News, tips, partners, and perspectives for the Oracle Linux operating system and upstream Linux kernel work
-
/ Linux
March 4, 2019
Easy Compute Instance Metadata Access with OCI Utils
About OCI Utilities
Instances created in Oracle Cloud Infrastructure using Oracle-Provided Images based on Oracle Linux include a pre-installed set of utilities that are designed to make it easier to work with Oracle Linux images. This is a quick blog post to demonstrate how the oci-metadata command included in OCI Utilities make quick work of accessing instance metadata.
Update - March 4th, 2019: This post was updated to include the --value-only option
As of this writing, the following components are included. You can read more about each of the utilities in the OCI Utilities documentation.
- ocid
- oci-growfs
- oci-iscsi-config
- oci-metadata
- oci-network-config
- oci-network-inspector
- oci-network-inspector
- oci-public-ip
Working With Instance Metadata Using oci-metadata
Display all instance metadata
To display all metadata in human-readable format, simply run oci-metadata
$ oci-metadata
Instance details:
Display Name: autonomous blog
Region: iad - us-ashburn-1 (Ashburn, VA, USA)
Canonical Region Name: us-ashburn-1
Availability Domain: PDkt:US-ASHBURN-AD-3
Fault domain: FAULT-DOMAIN-2
OCID: ocid1.instance.oc1.iad.abuwcl.................7crrhz2g......aq
Compartment OCID: ocid1.tenancy.oc1..aaaaaaaa5............qok3lunzc6.....jw7q
Instance shape: VM.Standard2.1
Image ID: ocid1.image.oc1.iad.aaaaaaaawuf..............zjc7klojix6vmk42va
Created at: 1548877740674
state: Running
Instance Metadata:
user_data: dW5kZWZpbmVk
ssh_authorized_keys: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAxxxxxxxxxxVMheESQgRukanNBmLxaXA0kZw4DxaCispcEjTgAmBmHpUWQBsG7Y/s3zVQDUZ5irMKr2Rtc5DAkH+y6SsNw+xxxxxx+Zix85RClbmu3vl6Mf1++15VoxxxxxEP16mPZl+Cfk/T9LVIlMtV+brph8AQACxFxxxxxxWSNTj1tE8DTml2QnSA6F6MtP6OvOQ0KzQViNm1kN9MaarGOoNxxxxxxNyJGayh8YA6+n8Y07A3fr870H bmc
Networking details:
VNIC OCID: ocid1.vnic.oc1.iad.abuwcljsrul..............................hioysuicdmzcq
VLAN Tag: 804
MAC address: 02:00:17:01:78:09
Subnet CIDR block: 10.0.2.0/24
Virtual router IP address: 10.0.2.1
Private IP address: 10.0.2.3
To display all metadata in JSON format:
$ oci-metadata -j
oci-metadata -j
{
"instance": {
"compartmentId": "ocid1.tenancy.oc1..aaaaaaaa5............qok3lunzc6.....jw7q",
"displayName": "autonomous blog",
"timeCreated": 1548877740674,
"state": "Running",
"image": "ocid1.image.oc1.iad.aaaaaaaawufnve5jxze4xf7orejupw5iq3pms6cuadzjc7klojix6vmk42va",
"canonicalRegionName": "us-ashburn-1",
"metadata": {
...
Display a specific metadata key value
The following command displays the value of the canonicalRegionName key, trimming the path to the last component only using the --trim option.
$ oci-metadata -g canonicalRegionName --trim Canonical Region Name: us-ashburn-1
Exporting metadata values as environment variables
Using eval
To set an environment with the name and value from instance metadata:
$ eval $(oci-metadata --get compartmentId --export) $ echo $compartmentId ocid1.tenancy.oc1..aaaaaaaa5............qok3lunzc6.....jw7q
Using the --value-only option
The --value-only option, as the name implies, outputs only the key value without a label. For example:
$ oci-metadata -g "CanonicalRegionName" --value-only us-phoenix-1
Or, to assign the compartment ID to an environment variable:
$ export MYCOMPARTMENT=`oci-metadata -g "compartmentID" --value-only` $ echo MYCOMPARTMENT ocid1.tenancy.oc1..aaaaaaaa5............qok3lunzc6.....jw7q
Using jq
To set an environment variable you name yourself, you can extract the raw value of a key using the jq JSON processor:
$ export MYCOMPARTMENT=`oci-metadata -j --trim -g /instance/compartmentID | jq -r .[]` $ echo MYCOMPARTMENT ocid1.tenancy.oc1..aaaaaaaa5............qok3lunzc6.....jw7q
Display the Instance's Public IP Address
To display the instance's public IP address
$ oci-public-ip Public IP address: 129.xxx.yyy.175
And to extract just the IP address:
oci-public-ip -j | jq -r .[] 129.xxx.yyy.175