Enhancements: configurable database file path, default port, and optimised Docker image #109
Conversation
main.go
Outdated
| @@ -34,6 +34,9 @@ func main() { | |||
| http.HandleFunc("/get", GetCommentsHandler) | |||
|
|
|||
| port := os.Getenv("COMMENTO_PORT") | |||
| if port == "" { | |||
| port = "8080" | |||
| } | |||
There was a problem hiding this comment.
This is already done: see config.go:12.
There was a problem hiding this comment.
Ah yes, that's right. For some reason it didn't work at some point. I should've checked config.go. This will be resolved.
main.go
Outdated
| fp := os.Getenv("COMMENTO_DATABASE_FILE") | ||
| if fp == "" { | ||
| fp = "sqlite3.db" | ||
| } |
There was a problem hiding this comment.
This should be performed in config.go.
main.go
Outdated
| fp = "sqlite3.db" | ||
| } | ||
|
|
||
| err = LoadDatabase("sqlite:file=" + fp) |
There was a problem hiding this comment.
Do os.Getenv("...") directly after you've made the config.go change
| .editorconfig | ||
| .gitignore | ||
| Dockerfile | ||
| example/ |
There was a problem hiding this comment.
For some reason, this isn't being reflected on the Github editor / viewer. But I've definitely added it.
| RUN go get -v . | ||
| RUN go install . | ||
| RUN go build -ldflags '-linkmode external -extldflags -static -w' |
There was a problem hiding this comment.
Not a review comment, just curious: what does this do? I haven't been writing Go long enough ^^
Searching tells me -linkmode external can be used to load go variables at compile time. Is that the reasoning?
-static is static linking, I can tell. -w is some kind of executable size reduction technique from what I read (add -s as well?).
There was a problem hiding this comment.
The reason I went with this versus a standard go build is because I wanted to build a static binary from the golang Docker image, and still be able to use it in alpine. There are a couple of problems if we rely on the former.
One of which is your project's use of mattn/go-sqlite3. It is a cgo package, not a Go package. Your project however, is in Go. So we have situation where we need a combination of Go, and non-Go code to be in the final executable without dynamic libraries. So, -linkmode external simply tells cmd/linker to invoke the host linker (often gcc) to combine your Go code (compiled by Go to an object file go.o, but not processed any further) with your non-Go code.
It is also possibly using cgo from the net library (see https://golang.org/pkg/net/#hdr-Name_Resolution).
Everything after -extldflags are flags for gcc (-w to suppress warnings IIRC).
TL;DR: I just want a static binary. If I relied on the standard go build, we'd get an 'output' that relies on dynamic linking, and it will not be executable on alpine.
(see mattn/go-sqlite3#384 (comment) for more information)
There was a problem hiding this comment.
Agreed, thanks for the explanation.
|
(PS: @MrSaints you'll need to use git-rebase to amend the commits; don't use merge commits or add a new commit on top of the three.) |
Set it to `/data/` by default for Docker
… size The main goal here is to optimise for caching, build speed and final image size. It takes advantage of a multi-stage Docker build. - Build backend, and frontend in separate images - Copy artifacts from build images to final, execution image - Add `.dockerignore` to speed up build times (and improve caching) - Copy, and install npm packages before building (again, to improve caching) - Build Go binary statically The final size is under 20MB compared to the hundreds it was before.
|
@adtac Cheers for the review. I've made the appropriate changes. |
Configurable database file path
The sqlite3 database file path is currently hardcoded. It'd be great if it can be configured. For example, if we were to mount a Docker volume for persistence, it'd be far easier if we could mount a data directory rather than a specific file which most implementations do not nicely support, e.g. Rancher.
Default port
I noticed that there's no default set, and the binding can be set to
:. I have set it to8080as per the default environment variable for it.Optimised Docker image
The main goal here is to optimise for caching, build speed and final image size. It takes advantage of a multi-stage Docker build.
.dockerignoreto speed up build times (and improve caching)The final size is under 20MB compared to the hundreds.