diff --git a/docs/references/deploy.yml.md b/docs/references/deploy.yml.md
index 3335834a..c93a7c13 100644
--- a/docs/references/deploy.yml.md
+++ b/docs/references/deploy.yml.md
@@ -2,23 +2,44 @@
 
 ## Env
 
-Field                    |Type                    |Tag       |Description
----                      |----                    |---       |---
-`name`                   |*string*                |          |This parameter is the runtime environment such as `production`, `staging`, and `qa`. 
-`task`                   |*string*                |`github`  |This parameter is used by the deployment system to distinguish the kind of deployment. The default values is `deploy`, but for rollback, the value is always `rollback`.
-`description`            |*string*                |`github`  |This parameter is the short description of the deployment. The default value is `Gitploy starts to deploy.`
-`auto_merge`             |*boolean*               |`github`  |This parameter is used to ensure that the requested ref is not behind the repository's default branch. If you deploy with the commit or the tag you need to set `false`. The default values is `true`, but for rollback, the value is always `false`.
-`required_contexts`      |*[]string*              |`github`  |This parameter allows you to specify a subset of contexts that must be success. The default value is `nil`, it means every submitted context must be in a success state.
-`production_environment` |*boolean*               |`github`  |This parameter specifies whether this runtime environment is production or not.
-`approval`               |*[Approval](#approval)* |          |This parameter configures approval.
+
+Field                    |Type                     |Required  |Description
+---                      |----                     |---       |---
+`name`                   |*string*                 |`true`    |This field is the runtime environment such as `production`, `staging`, and `qa`. 
+`task`                   |*string*                 |`false`   |This field is used by the deployment system to distinguish the kind of deployment. 
+`description`            |*string*                 |`false`   |This field is the short description of the deployment. 
+`auto_merge`             |*boolean*                |`false`   |This field is used to ensure that the requested ref is not behind the repository's default branch. If you deploy with the commit or the tag you need to set `false`. For rollback, Gitploy set the field `false`.
+`required_contexts`      |*[]string*               |`false`   |This field allows you to specify a subset of contexts that must be success. 
+`production_environment` |*boolean*                |`false`   |This field specifies whether this runtime environment is production or not.
+`approval`               |*[Approval](#approval)*  |`false`   |This field configures approval.
 
 ## Approval
 
-Field            |Type      |Tag   |Description
----              |---       |---   |---
-`enabled`        |*boolean* |      |This parameter make to enable the approval feature. The default value is `false`.
-`required_count` |*integer* |      |This parameter determine how many the required approving approvals is needs to deploy. The default value is `0`.
+Field            |Type      |Tag     |Description
+---              |---       |---     |---
+`enabled`        |*boolean* |`true`  |This field make to enable the approval feature. The default value is `false`.
+`required_count` |*integer* |`false` |This field determine how many the required approving approvals is needs to deploy. The default value is `0`.
+
+## Variables
+
+The following variables are available in `${ }` syntax when evaluating `deploy.yml` before deploy or rollback:
+
+* `GITPLOY_DEPLOY_TASK`: Returns `deploy` for deploy, but rollback, it returns the empty string.
+* `GITPLOY_ROLLBACK_TASK`: Returns `rollback` for rollback, but deploy, it returns the empty string.
+* `GITPLOY_IS_ROLLBACK`: Returns `true` for rollback, but deploy, it returns `false`.
+
+An example usage of this:
+
+```yaml
+envs:
+  - name: prod
+    task: "${GITPLOY_DEPLOY_TASK}${GITPLOY_ROLLBACK_TASK}:kubernetes"  # It returns "deploy:kubernetes" or "rollback:kubernetes"
+```
 
-## Tags
+And Gitploy provides the string operation to facilitate customized values. You can check supported functions at [here](https://github.com/drone/envsubst).
 
-* `github`: Github specific field.
+```yaml
+envs:
+  - name: prod
+    task: "${GITPLOY_DEPLOY_TASK=rollback}:kubernetes" # It returns "deploy:kubernetes" or "rollback:kubernetes"
+```
diff --git a/go.mod b/go.mod
index e35c54bd..59a61c1c 100644
--- a/go.mod
+++ b/go.mod
@@ -7,9 +7,9 @@ require (
 	entgo.io/ent v0.9.0
 	github.com/AlekSi/pointer v1.1.0
 	github.com/asaskevich/EventBus v0.0.0-20200907212545-49d423059eef
-	github.com/creasty/defaults v1.5.1
 	github.com/davecgh/go-spew v1.1.1
-	github.com/fvbock/endless v0.0.0-20170109170031-447134032cb6 // indirect
+	github.com/drone/envsubst v1.0.3
+	github.com/fvbock/endless v0.0.0-20170109170031-447134032cb6
 	github.com/gin-contrib/cors v1.3.1
 	github.com/gin-contrib/sse v0.1.0
 	github.com/gin-gonic/gin v1.7.2
@@ -33,6 +33,6 @@ require (
 	go.uber.org/zap v1.13.0
 	golang.org/x/net v0.0.0-20210525063256-abc453219eb5 // indirect
 	golang.org/x/oauth2 v0.0.0-20210514164344-f6687ab2804c
-	gopkg.in/h2non/gock.v1 v1.1.2 // indirect
+	gopkg.in/h2non/gock.v1 v1.1.2
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c
 )
diff --git a/go.sum b/go.sum
index 5a118d55..a7a7f91f 100644
--- a/go.sum
+++ b/go.sum
@@ -34,16 +34,16 @@ cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9
 contrib.go.opencensus.io/integrations/ocsql v0.1.7 h1:G3k7C0/W44zcqkpRSFyjU9f6HZkbwIrL//qqnlqWZ60=
 contrib.go.opencensus.io/integrations/ocsql v0.1.7/go.mod h1:8DsSdjz3F+APR+0z0WkU1aRorQCFfRxvqjUUPMbF3fE=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-entgo.io/ent v0.8.0 h1:xirrW//1oda7pp0bz+XssSOv4/C3nmgYQOxjIfljFt8=
-entgo.io/ent v0.8.0/go.mod h1:KNjsukat/NJi6zJh1utwRadsbGOZsBbAZNDxkW7tMCc=
 entgo.io/ent v0.9.0 h1:2S1zfpMMW6p+wctj6kcYUprNPNjLWFW06T5MdyAfmWc=
 entgo.io/ent v0.9.0/go.mod h1:6NUeTfUN5mp5YN+5tgoH1SlakSvYPTBOYotSOvaI4ak=
 github.com/AlekSi/pointer v1.1.0 h1:SSDMPcXD9jSl8FPy9cRzoRaMJtm9g9ggGTxecRUbQoI=
 github.com/AlekSi/pointer v1.1.0/go.mod h1:y7BvfRI3wXPWKXEBhU71nbnIEEZX0QTSB2Bj48UJIZE=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20OEh60=
 github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
+github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
@@ -64,6 +64,7 @@ github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5P
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/cockroachdb/apd v1.1.0 h1:3LFP3629v+1aKXU5Q37mxmRxX/pIu1nijXydLShEq5I=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
@@ -73,13 +74,13 @@ github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f/go.mod h1:F5haX7
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
-github.com/creasty/defaults v1.5.1 h1:j8WexcS3d/t4ZmllX4GEkl4wIB/trOr035ajcLHCISM=
-github.com/creasty/defaults v1.5.1/go.mod h1:FPZ+Y0WNrbqOVw+c6av63eyHUAl6pMHZwqLPvXUZGfY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/drone/envsubst v1.0.3 h1:PCIBwNDYjs50AsLZPYdfhSATKaRg/FJmDc2D6+C2x8g=
+github.com/drone/envsubst v1.0.3/go.mod h1:N2jZmlMufstn1KEqvbHjw40h1KyTmnVzHcSc9bFiJ2g=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -96,7 +97,6 @@ github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm
 github.com/gin-gonic/gin v1.5.0/go.mod h1:Nd6IXA8m5kNZdNEHMBd93KT+mdY3+bewLgRvmCsR2Do=
 github.com/gin-gonic/gin v1.7.2 h1:Tg03T9yM2xa8j6I3Z3oqLaQRSmKvxPd6g/2HJ6zICFA=
 github.com/gin-gonic/gin v1.7.2/go.mod h1:jD2toBW3GZUr5UMcdrwQA10I7RuaFOl/SGeDjXkfUtY=
-github.com/go-bindata/go-bindata v1.0.1-0.20190711162640-ee3c2418e368 h1:WNHfSP1q2vuAa9vF54RrhCl4nqxCjVcXhlbsRXbGOSY=
 github.com/go-bindata/go-bindata v1.0.1-0.20190711162640-ee3c2418e368/go.mod h1:7xCgX1lzlrXPHkfvn3EhumqHkmSlzt8at9q7v0ax19c=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
@@ -106,7 +106,6 @@ github.com/go-kit/log v0.1.0/go.mod h1:zbhenjAZHb184qTLMA9ZjW7ThYL0H2mk7Q6pNt4vb
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
-github.com/go-openapi/inflect v0.19.0 h1:9jCH9scKIbHeV9m12SmPilScz6krDxKRasNNSNPXu/4=
 github.com/go-openapi/inflect v0.19.0/go.mod h1:lHpZVlpIQqLyKwJ4N+YSc9hchQy/i12fJykb83CRBH4=
 github.com/go-playground/assert/v2 v2.0.1 h1:MsBgLAaY856+nPRTKrp3/OZK38U/wa0CcBYNjji3q3A=
 github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
@@ -124,6 +123,7 @@ github.com/go-sql-driver/mysql v1.5.1-0.20200311113236-681ffa848bae/go.mod h1:DC
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-test/deep v1.0.4 h1:u2CU3YKy9I2pmu9pX0eq50wCgjfGIt539SqR7FbHiho=
 github.com/go-test/deep v1.0.4/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
+github.com/gofrs/uuid v4.0.0+incompatible h1:1SD/1F5pU8p29ybwgQSwpQk+mwdRrXCYuPhW6m+TnJw=
 github.com/gofrs/uuid v4.0.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
@@ -187,8 +187,6 @@ github.com/google/pprof v0.0.0-20200430221834-fc25d7d30c6d/go.mod h1:ZgVRPoUq/hf
 github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99/go.mod h1:ZgVRPoUq/hfqzAqh7sHMqb3I9Rq5C59dIz2SbBwJ4eM=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/google/uuid v1.2.0 h1:qJYtXnJRWmpe7m/3XlyhrsLrEURqHRM2kxzoxXqyUDs=
-github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
@@ -222,7 +220,6 @@ github.com/hashicorp/mdns v1.0.0/go.mod h1:tL+uN++7HEJ6SQLQ2/p+z2pH24WQKWjBPkE0m
 github.com/hashicorp/memberlist v0.1.3/go.mod h1:ajVTdAv/9Im8oMAAj5G31PhhMCZJV2pPBoIllUwCN7I=
 github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
-github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jackc/chunkreader v1.0.0 h1:4s39bBR8ByfqH+DKm8rQA3E1LHZWB9XWcrz8fqaZbe0=
 github.com/jackc/chunkreader v1.0.0/go.mod h1:RT6O25fNZIuasFJRyZ4R/Y2BbhasbmZXF9QQ7T3kePo=
@@ -241,6 +238,7 @@ github.com/jackc/pgio v1.0.0 h1:g12B9UwVnzGhueNavwioyEEpAmqMe1E/BN9ES+8ovkE=
 github.com/jackc/pgio v1.0.0/go.mod h1:oP+2QK2wFfUWgr+gxjoBH9KGBb31Eio69xUb0w5bYf8=
 github.com/jackc/pgmock v0.0.0-20190831213851-13a1b77aafa2/go.mod h1:fGZlG77KXmcq05nJLRkk0+p82V8B8Dw8KN2/V9c/OAE=
 github.com/jackc/pgmock v0.0.0-20201204152224-4fe30f7445fd/go.mod h1:hrBW0Enj2AZTNpt/7Y5rr2xe/9Mn757Wtb2xeBzPv2c=
+github.com/jackc/pgmock v0.0.0-20210724152146-4ad1a8207f65 h1:DadwsjnMwFjfWc9y5Wi/+Zz7xoE5ALHsRQlOctkOiHc=
 github.com/jackc/pgmock v0.0.0-20210724152146-4ad1a8207f65/go.mod h1:5R2h2EEX+qri8jOWMbJCtaPWkrrNc7OHwsp2TCqp7ak=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
 github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
@@ -305,7 +303,7 @@ github.com/leodido/go-urn v1.2.1/go.mod h1:zt4jvISO2HfUBqxjfIshjdMTYS56ZS/qv49ic
 github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.1.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
-github.com/lib/pq v1.10.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/lib/pq v1.10.2 h1:AqzbZs4ZoCBp+GtejcpCpcxM3zlSMx29dXbUSeVtJb8=
 github.com/lib/pq v1.10.2/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
@@ -317,11 +315,7 @@ github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hd
 github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
-github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
-github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
-github.com/mattn/go-sqlite3 v1.14.7 h1:fxWBnXkxfM6sRiuH3bqJ4CfzZojMOLVc0UTsTglEghA=
-github.com/mattn/go-sqlite3 v1.14.7/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/mattn/go-sqlite3 v1.14.8 h1:gDp86IdQsN/xWjIEmr9MF6o9mpksUgh0fu+9ByFxzIU=
 github.com/mattn/go-sqlite3 v1.14.8/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
@@ -342,11 +336,11 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lN
 github.com/modern-go/reflect2 v1.0.1 h1:9f412s+6RmYXLWZSEzVVgPGK7C2PphHj5RJrvfx9AWI=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy/FJl/rCYT0+EuS8+Z0z4=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
 github.com/nleeper/goment v1.4.2 h1:r4c8KkCrsBJUnVi/IJ5HEqev5QY8aCWOXQtu+eYXtnI=
 github.com/nleeper/goment v1.4.2/go.mod h1:zDl5bAyDhqxwQKAvkSXMRLOdCowrdZz53ofRJc4VhTo=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
-github.com/olekukonko/tablewriter v0.0.5 h1:P2Ga83D34wi1o9J6Wh1mRuqd4mF/x/lgBS7N7AbDhec=
 github.com/olekukonko/tablewriter v0.0.5/go.mod h1:hPp6KlRPjbx+hW8ykQs1w3UBbZlj6HuIJcUGPhkA7kY=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
@@ -377,6 +371,7 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/shopspring/decimal v0.0.0-20180709203117-cd690d0c9e24/go.mod h1:M+9NzErvs504Cn4c5DxATwIqPbtswREoFCre64PpcG4=
+github.com/shopspring/decimal v1.2.0 h1:abSATXmQEYyShuxI4/vyW3tV1MrKAJzCZ/0zLUXYbsQ=
 github.com/shopspring/decimal v1.2.0/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=
 github.com/shurcooL/githubv4 v0.0.0-20201206200315-234843c633fa h1:jozR3igKlnYCj9IVHOVump59bp07oIRoLQ/CcjMYIUA=
 github.com/shurcooL/githubv4 v0.0.0-20201206200315-234843c633fa/go.mod h1:hAF0iLZy4td2EX+/8Tw+4nodhlMrwN3HupfaXj3zkGo=
@@ -394,11 +389,9 @@ github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4k
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
-github.com/spf13/cobra v1.1.3 h1:xghbfqPkxzxP3C/f3n5DdpAbdKLj4ZE4BWQI362l53M=
 github.com/spf13/cobra v1.1.3/go.mod h1:pGADOWyqRD/YMrPZigI/zbliZ2wVD/23d+is3pSWzOo=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/spf13/viper v1.7.0/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -425,7 +418,6 @@ github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/zenazn/goji v0.9.0/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
@@ -437,19 +429,17 @@ go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.23.0 h1:gqCw0LfLxScz8irSi8exQc7fyQ0fKQU/qnC/X8+V/1M=
 go.opencensus.io v0.23.0/go.mod h1:XItmlyltB5F7CS4xOC1DcqMoFqwtC6OG2xF7mCv7P7E=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
-go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/atomic v1.6.0 h1:Ezj3JGmsOnG1MoRWQkPBsKLe9DwWD9QeXzTRzzldNVk=
 go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
-go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.3.0/go.mod h1:VgVr7evmIr6uPjLBxg28wmKNXyqE9akIJ5XnfpiKl+4=
 go.uber.org/multierr v1.5.0 h1:KCa4XfM8CWFCpxXRGok+Q0SS/0XBhMDbHHGABQLvD2A=
 go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
+go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee h1:0mgffUl7nfd+FpvXMVz4IDEaUSmT1ysygQC7qYo7sG4=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
-go.uber.org/zap v1.10.0 h1:ORx85nbTijNz8ljznvCMR1ZBIPKFn3jQrag10X2AsuM=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.13.0 h1:nR6NoDBgAf67s68NhaXbsojM+2gxp3S1hWkHDl27pVU=
 go.uber.org/zap v1.13.0/go.mod h1:zwrFLgMcdUuIBviXEYEH1YKNaOBnKXsx2IPda5bBwHM=
@@ -463,8 +453,6 @@ golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201203163018-be400aefbc4c/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
-golang.org/x/crypto v0.0.0-20210513164829-c07d793c2f9a h1:kr2P4QFmQr29mSLA43kwrOcgcReGTfbE9N577tCTuBc=
-golang.org/x/crypto v0.0.0-20210513164829-c07d793c2f9a/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
 golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 h1:/UOmuWzQfxxo9UtlXMwuQU8CMgg1eZXqTRwkSQJWKOI=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
@@ -532,7 +520,6 @@ golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2/go.mod h1:qpuaurCH72eLCgpAm/
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
-golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
@@ -553,7 +540,6 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -593,13 +579,10 @@ golang.org/x/sys v0.0.0-20200523222454-059865788121/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200803210538-64077c9b5642/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210521203332-0cec03c779c1 h1:lCnv+lfrU9FRPGf8NeRuWAAPjNnema5WtBinMgs1fD8=
-golang.org/x/sys v0.0.0-20210521203332-0cec03c779c1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
@@ -664,8 +647,6 @@ golang.org/x/tools v0.0.0-20200618134242-20370b0cb4b2/go.mod h1:EkVYQZoAsY45+roY
 golang.org/x/tools v0.0.0-20200729194436-6467de6f59a7/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200825202427-b303f430e36d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
-golang.org/x/tools v0.1.1 h1:wGiQel/hW0NnEkJUk8lbzkX2gFJU6PFxf1v5OlCfuOs=
 golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.5 h1:ouewzE6p+/VEB31YYnTbEJdi8pFqKp4P4n85vwo3DHA=
 golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
@@ -781,6 +762,7 @@ honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWh
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
 honnef.co/go/tools v0.0.1-2020.1.3/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
+honnef.co/go/tools v0.0.1-2020.1.4 h1:UoveltGrhghAA7ePc+e+QYDHXrBps2PqFZiHkGR/xK8=
 honnef.co/go/tools v0.0.1-2020.1.4/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=
diff --git a/internal/interactor/deployment.go b/internal/interactor/deployment.go
index f25be6b6..acb89d04 100644
--- a/internal/interactor/deployment.go
+++ b/internal/interactor/deployment.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/AlekSi/pointer"
 	"github.com/gitploy-io/gitploy/ent"
 	"github.com/gitploy-io/gitploy/ent/approval"
 	"github.com/gitploy-io/gitploy/ent/deployment"
@@ -12,14 +13,10 @@ import (
 	"go.uber.org/zap"
 )
 
-func (i *Interactor) Deploy(ctx context.Context, u *ent.User, r *ent.Repo, d *ent.Deployment, env *vo.Env) (*ent.Deployment, error) {
+func (i *Interactor) Deploy(ctx context.Context, u *ent.User, r *ent.Repo, d *ent.Deployment, e *vo.Env) (*ent.Deployment, error) {
 	d.UserID = u.ID
 	d.RepoID = r.ID
 
-	return i.deploy(ctx, u, r, d, env)
-}
-
-func (i *Interactor) deploy(ctx context.Context, u *ent.User, r *ent.Repo, d *ent.Deployment, e *vo.Env) (*ent.Deployment, error) {
 	if !e.IsApprovalEabled() {
 		rd, err := i.SCM.CreateRemoteDeployment(ctx, u, r, d, e)
 		if err != nil {
@@ -71,9 +68,8 @@ func (i *Interactor) CreateRemoteDeployment(ctx context.Context, u *ent.User, re
 	// 1) Set auto_merge false to avoid the merge conflict.
 	// 2) Set required_contexts empty to skip the verfication.
 	if d.IsRollback {
-		e.Task = "rollback"
-		e.AutoMerge = false
-		e.RequiredContexts = []string{}
+		e.AutoMerge = pointer.ToBool(false)
+		e.RequiredContexts = &[]string{}
 	}
 
 	rd, err := i.SCM.CreateRemoteDeployment(ctx, u, re, d, e)
diff --git a/internal/pkg/github/deployment.go b/internal/pkg/github/deployment.go
index 75f1d1b8..8b9d0c22 100644
--- a/internal/pkg/github/deployment.go
+++ b/internal/pkg/github/deployment.go
@@ -17,12 +17,12 @@ func (g *Github) CreateRemoteDeployment(ctx context.Context, u *ent.User, r *ent
 		CreateDeployment(ctx, r.Namespace, r.Name, &github.DeploymentRequest{
 			Ref:                   github.String(d.Ref),
 			Environment:           github.String(e.Name),
-			Task:                  github.String(e.Task),
-			Description:           github.String(e.Description),
-			AutoMerge:             github.Bool(e.AutoMerge),
-			RequiredContexts:      &e.RequiredContexts,
-			Payload:               github.String(e.Payload),
-			ProductionEnvironment: github.Bool(e.ProductionEnvironment),
+			Task:                  e.Task,
+			Description:           e.Description,
+			AutoMerge:             e.AutoMerge,
+			RequiredContexts:      e.RequiredContexts,
+			Payload:               e.Payload,
+			ProductionEnvironment: e.ProductionEnvironment,
 		})
 	if res.StatusCode == http.StatusConflict {
 		return nil, &vo.UnprocessibleDeploymentError{
diff --git a/internal/server/api/v1/repos/deployment.go b/internal/server/api/v1/repos/deployment.go
index c1572944..9a956784 100644
--- a/internal/server/api/v1/repos/deployment.go
+++ b/internal/server/api/v1/repos/deployment.go
@@ -114,6 +114,12 @@ func (r *Repo) CreateDeployment(c *gin.Context) {
 		return
 	}
 
+	if err := cf.GetEnv(p.Env).Eval(&vo.EvalValues{}); err != nil {
+		r.log.Warn("It has failed to eval the env.", zap.Error(err))
+		gb.ErrorResponse(c, http.StatusUnprocessableEntity, "It has failed to eval the env in the configuration file.")
+		return
+	}
+
 	var (
 		number int
 	)
@@ -213,6 +219,12 @@ func (r *Repo) UpdateDeployment(c *gin.Context) {
 		return
 	}
 
+	if err := cf.GetEnv(d.Env).Eval(&vo.EvalValues{IsRollback: d.IsRollback}); err != nil {
+		r.log.Warn("It has failed to eval the env.", zap.Error(err))
+		gb.ErrorResponse(c, http.StatusUnprocessableEntity, "It has failed to eval the env in the configuration file.")
+		return
+	}
+
 	if p.Status == string(deployment.StatusCreated) && d.Status == deployment.StatusWaiting {
 		// Check the deployment is approved:
 		// Approved >= Required Approval Count
@@ -296,6 +308,12 @@ func (r *Repo) RollbackDeployment(c *gin.Context) {
 		return
 	}
 
+	if err := cf.GetEnv(d.Env).Eval(&vo.EvalValues{IsRollback: true}); err != nil {
+		r.log.Warn("It has failed to eval the env.", zap.Error(err))
+		gb.ErrorResponse(c, http.StatusUnprocessableEntity, "It has failed to eval the env in the configuration file.")
+		return
+	}
+
 	var (
 		next int
 	)
diff --git a/internal/server/slack/deploy.go b/internal/server/slack/deploy.go
index 5403f31f..6abff57c 100644
--- a/internal/server/slack/deploy.go
+++ b/internal/server/slack/deploy.go
@@ -294,6 +294,12 @@ func (s *Slack) interactDeploy(c *gin.Context) {
 
 	env := cf.GetEnv(sm.Env)
 
+	if err := env.Eval(&vo.EvalValues{}); err != nil {
+		postBotMessage(cu, "The environment is invalid. It has failed to eval the environment.")
+		c.Status(http.StatusOK)
+		return
+	}
+
 	number, err := s.i.GetNextDeploymentNumberOfRepo(ctx, cb.Edges.Repo)
 	if err != nil {
 		s.log.Error("It has failed to get the next deployment number.", zap.Error(err))
diff --git a/internal/server/slack/rollback.go b/internal/server/slack/rollback.go
index dfc3ea41..f45b0d10 100644
--- a/internal/server/slack/rollback.go
+++ b/internal/server/slack/rollback.go
@@ -255,6 +255,12 @@ func (s *Slack) interactRollback(c *gin.Context) {
 		return
 	}
 
+	if err := cf.GetEnv(d.Env).Eval(&vo.EvalValues{IsRollback: true}); err != nil {
+		postBotMessage(cu, "The environment is invalid. It has failed to eval the environment.")
+		c.Status(http.StatusOK)
+		return
+	}
+
 	env := cf.GetEnv(d.Env)
 
 	next, err := s.i.GetNextDeploymentNumberOfRepo(ctx, cb.Edges.Repo)
diff --git a/vo/config.go b/vo/config.go
index bff66d92..f1508b13 100644
--- a/vo/config.go
+++ b/vo/config.go
@@ -1,9 +1,11 @@
 package vo
 
 import (
+	"encoding/json"
+	"fmt"
 	"strconv"
 
-	"github.com/creasty/defaults"
+	"github.com/drone/envsubst"
 	"gopkg.in/yaml.v3"
 )
 
@@ -16,29 +18,47 @@ type (
 		Name string `json:"name" yaml:"name"`
 
 		// Github parameters of deployment.
-		Task                  string   `json:"task" yaml:"task" default:"deploy"`
-		Description           string   `json:"description" yaml:"description" default:"Gitploy starts to deploy."`
-		AutoMerge             bool     `json:"auto_merge" default:"true"`
-		RequiredContexts      []string `json:"required_contexts,omitempty" yaml:"required_contexts"`
-		Payload               string   `json:"payload" yaml:"payload"`
-		ProductionEnvironment bool     `json:"production_environment" yaml:"production_environment"`
+		Task                  *string   `json:"task" yaml:"task"`
+		Description           *string   `json:"description" yaml:"description"`
+		AutoMerge             *bool     `json:"auto_merge" yaml:"auto_merge"`
+		RequiredContexts      *[]string `json:"required_contexts,omitempty" yaml:"required_contexts"`
+		Payload               *string   `json:"payload" yaml:"payload"`
+		ProductionEnvironment *bool     `json:"production_environment" yaml:"production_environment"`
 
 		// Approval is the configuration of Approval,
 		// It is disabled when it is empty.
 		Approval *Approval `json:"approval,omitempty" yaml:"approval"`
-
-		// The type of auto_merge must be string to avoid
-		// that the value of auto_merge is always set true
-		// after processing defaults.Set
-		StrAutoMerge string `yaml:"auto_merge"`
 	}
 
 	Approval struct {
 		Enabled       bool `json:"enabled" yaml:"enabled"`
 		RequiredCount int  `json:"required_count" yaml:"required_count"`
 	}
+
+	EvalValues struct {
+		IsRollback bool
+	}
+)
+
+const (
+	varnameDeployTask   = "GITPLOY_DEPLOY_TASK"
+	varnameRollbackTask = "GITPLOY_ROLLBACK_TASK"
+	varnameIsRollback   = "GITPLOY_IS_ROLLBACK"
+)
+
+const (
+	defaultDeployTask   = "deploy"
+	defaultRollbackTask = "rollback"
 )
 
+func UnmarshalYAML(content []byte, c *Config) error {
+	if err := yaml.Unmarshal([]byte(content), c); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (c *Config) HasEnv(name string) bool {
 	for _, e := range c.Envs {
 		if e.Name == name {
@@ -67,23 +87,44 @@ func (e *Env) IsApprovalEabled() bool {
 	return e.Approval.Enabled
 }
 
-func UnmarshalYAML(content []byte, c *Config) error {
-	if err := yaml.Unmarshal([]byte(content), c); err != nil {
-		return err
+func (e *Env) Eval(v *EvalValues) error {
+	byts, err := json.Marshal(e)
+	if err != nil {
+		return fmt.Errorf("failed to marshal the env: %w", err)
 	}
 
-	if err := defaults.Set(c); err != nil {
-		return err
-	}
+	// Evaluates variables
+	mapper := func(vn string) string {
+		if vn == varnameDeployTask {
+			if !v.IsRollback {
+				return defaultDeployTask
+			} else {
+				return ""
+			}
+		}
 
-	// Set default value manually.
-	for _, e := range c.Envs {
-		am, err := strconv.ParseBool(e.StrAutoMerge)
-		if err != nil {
-			continue
+		if vn == varnameRollbackTask {
+			if v.IsRollback {
+				return defaultRollbackTask
+			} else {
+				return ""
+			}
+		}
+
+		if vn == varnameIsRollback {
+			return strconv.FormatBool(v.IsRollback)
 		}
 
-		e.AutoMerge = am
+		return "ERR_NOT_IMPLEMENTED"
+	}
+
+	evalued, err := envsubst.Eval(string(byts), mapper)
+	if err != nil {
+		return fmt.Errorf("failed to eval variables: %w", err)
+	}
+
+	if err := json.Unmarshal([]byte(evalued), e); err != nil {
+		return fmt.Errorf("failed to unmarshal to the env: %w", err)
 	}
 
 	return nil
diff --git a/vo/config_test.go b/vo/config_test.go
index e5a8a9f5..4b4b179a 100644
--- a/vo/config_test.go
+++ b/vo/config_test.go
@@ -1,14 +1,16 @@
 package vo
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 
+	"github.com/AlekSi/pointer"
 	"github.com/davecgh/go-spew/spew"
 )
 
-func TestParseConfig(t *testing.T) {
-	t.Run("parse required_context field", func(tt *testing.T) {
+func TestUnmarshalYAML(t *testing.T) {
+	t.Run("unmarhsal the required_context field", func(tt *testing.T) {
 		s := `
 envs:
   - name: dev
@@ -25,14 +27,8 @@ envs:
 		e := &Config{
 			Envs: []*Env{
 				{
-					Name:                  "dev",
-					Task:                  "deploy",
-					Description:           "Gitploy starts to deploy.",
-					AutoMerge:             true,
-					RequiredContexts:      []string{"github-action"},
-					Payload:               "",
-					ProductionEnvironment: false,
-					Approval:              nil,
+					Name:             "dev",
+					RequiredContexts: &[]string{"github-action"},
 				},
 			},
 		}
@@ -41,12 +37,11 @@ envs:
 		}
 	})
 
-	t.Run("parse approval field", func(tt *testing.T) {
+	t.Run("unmarshal auto_merge: false ", func(tt *testing.T) {
 		s := `
 envs:
   - name: dev
-    approval:
-      enabled: true`
+    auto_merge: false`
 		c := &Config{}
 
 		err := UnmarshalYAML([]byte(s), c)
@@ -58,16 +53,8 @@ envs:
 		e := &Config{
 			Envs: []*Env{
 				{
-					Name:                  "dev",
-					Task:                  "deploy",
-					Description:           "Gitploy starts to deploy.",
-					AutoMerge:             true,
-					RequiredContexts:      nil,
-					Payload:               "",
-					ProductionEnvironment: false,
-					Approval: &Approval{
-						Enabled: true,
-					},
+					Name:      "dev",
+					AutoMerge: pointer.ToBool(false),
 				},
 			},
 		}
@@ -76,11 +63,11 @@ envs:
 		}
 	})
 
-	t.Run("parse auto_merge field.", func(tt *testing.T) {
+	t.Run("unmarshal auto_merge: true", func(tt *testing.T) {
 		s := `
 envs:
   - name: dev
-    auto_merge: false`
+    auto_merge: true`
 		c := &Config{}
 
 		err := UnmarshalYAML([]byte(s), c)
@@ -92,15 +79,8 @@ envs:
 		e := &Config{
 			Envs: []*Env{
 				{
-					Name:                  "dev",
-					Task:                  "deploy",
-					Description:           "Gitploy starts to deploy.",
-					StrAutoMerge:          "false",
-					AutoMerge:             false,
-					RequiredContexts:      nil,
-					Payload:               "",
-					ProductionEnvironment: false,
-					Approval:              nil,
+					Name:      "dev",
+					AutoMerge: pointer.ToBool(true),
 				},
 			},
 		}
@@ -109,3 +89,79 @@ envs:
 		}
 	})
 }
+
+func TestEnv_Eval(t *testing.T) {
+	t.Run("eval the task.", func(t *testing.T) {
+		cs := []struct {
+			env  *Env
+			want *Env
+		}{
+			{
+				env: &Env{
+					Task: pointer.ToString("${GITPLOY_DEPLOY_TASK}"),
+				},
+				want: &Env{
+					Task: pointer.ToString(defaultDeployTask),
+				},
+			},
+			{
+				env: &Env{
+					Task: pointer.ToString("${GITPLOY_DEPLOY_TASK}:kubernetes"),
+				},
+				want: &Env{
+					Task: pointer.ToString(fmt.Sprintf("%s:kubernetes", defaultDeployTask)),
+				},
+			},
+			{
+				env: &Env{
+					Task: pointer.ToString("${GITPLOY_DEPLOY_TASK}${GITPLOY_ROLLBACK_TASK}"),
+				},
+				want: &Env{
+					Task: pointer.ToString(defaultDeployTask),
+				},
+			},
+		}
+
+		for _, c := range cs {
+			err := c.env.Eval(&EvalValues{})
+			if err != nil {
+				t.Fatalf("Eval returns an error: %s", err)
+			}
+			if !reflect.DeepEqual(c.env, c.want) {
+				t.Fatalf("Eval = %v, wanted %v", *c.env.Task, *c.want.Task)
+			}
+		}
+	})
+
+	t.Run("eval the is_rollback.", func(t *testing.T) {
+		const (
+			isRollback = true
+		)
+
+		cs := []struct {
+			env  *Env
+			want *Env
+		}{
+			{
+				env: &Env{
+					Payload: pointer.ToString("{\"is_rollback\": ${GITPLOY_IS_ROLLBACK}}"),
+				},
+				want: &Env{
+					Payload: pointer.ToString("{\"is_rollback\": true}"),
+				},
+			},
+		}
+
+		for _, c := range cs {
+			err := c.env.Eval(&EvalValues{
+				IsRollback: isRollback,
+			})
+			if err != nil {
+				t.Fatalf("Eval returns an error: %s", err)
+			}
+			if !reflect.DeepEqual(c.env, c.want) {
+				t.Fatalf("Eval = %v, wanted %v", c.env, c.want)
+			}
+		}
+	})
+}