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Oracle Cloud Infrastructure and SSH Keys – Jump!

Jump!

In our Trivadis Oracle Cloud Infrastructure training environments, we never use direct access to an application or database server by a public IP address. For this case, we use an Oracle Linux based bastion host which acts as a jump host. For security reasons, I never put any SSH keys on a bastion host to connect from there to the target instances. If your bastion host is compromitted, your SSH keys are lost! In one of the last trainings, some participants had problems with. So I decided to blog about. This blog post shows you the different methods to connect to an Oracle Cloud Infrastructure private/public network by using a bastion host. 

SSH Keys

Oracle Cloud Infrastructure Linux based offerings like compute instances and virtual machines for databases are accessible by SSH key as per default. For working with these machines, I use these three types of SSH keys:

  • id_rsa_oci – Private key generated by ssh-keygen
  • id_rsa_oci.pub – Public key generated by ssh-keygen
  • id_rsa_oci.ppk – Puttygen-converted private key

This gives me the flexibility, to connect to running OCI instances on different ways like Putty, MobaXterm, Windows Subsystem for Linux, WinSCP etc. 

Oracle Cloud Infrastructure Sample Setup

 

Host Public IP Private IP Accessible by
Bastion Host 140.238.216.114 10.0.0.2 SSH 
Windows Application Server   10.0.1.2 RDP
Oracle Database Server   10.0.2.2 SSH

 

Reminder: In OCI only SSH port 22 is open in the subnet security lists as per default when the VCN is created by the VCN Wizard. If you want to allow connection from the public to the private subnet by RDP and Oracle Net, then port 3389 and 1521 must be added in the security list for the private subnet. Create stateful ingress rules and restrict the source connections to the bastion host private IP range.

Build your own SSH Tunnel

There different ways to build a SSH (tunnel) configuration to Oracle Cloud Infrastructure instances on a Windows based platform, my favourites:

  1. Windows Subsystem for Linux (WSL)
  2. MobaXterm
  3. Putty

Here are some connection examples how to work with instances in a private subnet via bastion host with this three methods. As a Windows 10 user, for some connections I d’ like to use WSL Ubuntu more and more – now available in version 20 🙂

1. Connect by using Windows Subsystem for Linux (WSL)

Test: Verify the Connection to the Bastion Host public IP Address

Database Server: SSH Connect via Bastion Host

This opens a session on the database server as user opc.

Database Server: Create a new SSH Tunnel to forward port 1521 as port 15210

This opens a connection to the bastion host.

Database Server: Connect to the Database by SQL Developer

Use port 15210 and localhost as hostname.

Verify the Oracle Net service name from the DBA panel menu.

Application Server: Create a new SSH Tunnel to forward port 3389 as port 33890

This opens a connection to the bastion host.

Application Server: Connect to the Windows Desktop by Remote Desktop Connection

Use port 33890 and localhost as hostname.

2. Connect by using MobaXterm

Database Server: SSH Connect via Bastion Host

This opens a session ion the database server as user opc.

Fill in Remote Host, Specify username and Port. Activate Use private key and select the local private SSH key in Putty format.

Activate Connect through SSH gateway, fill in Gateway SSH server, Port, User. Activate Use private key and select the local private SSH key in Putty format.

Start the session.

As you can see in the MobaXterm Header, X-Forwarding works too.

Database Server: Create a new SSH Tunnel to forward port 1521 as port 15210

Open MobaXterm Tunneling menu and add a New SSH tunnel. Fill in Forwarded port, Remote server, Remote port, SSH server, SSH login and SSH port. Save the tunnel settings. For an application server tunnel, just replace Remote server, Remote port and Forwared port settings.

Add the private SSH key in Putty format by click on the key icon. Start the tunnel.

Database Server: Connect to the Database by SQL Developer

Use port 15210 and localhost as hostname.

Verify the database control file settings from the DBA panel menu.

3. Connect by using Putty

Database Server: SSH Connect via Bastion Host

As prerequisite, I have created a Putty session called OCI Bastion Host for the jump host connection with the SSH private key in Putty format and user opc. This session is now used as Proxy.

Fill in database server private IP. The red one is the already existing session.

Add proxy command and save session settings. Optioanl enable proxy diagnostics.

Open the new created session to connect to database server with user opc.

Application Server: Create a new SSH Tunnel to forward port 3389 as port 33890

This opens a connection to the bastion host. Fill in bastion host public IP. 

Add private key file in Putty format and enable checkbox Allow agent forwarding.

Add a port forwarding rule for RDP. Save session.

Open the new created session to enable port forwarding for Remote Desktop Protocol.

Application Server: Connect to the Windows Desktop by Remote Desktop Connection

Use port 33890 and localhost as hostname.

Alternative Method – Start Putty from Command Line

Start Putty with the port forwarding settings by command line. This opens a Putty session and port 3389 can be used. No addtional settings are required.

Summary

A bastion host is an “easy-to-setup” alternative to a VPN connection without any huge infrastructure overhead. There are several ways how to connect & tunnel to the target servers. Use the method which are you familiar with it, but NEVER place SSH keys on a bastion host. 

And now: click here to make some noise – Jump by Van Halen

Links

Oracle Enterprise Manager 13c Release 4 – Time to Upgrade – First Experiences

The roll-out of the newest Oracle Enterprise Manager 13 Release 4 is a few days old, about time to try out the upgrade process in my ESXi lab environment.

First: This blog post about the OEM upgrade process is based on my own experience.

Software

https://www.oracle.com/enterprise-manager/downloads/cloud-control-downloads.html

Documents

https://docs.oracle.com/en/enterprise-manager/cloud-control/enterprise-manager-cloud-control/13.4/emupg/index.html

The Environment

  • Oracle Enterprise Manager 13.3 running on Oracle Linux 7.6 – OEM Patchlevel January 2020 – Non-HA
  • Oracle Enterprise Edition Repository 19.6.0 Single Tenant Database 
  • Oracle Restart / ASM 19.6.0
  • Additional Oracle Linux Server with 19.3.0 Container Databases
  • All targets up and running
  • My Oracle Support connected
  • Software staged directory in /u01/app/oracle/stage/em13cr4 and permission changed to execute bin file (chmod u+x em13400_linux64.bin).

Prerequisites

It’s important to verify the changed prerequisites – Chapter 3 – Prerequisites for Upgrading to Enterprise Manager Cloud Control 13c Release 4 – I had do disable all adaptive features in the repository pluggable database:

Restart the database after the changed settings.From my view this sentence here is wrong is the documentation (my database has version 19.6.0):

If your Management Repository is using Oracle Database 12.2 or higher, none of these parameters need to be set. 

Why? If these parameters are not set, the installer refuses working.

EMKEY Copy Requirements

The Key was copied to the repository. It well be removed after the successful upgrade.

Run Installer

Start the Oracle Universal Installer

The OMS is down now (emctl stop oms -all). Start the installer.

My Oracle Support Details

I am a registered user in My Oracle Support, I get enough information every week… I don’t enable this checkbox.

Software Updates

At the moment, there are no updates available. Maybe in future there will be any patches available for auto apply during the installation/upgrade process.

Installation Type

Upgrade an existing Enterprise Manager system, this one is my existing installation.

 

Installation Details

Enter a new Middleware Home Location.

Database Connection Details

Enter the SYS and SYSMAN password of the running repository. DDMP (Deferred Data Migration) Jobs are enabled. According the documentation, these jobs are running in the background when the OEM is starting up during the upgrade process to convert old data to the new format. If you have a huge amount of data in your earlier release, then the upgrade can take longer. You can run this job – if disabled – later as Post Upgrade Tasks.

Warnings

I will change to SHA communication later.

The repository has 19.6.0, all required patches are included.

I confirm that the JVMD engine is stopped, this has happened by stopping the OMS.

I had to stop the agent which was running on the management server.

Fix Parameter Settings by the Installer

For my environment, I let the installer fix this settings.

Plug-in Upgrade

Here we see the already installed plugins, they will be upgraded too.

Select Plug-ins

I don’t ant to install additional plug-ins.

Extend WebLogic Server Domain

Enter the password for the weblogic user and define the OMS Instance Base Location.

Enterprise Manager Shared Location Details

My Oracle Enterprise Manager doesn’t run in a high availability setup, I don’t need any shared location.

Port Configuration Details

I use the settings from the existing installation.

Review

Let’s start the upgrade!

Repository Upgrade failed

The upgrade process fails at the step where the repository has to be upgraded.

View Log – ORA-01950

When I scroll up the provided log from the installer, I see this error message here:

The schema manager logfile located in the 13.4 subdirectory $ORACLE_HOME/sysman/log/schemamanager confirms this error.

At this point, this is curious, because in 13.3, there were no objects of the SYSMAN in the USERS tablespace. All objects are located in OEM tablespaces with the MGMT prefix. Here is a list of objects in a repository where an Oracle Enterprise Manager 13c Release 3 is up and running.

The solution is simple. Just grant the permissions for the USERS tablespace to SYSMAN and retry the installation progress.But, don’t ask me why SYSMAN creates now objects in USERS…

After a while, you can see new created tables and indexes in tablespace USERS for user SYSMAN.

The repository upgrade step runs fine now, the whole upgrade process continuous.

Finish

After while, yes we did it, the root script execution is the last task. 

Script execution.

The Enterprise Manager is now running with Release 4.

About Enterprise Manager

Next steps are

  • upgrade the Oracle agents
  • uninstall the old OEM software –  btw, the installer already detaches the old ORACLE_HOME from Oracle’s central inventory for you and removes the emkey from the repository 🙂

Summary

This is a lab environment, not a huge setup with hundreds of targets. But we can see here two important points for the upgrade process. a) read the manual and disable all adaptive features, even when you have an 19c database and b) user SYSMAN needs permission on the USERS tablespace. This is very unusual and should be corrected from my side. But now, enjoy Oracle Enterprise Manager 13c Release 4!

MV2ADB – One-Click Move of your Data into OCI Autonomous Databases – Auto Operation

In the previous blog post MV2ADB – One-Click Move of your Data into OCI Autonomous Databases – Step by Step I wrote about the new Oracle Cloud Infrastructure tool to transfer local data into Autonomous Databases step by step. There you see how to install and configure mv2adb and how to transfer your data to ADB step by step.

The auto operation parameter is now “all in one”, one parameter and all required steps like export, transfer etc. are done fully automated.

Prerequisites

  • mv2adb rpm package installed, always get the newest version from My Oracle Support (Doc ID 2463574.1)
  • HTTP/SQL*Net Connectivity from the on premises server to the Autonomous Database
  • Autonomous Database Wallet (can be downloaded from the ATP main page)
  • Instant Client with Basic Package, SQL*Plus Package and Data Pump, SQL*Loader and Workload Replay Client – if there is an existing RDBMS installation 18.3 or higher, you can use it
  • Java executable – same like above, you can use the RDBMS installation too
  • Perl Release 5.10 or above
  • Optional: Oracle OCI Command Line Interface – https://docs.cloud.oracle.com/iaas/Content/API/Concepts/cliconcepts.htm installed and configured

Let’s go – we transfer the local HR Schema to ADB fully automated

Example with parameter OCIC=true – visible in the output lines where the OCI bucket upload is done.

Verification

Summary

The auto function completely eliminates the manual steps to upload your data into an Autonomous Database steps. And in case of any error, you have the same logfiles like you do it step by step. Great!

#ilikeit

OCI Database Backup Service Configuration – Avoid 401 Unauthorized Error

While I a preparing new exercises for an Oracle Cloud Infrastructure training, I ran into an issue while configuring the Oracle Database Backup Service for the Object Storage. The OCI backup module installer returns an error 401.

My Environment

  • Oracle Linux 7 Virtual Box Machine
  • Oracle 19c RDBMS

Backup Service Module Installation Error

The installation was done according the documenation https://docs.oracle.com/en/cloud/paas/db-backup-cloud/csdbb/oracle-database-cloud-backup-module-oci.html

Error Message – java.io.IOException: testConnection: 401 Unauthorized

What I have verified:

  • Private key format and permissions
  • OCIDs
  • FingerPrint

But all of them were correct. There is no My Oracle Support note available about this error together with Oracle Database Backup Service. But after some more investigation, I found this note here: EBSCloudBackup.pl Failed When Performing Database Tier Upload Task (Doc ID 2588278.1) – bingo! This note described exactly my case with the cloud backup. The machine time is wrong!

My actual Machine Time and Date

The timezone CEST is correct. But wait, here in Kestenholz at the famous Jurasüdfuss / Switzerland, we have 14:38 local time. The virtual machine was 2 hours “in the future”. Let’s install the NTP service deamon.

NTP Installation and Configuration

Now the time is right:

OCI Backup Configuration – 2nd Try

Now the oci_installer.jar runs fine and the configuration will be created. Et voilà.

Lesson learned

Take care about time and date settings when you build virtual machines for testing purposes. And aways install a time service like NTP or chrony.

Monitor your Oracle Cloud Free Tier with Grafana on Oracle Linux 8

In a previous blog post I wrote about monitoring Oracle Cloud Infrastructure components by Grafana. In the meantime, we got the Oracle Cloud Free Tier. Here is an updated version.

This blog post shows you how to install and configure the Grafana plugin based on the Oracle blog entry https://blogs.oracle.com/cloudnative/data-source-grafana on an Oracle Enterprise Linux 8 server.

Steps to monitor the Oracle Cloud Free Tier by the OCI Grafana Plugin

  1. Install and configure the Oracle Cloud Infrastructure CLI – by download or by YUM install
  2. Configure Group, User and Policy in Oracle Cloud Infrastructure Console
  3. Install Grafana and the OCI Plugin
  4. Configure the Grafana DataSource
  5. Create a new Dashboard with OCI Metrics

Machine Requirements

The server needs access to the internet.

Install and configure the Oracle Cloud Infrastructure CLI

Link: https://docs.cloud.oracle.com/iaas/Content/API/SDKDocs/cliinstall.htm

In this step, the software will be installed an configured. The new created SSH public key has to be added in the OCI console for further actions.

As OS user root we create a new user for OCI actions. 

Login as user oci, execute the CLI download and installation script. Answer questions with Y / Enter to get the default installation.

Default values:

install directory /home/oci/lib/oracle-cli
executable directory /home/oci/bin
OCI scripts /home/oci/bin/oci-cli-scripts
optional CLI packages db
shell/tab completion Y
path to rc file /home/oci/.bashrc

 

After the successful CLI installation, you have to configure it.

Based on your OCI account, these information are required – let the config and key location on default values.

config location /home/oci/.oci/config
user OCID OCI > Identity > Users > [YOUR_USER] > OCID
tenancy OCID OCI > Administration > Tenancy Details > [YOUR_TENANCY] > OCID
region choose your region, e.g. eu-zurich-1
generate a new key pair Y -> only if you don’t have already created a key pair
key directory /home/oci/.oci
key name oci_api_key

 

Add the content of the public key file in the OCI console to your user which you want to work with.

Attention: Be sure that you add the public key to the user which you have used for the CLI configuration!

Test the CLI configuration – example to list all compartments in your tenant.

Alternative Method Oracle Linux 7 – YUM Repository

Thanks to Sergio Leunissen from Oracle for his input, the Python SDK and oci utilities are is available in the YUM repository too and ready to install. Take a look at his blog post to see how to work with the Python SDK and OCI metadata:

Configure Group, modify User and add a Policy in Oracle Cloud Infrastructure Web Interface

Group

Create a new OCI group called Grafana. OCI > Identity > Groups.

Modify User

Add the selected user to the group – for example this is my user.

Add a Policy

Create a new policy called GrafanaPolicy. OCI > Identity > Policies.

allow group grafana to read metrics in tenancy
allow group grafana to read compartments in tenancy

Install Grafana and the OCI Plugin

Link: https://grafana.com/grafana/download?platform=linux

Login as user root and install Grafana.

Enable auto start and start the Grafana server manually.

Enable port 3000 (Grafana default port in firewall – the port can be changed in /etc/grafana/grafana.ini) to provide web access to Grafana.

Install the Grafana Oracle Cloud Infrastructure oci-datasource plugin.

Verify the Grafana plugin directory with the installed plugin.

Grafana needs the configuration file and the SSH Key from the user oci. As user root, copy the files and set the ownership to OS user grafana.

Change the path to the key file in /usr/share/grafana/.oci/config.

# vi /usr/share/grafana/.oci/config

From:

To:

Create a new Dashboard based on OCI Metrics

Open your browser and log in into Grafana with [SERVERNAME]:3000. Username and password are admin/admin. You have to change your initial password imme diately.

Add data source

Select Oracle Cloud Infrastructure

Configure the Data Source

Fill in your tenancy OCI, region and set Environment = Local. Test the connection. For troubleshooting see Grafana logfile in directory /var/log/grafana. If your default region like ZRH / EU-ZURICH-1 is not listed, then you have to edit the a plugin file as described below. Otherweise no metrics are shown.

Example to use Grafana for the Datacenter eu-zurich-1:

Edit the file /var/lib/grafana/plugins/oci-datasource/dist/constants.js and add your missed region – restart Grafana.

Error message in the grafana.log when your region is not added in file content.js but you select the region as data source:

Create a new Dashboard and Add Query

Create a Query to visualize Data

In this dashboard example I used the region eu-zurich-1, my compartment, the namespace oci_autonomous_database and the metric CpuUtilization.

There are a lot of other metrics available like:

  • CurrentLogons
  • ExecutionCount
  • Sessions
  • StorageUtilization (in %)
  • etc.

Available Metrics

 Learn more about metrics and monitoring in the OCI documentation here:

Summary

The OCI Grafana plugin is a nice solution to visualize your Oracle Cloud Free Tier environment based on Open Source software. Take care, Grafana needs access to the OCI CLI SSH information for the Oracle Cloud Infrastructure connection.