Loop through a template

[bonecountysheriff]

What exactly are you trying to do?

I'm trying to configure SSH for multiple users on github and gitlab and am considering using chezmoi templates for the purpose since I already use it for managing dotfiles.

The config file is located at ~/.ssh/config. SSH configuration feels quite inflexible and doesn't support features like including an external file or looping. So everything needs to be done by chezmoi. I'm starting with a template file which looks something like this.

config.tmpl

Host gitlab-$name
    User git
    HostName gitlab.com
    IdentityFile ~/.ssh/$name

Host github-$name
    User git
    HostName github.com
    IdentityFile ~/.ssh/$name

In the above template, suppose $name assumes three different values - user1, user2 and user3. Then the output (final config) should be the following.

~/.ssh/config

Host gitlab-user1
    User git
    HostName gitlab.com
    IdentityFile ~/.ssh/user1

Host github-user1
    User git
    HostName github.com
    IdentityFile ~/.ssh/user1

Host gitlab-user2
    User git
    HostName gitlab.com
    IdentityFile ~/.ssh/user2

Host github-user2
    User git
    HostName github.com
    IdentityFile ~/.ssh/user2

Host gitlab-user3
    User git
    HostName gitlab.com
    IdentityFile ~/.ssh/user3

Host github-user3
    User git
    HostName github.com
    IdentityFile ~/.ssh/user3

I have looked through chezmoi's template guide, but there was no mention of loops. I was hoping if this could be achieved in a different way.

Where else have you checked for solutions?

• [x] I have read chezmoi's user guide, and not found the answer.
• [ ] I have searched chezmoi's reference guide, and not found the answer.
• [ ] Other, please give details.

Output of chezmoi doctor

```console $ chezmoi doctor RESULT CHECK MESSAGE warning version v2.27.0, built at 2022-11-09T13:20:09Z warning latest-version v2.27.1 ok os-arch linux/amd64 (Arch Linux) ok uname Linux archlinux 6.0.8-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 10 Nov 2022 21:14:24 +0000 x86_64 GNU/Linux ok go-version go1.19.3 (gc) ok executable /usr/bin/chezmoi ok config-file no config file found error source-dir open ~/.local/share/chezmoi: no such file or directory ok suspicious-entries ~/.local/share/chezmoi: no such file or directory error working-tree open ~/.local/share/chezmoi: no such file or directory ok dest-dir ~ is a directory ok umask 022 ok cd-command found /bin/zsh ok cd-args /bin/zsh info diff-command not set warning edit-command vi not found in $PATH ok edit-args vi ok git-command found /usr/bin/git, version 2.38.1 warning merge-command vimdiff not found in $PATH ok shell-command found /bin/zsh ok shell-args /bin/zsh info age-command age not found in $PATH ok gpg-command found /usr/bin/gpg, version 2.2.40 info pinentry-command not set info 1password-command op not found in $PATH info bitwarden-command bw not found in $PATH info gopass-command gopass not found in $PATH info keepassxc-command keepassxc-cli not found in $PATH info keepassxc-db not set info keeper-command keeper not found in $PATH info lastpass-command lpass not found in $PATH info pass-command pass not found in $PATH info passhole-command ph not found in $PATH info vault-command vault not found in $PATH info secret-command not set ```

[twpayne]

chezmoi uses Go'stext/template package for templates. For loops, use the range action.

[bonecountysheriff]

Thank you for the quick reply, I'm going through the documentation for go templates right now and if everything works, I'll close the issue right away.

[bradenhilton]

{{ range $_, $name := list "user1" "user2" "user3" -}}
{{   range $_, $host := list "gitlab" "github" -}}
Host {{ $host -}}-{{- $name }}
    User git
    HostName {{ $host -}}.com
    IdentityFile ~/.ssh/{{- $name }}

{{   end -}}
{{ end -}}

[bonecountysheriff]

Thanks a lot @bradenhilton, I really like this solution. The documentation on this has been a little hard to find. May I know what the hyphens and $_ are for?

It seems some of the usernames must not be present in the dotfiles. Is there a way add them from outside the config file?

[bradenhilton]

The hyphens are there to control whitespace, the ones around the variables (e.g. {{ $host -}}) aren't actually necessary in my example but I add them habitually.

$_ was used because range can assign a index and element variable. It is similarly unnecessary and was also used habitually.

As for your other question, I'm sorry but I don't understand. How are you gathering the usernames currently?

[bonecountysheriff]

I just add them manually without any template.

I meant to ask if there is a way to assign an array from the command line for example. Something like this -

prompt> name=(some array) chezmoi apply filename

[twpayne]

I meant to ask if there is a way to assign an array from the command line for example. Something like this -

prompt> name=(some array) chezmoi apply filename

This is possible, but you should not do it.

Firstly, this is possible because you can set an environment variable and then read it in a template with the env template function.

Secondly, you should not do this because you'll have to specify name= every time you run a chezmoi command that evaluates the source state, like chezmoi diff, chezmoi status, or chezmoi apply. If you want to store structured data in a semi-permanent way such that you don't have to specify it every time then consider using a .chezmoidata file.