Add writeToFile function

[anhdat]

Fixes #1077
Based on the implementation of savetofile plugin.
writeToFile writes the content to a file with username, group name, permissions. There are optional flags to select appending mode or add a newline.

For example:

{{ key "my/key/path" | writeToFile "/my/file/path.txt" "my-user" "my-group" "0644" }}
{{ key "my/key/path" | writeToFile "/my/file/path.txt" "my-user" "my-group" "0644" "append" }}
{{ key "my/key/path" | writeToFile "/my/file/path.txt" "my-user" "my-group" "0644" "append,newline" }}

This is my first PR in this repository, please guide me on how to finish this PR. Thank you in advance!

[eikenb]

Thankjs for the PR @anhdat,

I know this is frequently requested and will definitely look at this for the next feature release. I'm currently debating about doing a bugfix 0.26.1 release or just jumping to 0.27.0... if the latter I'll definitely include this.

[eikenb]

One thing... I'm not going to consider it a blocker as I'd like to get this feature added, but if you get a chance I'd love to see a test added for this. If you decide to add test(s) there are 2 possible places, in template_tests.go as an entry in the test table in TestTemplate_Execute or you can test it directly in funcs_test.go. Either one would be great and, if you do decide to write the test, I'll leave it to you to pick which you method you prefer.

Thanks.

[anhdat]

Hi @eikenb, thanks for the guidance. I've added the tests to the template_tests.go file. The writeToFile function requires a different testing setup, so I created a function Test_writeToFile alongside TestTemplate_Execute. Please let me know if this works. Thanks.

[anhdat]

The build is failing in consul-template/manager:

foo--- FAIL: TestDedup_IsLeader (2.00s)
    dedup_test.go:46: timeout
--- FAIL: TestDedup_UpdateDeps (2.00s)
    dedup_test.go:76: timeout
--- FAIL: TestDedup_FollowerUpdate (2.00s)
    dedup_test.go:135: timeout
FAIL
FAIL	github.com/hashicorp/consul-template/manager	5.094s

Would a retry fix this?

[eikenb]

Thanks for the tests!

A re-run did fix that test failure. I've been working to eliminate them, but there are still a number of race conditions lurking in the tests. That dedup one has been particularly annoying.

The github-actions CI is still failing due to it finding a data race in a test that passes on every other platform (???)... I'm going to look into that, but I'm only testing github-actions CI at this point so I'm not going to consider it a blocker. I think it really just comes down to the use of t.Parallel() and I plan on removing all of those very soon anyways (they make debugging tests a PITA) and then, maybe, add some back if they actually help.

[wavedocs]

Guys, I propose to supplement the code that will function to create nested directories if they are missing.

diff --git a/template/funcs.go b/template/funcs.go
index 66990b1c..376e6afe 100644
--- a/template/funcs.go
+++ b/template/funcs.go
@@ -1628,6 +1628,15 @@ func writeToFile(path, username, groupName, permissions string, args ...string)
                        return "", err
                }
        } else {
+               dirPath := filepath.Dir(path)
+
+               if _, err := os.Stat(dirPath); err != nil {
+                       err := os.MkdirAll(dirPath, os.ModePerm)
+                       if err != nil {
+                               return "", err
+                       }
+               }
+
                f, err = os.Create(path)
                if err != nil {
                        return "", err

[eikenb]

Hey @wavedocs,

Thanks for raising your concern. I suggest submitting a PR with this change and linking it back here. Having a PR will make it easy to merge and for others to take a more active part of the discussion. If you do submit a PR with this please add a test for the added functionality in addition to the feature.

Thanks.

[mbillow]

@wavedocs @eikenb I included the directory creation and subsequent tests in #1549, FYI.