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(maint) Add puppetserver alias puppet.internal
- Remove the domain introspection / setting of AZURE_DOMAIN env var as this does not work as originally thought. Instead, hardcode the DNS suffix `.internal` to each service in the compose stack, and make sure that `dns_search` for `internal` will use the Docker DNS resolver when dealing with these hosts. Note that these compose file settings only affect the configuration of the DNS resolver, *not* resolv.conf. This is different from the docker run behavior, which *does* modify resolv.conf. Also note, config file locations vary depending on whether or not systemd is running in the container. It's not "safe" to refer to services in the cluster by only their short service names like `puppet`, `puppetdb` or `postgres` as they can conflict with hosts on the external network with these names when `resolv.conf` appends DNS search suffixes. When docker compose creates the user defined network, it copies the DNS settings from the host to the `resolv.conf` in each of the containers. This often takes search domains from the outside network and applies them to containers. When network resolutions happen, any default search suffix will be applied to short names when the dns option for ndots is not set to 0. So for instance, given a `resolv.conf` that contains: search delivery.puppetlabs.net A DNS request for `puppet` becomes `puppet.delivery.puppetlabs.net` which will fail to resolve in the Docker DNS resolver, then be sent to the next DNS server in the `nameserver` list, which may resolve it to a different host in the external network. This behaves this way because `resolv.conf` also sets secondary DNS servers from the host. While it is possible to try and service requests for an external domain like `delivery.puppetlabs.net` with the embedded Docker DNS resolver, it's better to instead choose a domain suffix to use inside the cluster. There are some good details on how various network types configure: docker/for-linux#488 (comment) - Note that the .internal domain is typically not recommended for production given the only IANA reserved domains are .example, .test, .invalid or .localhost. However, given the DNS resolver is set to own the resolution of .internal, this is a compromise. In production its recommended to use a subdomain of a domain that you own, but that's not yet configurable in this compose file. A future commit will make this configurable. - Another workaround for this problem would be to set the ndots option in resolv.conf to 0 per the documentation at http://man7.org/linux/man-pages/man5/resolv.conf.5.html However that can't be done for two reasons: - docker-compose schema doesn't actually support setting DNS options docker/cli#1557 - k8s sets ndots to 5 by default, so we don't want to be at odds - A further, but implausible workaround would be to modify the host DNS settings to remove any search suffixes. - The original FQDN change being reverted in this commit was introduced in 8b38620 " Lastly, the Windows specific docker-compose.windows.yml sets up a custom alias in the "default" network so that an extra DNS name for puppetserver can be set based on the FQDN that Facter determines. Without this additional DNS reservation, the `puppetserver ca` command will be unable to connect to the REST endpoint. A better long-term solution is making sure puppetserver is setup to point to `puppet` as the host instead of an FQDN. " With the PUPPETSERVER_HOSTNAME value set on the puppetserver container, both certname and server are set to puppet.internal, inside of puppet.conf, preventing a need to inject a domain name as was done previously. This is necessary because of a discrepancy in how Facter 3 behaves vs Facter 2, which creates a mismatch between how the host cert is initially generated (using Facter 3) and how `puppetserver ca` finds the files on disk (using Facter 2), that setting PUPPETSERVER_HOSTNAME will explicitly work around. Specifically, Facter 2 may return a different Facter.value('domain') than calling `facter domain` using Facter 3 at the command line. Such is the case inside the puppet network, where Facter 2 returns `ops.puppetlabs.net` while Facter 3 returns `delivery.puppetlabs.net` Without explicitly setting PUPPETSERVER_HOSTNAME, this makes cert files on disk get written as *.delivery.puppetlabs.net, yet the `puppetserver ca` application looks for the client certs on disk as *.ops.puppetlabs.net, which causes `puppetserver ca` to fail. - Facter 2 should not be included in the puppetserver packages, and changes have been made to packaging for future releases, which may remove the need for the above. - This PR is also made possible by switching over to using the Ubuntu based container from the Alpine container (performed in a prior commit), due to DNS resolution problems with Alpine inside LCOW: moby/libnetwork#2371 microsoft/opengcs#303 - Another avenue that was investigated to resolve the DNS problem in Alpine was to feed host:ip mappings in through --add-host, but it turns out that Windows doesn't yet support that feature per docker/for-win#1455 - Finally, these changes are also made in preparation of switching the pupperware-commercial repo over to a private builder - Additionally update k8s / Bolt specs to be consistent with updated naming
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