7a6334e4bc
Each datasource had a bit of doc with it, and those were just landing in doc/. I've moved them to doc/sources now.
49 lines
1.9 KiB
Plaintext
49 lines
1.9 KiB
Plaintext
In order to allow an ephemeral, or otherwise pristine image to
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receive some configuration, cloud-init will read a url directed by
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the kernel command line and proceed as if its data had previously existed.
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This allows for configuring a meta-data service, or some other data.
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Note, that usage of the kernel command line is somewhat of a last resort,
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as it requires knowing in advance the correct command line or modifying
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the boot loader to append data.
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For example, when 'cloud-init start' runs, it will check to
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see if if one of 'cloud-config-url' or 'url' appear in key/value fashion
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in the kernel command line as in:
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root=/dev/sda ro url=http://foo.bar.zee/abcde
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Cloud-init will then read the contents of the given url.
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If the content starts with '#cloud-config', it will store
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that data to the local filesystem in a static filename
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'/etc/cloud/cloud.cfg.d/91_kernel_cmdline_url.cfg', and consider it as
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part of the config from that point forward.
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If that file exists already, it will not be overwritten, and the url parameters
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completely ignored.
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Then, when the DataSource runs, it will find that config already available.
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So, in able to configure the MAAS DataSource by controlling the kernel
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command line from outside the image, you can append:
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url=http://your.url.here/abcdefg
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or
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cloud-config-url=http://your.url.here/abcdefg
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Then, have the following content at that url:
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#cloud-config
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datasource:
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MAAS:
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metadata_url: http://mass-host.localdomain/source
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consumer_key: Xh234sdkljf
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token_key: kjfhgb3n
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token_secret: 24uysdfx1w4
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Notes:
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* Because 'url=' is so very generic, in order to avoid false positives,
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cloud-init requires the content to start with '#cloud-config' in order
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for it to be considered.
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* The url= is un-authed http GET, and contains credentials
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It could be set up to be randomly generated and also check source
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address in order to be more secure
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