blog: Containerized development workflow using remote gopls server

.drone.yml

@@ -2,11 +2,9 @@
 kind: pipeline
 type: docker
 name: default
-trigger:
-  branch:
-    - master
+
 steps:
-  - name: ssh commands
+  - name: ssh commands for rohanverma.net
     image: appleboy/drone-ssh
     settings:
       host: 159.89.175.2
@@ -15,6 +13,9 @@ steps:
       key:
         from_secret: ssh_key
       script_stop: true
+      trigger:
+        branch:
+          - master
       script:
         - cd /home/rhnvrm/apps/rohanverma.net
         - git fetch origin
@@ -22,3 +23,22 @@ steps:
         - cd /home/rhnvrm/proxy
         - docker-compose build rohanvermanet
         - docker-compose up -d rohanvermanet
+  - name: ssh commands for next.rohanverma.net
+    image: appleboy/drone-ssh
+    settings:
+      host: 159.89.175.2
+      username: deploy
+      port: 22
+      key:
+        from_secret: ssh_key
+      script_stop: true
+      trigger:
+        branch:
+          - develop
+      script:
+        - cd /home/rhnvrm/apps/rohanverma.net
+        - git fetch origin
+        - git checkout origin/develop
+        - cd /home/rhnvrm/proxy
+        - docker-compose build nextrohanvermanet
+        - docker-compose up -d nextrohanvermanet

content/blog/2019-08-04.md

@@ -5,7 +5,7 @@ date = "2019-06-26T07:30:00+00:00"
 draft = true
 tags = ["books"]
 title = "Deep Work by Cal Newport - A summary"
-type = ""
+type = "post"
 url = "blog/2019/06/26/deep-work-a-summary"
 
 +++

content/blog/2019-10-25-paisavasool-hackinout-2019.md

@@ -90,5 +90,5 @@ We figured out that:
 - The user can check the state and see all his transactions from our app.
 
 ## Future
-- The [Sahamati framework](http://www.sahamati.org/) in the future will allow users to share their bank transaction ledger details with apps directly in a standardized format via Aggregators.
+- The [Sahamati framework](https://sahamati.org.in/) in the future will allow users to share their bank transaction ledger details with apps directly in a standardized format via Aggregators.
 - UPI roadmap has split requests planned for the future.

content/blog/2019-11-05-docker-gopls.md

@@ -0,0 +1,103 @@
++++
+title = "Containerized development workflow using remote gopls server"
+date = 2019-11-05T15:30:03+05:30
+draft = false
+categories = ["golang"]
+type = "post"
+url = "blog/2019/11/05/containerized-dev-using-remote-gopls"
+author = "Rohan Verma"
++++
+
+If your CGO development toolchain depends on external dependencies such 
+as system libraries, or you want to develop on an older version of
+go while having a different version on your host, you can use a docker container and mount the source from your host machine and build the project inside the 
+container. This can enable us to have a consistent development environment across
+various developers and their host systems without having to modify system 
+libraries. 
+
+This article is a follow up to my previous article on [using containers
+to develop on archaic projects](/blog/2019/08/04/docker-containers-to-build-archaic-projects/) 
+that require specific system libraries. Last time I discussed how to create a
+container having all the dependencies and dev tools installed and use them to
+operate on the host file system. Taking this a step forward, 
+the biggest roadblock that arises with this approach is that our host machine  
+now loses the ability to run gotools on our source code. That means your editor
+cannot run any of the tools you depend on to write, lint, or format your go 
+source code. 
+
+To overcome this, we can use the experimental [remote lsp server](https://godoc.org/golang.org/x/tools/internal/lsp/cmd#Application) 
+feature available in gopls. [gopls](https://github.com/golang/tools/tree/master/gopls) (pronounced: "go please") is the official language server for the Go language. 
+With this mode, the gopls running on the host 
+forwards all the commands to the gopls in our container. This way the host system
+does not need to have any of the dependencies installed and can then use the 
+container gopls server to modify the source in the editor of the host.
+
+Let us look at the Dockerfile for this system.
+
+```Dockerfile
+FROM ubuntu:xenial AS builder
+RUN apt-get update
+# Install system dependencies that we might need
+RUN apt-get install -y gcc g++
+
+# Install Depencies like Go and Swig in our container.
+WORKDIR /tmp
+# Install Go
+RUN wget https://dl.google.com/go/go1.12.9.linux-amd64.tar.gz
+RUN tar -C /usr/local -xzf go1.12.9.linux-amd64.tar.gz
+# Install Swig
+RUN wget http://prdownloads.sourceforge.net/swig/swig-4.0.1.tar.gz
+RUN tar -zxvf swig-4.0.1.tar.gz
+RUN cd /tmp/swig-4.0.1 && ./configure && make && make install
+
+# Create user
+RUN useradd -m -r -u 1000 myuser
+RUN groupmod -g 1000 myuser
+
+# Replicate/fake the host system tree
+RUN mkdir -p /home/myuser/code/go/myhostdir/myproject
+RUN chown -R myuser:myuser /home/myuser/code/go/myhostdir/myproject
+USER myuser
+
+WORKDIR /home/myuser/code/go/myhostdir/myproject
+
+RUN GO111MODULE=on go get golang.org/x/tools/gopls@latest
+CMD gopls -listen=":7050"
+```
+
+Firstly, we install all the dependencies and then create
+a user which will have access to the source code. 
+
+Then we have to replicate the
+host path in the container and set that as our work directory. This is a quirk
+of gopls, if there is a mismatch in the path, the host will communicate the
+wrong path to the server running in the container and will be unable to find it
+inside the container. 
+
+Finally, we install gopls in the container and then start it in the container
+with the `-listen=":7050"` flag.
+
+
+Now we can expose this port to our host machine.
+
+```bash
+docker run -d --name "myproject" -u `id -u` -p 7050:7050 \
+    -v /home/myuser/code/go/myhostdir/myproject:/home/myuser/code/go/myhostdir/ \
+    myproject myproject:latest
+```
+
+Notice, that we also mount the host source in the container with the same path,
+the reason is explained above.
+
+We must now add the following flag to your editor config along with any other
+flags we use for the language server to connect to the remote gopls server.
+
+```bash
+gopls -remote "localhost:7050"
+```
+
+After adding this flag, you will now be able to edit your source with all the
+added benefits that come with a language server. 
+
+Since this is an experimental feature, it might break (a lot). Do let me know 
+in the comments if this was helpful for you.