Note: Applies to CLI v2.
It’s typically necessary to separate passwords, certificates, S3 bucket names etc. from YAML documents used with CLI commands such as
bosh create-env and
bosh deploy. Even though the structure of a YAML document (manifest) does not change these values are typically different. CLI provides special syntax in YAML documents to annotate such values making plain YAML document into a parameterized template.
Note: Changing structure of a YAML document such as adding an S3 access configuration section is a bit more than just YAML document parameterization. Look into [operations files](cli-ops-files.html) for additional details.
Variables provide a way to define parameters for a YAML document. Each variable has a value, one or more reference locations and an optional type and generation options.
Following example shows how to add two variables to a YAML document (
s3_access_key_id: ((access_key_id)) s3_access_secret_key: ((access_secret_key))
access_secret_key variables are implicitly defined just by being present within double parentheses. By parameterizing above YAML document it can now be used as a template.
Commands that accept YAML documents such as
bosh deploy and
bosh update-cloud-config typically have a set of flags that can be used to provide variable values.
bosh interpolate command can be used to experiment with such flags as its only job is to print result of variable interpolation.
Note that once Director officially supports config server API, it will be recommended to use connected config server to store variable values instead of providing them via CLI flags.
CLI allows to provide variable values via usage of one or more of the following flags:
-v) flag sets single variable value as an argument
$ bosh interpolate base.yml -v access_key_id=some-key -v access_secret_key=some-secret s3_access_key_id: some-key s3_access_secret_key: some-secret
--var-file=key=pathflag sets single variable value as an entire file
$ cat 1.txt some-key $ cat 2.txt some-secret $ bosh interpolate base.yml --var-file access_key_id=1.txt --var-file access_secret_key=2.txt s3_access_key_id: some-key s3_access_secret_key: some-secret
-l) flag sets file that contains multiple variable values
$ cat secrets.yml access_key_id: some-key access_secret_key: some-secret $ bosh interpolate base.yml -l secrets.yml s3_access_key_id: some-key s3_access_secret_key: some-secret
--vars-store=pathflag flag sets file that contains multiple variable values (with a possibility that missing variables will be automatically generated)
--vars-env=prefixflag sets variable values found in prefixed environment variables (casing is important)
$ export FOO_access_key_id=some-key $ export FOO_access_secret_key=some-secret $ bosh interpolate base.yml --vars-env FOO s3_access_key_id: some-key s3_access_secret_key: some-secret
Here is a more realistic example of using base YAML document (
bosh.yml) from cloudfoundry/bosh-deployment repo and specifying several variables and operations files to provide necessary missing values:
$ bosh create-env ~/workspace/bosh-deployment/bosh.yml \ --state state.json \ --vars-store ./creds.yml -o ~/workspace/bosh-deployment/virtualbox/cpi.yml \ -o ~/workspace/bosh-deployment/virtualbox/outbound-network.yml \ -o ~/workspace/bosh-deployment/bosh-lite.yml \ -o ~/workspace/bosh-deployment/jumpbox-user.yml \ -v director_name=vbox \ -v internal_ip=192.168.56.6 \ -v internal_gw=192.168.56.1 \ -v internal_cidr=192.168.56.0/24 \ -v network_name=vboxnet0 \ -v outbound_network_name=NatNetwork
In addition to just implicitly declaring variables it may be useful to explicitly declare them and provide additional details about used variables so that either the CLI or the Director (actually connected config server) can validate, automatically store and generate variable values.
Dedicated top level
variables section exists where variable definitions are specified:
variables: - name: admin_password type: password - name: postgres_password type: password - name: default_ca type: certificate options: is_ca: true common_name: bosh-ca - name: director_ssl type: certificate options: ca: default_ca common_name: ((internal_ip)) alternative_names: [((internal_ip))]
A variable can define its type and generation options.
--vars-store=path flag provides a read write value source unlike all other variables flags that provide read only source. It is able to lazily generate and save (to a given file location) variable values based on their type and options.
Note that once Director officially supports config server API, it will be recommended to avoid using `–vars-store` flag for all commands except `bosh create-env`. `bosh create-env` command will not be able to use config server API since it most likely will be deploying a config server alongside the Director.
Currently CLI supports
ssh types. The Director (connected to a config server) may support additional types known by the config server.
See Variable Types for details on variable generation.
$ cat base.yml pass: ((admin_password)) variables: - name: admin_password type: password $ bosh interpolate base.yml --vars-store=creds.yml pass: vbvdhjbzqelnq7cfyw09 $ cat creds.yml admin_password: vbvdhjbzqelnq7cfyw09
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