prepare for multi db setup

Makefile

@@ -1,4 +1,4 @@
 serv:
-	go run -tags='sqlite_fts5' cmd/frontend/* 
+	DB_DRIVER="sqlite3" DB_URL="./persistence/app.db" go run -tags='sqlite_fts5' cmd/frontend/* 
 crawl:
 	go run -tags='sqlite_fts5' cmd/crawler/main.go

cmd/crawler/collectors/collector.go

@@ -1,7 +1,7 @@
 package collectors
 
-import "crowsnest/internal/model/sqlite"
+import "crowsnest/internal/model/database"
 
 type Collector struct {
-    Responses *sqlite.ResponseModel
+	Responses *database.ResponseModel
 }

cmd/crawler/extractors/extractor.go

@@ -1,8 +1,8 @@
 package extractors
 
-import "crowsnest/internal/model/sqlite"
+import "crowsnest/internal/model/database"
 
 type Extractor struct {
-	Responses *sqlite.ResponseModel
-	Articles  *sqlite.ArticleModel
+	Responses *database.ResponseModel
+	Articles  *database.ArticleModel
 }

cmd/crawler/main.go

@@ -3,7 +3,7 @@ package main
 import (
 	"crowsnest/cmd/crawler/collectors"
 	"crowsnest/cmd/crawler/extractors"
-	"crowsnest/internal/model/sqlite"
+	"crowsnest/internal/model/database"
 	"database/sql"
 	"log"
 
@@ -19,7 +19,7 @@ func main() {
 
 	// collect websites
 	_ = collectors.Collector{
-		Responses: &sqlite.ResponseModel{DB: db},
+		Responses: &database.ResponseModel{DB: db},
 	}
 
 	//coll.Spiegel()
@@ -27,9 +27,9 @@ func main() {
 
 	// extract articles from websites
 	extr := extractors.Extractor{
-		Responses: &sqlite.ResponseModel{DB: db},
-		Articles:  &sqlite.ArticleModel{DB: db},
+		Responses: &database.ResponseModel{DB: db},
+		Articles:  &database.ArticleModel{DB: db},
 	}
 
-    extr.Spiegel()
+	extr.Spiegel()
 }

cmd/frontend/main.go

@@ -1,32 +1,50 @@
 package main
 
 import (
-	"crowsnest/internal/model/sqlite"
+	"crowsnest/internal/model/database"
 	"database/sql"
+	"errors"
 	"log"
 	"net/http"
+	"os"
 
+	_ "github.com/lib/pq"
 	_ "github.com/mattn/go-sqlite3"
 )
 
-
 type App struct {
-    articles *sqlite.ArticleModel
+	articles *database.ArticleModel
 }
 
 func main() {
-    db, err := sql.Open("sqlite3", "./persistence/app.db")
-    if err != nil { log.Fatal(err) }
+	// collect environement variables
+	databaseURL := os.Getenv("DB_URL")
+	dbDriver := os.Getenv("DB_DRIVER")
 
-    app := &App{
-        articles: &sqlite.ArticleModel{ DB: db },
-    }
+	// connect to database
+	var db *sql.DB
+	var err error
+	switch {
+	case dbDriver == "sqlite3":
+		db, err = sql.Open("sqlite3", databaseURL)
+		if err != nil {
+			log.Fatal(err)
+		}
+	default:
+		log.Fatal(errors.New("given DB_DRIVER is not supported"))
+	}
 
-    server := http.Server{
-        Addr:    ":8080",
-        Handler: app.routes(),
-    }
+	// define app
+	app := &App{
+		articles: &database.ArticleModel{DB: db, DbDriver: dbDriver},
+	}
 
-    log.Println("server started, listening on :8080")
-    server.ListenAndServe()
+	// start web server
+	server := http.Server{
+		Addr:    ":8080",
+		Handler: app.routes(),
+	}
+
+	log.Println("server started, listening on :8080")
+	server.ListenAndServe()
 }

internal/model/database/articles.go

@@ -0,0 +1,132 @@
+package database
+
+import (
+	"crowsnest/internal/model"
+	"database/sql"
+)
+
+// TODO docstring
+type ArticleModel struct {
+	DB       *sql.DB
+	DbDriver string
+}
+
+// TODO docstring
+func (m *ArticleModel) All() ([]model.Article, error) {
+	stmt := `
+        SELECT id, title, sourceUrl, author, content, publishDate, fetchDate 
+        FROM articles 
+        ORDER BY publishDate DESC
+    `
+	rows, err := m.DB.Query(stmt)
+	if err != nil {
+		return nil, err
+	}
+
+	articles := []model.Article{}
+	for rows.Next() {
+		a := model.Article{}
+		err := rows.Scan(&a.Identifier, &a.Title, &a.SourceUrl, &a.Author, &a.Content, &a.PublishDate, &a.FetchDate)
+		if err != nil {
+			return nil, err
+		}
+
+		articles = append(articles, a)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return articles, nil
+}
+
+// TODO docstring
+func (m *ArticleModel) Search(query string) ([]model.Article, error) {
+	stmt := `
+        SELECT id, title, sourceUrl, author, content, publishDate, fetchDate
+        FROM articles JOIN ( 
+            SELECT id as id2, rank FROM fts_articles WHERE content MATCH ?
+        ) ON id = id2 
+        ORDER BY rank ASC, publishDate DESC
+        LIMIT 10
+    `
+	rows, err := m.DB.Query(stmt, query)
+	if err != nil {
+		return nil, err
+	}
+
+	articles := []model.Article{}
+	for rows.Next() {
+		a := model.Article{}
+		err := rows.Scan(&a.Identifier, &a.Title, &a.SourceUrl, &a.Author, &a.Content, &a.PublishDate, &a.FetchDate)
+		if err != nil {
+			return nil, err
+		}
+
+		articles = append(articles, a)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return articles, nil
+}
+
+// Inserts a new article into the database. The id attribute of the given
+// article will be ignored. May throw an error if the execution of the database
+// query fails.
+func (m *ArticleModel) Insert(a *model.Article) error {
+	// begin transaction
+	_, err := m.DB.Begin()
+	if err != nil {
+		return err
+	}
+
+	// insert article
+	stmt := `INSERT INTO articles (title, sourceUrl, author, content, publishDate, fetchDate)
+             VALUES (?, ?, ?, ?, ?, ?)
+    `
+	result, err := m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Author, a.Content, a.PublishDate, a.FetchDate)
+	if err != nil {
+		return err
+	}
+	lastId, err := result.LastInsertId()
+	if err != nil {
+		return err
+	}
+
+	// insert into fts_articles for full-text search
+	stmt = `INSERT INTO fts_articles (id, content)
+             VALUES (?, ? || '\n' || ? || '\n' || ?)
+    `
+	_, err = m.DB.Exec(stmt, lastId, a.Title, a.Author, a.Content)
+	return err
+}
+
+// TODO docstring
+func (m *ArticleModel) Update(a *model.Article) error {
+	// begin transaction
+	_, err := m.DB.Begin()
+	if err != nil {
+		return err
+	}
+
+	// insert article
+	stmt := `UPDATE articles 
+             SET title = ?, sourceUrl = ?, author = ?, content = ?, publishDate = ?, fetchDate = ?
+             WHERE id = ?
+    `
+	_, err = m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Author, a.Content, a.PublishDate, a.FetchDate, a.Identifier)
+	if err != nil {
+		return err
+	}
+
+	// insert into fts_articles for full-text search
+	stmt = `INSERT INTO fts_articles (id, content)
+             VALUES (?, ? || '\n' || ? || '\n' || ?)
+    `
+	_, err = m.DB.Exec(stmt, a.Identifier, a.Title, a.Author, a.Content)
+	return err
+}

internal/model/database/responeses.go

@@ -0,0 +1,103 @@
+package database
+
+import (
+	"crowsnest/internal/model"
+	"database/sql"
+)
+
+type ResponseModel struct {
+	DB       *sql.DB
+	DbDriver string
+}
+
+// TODO docstring
+func (m *ResponseModel) All() ([]model.Response, error) {
+	stmt := `
+        SELECT url, content, fetchDate, processed
+        FROM responses 
+    `
+	rows, err := m.DB.Query(stmt)
+	if err != nil {
+		return nil, err
+	}
+
+	responses := []model.Response{}
+	for rows.Next() {
+		r := model.Response{}
+		err := rows.Scan(&r.Url, &r.Content, &r.FetchDate, &r.Processed)
+		if err != nil {
+			return nil, err
+		}
+
+		responses = append(responses, r)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return responses, nil
+}
+
+// TODO docstring
+func (m *ResponseModel) UnprocessedUrls() ([]string, error) {
+	stmt := `
+        SELECT url 
+        FROM responses 
+        WHERE NOT processed 
+    `
+	rows, err := m.DB.Query(stmt)
+	if err != nil {
+		return nil, err
+	}
+
+	urls := make([]string, 0)
+	for rows.Next() {
+		r := ""
+		err := rows.Scan(&r)
+		if err != nil {
+			return nil, err
+		}
+
+		urls = append(urls, r)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return urls, nil
+}
+
+// TODO docstring
+func (m *ResponseModel) GetByUrl(url string) (model.Response, error) {
+	stmt := `
+        SELECT url, content, fetchDate, processed
+        FROM responses 
+        WHERE url = ?
+    `
+
+	res := model.Response{}
+	row := m.DB.QueryRow(stmt, url)
+	err := row.Scan(&res.Url, &res.Content, &res.FetchDate, &res.Processed)
+
+	return res, err
+}
+
+// TODO docstring
+func (m *ResponseModel) Insert(url string, content string) error {
+	// insert response
+	stmt := `INSERT INTO responses (url, content) VALUES (?, ?)`
+	_, err := m.DB.Exec(stmt, url, content)
+
+	return err
+}
+
+// TODO docstring
+func (m *ResponseModel) Processed(url string) error {
+	// insert response
+	stmt := `UPDATE responses SET processed = true WHERE url = ?`
+	_, err := m.DB.Exec(stmt, url)
+
+	return err
+}

internal/model/sqlite/articles.go

@@ -1,109 +0,0 @@
-package sqlite
-
-import (
-	"crowsnest/internal/model"
-	"database/sql"
-)
-
-// TODO docstring
-type ArticleModel struct {
-    DB *sql.DB
-}
-
-// TODO docstring
-func (m *ArticleModel) All() ([]model.Article, error) {
-    stmt := `
-        SELECT id, title, sourceUrl, author, content, publishDate, fetchDate 
-        FROM articles 
-        ORDER BY publishDate DESC
-    `
-    rows, err := m.DB.Query(stmt)
-    if err != nil { return nil, err }
-
-    articles := []model.Article{}
-    for rows.Next() {
-        a := model.Article{}
-        err := rows.Scan(&a.Identifier, &a.Title, &a.SourceUrl, &a.Author, &a.Content, &a.PublishDate, &a.FetchDate)
-        if err != nil { return nil, err }
-
-        articles = append(articles, a)
-    }
-    
-    if err = rows.Err(); err != nil { return nil,  err }
-
-    return articles, nil
-}
-
-// TODO docstring
-func (m *ArticleModel) Search(query string) ([]model.Article, error) {
-    stmt := `
-        SELECT id, title, sourceUrl, author, content, publishDate, fetchDate
-        FROM articles JOIN ( 
-            SELECT id as id2, rank FROM fts_articles WHERE content MATCH ?
-        ) ON id = id2 
-        ORDER BY rank ASC, publishDate DESC
-        LIMIT 10
-    `
-    rows, err := m.DB.Query(stmt, query)
-    if err != nil { return nil, err }
-
-    articles := []model.Article{}
-    for rows.Next() {
-        a := model.Article{}
-        err := rows.Scan(&a.Identifier, &a.Title, &a.SourceUrl, &a.Author, &a.Content, &a.PublishDate, &a.FetchDate)
-        if err != nil { return nil, err }
-
-        articles = append(articles, a)
-    }
-    
-    if err = rows.Err(); err != nil { return nil,  err }
-
-    return articles, nil
-}
-
-// Inserts a new article into the database. The id attribute of the given
-// article will be ignored. May throw an error if the execution of the database
-// query fails.
-func (m *ArticleModel) Insert(a *model.Article) error {
-    // begin transaction 
-    _, err := m.DB.Begin()
-    if err != nil { return err }
-
-    // insert article
-    stmt := `INSERT INTO articles (title, sourceUrl, author, content, publishDate, fetchDate)
-             VALUES (?, ?, ?, ?, ?, ?)
-    `
-    result, err := m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Author, a.Content, a.PublishDate, a.FetchDate)
-    if err != nil { return err }
-    lastId, err := result.LastInsertId()
-    if err != nil { return err }
-
-    // insert into fts_articles for full-text search
-    stmt = `INSERT INTO fts_articles (id, content)
-             VALUES (?, ? || '\n' || ? || '\n' || ?)
-    `
-    _, err = m.DB.Exec(stmt, lastId, a.Title, a.Author, a.Content)
-    return err
-}
-
-// TODO docstring
-func (m *ArticleModel) Update(a *model.Article) error {
-    // begin transaction 
-    _, err := m.DB.Begin()
-    if err != nil { return err }
-
-    // insert article
-    stmt := `UPDATE articles 
-             SET title = ?, sourceUrl = ?, author = ?, content = ?, publishDate = ?, fetchDate = ?
-             WHERE id = ?
-    `
-    _, err = m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Author, a.Content, a.PublishDate, a.FetchDate, a.Identifier)
-    if err != nil { return err }
-
-    // insert into fts_articles for full-text search
-    stmt = `INSERT INTO fts_articles (id, content)
-             VALUES (?, ? || '\n' || ? || '\n' || ?)
-    `
-    _, err = m.DB.Exec(stmt, a.Identifier, a.Title, a.Author, a.Content)
-    return err
-}

internal/model/sqlite/responeses.go

@@ -1,91 +0,0 @@
-package sqlite
-
-import (
-	"crowsnest/internal/model"
-	"database/sql"
-)
-
-type ResponseModel struct {
-    DB *sql.DB
-}
-
-
-// TODO docstring
-func (m *ResponseModel) All() ([]model.Response, error) {
-    stmt := `
-        SELECT url, content, fetchDate, processed
-        FROM responses 
-    `
-    rows, err := m.DB.Query(stmt)
-    if err != nil { return nil, err }
-
-    responses := []model.Response{}
-    for rows.Next() {
-        r := model.Response{}
-        err := rows.Scan(&r.Url, &r.Content, &r.FetchDate, &r.Processed)
-        if err != nil { return nil, err }
-
-        responses = append(responses, r)
-    }
-    
-    if err = rows.Err(); err != nil { return nil,  err }
-
-    return responses, nil
-}
-
-// TODO docstring
-func (m *ResponseModel) UnprocessedUrls() ([]string, error) {
-    stmt := `
-        SELECT url 
-        FROM responses 
-        WHERE NOT processed 
-    `
-    rows, err := m.DB.Query(stmt)
-    if err != nil { return nil, err }
-
-    urls := make([]string, 0)
-    for rows.Next() {
-        r := ""
-        err := rows.Scan(&r)
-        if err != nil { return nil, err }
-
-        urls = append(urls, r)
-    }
-    
-    if err = rows.Err(); err != nil { return nil,  err }
-
-    return urls, nil
-}
-
-// TODO docstring
-func (m *ResponseModel) GetByUrl(url string) (model.Response, error) {
-    stmt := `
-        SELECT url, content, fetchDate, processed
-        FROM responses 
-        WHERE url = ?
-    `
-
-    res := model.Response{}
-    row := m.DB.QueryRow(stmt, url)
-    err := row.Scan(&res.Url, &res.Content, &res.FetchDate, &res.Processed)
-
-    return res, err
-}
-
-// TODO docstring
-func (m *ResponseModel) Insert(url string, content string) error {
-    // insert response
-    stmt := `INSERT INTO responses (url, content) VALUES (?, ?)`
-    _, err := m.DB.Exec(stmt, url, content)
-
-    return err
-}
-
-// TODO docstring
-func (m *ResponseModel) Processed(url string) error {
-    // insert response
-    stmt := `UPDATE responses SET processed = true WHERE url = ?`
-    _, err := m.DB.Exec(stmt, url)
-
-    return err
-}