Siarhei Kresik

.editorconfig

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+root = true
+
+[*]
+indent_size = 4

.gitignore

@@ -1,12 +1,4 @@
-# Binaries for programs and plugins
-*.exe
-*.exe~
-*.dll
-*.so
-*.dylib
-
-# Test binary, build with `go test -c`
-*.test
-
-# Output of the go coverage tool, specifically when used with LiteIDE
-*.out
+.vscode/go-kvdb.code-workspace
+bin/
+coverage.out
+go-kvdb.db*

Dockerfile

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+
+ARG GO_VERSION=1.11.1
+FROM golang:${GO_VERSION}-alpine AS dev
+RUN apk add git
+RUN go get golang.org/x/lint/golint
+RUN go get golang.org/x/tools/cmd/goimports
+
+FROM alpine AS prod
+WORKDIR /app/
+COPY ./bin/client .
+COPY ./bin/server .
+EXPOSE 9090
+ENTRYPOINT ["/app/server"]

Makefile

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+.DEFAULT_GOAL := build
+
+DEV := dev
+PROD := prod
+TAG := latest
+
+BIN := bin
+SRC := src
+
+APP_BASE_NAME := go-kvdb
+APP_CLIENT_NAME := client
+APP_SERVER_NAME := server
+
+REPOSITORY_PATH := github.com/SiarheiKresik
+
+DEV_GOPATH := /go
+DEV_GOPATH_BIN := $(DEV_GOPATH)/$(BIN)
+DEV_GOPATH_SRC := $(DEV_GOPATH)/$(SRC)
+DEV_WORKDIR := $(DEV_GOPATH_SRC)/$(REPOSITORY_PATH)/$(APP_BASE_NAME)
+
+SRC_MOUNT := "$(PWD):$(DEV_GOPATH_SRC)/$(REPOSITORY_PATH)/$(APP_BASE_NAME)"
+BIN_MOUNT := "$(PWD)/$(BIN):$(DEV_GOPATH_BIN)"
+
+DEV_IMAGE := $(APP_BASE_NAME)-${DEV}
+PROD_IMAGE := $(APP_BASE_NAME)
+
+BUILDER := docker build
+RUNNER := docker run --rm
+CHECKER := $(RUNNER) -v $(SRC_MOUNT) -w $(DEV_WORKDIR) $(DEV_IMAGE)
+
+COVERAGE := coverage.out
+
+SEARCH_GOFILES = find -not -path '*/vendor/*' -type f -name "*.go"
+
+DELIMITER="----------------------"
+define print_target_name
+	@echo $(DELIMITER)
+	@echo $(1)
+	@echo $(DELIMITER)
+endef
+
+### targets ###
+
+build: build-dev-image build-dev build-prod-image clean
+
+build-dev-image:
+	$(call print_target_name, "Building an image with go tools for development...")
+	$(BUILDER) -t $(DEV_IMAGE) --target $(DEV) .
+
+build-dev:
+	$(call print_target_name, "Compile binaries...")
+	@mkdir $(BIN)
+	$(RUNNER) -v $(BIN_MOUNT) -v $(SRC_MOUNT) -w $(DEV_WORKDIR) $(DEV_IMAGE) sh -c "go install ./..."
+
+build-prod-image:
+	$(call print_target_name, "Building an image with server and client binaries")
+	$(BUILDER) -t $(PROD_IMAGE) --target $(PROD) .
+
+test: test-ut coverage
+
+test-ut:
+	$(call print_target_name, "Run unit tests...")
+	@$(CHECKER) sh -c 'CGO_ENABLED="0" go test ./...'
+
+coverage:
+	$(call print_target_name, "Measure test coverage...")
+	@$(CHECKER) sh -c '\
+		CGO_ENABLED="0" go test ./... -coverprofile=/dev/null | tee $(COVERAGE) \
+		&& chmod 666 $(COVERAGE)'
+
+check: build-dev-image check-goimports check-golint check-govet
+
+check-govet:
+	$(call print_target_name, "Checks (go vet)...")
+	@$(CHECKER) sh -c 'go tool vet -v . | grep -v "Checking file"'
+
+check-goimports:
+	$(call print_target_name, "Checks (goimports)...")
+	@$(CHECKER) sh -c 'test -z "`goimports -e -d .`"'
+
+check-golint:
+	$(call print_target_name, "Checks (golint)...")
+	@$(CHECKER) sh -c 'test -z "`golint ./...`"'
+
+check-golint-verbose:
+	$(call print_target_name, "Checks (golint)...")
+	@$(CHECKER) sh -c 'golint ./...'
+
+run: run-server
+
+run-server:
+	$(call print_target_name, "Run server...")
+	$(RUNNER) -p 9090:9090 $(APP_BASE_NAME):$(TAG) $(ARGS)
+
+run-client:
+	$(call print_target_name, "Run client...")
+	$(RUNNER) -it --entrypoint /app/client $(APP_BASE_NAME):$(TAG) $(ARGS)
+
+run-dev:
+	$(RUNNER) -it -v $(SRC_MOUNT) -w $(DEV_WORKDIR) $(DEV_IMAGE) sh
+
+clean:
+	$(call print_target_name, "Cleaning...")
+	@rm -rf ./$(BIN)/
+	@rm -f $(COVERAGE) \
+
+prune:
+	docker image prune

README.md

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+# go-kvdb
+
+Go implementation of the server-client solution for storing key-value data.
+
+## Requirements
+
+-   [make](https://www.gnu.org/software/make/)
+-   [docker](https://www.docker.com/)  
+    Note: in order to run docker commands in the makefile targets without sudo you have to follow the next [guide](https://docs.docker.com/install/linux/linux-postinstall/).
+
+## Getting source files
+
+If you have `go` tool installed:
+
+-   get source files: `go get github.com/SiarheiKresik/go-kvdb`
+-   `cd $GOPATH/src/github.com/SiarheiKresik/go-kvdb`
+
+Or get source files by cloning repository directly:
+
+-   get source files: `git clone https://github.com/SiarheiKresik/go-kvdb.git`
+-   `cd go-kvdb`
+
+## Building
+
+Run `make`. This builds the `go-kvdb` docker container with the server and client binaries.
+
+## Running
+
+Run server in a docker container:
+
+-   `make run [ARGS="<args>"]` or
+-   `docker run --rm -p 9090:9090 go-kvdb:latest [ARG...]`
+
+Run client in a docker container:
+
+-   `make run-client [ARGS="<args>"]` or
+-   `docker run --rm -it --entrypoint /app/client go-kvdb:latest [ARG...]`
+
+## Other make targets
+
+-   `make check`—runs code linting and verification
+-   `make test`—runs tests for the project files
+-   `make coverage`—measures test coverage, saves result to the `coverage.out` file
+
+## Server
+
+Starting options:
+
+-   `-m`, `--mode`
+    The possible storage option (_disk_—stores database to disk, _memory_—database runs only in memory)
+-   `-p`, `--port`
+    The port for listening on (default—_9090_)
+-   `-v`, `--verbose`
+    Verbose mode, full log of the client requests
+
+## Client
+
+Starting options:
+
+-   `-p`, `--port`
+    The port to connect to the server (default—_9090_)
+-   `-h`, `--host`
+    The host to connect to the server (default—_127.0.0.1_)
+
+## Supported commands
+
+-   **SET** - updates a key at a time with the given value
+-   **GET** - returns the value of a key
+-   **DEL** - removes a key
+-   **KEYS** - returns all keys matching pattern; pattern could include '\*' symbol which matches zero or
+    more characters
+-   **DUMP** - (optional) - returns database data in the json format
+
+## References
+
+1. https://systembash.com/a-simple-go-tcp-server-and-tcp-client/
+2. https://www.oreilly.com/ideas/building-messaging-in-go-network-clients
+3. https://medium.com/@kpbird/golang-serialize-struct-using-gob-part-1-e927a6547c00

client/args.go

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+package main
+
+import (
+	"flag"
+)
+
+// Config represents a set of parsed flags for client settings.
+type Config struct {
+	port    int
+	host    string
+	dump    bool
+	restore bool
+}
+
+var config Config
+
+func init() {
+	const (
+		defaultPort = 9090
+		portDesc    = "The port to connect to the server"
+
+		defaultHost = "127.0.0.1"
+		hostDesc    = "The host to connect to the server"
+
+		defaultDump = false
+		dumpDesc    = "Dump the whole database to the JSON format on STDOUT"
+
+		defaultRestore = false
+		restoreDesc    = "Restore the database from the dumped file"
+	)
+
+	shorhand := " (shorthand)"
+
+	flag.IntVar(&config.port, "port", defaultPort, portDesc)
+	flag.IntVar(&config.port, "p", defaultPort, portDesc+shorhand)
+
+	flag.StringVar(&config.host, "host", defaultHost, hostDesc)
+	flag.StringVar(&config.host, "h", defaultHost, hostDesc+shorhand)
+}

client/cli.go

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+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
+
+// Cli represents command line interface of a client.
+type Cli struct {
+	r *bufio.Reader
+}
+
+// NewCli returns an initialized Cli struct.
+func NewCli() *Cli {
+	return &Cli{
+		r: bufio.NewReader(os.Stdin),
+	}
+}
+
+// Write writes text to stdout.
+func (c *Cli) Write(text string) {
+	fmt.Print(text)
+}
+
+// Read returns user's input text.
+func (c *Cli) Read() (string, error) {
+	return c.r.ReadString('\n')
+}
+
+// Prompt formats text and writes it to stdout.
+func (c *Cli) Prompt(text string) {
+	fmt.Printf("%s > ", text)
+}

client/client.go

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+package main
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+)
+
+// Client connects and communicates with a server.
+type Client struct {
+	conn net.Conn
+	w    *bufio.Writer
+	ch   chan string
+}
+
+// NewClient initializes a new client.
+func NewClient() *Client {
+	return &Client{}
+}
+
+// Connect connects the client to a server on the specified address.
+func (c *Client) Connect(addr string) (net.Addr, error) {
+	conn, err := net.Dial(protocol, addr)
+	if err != nil {
+		return nil, err
+	}
+	c.conn = conn
+	c.w = bufio.NewWriter(conn)
+	return c.conn.RemoteAddr(), nil
+}
+
+// Close closes connection with a server.
+func (c *Client) Close() {
+	c.conn.Close()
+}
+
+// Send sends a message to a server.
+func (c *Client) Send(msg string) error {
+	_, err := fmt.Fprintf(c.conn, msg)
+	if err != nil {
+		return err
+	}
+	return nil
+}