Forked from https://github.com/bippio/go-impala
go get github.com/hoilc/go-impala
The connection string uses a URL format: impala://username:password@host:port?param1=value¶m2=value
auth
- string. Authentication mode. Supported values: "noauth", "ldap"tls
- boolean. Enable TLSca-cert
- The file that contains the public key certificate of the CA that signed the impala certificatebatch-size
- integer value (default: 1024). Maximum number of rows fetched per requestbuffer-size
- in bytes (default: 4096); Buffer size for the Thrift transportmem-limit
- string value (example: 3m); Memory limit for query
A string of this format can be constructed using the URL type in the net/url package.
query := url.Values{}
query.Add("auth", "ldap")
u := &url.URL{
Scheme: "impala",
User: url.UserPassword(username, password),
Host: net.JoinHostPort(hostname, port),
RawQuery: query.Encode(),
}
db, err := sql.Open("impala", u.String())
Also, you can bypass string-base data source name by using sql.OpenDB:
opts := impala.DefaultOptions
opts.Host = hostname
opts.UseLDAP = true
opts.Username = username
opts.Password = password
connector := impala.NewConnector(&opts)
db := sql.OpenDB(connector)
package main
// Simple program to list databases and the tables
import (
"context"
"database/sql"
"log"
"github.com/hoilc/go-impala"
)
func main() {
opts := impala.DefaultOptions
opts.Host = "<impala host>"
opts.Port = "21050"
// enable LDAP authentication:
opts.UseLDAP = true
opts.Username = "<ldap username>"
opts.Password = "<ldap password>"
// enable TLS
opts.UseTLS = true
opts.CACertPath = "/path/to/cacert"
connector := impala.NewConnector(&opts)
db := sql.OpenDB(connector)
defer db.Close()
ctx := context.Background()
rows, err := db.QueryContext(ctx, "SHOW DATABASES")
if err != nil {
log.Fatal(err)
}
r := struct {
name string
comment string
}{}
databases := make([]string, 0) // databases will contain all the DBs to enumerate later
for rows.Next() {
if err := rows.Scan(&r.name, &r.comment); err != nil {
log.Fatal(err)
}
databases = append(databases, r.name)
}
if err := rows.Err(); err != nil {
log.Fatal(err)
}
log.Println("List of Databases", databases)
stmt, err := db.PrepareContext(ctx, "SHOW TABLES IN ?")
if err != nil {
log.Fatal(err)
}
tbl := struct {
name string
}{}
for _, d := range databases {
rows, err := stmt.QueryContext(ctx, d)
if err != nil {
log.Printf("error in querying database %s: %s", d, err.Error())
continue
}
tables := make([]string, 0)
for rows.Next() {
if err := rows.Scan(&tbl.name); err != nil {
log.Println(err)
continue
}
tables = append(tables, tbl.name)
}
log.Printf("List of Tables in Database %s: %v\n", d, tables)
}
}