lib/ambari-server/resources/version",
      "shared.resources.dir" : "/usr/lib/ambari-server/lib/ambari_commons/resources",
      "skip.service.checks" : "false",
      "stackadvisor.script" : "/var/lib/ambari-server/resources/scripts/stack_advisor.py",
      "ulimit.open.files" : "10000",
      "user.inactivity.timeout.default" : "0",
      "user.inactivity.timeout.role.readonly.default" : "0",
      "views.ambari.request.connect.timeout.millis" : "60000",
      "views.ambari.request.read.timeout.millis" : "45000",
      "views.http.strict-transport-security" : "max-age=31536000",
      "views.http.x-frame-options" : "SAMEORIGIN",
      "views.http.x-xss-protection" : "1; mode=blocki",
      "views.request.connect.timeout.millis" : "30000",
      "views.request.read.timeout.millis" : "60000",
      "webapp.dir" : "/usr/lib/ambari-server/web"
    }
  },
  "hostComponents" : [
    {
      "href" : "http://erie1.example.com:8080/api/v1/services/AMBARI/hosts/erie1.example.com/hostComponents/AMBARI_SERVER",
      "RootServiceHostComponents" : {
        "component_name" : "AMBARI_SERVER",
        "host_name" : "erie1.example.com",
        "service_name" : "AMBARI"
      }
    }
  ]
}

.

**NOTE:** The HttpResponse that we are getting only shows the current state of the "/etc/ambari-server/conf/ambari.properties", Which means even if we make a new change in the properties file (like adding a new property AAA = BBB) it will be immediately reflected when we get the HttpResponse. But ambari-server will read this properties file only during the restart. So any changes made to the ambari.properties requires a restart. .

.