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Eric GableWindows Azure Linux Agent User Guide Introduction The Windows Azure Linux Agent (waagent) manages VM interaction with the Windows Azure Fabric Controller. It provides the following functionality for Linux IaaS deployments: * Image Provisioning - Creation of a user account. - Configuring SSH authentication types. - Deployment of SSH public keys and key pairs - Setting the host name - Publishing the host name to the platform DNS - Reporting SSH host key fingerprint to the platform - Resource Disk Management - Formatting and mounting the resource disk - Configuring swap space * Networking - Manages routes to improve compatibility with platform DHCP servers - Ensures the stability of the network interface name * Kernel - Configuring virtual NUMA - Consume Hyper-V entropy for /dev/random - Configuring SCSI timeouts for the root device (which could be remote) * Diagnostics - Console redirection to the serial port The information flow from the platform to the agent occurs via two channels: A TCP endpoint exposing a REST API and a boot-time attached DVD for IaaS deployments. The DVD includes an OVF-compliant configuration file that includes all provisioning information other than the actual SSH keypairs. The deployment configuration and topology are obtained over the REST API. Supported Linux Distributions 1.CentOS 6.0+ 2.Ubuntu 12.04+ 3.Suse (SLES) 11SP2+ 4.Open Suse 12.1+ Requirements Waagent depends on some system packages in order to function properly: 1.Python 2.4+ 2.Openssl 1.0+ 3.Openssh 5.3+ 4.Filesystem utilities: sfdisk, fdisk, mkfs 5.Password tools: chpasswd 6.Text processing tools: sed, grep Installation Installation using an RPM or a DEB package is preferred. If installing manually,waagent should be copied to /usr/sbin/waagent and installed by running: /usr/sbin/waagent -install Command Line Options Flags -verbose: Increase verbosity of specified command -force: Skip interactive confirmation for some commands Commands -help: Lists the supported commands and flags. -install: Checks the system for required dependencies. Creates the SysV init script (/etc/init.d/waagent), the logrotate configuration file (/etc/logrotate.d/waagent), and configures the image to run the init script on boot. Writes sample configuration file to /etc/waagent.conf. Any existing configuration file is moved to /etc/waagent.conf.old. Detects kernel version and apply VNUMA workaround if necessary. Moves udev rules that may interfere with networking (/lib/udev/rules.d/75-persistent-net-generator.rules, /etc/udev/rules.d/70-persistent-net.rules) to /var/lib/waagent/. -uninstall: Unregisters the init script from the system and deletes it. Deletes the logrotate configuration and the waagent config file in /etc/waagent.conf. Automatic reverting of the VNUMA workaround is not supported – please edit the GRUB configuration files by hand to re-enable NUMA if required. Restores any moved udev rules. -deprovision: Attempt to clean the system and make it suitable for re-provisioning. Deletes the following: 1. All SSH host keys (if Provisioning.RegenerateSshHostKeyPair is set in the configuration file) 2. Nameserver configuration in /etc/resolv.conf 3. Root password from /etc/shadow (if Provisioning.DeleteRootPassword is set in the configuration file) 4. Cached DHCP client leases. 5. Resets host name to localhost.localdomain. WARNING! This doesn’t guarantee that the image is cleared of all sensitive information and suitable for redistribution. -deprovision+user: Everything under deprovision (above) and also deletes the last provisioned user account and associated data. -version: Displays the version of waagent -serialconsole: Configures GRUB to mark ttyS0 (the first serial port) as the boot console. This ensures that kernel bootup logs are sent to the serial port and made available for debugging. -daemon: Run waagent as a daemon to manage interaction with the platform. This argument is specified to waagent in the waagent init script. Configuration A configuration file (/etc/waagent.conf) controls the actions of waagent. A sample configuration file is shown below: # # Windows Azure Linux Agent Configuration # Role.StateConsumer=None Role.ConfigurationConsumer=None Role.TopologyConsumer=None Provisioning.Enabled=y Provisioning.DeleteRootPassword=n Provisioning.RegenerateSshHostKeyPair=y Provisioning.SshHostKeyPairType=rsa Provisioning.MonitorHostName=y ResourceDisk.Format=y ResourceDisk.Filesystem=ext4 ResourceDisk.MountPoint=/mnt/resource ResourceDisk.EnableSwap=n ResourceDisk.SwapSizeMB=0 LBProbeResponder=y Logs.Verbose=n OS.RootDeviceScsiTimeout=300 OS.OpensslPath=None The various configuration options are described in detail below. Configuration options are of three types : Boolean, String or Integer. The Boolean configuration options can be specified as “y” or “n”. The special keyword “None” may be used for some string type configuration entries as detailed below. Role.StateConsumer: Type: String Default: None If a path to an executable program is specified, the program is invoked at two events. 1.When the waagent has provisioned the image and the “Ready” state is about to be reported to the Fabric. The argument specified to the program will be “Ready”. waagent will not wait for the program to return before continuing. 2.When the waagent has received a shutdown request from the Fabric and is about to shutdown the VM. The argument specified to the program will be “Shutdown”. waagent will wait for the program to return before initiating the shutdown process. Role.ConfigurationConsumer: Type: String Default: None If a path to an executable program is specified, the program is invoked when the Fabric indicates that a configuration file is available for the VM. The path to the XML configuration file is provided as an argument to the executable. This may be invoked multiple times whenever the configuration file changes. A sample file is provided in the Appendix. Please note that the XML schema used in this file may change in the future. The current path of this file is /var/lib/waagent/HostingEnvironmentConfig.xml. Role.TopologyConsumer: Type: String Default: None If a path to an executable program is specified, the program is invoked when the Fabric indicates that a new network topology layout is available for the VM.The path to the XML configuration file is provided as an argument to the executable. This may be invoked multiple times whenever the network topology changes (due to service healing for example). A sample file is provided in the Appendix. Please note that the XML schema used in this file may change in the future. The current location of this file is /var/lib/waagent/SharedConfig.xml. Provisioning.Enabled: Type: Boolean Default: y This allows the user to enable or disable the provisioning functionality in the agent. Valid values are “y” or “n”. If provisioning is disabled, SSH host and user keys in the image are preserved and any configuration specified in the Windows Azure provisioning API is ignored. Provisioning.DeleteRootPassword: Type: Boolean Default: n If set, the root password in the /etc/shadow file is erased during the provisioning process. Provisioning.RegenerateSshHostKeyPair: Type: Boolean Default: y If set, all SSH host key pairs (ecdsa, dsa and rsa) are deleted during the provisioning process from /etc/ssh/. And a single fresh key pair is generated. The encryption type for the fresh key pair is configurable by the Provisioning.SshHostKeyPairType entry. Please note that some distributions will re-create SSH key pairs for any missing encryption types when the SSH daemon is restarted (for example, upon a reboot). Provisioning.SshHostKeyPairType: Type: String Default: rsa This can be set to an encryption algorithm type that is supported by the SSH daemon on the VM. The typically supported values are “rsa”, “dsa” and “ecdsa”. Note that “putty.exe” on Windows does not support “ecdsa”. So, if you intend to use putty.exe on Windows to connect to a Linux deployment, please use “rsa” or “dsa”. Provisioning.MonitorHostName: Type: Boolean Default: y If set, waagent will monitor the Linux VM for hostname changes (as returned by the “hostname” command) and automatically update the networking configuration in the image to reflect the change. In order to push the name change to the DNS servers, networking will be restarted in the VM. This will result in brief loss of Internet connectivity. ResourceDisk.Format: Type: Boolean Default: y If set, the resource disk provided by the platform will be formatted and mounted by waagent if the filesystem type requested by the user in "ResourceDisk.Filesystem" is anything other than "ntfs". A single partition of type Linux (83) will be made available on the disk. Note that this partition will not be formatted if it can be successfully mounted. ResourceDisk.Filesystem: Type: String Default: ext4 This specifies the filesystem type for the resource disk. Supported values vary by Linux distribution. If the string is X, then mkfs.X should be present on the Linux image. ResourceDisk.MountPoint: Type: String Default: /mnt/resource This specifies the path at which the resource disk is mounted. ResourceDisk.EnableSwap: Type: Boolean Default: n If set, a swap file (/swapfile) is created on the resource disk and added to the system swap space. ResourceDisk.SwapSizeMB: Type: Integer Default: 0 The size of the swap file in megabytes. LBProbeResponder: Type: Boolean Default: y If set, waagent will respond to load balancer probes from the platform (if present). Logs.Verbose: Type: Boolean Default: n If set, log verbosity is boosted. Waagent logs to /var/log/waagent.log and leverages the system logrotate functionality to rotate logs. OS.RootDeviceScsiTimeout: Type: Integer Default: 300 This configures the SCSI timeout in seconds on the root device. If not set, the system defaults are used. OS.OpensslPath: Type: String Default: None This can be used to specify an alternate path for the openssl binary to use for cryptographic operations. Appendix Sample Role Configuration File <?xml version="1.0" encoding="utf-8"?> <HostingEnvironmentConfig version="1.0.0.0" goalStateIncarnation="1"> <StoredCertificates> <StoredCertificate name="Stored0Microsoft.WindowsAzure.Plugins.RemoteAccess.PasswordEncryption" certificateId="sha1:C093FA5CD3AAE057CB7C4E04532B2E16E07C26CA" storeName="My" configurationLevel="System" /> </StoredCertificates> <Deployment name="a99549a92e38498f98cf2989330cd2f1" guid="{374ef9a2-de81-4412-ac87-e586fc869923}" incarnation="14"> <Service name="LinuxDemo1" guid="{00000000-0000-0000-0000-000000000000}" /> <ServiceInstance name="a99549a92e38498f98cf2989330cd2f1.4" guid="{250ac9df-e14c-4c5b-9cbc-f8a826ced0e7}" /> </Deployment> <Incarnation number="1" instance="LinuxVM_IN_2" guid="{5c87ab8b-2f6a-4758-9f74-37e68c3e957b}" /> <Role guid="{47a04da2-d0b7-26e2-f039-b1f1ab11337a}" name="LinuxVM" hostingEnvironmentVersion="1" software="" softwareType="ApplicationPackage" entryPoint="" parameters="" settleTimeSeconds="10" /> <HostingEnvironmentSettings name="full" Runtime="rd_fabric_stable.111026-1712.RuntimePackage_1.0.0.9.zip"> <CAS mode="full" /> <PrivilegeLevel mode="max" /> <AdditionalProperties><CgiHandlers></CgiHandlers></AdditionalProperties></HostingEnvironmentSettings> <ApplicationSettings> <Setting name="__ModelData" value="<m role="LinuxVM" xmlns="urn:azure:m:v1"><r name="LinuxVM"><e name="HTTP" /><e name="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" /><e name="Microsoft.WindowsAzure.Plugins.RemoteForwarder.RdpInput" /><e name="SSH" /></r></m>" /> <Setting name="Microsoft.WindowsAzure.Plugins.RemoteAccess.AccountEncryptedPassword" value="…" /> <Setting name="Microsoft.WindowsAzure.Plugins.RemoteAccess.AccountExpiration" value="2015-11-06T23:59:59.0000000-08:00" /> <Setting name="Microsoft.WindowsAzure.Plugins.RemoteAccess.AccountUsername" value="rdos" /> <Setting name="Microsoft.WindowsAzure.Plugins.RemoteAccess.Enabled" value="true" /> <Setting name="Microsoft.WindowsAzure.Plugins.RemoteForwarder.Enabled" value="true" /> <Setting name="startpage" value="Hello World!" /> <Setting name="Certificate|Microsoft.WindowsAzure.Plugins.RemoteAccess.PasswordEncryption" value="sha1:C093FA5CD3AAE057CB7C4E04532B2E16E07C26CA" /> </ApplicationSettings> <ResourceReferences> <Resource name="DiagnosticStore" type="directory" request="Microsoft.Cis.Fabric.Controller.Descriptions.ServiceDescription.Data.Policy" sticky="true" size="1" path="a99549a92e38498f98cf2989330cd2f1.LinuxVM.DiagnosticStore\" disableQuota="false" /> </ResourceReferences> </HostingEnvironmentConfig> Sample Role Topology File <?xml version="1.0" encoding="utf-8"?> <SharedConfig version="1.0.0.0" goalStateIncarnation="2"> <Deployment name="a99549a92e38498f98cf2989330cd2f1" guid="{374ef9a2-de81-4412-ac87-e586fc869923}" incarnation="14"> <Service name="LinuxDemo1" guid="{00000000-0000-0000-0000-000000000000}" /> <ServiceInstance name="a99549a92e38498f98cf2989330cd2f1.4" guid="{250ac9df-e14c-4c5b-9cbc-f8a826ced0e7}" /> </Deployment> <Incarnation number="1" instance="LinuxVM_IN_1" guid="{a7b94774-db5c-4007-8707-0b9e91fd808d}" /> <Role guid="{47a04da2-d0b7-26e2-f039-b1f1ab11337a}" name="LinuxVM" settleTimeSeconds="10" /> <LoadBalancerSettings timeoutSeconds="32" waitLoadBalancerProbeCount="8"> <Probes> <Probe name="LinuxVM" /> <Probe name="03F7F19398C4358108B7ED059966EEBD" /> <Probe name="47194D0E3AB3FCAD621CAAF698EC82D8" /> </Probes> </LoadBalancerSettings> <OutputEndpoints> <Endpoint name="LinuxVM:Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" type="SFS"> <Target instance="LinuxVM_IN_0" endpoint="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" /> <Target instance="LinuxVM_IN_1" endpoint="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" /> <Target instance="LinuxVM_IN_2" endpoint="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" /> </Endpoint> </OutputEndpoints> <Instances> <Instance id="LinuxVM_IN_1" address="10.115.38.202"> <FaultDomains randomId="1" updateId="1" updateCount="2" /> <InputEndpoints> <Endpoint name="HTTP" address="10.115.38.202:80" protocol="tcp" isPublic="true" loadBalancedPublicAddress="70.37.56.176:80" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="80" to="80" /> </LocalPorts> </Endpoint> <Endpoint name="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" address="10.115.38.202:3389" protocol="tcp" isPublic="false" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="3389" to="3389" /> </LocalPorts> <RemoteInstances> <RemoteInstance instance="LinuxVM_IN_0" /> <RemoteInstance instance="LinuxVM_IN_2" /> </RemoteInstances> </Endpoint> <Endpoint name="Microsoft.WindowsAzure.Plugins.RemoteForwarder.RdpInput" address="10.115.38.202:20000" protocol="tcp" isPublic="true" loadBalancedPublicAddress="70.37.56.176:3389" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="20000" to="20000" /> </LocalPorts> </Endpoint> <Endpoint name="SSH" address="10.115.38.202:22" protocol="tcp" isPublic="true" loadBalancedPublicAddress="70.37.56.176:22" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="22" to="22" /> </LocalPorts> </Endpoint> </InputEndpoints> </Instance> <Instance id="LinuxVM_IN_0" address="10.115.58.82"> <FaultDomains randomId="0" updateId="0" updateCount="2" /> <InputEndpoints> <Endpoint name="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" address="10.115.58.82:3389" protocol="tcp" isPublic="false" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="3389" to="3389" /> </LocalPorts> </Endpoint> </InputEndpoints> </Instance> <Instance id="LinuxVM_IN_2" address="10.115.58.148"> <FaultDomains randomId="0" updateId="2" updateCount="2" /> <InputEndpoints> <Endpoint name="Microsoft.WindowsAzure.Plugins.RemoteAccess.Rdp" address="10.115.58.148:3389" protocol="tcp" isPublic="false" enableDirectServerReturn="false" isDirectAddress="false" disableStealthMode="false"> <LocalPorts> <LocalPortRange from="3389" to="3389" /> </LocalPorts> </Endpoint> </InputEndpoints> </Instance> </Instances> </SharedConfig>